Citation
Ecology and control of the principal flies associated with a compost plant

Material Information

Title:
Ecology and control of the principal flies associated with a compost plant
Creator:
Alvarez, Calvin Gale, 1943- ( Dissertant )
Blanton, Franklin S. ( Thesis advisor )
Putnam, H. D. ( Thesis advisor )
LaBrecque, G. C. ( Reviewer )
Place of Publication:
Gainesville, Fla.
Publisher:
University of Florida
Publication Date:
Copyright Date:
1971
Language:
English
Physical Description:
121 leaves : ill. ; 28 cm.

Subjects

Subjects / Keywords:
Adult animals ( jstor )
Adult insects ( jstor )
Adults ( jstor )
Aprons ( jstor )
Conveyors ( jstor )
Houses ( jstor )
Insecticides ( jstor )
Landfills ( jstor )
Larvae ( jstor )
Refuse compost ( jstor )
Dissertations, Academic -- Entomology and Nematology -- UF
Entomology and Nematology thesis Ph. D
Flies -- Control ( lcsh )
City of Gainesville ( local )
Genre:
bibliography ( marcgt )
non-fiction ( marcgt )
Spatial Coverage:
United States -- Florida -- Gainesville

Notes

Abstract:
Seasonal fluctuations of Diptera indigenous to domestic solid waste were examined at the Gainesville, Florida, municipal compost plant during 1968-1969. Population of both immature and mature forms were estimated and the efficiency of chemical and physical control procedures was tested. Adult dispersal studies were conducted during 1970 at the city landfill. The major fly source at the compost plant was found to be from larvae-infested incoming refuse. The greenbottle blow fly, Phaenicia cuprina (Shannon), comprised more than 90 percent of the larvae which migrated into protected areas where they developed into adults. Approximately 450,000 adult flies per week were produced during the summer months. This figure could be reduced by more than 63 percent by procedural and good housekeeping. The daily application of dichlorvos sugar bait reduced the number of flies by 66.7 per cent while a single application of dimethoare reduced the population by more than 50 percent for 1 week. {Illegible} were also effective as shown by laboratory tests. The number of house flies captured on sticky tapes was shown to be proportional to the number present in a large outdoor cage. Sticky tapes were used to show seasonal fluctuations of house flies in the digester building. House flies were the predominant insect breeding in compost. They were limited to the top 2.5cm in the digesters because of temperature. The optimum moisture content for house fly breeding was 75 percent to 14 percent of the eggs placed in compost at 45-55 percent moisture (normal operating conditions) developed into pupae. Egg survival to pupae decreased significantly when placed in refuse after 5-10 days of composting. P. cuprina males flew an average of 19,405.4 m and a maximum of 30,137 m when attached to a flight mill until death. Females flew an average of 25,235.2 m and a maximum of 45,030 m. Wild P. cuprina and M. comestica were marked and released 1 mi from a landfill and later recaptured at the landfill. An average of 10.17 percent of the wild P. cuprina and 1.66 percent of wild K. domestica released at the landfill on days followed by 24 hr without rain were recaptured 24 hr after release. An average of 10.7 percent of the wild P. cuprina released at the compost plant were recaptured in the same area 24 hr later. An average of 11.3 percent of laboratory-reared P. cuprina released at the landfill were recaptured 24 hr later. Baited traps surrounding the landfill recaptured only 2 flies after a total release of 255,000 flies.
Thesis:
Thesis (Ph. D.)--University of Florida, 1971.
Bibliography:
Includes bibliographical references (leaves 115-120).
General Note:
Typescript.
General Note:
Vita.
Statement of Responsibility:
by Calvin Gale Alvarez.

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
Copyright [name of dissertation author]. Permission granted to the University of Florida to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Resource Identifier:
030179223 ( AlephBibNum )
37639609 ( OCLC )
ACJ0008 ( NOTIS )

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Ecology and Control of the Principal Flies
Associated with a Compost Plant











By

CALVIN GALE ALVAREZ


A DISSERTATI'N PRESENTED TO THE GRADUATE COUNCIL OF
THE UNIVERSITY OF FLORIDA IN PARTIAL
FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY








UNIVERSITY OF FLORIDA
1971




































Uti,.'ERSiT OF FLORIDA
31 1262 08552 47821 1 11 1
3 1262 08552 4782













AC KIOWLEDGMENTS


The author wishes to extend his sincere thanks and gratitude to the

many persons who have made this endeavor possible:

To Dr. F. S. Blanton and Dr. H. D. Putnam for serving as co-chairmen

of the supervisory committee, and their assistance and friendship through-

out this investigation.

To.Dr. G. C. LaBrecque for serving as a committee member, for his

assistance, direction, and friendship, and for providing equipment and

working space at the United States Department of Agriculture's Insects

Affecting Man and Animals Laboratory, Gainesville, Florida.

To Dr. J. F. Butler for his participation with the committee, for

providing equipment and working space at the Medical Entomology Laboratory,

and for his tolerance of the odors of rearing blow flies.

To Dr. D. H. Habeck for his assistance and work with the committee.

To Dr. W. G. Eden for his guidance, encouragement, and assistance.

To Dr. D. L. Bailey for providing equipment and advice.

To Dr. D. E. Weidhass and all the other members of the Insects

Affecting Man and Animals Laboratory for providing counsel and aid on

many occasions.

To Mr. Dan Wojcik and Mr. Terry Marable for photographic assistance.

To the Department of Environmental Engineering of the University

of Florida for financial assistance provided by Contract number 5-701-UI-

01029-09 from the United States Public Health Service.









To Mr. Herb Houston, project director of the Cainesville Municipal

Waste Conversion Authority, :r.c., and Dr. D. T. Knuth, Environrmer.:al

Engineering, Inc., for furn sh> n; eqjiT.D.-t ar.d faci i:!es as provided

by Department of Hea!lh, Educa:ion, and welfare e De-or.strat:cn Grar.t

number 5-D01-U1-00030-02.

Finally,, the author wishes to express his deepest gratitude to

his wife, Judi, for her patience and constant enccuragemert during this

stuay.














TABLE OF CONTENTS
Page

ACKNOWLEDGMENTS .................................................. i

LIST OF TABLES.................................................. vi

LIST OF FIGURES................................................ viii

ABSTRACT........................................................ x

INTRODUCTION................................................. 1
Statement of the Problem............................ 3
Location of Compost Plant.......................... 4
Operation of Compost Plant......................... 5
Flies .................................... ........... 9

SECTION

I. FLY LARVAL MIGRATION FROM REFUSE......................... 13
Methods............................................. 15
Result and Discussion .............................. 17

II. CONTROL OF BLOW FLIES.................................... 26
Blo.w Fly Traps...................................... 26
Field Tests........................................ 29
Rearing Blow Fl ies.................. ............... 37
Laboratory Screening of Insecticides for
Control of P. cuprina........................... 41

III. DENSITY AND SEASONAL FLUCTUATIONS OF HOUSE FLIES AT
THE COMPOST PLANT ...................................... 46
Rearing House Flies............... .... ..... ....... 46
Seasonal Fluctuations of House Flies............... 47
Evaluation of Fly Sticky Tapes..................... 54
Determination of the Magnitude of the House Fly
Population...................................... 57

IV. HOUSE FLY BREEDING IN COMPOST............................ 60
Moisture and Age of Compost........................ 60
Sludge and Grinding. ................................ 64
Temperature ................... ..................... 67







TABLE OF CONTENTS (Continued)
Page
SECTION

V. MIGRATION AND DISPERSAL ....................... .......... 72
Literature Review ..................... ............ 72
Flight M ills....................................... 75
Bl1~ Flies Released at Compost Plant............... 78
Fly Releases at the City Landfill.................. 81

SUMMARY, CONCLUSIONS AND RECOMM;ENDATIONS....................... 100

APPENDIX

1. Test for the precision of the counting technique used to
determine total number of larvae collected under
the apron conveyor................................. 108

2. Fly larvae trapped under apron conveyor during 1969, at
the Gainesville coTpost plant....................... 109

3. Percent mortality of 5-day old Phaenicia cuprina
females 24 hr after exposure to insecticides
in a wind tunnel .................................. Ill

4. Temperature in digesters ................................... 114

LITERATURE CITED................................................ 115















LIST OF TABLES


Page
TABLE

1. Percent abundance of species of fly larvae trapped
under apron conveyor during 1969................... 19

2. Total number of larvae collected under apron conveyor
compared to number of larvae trapped the same day.. 20

3. Total number of larvae collected per day under apron
conveyor compared to the number caught in the
same area during the night......................... 22

4. Sex, species, and abundance (%) of flies caught in
cone traps baited with I-day old fish heads
at Gainesville compost plant....................... 29

5. Number of flies caught per day in cone traps baited
with fish heads as a monitor of procedures to
control adult flies at the Gainesville compost
plant.............................................. 30

6. Sex, species, and abundance (%) of flies caught by
sweep net in grass adjacent to receiving area
of Gainesville compost plant........................ 34

7. Analysis of several rearing media to determine the most
suitable method of rearing Phaenicia cuprina....... 39

8. LC50 of 5-day old Phaenicia cuprina females to
insecticides in a wind tunnel ...................... 43

9. Air temperatures recorded 15 cm above compost in
digesters at Gainesville compost plant ...... ..... 51

10. Number of adult house flies caught on sticky tapes in
different ages of compost....................... ... 53

11. Recapture of 3-day old marked laboratory reared house
flies by sticky tapes hung in digesters for 24 hr
following release of flies in the same area at
the Gainesville compost plant during 1969.......... 59








LIST OF TABLES (Continued)
Page
TABLE

12. Influence of moisture and age of compost on maturation
of immature house flies reared in compost.......... 63

13. Influence of moisture on maturation of immature house
flies reared in 3-day old compost................. 65

14. Influence of sludge and grinding of refuse on maturation
of immature house flies reared in compost.......... 66

15. Temperatures observed ir house fly rearing containers.... 69

16. Temperatures observed in 4-day old compost in
digesters.......................................... 71

17. Mean distances fla.n in 24 hr by adult Phaenicia
cuprina attached to an insect flight mill......... 79

18. Distance flaomn until death by adult Phaenicia
cuprina attached to an insect flight mill......... 80

19. Recapture of wild marked flies by sweep net and
baited traps 24 hr after release................... 82

20. Recapture of marked wild flies at Gainesville sanitary
landfill by sweep net after release............... 91

21. Observations of marked wild P. cuprina remaining at
Gainesville landfill after release............... 93

22. Observations of marked wild M. domestic remaining at
Gainesville landfill after release ................ 94

23. Average percentage of flies remaining at city landfill
under different weather conditions................. 95

24. Rainfall recorded at Gainesville Municipal Airport
during release studies at city landfill........... 96

25. Observations of 2-day old marked laboratory reared
Phaenicia cuorina remaining at Gainesville
landfill after release............................ .98















LIST CF FIGURES


FIGURE

1. Floor plan of Gainesville municipal caipos: plant...........

2. Refuse flao plan of Gair.esville coinpost plant............... 7

3. Receiving building filled with refuse....................... 3

4. Sorting conveyor carries refuse to sorting platform..........

5. Composting takes place in concrete digesters................ 1

6. The finished product is discharged zo outdoor storage areas. 1C

7. Fly larvae and pupae unJer receiving hopper................. 4

8. Fly larvae migrating from refuse to pupation s:tes under
wall of receiving ouild r......................... .......... 14

9. lumber of fly larvae caught under apron conveyor per
week at Gainesville compost plant during 1969....... 18

10. Eastern edge of approach ramp........... ............... .... 24

11. Fly larvae aiong base of eastern wall of approach ranp...... 24

12. Cone trap baited with 1-day old fish heads to sample
fly populations at compost plant..................... 28

13. Rear vie.- of receiving building shcx-ing receiving hopper
and pavement behind building.................... .... 23

14. tMean number of adult flies captured per sticky tape per
week during 1969, in digesters at Gainesville
compost plant....................................... 50

15. Number of house flies captured on sticky tapes within
24 hr after release in a large outdoor cage......... 56

16. Position of tia'perature process in house fl' rearir.g
containers.................................... 68


viii








LIST OF FIGURES (Continued)


Page
FIGURE

17. Diagram of insect flight mill............................. 77

18. Fly larvae in animal disposal area of city landfill....... 84

19. P. cuprina roosting on grass tassel at night at city
landfill ........................................... 84

20. Predominantly 1. domestic roosting on weed at night
at city landfill................................... 85

21. Predominantly C. macellaria with some M. domestic
roosting or, dead brush in refuse at night
at city landfill................................... 85





Abstract of Dissertation Presented to the
Graduate Council of the University of Florida in Partial Fulfillment
of the Requirements for the Degree of Doctor of Philosophy


ECOLOGY AND CONTROL 0 T:HE PRINCIPAL FLIES ASSOCIATED
..'ITH A CC,-.POST PLANT


By

Calvin Gale Alvarez

March, 1971


Chairman: Dr. F. S. Elanton
Cc-chairman: Dr. H. D. Putnam
Major Department: En:ztcology and rematology
Minor Department: Environmental Engineering


Seasonal fluctuations of Diptera indigenous to domestic solid.waste

w ere examined at the Gainesville, Florida, municipal compost plant during

1968-1969. Populations of both immature and mature forms were estimated

and the efficiency of chemical and physical control procedures -.as

tested. Adult dispersal studies were conducted during 1970 at tne city

landfill.

The major fly source at the compost plant was found to be from

larvae-infested incoming refuse. The greenbottle blow fly, Phaenicia

cuorina (Shannon), comprised more than 90 percent of the larvae ,-hich

migrated into protected areas where they developed into adults. Approxi-

mately 450,000 adult flies per week were produced during the summer

months. This figure could be reduced by more than 63 percent by pro-

cedural changes and good housekeeping.

The daily application of a dichlorvos sugar bait reduced the number

of flies ry Si., percent -.-:hile a s ngle applicat3or. of d:m-ct.loate reduced

t.ne population by m.or th-n 50 perccr.t: for :.ek. ara..: cn, S rba,-.,

naled, ar.d diazinon 'ere a!so .ffcct ve 4s shc.ar. by laorato.-y tests.







The number of house flies captured on sticky tapes was sho.-.n to

be proportional to the number present in a large outdoor cage. Sticky

tapes were used to sho.. seasonal fluctuations of house flies in the

digester building.

House flies we.e the predcxinar.t insect breeding in cocTmpcs:. They

were l imiad to the top 2.5 cm in the digesters because of t iperature.

The optimum moisture content for hcuse fly breed:rn was 73 perc:-.:. r.c

to 14 percent of the eggs placed in ccnpost at 45-55 percent moisture

(normal operating conditions) developed ?nto pupae. Egg survival to

pupce decreased s gnificantly when placed in refuse after 5-10 days of

ccnpos t i r.g.

P. cuj.:n3 -males flea an average of 19,1.05.4 m and a maximum of

30,137 m when attached to a flight mnll until death. Fe.Tales flea. an

average of 25,235.2 m and a maximum.- of 45,030 n.

\-ild P. cuprina and Nt. comestica were marked and released I mi from

a.landfill and later recaptured at the landfill. An average of 10.17

percent of the wild P. cuDrina ar.d 1.66 percent of wild 1I. domestic

released at the landfilll on days follcaed by 24 hr without rain were

recaptured 24 hr after release. An average of 10.7 percent of the wild

P. cuorina released a: the compost plant were recaptured in the same area

24 hr later. An average of 11.3 percent of laboratory-reared P. cup.-Ina

released at the landfill %ere recaptured 24 hr later. Baited traps

surrounding the landfill recaptured only 2 flies after a total release

of 255,000 flies.















I :.T.U,, ) CT '. 3.


The de.T.ands of our affluent soc:et,, for more Socds c.nd cor.'..-.'-.

it-ms such as r.o deposit and non-rczurr.able materials, reL:'t in .f-.2

ger.rati~n of waste products in gigantic proportions. ,1s tne aff,~r.ce

and the population increase, the per capital and total amount of waste

increase proportion iy. The disposal of these tre.-nendcjs c-.z,~tiies

of wastes has primarily been an urban problem. Since the trend in the

United States "s toward urbanization the problems of refuse disposal

becar-e increasingly more important. This becomes evident when it is

noted that in 1960 the estimated median waste per capital per year in urban

areas was 1,430 pounds. This amounted to 1'80 billion pounds per year

ar.d the cost of collecting and disposing of this refuse was more than

1.5 b:llicn doi!ars (1).

To combat the rising problem of refuse disposal the "Sol id Waste
P
Disposal Act" was enacted in 1965 to support a national program designed

to implement and evaluate more efficient methods of coping with the

sol id waste problems. Under this act the Bureau of Solid WLaste Manage-

mer.t awarded a contract to the Gainesville -,Mnicipal Waste Conversion

Authority for the construction and operation of a refuse conpost:ng

facility. The purpose of this project was to "demonstrate the rel iabil ity,

su iab; ity', tcc.-.c.-r:c fL-s ; :it';, ar, L.L n-ita- and nu tance-rre o0.eretIon

of a rccertly Zc>ve. pi d ;',-.- tL, ;.,:J-.,.2,:c-: canpost,.s sys:ttm for ;he

d :spcsc.: cf r-.F :c'..p C fr.. .. ( ,. CI .








The primary objective cf c o costing is to dispose of refuse by

biological degradation of the organic materials. Modern scientific

cc-posting prccecures W'h;ch are emiplc'ed in municipal disposal sy'ste-:.s

involve the rap:d partial deccmnpos i;icn of orcar.ic matter by the use

of aerobic microorganisms under controlled conditions (1), municipal l

composting is a fairly conmon practice in many European countries. It

is rarely used in the United States because lard for refuse disposal was

available in close proximity to urban centers in the past. Th.

increasing demand for land provided the stimulus for municipalities

to seek a more acceptable form of refuse disposal. As late as .53,

ti.ere was little scientific information available on municipal composting

in the United States. Since then several universities and the United

States Public Health Service conducted studies that have as yet yielded

only a limited amount of practical information. The capital and operating

costs of comwposting are kno.-jn to be higher than most other forrs of

refuse disposal but the specific ecor.nnics involved in municipal co-,-

postir.g :n the United States are practically unknown. The feasibility

of co-iposting must be determined by the major advantage of c-nposting,

the recycling of waste products. The sale of marketable compost and

salvagable goods would reduce the net cost and may result in a profit.

There are 2 general composting processes that appear to be the most

efficient and economical under U.S. conditions. The first is mechanical

digestion, a process in which refuse is sorted, ground, and mechanically

manipulated in order to shorten the bioloc:cal degradation process. The

second method terr.med windrc.-.;ng involves the sorting, grinc:ng, and placing

of refuse in windrc. s allo.in; t.-.e rmateri,! to co.npost naturally. The

compost plant constructed a: Gai.-.csvile used .he mechanical .iqestion

process.








Stte-.ent of the P:oblem


As with other scientific informationn concerning composting in the

U.S., little is knawn concerning insect problems that may arise in this

type of operation. The original purpose of the present investigation was

to search out these problems, determine their magnitude, and suggest

possible solutions. Initial observations revealed that large numbers of

fly larvae entered the compost plant within the refuse. These larvae

seeking a suitable pupation site migrated from the refuse stored in the

refuse receiving building. These insects were aesthetically unpleasant

to the employees as the larvae were often crushed beneath their shoes and

sometimes crawled into the clothing of a resting employee. Many of the

immature insects eventually became adults and further tormented the

employees at the site by their constant presence while others were reputed

to invade the surrounding community. Thus, the primary areas of this

investigation were as follows:

To identify the larvae entering the compost plant with the refuse

and to determine the:r magnitude and seasonal fluctuations.

To search out possible processing procedures which may reduce the

number of larvae migrating into the plant.

To evaluate mechanical and insecticidal control procedures to reduce

the larval populations.

To screen several commercial insecticides for their effectiveness

against the emerging adult flies.

To determine the density and seasonal fluctuations of the adult house

flies at the compost plant.








To determTine the extent and some of the l imiting factors of hcuse

fly, breeding in compost.

To deter-mine the extent of fly c;spersal froT thie coripost pl a-t

;nto the surrour.dr.i cn;To.Tir.. ty.

Laboratoory stude: s ..erc co:.dc:ed at the USDA Insects .".ffect.r.

HMn and Animals Laboratory :n CaIne;v!f e, Fligica, and at the Lnive.:L.ly

of Florida medicall Enom-nology Lcaboratory. F eld s:udeis ccncCc:cea at t.-.c

cornpos plat were begun in June, 13. becausee of a lack o fL.'.cs th .

plant was closed on DecaTmber 31, 1939, ar.d scke cf tae stLcies '..ere not

cxpar._dcd as the author had inte.-.rc, M'.ost cf .~n disperse! s-ud es wrre

aP rform.ed at the C::y of Gainesville SaniZary Lr.-.dfill durinS t'.- s.-.;er

of 1970.



Lc, icn of Cc-.pos: Flant


The compost plant was constructed on a 5-acre tract of land located

ir southeast Gainesville at the city's sewage treatment complex. This

size was near a se.-jage treatment plant, an animal shelter, and an

abandoned dump.

A densely populated region of midd'de-incom.e apartment complexes

inhabited primarily by Universi:y of Florida students and a la.j-incocae

residential area were located in :ne immediate vicinity. A woodland area

buffered a middle- and high-income residential area located one-half

mile from the plant.








C'oeration of CTomost Plant


The floor pl..n c. he cac.post plar.; is p.-csc..ted in Fig. I and tr.c

central flao plan o- ti, r s' .; s .-.n .-. F'.. 2. Fefuse wa. Lro r.. by

trLck andu dLmpcd or. t:.e f:cor of the -eceivir.g .l ldir.g (F:g. ;). re

refuse was then placed n:: a .-ece.:ving hopper by a actortr .o.;fi~; wj. ;

a front-end loader. The hopper ('%.8 r long, 3.6 m wide, -r. 3.i n ec,

constituted the rear side of the building. An apron conveyor which

consisted of a series of ov.erla ppr.; or inter:ockir.g r ron pans %.-s

located at the bottom of th:s hopper. Tne refuse was transported alo-.

the conveyor onto an oscu'lating taZbl. T:.;s ta2.e loosened zne packed

re.use in order to assure c. un:,or. -flo..-. A sor-:ng conveyor car.-ied

the refuse frc., the oscil.ating table to a platform where 6 labo-rrs

manually re .rved salvagemble paper, cardboard, and large bulky items

(Fig. 4). The paper and cardboard were dropped into chutes which fed

into a baler and the bulky teamss were placed in chutes that emptied into

a dump truck which carried these materials to a landfill. Tne sorted

refuse then proceeded directly into a crusher-disintegrator grinding mrill.

The ground refuse discharged froT- the crusher averaged 7.6 cm but varied

in size depending upon the type and amount of material fed into the

machine (20).

Refuse passed frin the first grinder into a second grinding unit which

reduced the particle size to approximately 5 cm It was then discharged

fro- the bottom of the secondary grinder into mixing screws where 2 ccunter-

roating ribbon-cype scre..s, p aced s:de by :ide in a common trough,

blended th. r..a:eria' with wte,- or sludge. A conveyor belt carri-d the

molstcned refuse unctr a rma. tic: separaoe- .- h:ch removed the ferrous







































Ig.r.zr **nrloa blowr
S Illoder m /ealoadl| *bhgCrl* touvyo
giloader creeler car relle
2 I e..r ucloadln co. nyor
Lloader LrecaJr car
e r ld le.dlin convyor
a|riad drcrrlbualg ecrrw conveyor
OlrLOd mll felder ecrer coroveryors(2)
eprlod mille (2)
lalg ad ovar.loa arm roaaeyar
leariad dLschars cvarwr conveyor
Lochplilog belt coaveyor
.toraee buildLng Vorrc c loadLng ramp
.vetorl a*d *r, re
S Ilectricl evitcrner room



1 -"


Fig










































































4TOC.L P II



















































Fig. 1. Floor plan of Gainesville municipal compost plant (20),





















zeCeh.CItI- ,O4PfI


MAN5IIIC 5EPADPL'OI

BUIZN,


pIcuII4 r.bL.5


4TroC- PIL6.


1MAiw MPAN


Fig. 2. Refuse flow plan of Gainesville compost plant (20).





8























Fig. 3. Receiving building filled with refuse.


Fig. 4. Sorting conveyor carries refuse to sorting platform.





9

mTiGtc.,s a...', :;".n 3=t ,-,. o.'.O t .2 ". 2C.C c,'cr.'/Gcyor D '. z o't '-h exc" de.. t

;:a.-.:h of :e d:gestrs. A s.-.ht:.e ccnvey'or, which travelled on a pal- o;

steel rails betwee. the cigeste.-s discharged the refuse into these ur..:s.

T7. disest.- s or c. gst ..g ;ar.,-.s were 2 cc.-.crete rcja, s S9 n c.-.g,

6 m wide, and 2.7 m deep (F:g. 5). The digester walls were constructed of

concrete blocks and the floor was converted with perforated gelvan:zed

stee! plates. These pat:s were above an a.r pier.um into which air was dis-

charged by a centrifLgal 1c.-i pressure fan. River gravel approximately

0.6 crm in diameter covered the perforated plates to a depth of 7-10 -n.

This enabled the air to diffuse evenly through the small slots over the

entire floor of the tank. The refuse was placed in the digesters to a

depth of 1.8-2.4 m and allowed to compost for approximately 6 days (20).

(In t.n:s investigation "crIpost" refers to refuse that has remained in

the c:gesters for a period greater than 24 hours.)

Removal of the compost was accc-.pl ished by a machine called the

Ag:-Loadc.- (Me:ro-.c;ste Patent No. 3,294,451). This machine removed the

cc-post a-.d deposited it back onto the tripper conveyor. A system, of

cc..veyor bets transported the coTnpost to a final grinding mill. A finely

ground mater;ai approximately I cm was discharged froi this grinder and

was transported by conveyor to an outdoor storage area (Fig. 6).



Flies


..ce .mot r~cmerous species o. flies prcsr.: at -:.e c-mpost pla..t were

.hu com.-.cn house fly, Miusca do-est;ca Linnaeus, (.-,scidae, Diptera) and

... r.- .'c.bott e b,. c; fly, -.-: .c cj-..' a ,S. ) (Ca phor-id

Sr..era).































Fig. 5. Composting takes place in concrete digesters.


Fig. 6. The finished product is discharged to outdoor storage areas.







The house fly has beer. incrimin-ated as a carrier of nm.TeroLs diseases

of man and animals incl-ding typhoid fever, cholera, and amroebic dysentary

(27, 2); hc.-.ever, these cla'ns have been supported only by circunstant;:a

evidence. Hacse fly associatiu.-.s ;t;-, disas-s need farther cla-:ficatcon

as cxperimre.r:ta evidence .s sparse and con.tam.iatin of house fl s between.

caged mates has been shao.'n to o sporadic (2-).

Grcenbottle blce f! es may be cc.T.estc nuisances or carry d;seas2

organisms, but in. this coaac:ty ney are far less impc,: r.t: ..-:. other

flies. Hc..ever the damage -nd s-ffe.:r.%g which the Icr-.'ae ir.-I lc Lpo

domTestic animals in sci-e s ock<-.-a s i-o areas .s of tre.-er.dcus co.sequcr.ce.

In Australia, th:s fly is by far the rost important spe:Ies in fi st-ike

or cutaneoJs myas:s of sheep (LL:, 3). ',, strike is a condit:an pro -ced

by the development of blcw f'.l larvae on 1 giving sheep v-.hidh may lead to

death or a considerable loss of woo. This is a formidable problem in

Australia and ar.oun-s to an annual cess of 4,000,000 pounds to sheep

raisers (44, 6$).

The ccr,.on hcjse fly is well established as Musca domestic- Linnaeus

but the systematics of the greer.bottle blo.-j fly are scoTewhat confused.

Australian authors refer to this fly as Lucilia cuorina (v\.'idemann). Hall

(26) cc.mpa;-ed specimens from the United States and Australia and concluded

they were not the same species. He described the A.merican species as a

ne. ccnbinatIon, P. pallcscenes (Shannon). :.laterhouse and Paramo.ov (E0)

later examir.ed numero-s specimens fro-n Texas, Ns. York, 'New.j Orleans,

Washir.gton, and Austral ia ar.d concluded that there was no diiferenc, in

species, bjt a definite pa:r of subspL .- iJmes k2S) ccncLr:'cJ ir. ths

vie.-. .-all later in Sta.; c e al. (7c ma r.ta ,-,ec his cLm.T i ion of







on .cec-z (Sh no) r u reco, -zed the works of Watorhouse and


P -r ammv 7,0, 0u%,o T0scs the species -,z,7, from- Waterhouse and Paramonov

s ince the ir work appeared to be moa- ccr.-orchens ive than that of Hall.















SE-: .C !


FLY LARVA. MIRAT.:C:; FR.m-- REFUSE



The major source of fly infestation appeared to be from I-trodic:ir.

of larvae from. t'e coll ected refuse ar.. not :.-C m br.eca:ng at .:.e c:.,;.;:

plant Fly larvae that .4.ere breed;r.g in refcLe containers thrcj-;ic. :we

city were brought to t.e cC Ts:o p.c-at wiTh the refuse. Th;s infestedd

refuse w.;s stored z.-.'aiting process ..g in : e receiving arca. -an/ .:

the larvae were mature and the a-dc: stir..us of tr.e disruptive transfer

to the p!ant caused them to active/ seek a pupation site (F:gs.7 and 3).

Scne of these larvae migrated :nto the working areas where they' annoyed

the employees while others reached protective areas where they metamorphosed

to adults. Such occurrences v.ere not unique to the compost plant. Large

numbers of larvae may escape to pupation sites during the handling,

transferring, or processing of larvae-infested refuse. G-Cen and Kane (23)

found that 7200 larvae/hr/pcr ca. were escaping from railroad cars a-.aiting

dispatch to a rural disposal area.

The infestation of refuse bI larvae in the Gainesville area uas

anticipated because in a southern California cit, with a climate similar

to that of Gainesvile, Ecke et al. (13) reported that residential refuse

containers can h.v, zs many as C,000 .vae per cc..air,..: over a ]0-we.C

priced. These larvae crcw'.le c c. .? re s .-js c,. sh 't feed:.g period































Fig. 7. Fly larvae and pupae under receiving hopper.


Fig. 8. Fly larvae migrating from refuse to pupation sites under wall
of receiving building.






15

to pupate in the soil and later emerged as adults. During the hot summer

months it was reported that the feeding period was corpleted in 4 days

(79). This observation led to the recommendation and subsequent adoption

of a twice-weekly refuse collection system for several California cities

(17, 79).

The purpose of this investigation was to determine the species of the

larvae escaping into pupation sites at the plant, to determine the

magnitude and the seasonal fluctuations of this massive influx of insects,

and to search out possible processing procedures which would reduce the

total number of escaping insects.



Methods


Seasonal Fluctuations

Visual observations indicated that the majority of the larvae escaping

from the refuse were confined to the partially enclosed area under the

apron conveyor. The larvae reached this area either by crawling through

the openings between the metal pans of the conveyor or by falling through

the opening between the floor of the receiving building and the edge of

the receiving hopper. To determine the species present and the seasonal

fluctuations of the larvae entering the plant, a trap was placed in this

area. This trap was similar in function to the described by Roth (58) and

consisted of a 30.48 cm2 plywood box.. It was abutted to the wall under

the apron conveyor so that larvae falling through the opening between the

hopper and the floor would be trapped in the box. The trap was operated

from January 12 to December 31, 1969.






i

The trap wa:s checked daily and the number of larvae recorded. A

minimum of one sa.-.pl, catch per week was preserved in alcohol for identi-

fication.

PorL nation Factor

It was desired that the lc.-vai population trapped in the se-scnai

fluctuation survey b. used to estimate the total number of la-vae esca?:r.c

into the plant. To accomplish, this .t was necessary t: d.termi..u. ,1

total nL.-.ber of larvae that entered the plant, the percentacg o. t-h

larvae trapped, a.d the re. iab;lity of the trapping p.ocedure.

The tot:l number of larvae enterir.g :-e plant '.;oud be c.. i:L1t

figure to accuratel'y efine. Since the majority of the larvae migrate

under the apror. co..veyor was used tc deter-:ir.e zie total number of

larvae ;n that area and to determine the reliabil;zy.

The larval population under the apron conveyor was determined by

sweepi;.g the area -or a 10-day pe.-od baginnir.c ..ug-st 29, 1909. These

sweepings, which included the debris and .arvae that had fallen during

the p.-evlcus 24 hr, were placed into a 55-gallon (208 1) drum. The drum

ar.d its contents wire weighed, sealed, and thoroughly mixed by rolling

on the floor for several minutes, l..:.ediately a volume of aporoxi.-ately

0.5 1 was removed and weighed on a laborato.-y balance (4aus, Unicn, N.J.).

Tne larvae in the sample wura counted a:,d the total number of larvae in

tne drum or under the aron conveyor was calculated.

To deterr;n.: t.-.e precision of the above method, a sample of approxi-

mately 0.5 1 was .rcmo.'J, I'e'chca, counted, ar.d replaced ir. the drum. The

ccn er .ts cf .,, w..e .ga-; n r.'.xcd' and ..a pr.ced-re wc.s re.;" icated

5 tr:.es. -. .- :..:c c t t :.-. r.ethod was precise and are ;ivtn

in Appr.dA di ..







Effects of Clearina Receiv.inq Bi;ldina Cda'i'. of Refuse

It was standard operating procedure that a sufficient a.mcunt of

refuse remain in the receiving building o.vcrnig.h so that operations

could becin the folllja ing r.crr.t.g and proceed without inte.-ruptior. L.nt:]

the trucks began de iv.erinc refuse. To deter:.r.e :r. r.-mbe. of l r.'a

escap:r.g into :ne ccTpost plant as d d;:ect re'z-;t o. t;:, proved re,

the area under the cpron co.nveyo: was swept tuice da: .y; once at 7-30 a-,

before d-l'/y op-ration: began, :nd ag z.r, at c,:5 p., iT.:ed;a '/ a:-. :.

pzant closed. This was repeated for t consecutive cays during Septer oer,

1969. The larvae co elected were er.L.merated as described previous 1y.



Result and Discuss;on


Seas:onal Fluctuaticns

Tne resu'. s of a larval sample irg program to determine the species

present and seasonal fluctuations of the lacrvae escaping "nto the cc._.ost

plant are shown inr Fig. 9 and Appenrdix 2. These data show that relativ.Aly

fc-.' larvae were captured du.-ing Januar', Februar/, and March. The catch

increased :r. April wh.,e a cons ;stent h:gh number of larvae were t.-apped

frcm Junre to mid-October. Tr.e number declined thr-CghoJu November and

larvae became relatively scarce in DecemTber.

Phaen;cia cuprir.a was the predca.inant fly species collected in this

survey. Table 1 shc.is tnat greater than 97 percent. of the captured larvae

were P. cuorina. One. percent we.e M1. dc-,estica w.:.1 e the re..ainder L~.ere

cc-.pr.sed cf COchli -- ia T:c 11--ia a.or c:u.), hcr : :.llucens (Linna Ls),

cr.d S .co arm pp. T.. c c. ..a., o.- :pc c. s '.-.cs s ,.il r .-: :..cs3

report. Ly tr.2.- :.-.vcs.:;g :c... .- r cxA^ 2. -*r'" cc.,.opr.:s.d S9.'5









L
0

0

U
C
0
L.
a.
ru









4-

0-
a,


L.



L






o -
10
I--


Z4C


3 2""""t -i""I 1

M A M J J A S 0 4 D

1969 deeks


Fig. 9. Number of fly larvae
plant during 1969


caught under apron conveyor per week at Gainesville compost


(a Plant closed for repairs June 15-30.


_- less than 20 larvae


J F






19

Table 1. Percent abundance of species of fly larvae trapped under apron
conveyor during 1969.


Percent of total number of
larvae examined per week
Species Maximum Min mu.m Average

Phaenicia cuprina 100 90.5 97.2
Musca do-nestica 6.4 0 1.0
Cochlio-nyia macellaria 6.0 0 .7
Sarcophaga spp. 4.7 0 .7
Hermetia illucens 4.7 0 .6
Others <.01 0


percent of all larvae collected from residential refuse containers in

southern California (28, 18, 79). It was also the principal blow fly

found in garbage in Orlando, Florida (31). Green and Kane (23) reported

Phaenicia was the predominant genus occurring in London during the summer.

Population Factor

Table 2 gives the calculated number of larvae collected per day under

the apron conveyor and the percent trapped in the larval sampling program

for that same day. These data indicate that an average of 0.99 or approxi-

mately 1 percent of the larvae under the conveyor were caught in the trap.

The variance of 0.04 for these results indicates consistency.

Larval movement into the plant was not limited to the area under the

apron conveyor as migration from a pile of refuse could be expected to

occur randomly in all directions. Larvae migrating from the refuse in the

receiving building in an easterly direction found harborage behind a

wooden retaining wall. This was approximately 1 m from the outer wall of







Table 2. Total number of larvae collected under apron conveyor compared to number of larvae
trapped the same day.



Sweepings Sample Larvae/ No. larvae No. larvae Percent
(Kg) (Gm) sample collected trapped trapped

19.0 976 1741 34,100 487 1.41
27.0 1894 2676 38,200 452 1.17
1.8 200 1500 13,500 114 .84
18.4 642 3842 109,500 986 .89
10.7 1076 6855 67,980 297 .44
14.5 1009 4873 70,250 602 .86
9.8 673 1993 29,100 238 .82
17.4 862 1758 35,731 411 1.15
16.3 611 1796 45,851 490 1.07
22.2 885 3979 97,600 1294 1.31
Average .99







the building and extended the length of the receiving area. It was

difficult to sample this area and the larval population was an approxima-

tion based on visual observation. It was estimated that the number of

larvae escaping behind the east wall was approximately one-third of those

escaping under the apron conveyor for any given day.

The construction of the receiving area and the practice of handling

the refuse greatly reduced larval survival in other directions. Refuse

was deposited toward the east wall and as it was moved into the hopper

from east to west by the front-end loader, those larvae migrating in a

westerly direction were scraped into the receiving hopper. Northerly

migratioii resulted in little survival since the ramp and paved areas

provided no protected areas for pupation.

Coi-bi6ing the estimates that two-thirds of the larvae migrating into

the plant enter the area under the apron conveyor and 1 percent of these

are trapped results in a population factor of 133. This factor may be

multiplied by the daily larval catch to give an approximation of the

number of insects migrating from the refuse into the protected areas of

the plant. For example, Appendix 2 shows that 6116 larvae were trapped

the week of September 7, 1969. Multiplication by 133 gives an approximation

of 813,428 larvae entering the plant during that one-week period.

Effect of Clearing Receiving Buildinq Caily

Larvae collected under the apron conveyor during plant operation

were compared to collections in the same area during off hours. The results

are given in Table 3 and indicate that an average of 38.5 percent of the

larvae escaping into the compost plant migrated from piles of refuse

remaining in the receiving building after the plant was shut down for the








Total number of larvae collected per day under apron conveyor
caught in the same area during the night.


compared to the number


Sweepings Sample Larvae/ No. larvae Total daily Night catch
(Kg) (gm) sample Time collected catch Total catch

7.22 725 3400 D 36,180
2.95 351 3612 N 31,800 67,980 46.8

11.35 666 2508 D 42,700
3.18 343 2971 N 27,550 70,250 39.2

7.95 360 794 D 17,500
' ]85 313 1961 N 11,600 29,100 39.8

16.8 722 1318 D 30,700
.65 140 995 N 14,620 45,320 32.2

16.3 611 11156 D 44,400
3.35 283 2914 N 34,500 78,900 43.7

19.06 602 1992 D 63,200
2.57 282 2834 N 25,800 88,900 29.1

Average 38.5


= 7:00am 6:15pm
= 6:15pm 7:00am


Table 3.





23

day. It is obvious from these results that not storing refuse overnight

would reduce the number of larvae entering the plant by more than 35

percent and decrease the ensuing adult population.

The value of clearing the refuse from the receiving area daily was

further demonstrated by observing the large numbers of larvae along the

eastern edge of the approach ramp. When refuse remained on the approach

ramp for several days numerous larvae migrated from the refuse and fell

to the pavement below. On several occasions when this occurred fly larvae

were so numerous that the pavement along the edge of the ramp appeared

white. On one such occasion the pavement was swept clean and the larvae

collected 12 hr later. Their number was estimated to be 30,000 or 60,000

per day migrating from the ramp (Fig. 10 and 11).

Adult Development from Larvae

The majority of the larvae that migrated from the refuse were mature

and thus required only a suitable pupation site to develop into adults.

This was demonstrated by placing iO0 larvae collected under the apron

conveyor into waxed paper cups (0.946 1). Twent,-five gm of refuse debris

collected from the same area were added to one-half of the cups. The cups

were covered with cloth, secured with a rubber band, and placed under the apron

conveyor. Ten.days later the number of adult flies that had emerged were

counted. Nine replicates of each test gave an average of 65.3 percent

adult emergence from the cups to which only larvae had been added, and an

average of 88.8 percent adult emergence from the cups with debris added.

Generally there was a considerable amount of debris under the apron

conveyor and behind the east retaining wall, the main areas of larval

infestation. It was concluded that most of the escaping larvae reached































Fig. 10. Eastern edge of apporach ramp.


Fig. 11. Fly larvae along base of eastern wall of approach ramp.









adequate pupation sites and close to 88.8 percent adult emergence wlas

expected. Extending the previous example given for the week of

September 7, 1969, an approximation of 733,313 adult flies could be

expected to emerge within 10 days as a result of larval migration fr-om

the refuse.

Survival of Larvae Through Grinding Mills

Approximately 10,000 mature house fly'larvae were passed through

the secondary grinder in May, 1969. The primary grinder was not in

operation at that time because of equipment failure. Nine live larvae

were recovered in the discharged refuse. In July, 1969, 10,000 mature

house fly larvae were passed through the recently installed primary

grinder. No surviving larvae were found in the discharged refuse.














SECTION II


CONTROL OF BLO. FLIES



Studies were initiated in June, 1969, to evaluate several procedures

such as mechanical control and insecticide baits, fogs, and residues for

the control of blao- flies emerging from the incoming refuse. The

effectiveness of a control measure was determined by the reduction of

flies caught in two baited traps located behind the receiving building.

These investigations were terminated in October with the advent of

cooler weather.



Blao Fly Traps


A suitable method to estimate changes in the number of flies was

needed to evaluate the various control procedures. Sticky tapes were

ineffective because the large amount of dust created in the receiving

area rapidly coated the adhesive material. Grill counting was ineffective

because the counts varied with hourly density fluctuations and positive

species identification was nearly impossible (42, 45).

Norris (45) reported that bait trapping was the only generally

useful method available to study blow fly populations and that the bait

employed was the most important variable. He reported that animal tissue

was the best for blow flies, being more reliable than some of the more





27

recently developed synthetic attractants (14, 45). Ho:-.cver carrion is

not a uniformT bait. Its attractiveness varies with zae, moisture, and

deco:r.iposition (42). Ka.a: and Suenaga (S3) fund that fish 1-da'y-old

vwas tne most attractive to b,1 .-. .'ies.

The traPs se;'ctecd o." L e :: t. cc.pos .b r.. C' e '.o C .< 3 o .\

54 cm :n'.erted cone traps. The- were :ated 'i.1 :-d-y'-olo fish .e Ds

acquired Ioca l'ly. "ns asa of each trap .as encloscc by C.5 c:. sce..-.

wire to prever.t s.:all ar.;rals from sea .g :.'-. b.-: Tncse traps ..

sho.-in in F ; 12.

The tr.ps w'.:ere pieced on the pa'.zr.an: behind the receiving area,

see Figs.l and 15. The flies .were collected frcm the traps daily by

plac .-. the trap and '1 mi of eth',l acetate into a plastic bag. After

the flies %-.cre anesthetized, they were removed and placed in:o a small

plastic bag. T..e catches were then transported to tne laboratory for

coLr.cing ar.d identification.

Tab e 4 gives the ioenrtfication of flies caught in 15 different

daily catches. Tnis shows that 89 percent of the fiies trapped were

Pr.Lcr, icia spp., 6.8 percent were iiusca dciiestica, 3.7 percer.t were

Cochlic.n'-ij miacellar a, an.d 0.5 percent arcoohaqa spp. These figures

are close to those percanzag.s recorded in Table I which gives the

relative abundance of the various species of !arvae entering the plant

frc- the refuse. The differences that occur may be the result of the

trapping method e-.ployed, different survival rates of the species

involved, or ir-migration of adults from surrounding areas.































Fig. 12. Cone trap baited with I-day.old fish heads to sample fly
populations at compost plant.


Fig. 13. Rear view of receiving building showing receiving
hopper and pavement behind building.









Table 4. Sex, species, cr.d abur.nd nc- (;.,, c.f fli is c-ught in con.e tr.a.Ms
baized w\. chr 1-day o'd .:sh -.earls at Ceinesvillie coposci plar:.



erc r.._ C: Co ..
Spez ies .. .. .c.-J_ ,, L.-a *.. .'-, .m-- c

P c-.- r.-c a spp. C3.0 10.4 c' ."
;.LSC ac.-Costica 6. c 1.7 5 .c
Co:hi ia-.'i- -n-cel la.-' a ;.7 55. 2 ,*.:
rco haqa spp. .5 .t'3 iCL..j


atiean of 1- day catches zaken a- random.




F Ild Tests


Petr.ocs

Several adL't fyi cont.-oi procedures v. er evaluated to ceterm i;ne

their effectiveness and cost of app! cation dur r.g the summer of 1909.

The effaecr eness of th- ccnc.ro proc-cures w-.as determined by c cn-parirg

the number of flies caught per day in baited trap- during the treatment

period to t.ie nur.ber of f' "es ca9ugt dLur-r a prior period of no crea=-

mer.t. T..e duration of pre-treatT.a-.n ccntrcl spimpling wjas 7 days and

subsequent cc.,troi per ocs were 3 days. ,.reatmenc and control periods

were alterr.naed and fo;laJ ed c;h.c.-.olgc.ca'!ly :.i ;he order presented in

Taole 5, beginning July 14,, 1". fcjr :n 5 c'y/: elapsed between a

treatment and the c.auoing control .:r;oc.

The control procedures are descr bed as follao-s:

Sutr bi -- KcK:Ilr ~: al. (1) :n stud~, s L; durops fojr.d ':.i. t

trich.orfon b .:s g ve 'jc o.-.roi cf blo. f'". Sai;,'l c: a ()

re-o.:c.. t-,t di:t.. rvc: ..-. -..: so Ijcr a i:s cc;trollcd ho-se fl :e .






Table 5. Number of flies caught per day in cone traps baited with fish heads as a monitor of
procedures to control adult flies at the Gainesville conpost plant.


No. of flies caught No. of flies caught
per day % per day %
Day Control Sugar bait Control Day Control Sweepingc Control

1 2343 15-18 -
2 2796 19 1197
3 2268 20 2316
4 979 21 1954
5 1050 22 X = 1822 856 53.2
6 3456 23 1055 41.9
7 824 24 908 50.2
8 X = 1959 1178 40.4 25 667 63.4
9 875 55.4 26 353 81.6
10 285 85.5 27 1061 41.6
11 596 69.7 28 1775 3.6
12 1041 47.1 29 1493 18.0
13 490 75.0 30 1437 21.1
14 107 95.5 31 1315 25.8
x = 653 66.7 32 988 46.4
x = 1083 4.6


aNumber of flies caught per day when no control procedures were used.
b400 gm of 0.5% dichlorvos in sugar mixture applied daily as a bait.

CArea under apron conveyor swept daily.

Mean values represent the mean number of flies caught per day for that given procedure (column).







TI11 c $ (CoGt n1u1. I)


INo. of f 1 i s cai.l l;ht
_ _p.er dy
Colitl olflt ait


1 711
1397
1965
X> 1 6., 3


360
511
641
1 21i5
14167
597
1017
> = 831


I,:,. f fl i c, :u L l t


Control


Pay


78.8
69J. u
62.3
26. 7
13.8
6'. 9
510. 1
$1..


____pr 'd .'
Control


1 96/
191:





60 7
1 9i :







1601
18 1.


561
6":
r,61
V 5, '


Cont rol






7 7
65.5
70.7

67.3
1 0

5.2


12uC ml o' 1 .0": Cicil orlvc in 5r, rntil t olutioii, ap lied diil 1 a. ca L.i t.

I of 5.0/ feCnthio n in (Jo. 2 fuel oil appr l licJ ith a l ,c-. c : li0o;--aii- s :iI r. iJjer L.I dacl 53,
5'., aJ 55.


33-3(.
31
3 8
33J
*:
I ,



' 5
/, ',


47-5






Table 5 (Continucd)


No. of flies caught No. of flies caught
per day % per day %
Day Control Dimcthoatce Control Day Control Gardonai Control


28
"13
37
18
64
49
112
287
170
393
811
1256


76-80
81 1677
82 1170
98.5 83 1410
99.3 84 = 14]9
97.9 85
99.0 86
96.5 87
97.3 88
93.3 89
84.9 90
90.6
78.3
55.0
30.1


1056
653
1251
734
949
781
1090


25.6
54.1
12.0
48.4
34.4
45.0
23.3


g10% dimethoate solution applied at a rate of 2 gm (AI)/m2 to grassy areas adjacent to receiving
Building, one application on day 63.

h0% Gardona solution applied on day 83 at a rate of 2 gm(Al)/m2


1437
1719
2241+
x = 1799


--






33

Fly Bait, a 0.5 percent dichlorvos sugar bait obtained commercially from

the Fasco Chemical Co., was used prior to this investigation to control

the flies at the compost plant. This bait was evaluated when applied

at a rate of 400 gm per day. The bait was distributed along the conveyor

belt system for a 7-day period beginning on day 8 of Table 5.

Sweeping to remove larvae. -- The area under the apron conveyor has

previously been shaon to contain the majority of the larvae migrating

into the compost plant. To determine the effect of collecting and

removing these larvae on the total number of adult flies, this area

was swept daily for 15 days.

Malt bait. -- Malathion, diazinon, chlorthion, and dichlorvos in

malt or molasses were reported to be highly effective liquid baits for

blow fly control around dumps (76, 31, 34). A dichlorvos and malt

solution was used to determine the value of liquid baits for the control

of flies at the compost plant. Blue Ribbon malt was diluted with

distilled water to form a 25 percent malt solution. Technical grade

dichlorvos was added to produce a 1 percent dichlorvos solution which

was stored at 4 C until used. Fifty ml of this solution were applied

daily to each of 4 locations along the conveyor belt system for a 7-day

period beginning on day 40.

Foqqinq. -- Fogging is not a highly recommended procedure for

effective control of flies since fogging leaves no residue and a high

concentration is necessary to kill flies. However, the effectiveness of

fogging was evaluated since it was used to control flies at the Tennessee

Valley Authority com-post plant in Johnson City, Tennessee (61).

It was observed that the adult blow fl ies, predominantly Phaenicia

(Table 6), left the building at dusk and roosted in the grass irr.mediately











Tab!e Sex, -pcc es, and U.i.-C, ncc ('I' r f. 'c Cc .'lt by L. : t1
ir. Lrass -c cc ." LO rce.: r..] c-r. C Inesv.l il e CG...,c..
plant.



Prar.n of -
Spac es flie- c- : .' ,.'...
SI ICcC..S .f II e L L

3. Caught dur:r.g day
Phcanica sp?. 95.2 .3.1 56.
ML sca do esT ica -. 32.3

b. CucLgt a: r.igh-
en c:a .. S .? -.3.7 5 .
"usc, cc- s: '.c .3 S3.7 ..


a
I;.er. of ten s p.-.ples taken by fi.ve sweeps of net.



surroJndi.-.g :ha plant. Thesa areas were fcged az 9:0O pm or. day 53,

54, and 55 (Tabse 5) e icn a 3 percent fenathion :n \o. 2 fuel o;. sciutior.

d;stricjtt d by a portab:. ht-ci-r suing .ogger. This insectic:d, a-s

selected because o.- avii.biiiy and LaczJse a 5 percent fenzhion soition

k;ll>d 97 perc.-i: of t:-. caged :-.c-se flies 50 m froir a moving foggLr (4).

Resl -al srrais. -- Cc.tact a.id residual sprays are the most oftter.

recorm.ended methods of cc.ntroll ir.; flies. These sprays are r..cst cfrect ve

.whn applied to fading a ras and night-t ire rcting places such cs

shrubs and plant, in th- _irro.dir.ng area (34, 76).

SD;mt.-,o~te gave nme best control of hose fl es in Florida dair', barns

when applied a: a rate of 2 gm (Al)/.,- (5, 9, 10). A 10 percent dimuthoete

'.r. .w :, so.Iu.c i -p. iLc c..cc c.'. dy 3 -y a 2-g: al n F(.57 1) C.r.-

preosed-c Tr r.,. . -.',' c. .-* u ". 2 .,.. i..-../ tne grassy areas

surr c. .- .ac t.'- ., r...






Gardona, (2-chloro-1-2[2,4,5-trichlorophenyl] vinyl dimethyl

phosphate), a house fly larvicide, was provided by Dr. G. C. LaBrecque,

USDA Gainesville laboratory. A 10 percent Gardona in water solution

was applied on day 83 in the same manner as described for dimethoate.

Results

The results of the field tests are presented in Table 5.

Sugar bait. -- Daily application of a 0.5 percent dichlorvos sugar

bait reduced the number of flies trapped by an average of 66.7 percent

when compared to a previous 7-day period of no treatment. This control

procedure cost about $3.00 plus 0.5 man-hr per 6-day work week.

Sweeping to rer.ove larvae. -- The area under the apron conveyor

was swept daily to remove the larvae before they developed into adults.

An average of 40.6 percent reduction in the number of flies was noted

when compared to a previous 3-day control period. This reduction is

considered to be a minimal value. It ..as significantly lower than

expected since previous estimates indicated that 67 percent of the

larvae that migrated into the plant escaped under the apron conveyor.

The difference between the observed and predicted reduction may have been

influenced by the short test period. Since the larvae entering the plant

required 8-10 days to become adults the 15-day study period may not have

been long enough to ascertain the true results of cleaning the area.

Regular cleaning over a longer period should reduce the adult flies by a

factor approaching the percentage of larvae escaping into the area.

A second factor influencing these results was the operation of the

plant during the test period. Mechanical problems prevented regular

operation of the plant and refuse remained in the receiving area for








several days. This resulted in larval migration patterns differing

from those encountered under normal conditions.

Since the larvae entering the plant required 8-10 days to become

adults it is reasonable to assume that cleaning the area once a week

would produce the same results as daily cleaning at a reduced cost. The

effects of cleaning over a long period were not investigated.

The area under the apron conveyor could be cleaned once a week at

a cost of about 4 man-hr.

Malt bait. -- A 51.2 percent reduction in the number of flies was

observed over a 7-day period with the application of a dichlorvos malt

solution. This bait was found to have several disadvantages; (I) it is

not available commr.ercially, (2) it must be stored under refrigeration,

(3) it costs more and was less effective than dry sugar bait, and

(4) its syrupy consistency made it inconvenient to use.

Foqqing. -- The grassy areas of the compost were fogged for 3

consecutive nights producing an average reduction of 68.9 percent of

the number of flies trapped on the folla-ing 3 days. The effects of

fogging were minimal after 1 day as shawn by the post treatment counts

in Table 5. Thus, an effective control program would include a minimum

of 3 foggings per week. This would cost $15.00 plus 3 man-hr per week.

To determine if this fogging procedure was effective on P. cuprina,

100 adults were caught at night by a sweep net at the compost plant and

placed in a gauze cage. The cage was placed in the center of the grass

hill during the fogging operation. After the area was treated the flies

were transferred to a clean cage provided with fly food and water and

held for 24 hr. A control cage was set up and the fly mortal ity obse.-ved






-7

in each. r. is roc .ure' as cd p. 'd .:or c :h treatT.er-. An cVerace

of 97.2 percent of the tre::-d fl ies w- ere dad crter 24 hr whilee 6.1

percent mortal i:y was o'sas.r.'cd in the con;.ol cages.

Pesidual s rav, s. -- A ...C e ., o. ic:tio of dir, thoate gave better

than 95 perccnit cc-.tr3. _.- :.e : ies fc.- c te:e cid re,.-a rned e-,:.: .ve

for 10 days as shoin ii Tab'e : The cost cf cne apl ication vas

approx:.-ateiy $7.00 plus 0.5 m.,n-hr.

Gardcna '..as ir.nefi:ct ive as a r; 'dual spray for the control of

blo.- f i;es as sho.-in in Table 5.

Larvicides. -- Green (22) demonstrated that 59.1 percent orf -,ne

larvae escaping from s, ending refLuse :-a'ns could be controil1c b' dustirng

the area twice wee.
ur.der tne apron ccnv ',,or to control b"..k fl ics iwas rot atte7m.pted because

c: the large amount of debris fall :.-g daily i-to this area. The effects

of the lar.:cide woj.c be short-l: ,ed since incom-ing larvae probably would

not be exposed after 24 hr.



P.rari -c 61 Flies


e-'.thoas

To screen :n3ect cides ir. the Iaboratory fo,- their effectiver,ess

against P. cupr rna : w firs c r..cesscry to "ind a suitable reari..g

r.edoum so i;rge r.Lr.mors would be a'.vilabl . P. cuori..3 are easily reared

.i t'ie la borator..,' on a c.:t of Lecaying meat bt this medium is odoriferous

and also expor.siv/ .hu .rn l:r : r r._.nbc-rs of fl 's are rc-jired.

lga .'t n P.s s ': b.t a,~. l.T c. r,.. c .. _,r ,;oo.. .. n m Xi. cst i-

gaticr. was sta.r a to c-te.'r .r.. "- ... c.- *-c: .:.her :.._ ria. ,rricht b;






38

substituted for meat. Two series of tests were carried out which varied

the amount and kinds of test media used. In the first series the test

medium was placed in waxed paper cups (88.8 ml) with 200 P. cuprina eggs

collected from wild flies captured at the Gainesville landfill. Each

cup was then placed in a waxed paper cup (0.946 1) containing approximately

20 gm of dry builders sand. The larger cup was then covered with a

black cloth and secured with rubber bands. Eight days later the mature

larvae had pupated in the sand and the pupae were removed from the

medium by sifting the sand through an 18-mesh sieve. The pupae were

counted and the number recorded. One hundred of these pupae were randomly

selected, washed, dried on paper tacels, and weighed on a laboratory balance

(Mettler, Evanston, Illinois) to determine differences in the size of the

pupae reared on the various test media. Six replicates were prepared

for each medium.

The media tested included the following: lean ground beef; Alpo,

an all meat dog food; Chunx, a dry dog food; Strongheart, a canned grain

base dog food; and Chemical Specialist Manufactures Association house

fly rearing medium (CSMA). Various amounts and combinations of these

media were used as sha-vn in Table 7. Meat was added to several test

media because P. serricata was reared on CSMA fly rearing medium when

provided with sufficient meat for the larvae to develop to second

instars (35).

In the second series of tests 1 ml or approximately 6,500 P. cuprina

eggs collected from wild fl ies were placed with the test medium into

4 x 15 x 30 cm enamel trays. Each tray was placed on approximately 5 1

of dry builders sand in a 40 x 55 x 25 cm plastic tub. A piece of one-fourth





Table 7. Analysis of several rearing media to determine the most suitable method of rearing
Phacnicia cuprina.


Pupca developed Mean weight
Test medium % No. 100 pupae (gm)

a. 200 P. cuprina eggs + test medium placed in 88.8 ml paper cup
10 gm lean ground beef 81.55 163.1 1.513
25 gm lean ground beef 83.05 166.1 2.154
25 gm Alpo 82.4 164.8 2.067
15 gm Chunx + 15 ml water + I gm Alpo 80.1 160.2 1.501
15 gm Chunx + 15 ml water + 1 gm beef 86.4 172.8 1.514
10 gm CSIrA + 20 gm water + I gin beef 73.5 147.0 1.217
15 gm Chunx + 15 ml water 63.05 126.1 1.311
10 gm CSMA + 20 ml water 0 0 --
5 gm CSIIA + 7.5 gm CHunx + 17.5 ml water
+ I gm beef 80.4 160.8 1.533
Stronghcart 59.8 119.6 1.201
b. I ml (c.a. 6500) P. cuprina eggs + test medium placed in 19x30 cm
enamel trays
250 gm lean ground beef 26.5 1723 2.308
454 gm Alpo 34.8 2266 2.226
100 gm Chunx + 400 ml water + 50 gm Alpo 48.6 3160 1.689
400 gm Chunx + 400 ml water + 50 gm beef 62.1 4040 1.719
250 gm CSMA + 500 ml water + 50 gm beef 47.6 3092 1.078
100 gm Chunx + 400 ml water 17.0 1108 1.787
200 gm Chunx + 125 gm CSIMA + 450 ml water
+ 50 gm beef 52.1 3391 1.416






40

inch plywood with a 25 cm diameter circle cut in the center and covered

with muslin cloth for ventilation was placed over the tub and secured

by 4 bricks. Eight days after egging the medium the pupae were removed

by sifting them from the sand and the total number recorded. One hundred

pupae were then randomnly selected, washed, dried, and weighed. Six

replicates were prepared for each test medium.

The test media included lean ground beef, Alpo, Chunx plus Alpo,

Chunx plus ground beef, CSMA plus ground beef, Chunx, and Chunx plus

CSMA and ground beef.

Rearing tests were conducted on the screened porch of University of

Florida building number 618 which is located northwest of the medical

entomology laboratory. The porch was screened on 3 sides and covered

with a roof with 1 m eaves. Light, temperature, and humidity were

ambient. These tests were conducted during May and June of 1970.

Results

The results of the rearing tests are presented in Table 7. These

data show that i-mmature P. cuprina reared on a diet consisting only of

meat were larger than those reared on the other diets. When large

numbers of larvae were reared, as in the second test series, 4 of the

diets produced more flies than did the all meat diets.

The diet of the dry dog food, Chunx, plus water and 50 gm of ground

beef was cnosen to rear the flies used in the laboratory chemical

screening tests. This diet was superior to all other diets tested in

the nimnbers of pupae produced and cost less than the all meat diets

without producing offensive odors. Although the pupae were not as large

as those reared entirely on meat, these size differences were not








con.sid,.rcd ;reat encugh to ad-ersei' a-fect the teits or offset the

advanzSges of the ccg fco dI-.

Adult bl cow vlis usC in :~ chC-:cal scrcer.ing tests 'were rearec

rC .."i ,>, i co c :c a . ... .: : -

f' s -.ere re.-c to i-. .-. -er. r.---z: .0 c. . -... ... e: cc,'.ii -.:.- c.,

4CU 9gn CV..r.x, -.CO .ml tap .'a er, and S 1, !e .r, gro-nd beef ;.- r:-.-.r..-

described above for the second. :s: ser-e:. Aul: fi ies wr--re h!d .-

15 x 24 x 50 cm- gaSzc.--overed ca, es arc prov ded w ith fras zl: -:zr r.d

fly food daily. The fly food consise. of ,arrs 9ranulaLte sugar,

6 pa-ts nor .-fe d.y i/ i .<, n.d pa.-t c'ied ec-g olk. T'e cages --.ere

:-. d .r. the Un.ivers ity c/ Fl orida :.-aoicl n:C.o g'.. la, o rzz :y

er.,.iro, .ent-- con :tr cha.mn er .' h hr of artificial oa l ight

provide y Ir.ca.,descent lights. Temperature and hu.. idi;/ were ma;r.-

ta:ned a 2 at 2 nd 70 percent -..



Labcratorv Screenina of Insecticides for
Co.nrol of 2. cp. ina



Met hods

Five-day-old fe -aie P. cuor'na adults '..ere exposed to space sprays

cf 12 ccc.mr.erciall 1 av.ailabIe inscct;cides in the wind tur.nel described

by Dav;s sand Gzhan (15). Tne insecticide solutions were prepared oy

disso!vin each chem.- al in acetonc to attain the desired cor.centrations

(w/v). Thc original range of co.;centr options for eazn chemical was based

on the LC, values obtained fo: .r. insectC:cde SLsceoibl e stri:n of

.-cuse fil:s at -.; LC:.. La.-cra:.-y, C&:2.--lv>;'e.







42

The tests follaoed the procedures outlined by Bailey et al. (7, 8).

Twenty adult females were confined in test cages made of metal sleeves

closed with screen -';ire at each end. These cages were placed in tne wind

tunnel. One-fourth nil of the insecticide solution was atomrized at 1 psi

into the mouth of the machine, and drawn through the cages by a 4 mph

air current. Duplicate cages of flies were treated with each concentration.

mrrnediately after treatment the flies were transferred to clean holding

cages and a cotton pad saturated with a 10 percent sugar water solution

was placed on top of each cage as a source of food and water. The

treated flies were held under constant light at 250C and at 70 percent

RH for 24 hr when mortality was recorded. If the concentrations of the

chemical tested produced greater than 90 or less than 10 percent mortality

these data were discarded and other concentrations selected until a

minimum of 4 concentrations were used that produced mortalities within

the acceptable range. These data were used to calculate LC50's by the

probit analysis technique described by Finney (19).

Twelve compounds were evaluated in 13 tests, each of which included

from 4-7 insecticides, acetone, a dimethoate standard, and an untreated

check. The chemicals tested were as follows: dimethoate, parathion,

naled, diazinon, fenthion, ronnel, propoxur, carbaryl, malathion, Dursban

[0,0-diethyl 0-(3,5,6-trichloro-2-pryidyl) phosphorothioate], Gardona

[2-chloro-1-(2,4,5-trichlorophenyl) vinyl dimethyl phosphate], and Bayer

41831 [Sumithion] [0,0-dimethyl 0-(4-nitro-m-tolyl) phosphorothioate].

Results

The insecticides tested as space sprays are listed in Table 8 in

ascending order of the LC50 values obtained by probit analysis. The

fiducial limits (P-0.05) are also listed. Dimethoate was the most effective









Table 8. LC50 of 5-day old Phaenicia cuprina females to insecticides
in a wind tunnel.


LC Fiducidal limits LC susceptible
Insecticide (%i P=0.05 hose fly (%)a

dimethoate 0.0259 + 0.0064 0.04
parathion .0532 .0068 .05
Dursban .0567 .0063 .74
naled .0648 .0065 .018
diazinon .0857 .0063 .062
Gardona .126 .0063 .06
fenthion .133 .0065 .15
Sumithion .183 .063 .074
ronnel .246 .065 .13
propoxur .264 .092 .95
carbaryl 8.42 .67 >2.5
malthion >50. .81


aData obtained fror, the U.S.D.A. Gainesville laboratory.





chemical tested and along with parathion, Dursban, naled, and diazinon

demonstrated potential for use as a chemical control of P. cuprina.

Gardona, fenthion, Sumithion, ronnel, and propoxur were less effective.

Carbaryl and malathion were ineffective with 50 percent malathion failing

to kill 87 percent of the exposed flies. Appendix 3 shows the concen-

trations and percent mortalities used in the probit analysis to calculate

the LCc 's. The Chi square tests for chance variation of a homogeneous

population were acceptable at the 5 percent confidence level for all

tests and are listed in Appendix 3.









The CC0 a!ues obt.:rt; by tr.. U JS CIinc.i..i Lascrato.y .;
10
th Orlan.do SLusc-.t-t .r-in cf h, se- f: les .'or tie in-u, ct ici' s

te -eCd are I isted in Tab> : T.hee '. .. c.h.; c jT.-xc ed tc zi '.- 's

obtained it.-. :: c i . lc.] : c .: -, : '.:. a r;zasc:-. :, ccrr la: a :. eo'en

of :. e chc..:2:s -:C .c J c. -.-. s :.-S a v . s fcr .-c.-c .

bl .ow lies w.thir a factor of 2. The tolerance o. .;. cu L ir to t.ln s,

insecticides zppea.-ed to b. abcL tr sZ. .5 ; as '",0:O cf the u-scC t.,:

house fly s:rair. colc.r i-ze. c.c.- ; '/e,- a.o. Tr.,s is L.-.c~tstLcr,"' .e

s nce the bl a- f;y ..as r.ct been cer.cra.ly expO d ,t3 : o iisect;icidal p-ressuLres

over a -.id spread are3 n the Un:-:d Sta:je.

,.ie Ir.f.fe t e v ensess s f r.. ::.-ic. t to kil C. cuorir.a *..s u.nec oectec

as m.:cr.n;cn res :duz sp-ac's hva -.en re:cG=e..-.d-c to control bic.- fl ies

.t Florida ari'ps (34, 79). Th:s becomes less startling, ho.:.ever, -:hen

one c:nsicers that T..a:tni on. cid not cPr.:.-o1 CL'pr na on shucp in

Australia k57) and znaz r .:cr, has ir.ducea a very specific resistanrce

in the hcuse fly, in CJle: :a-s-: is C q. aid in the blo.- fly, Cr.r'scTivia

outoria Wiea. (1). .n the case of tr. blao fly, cariplate resistance

was induced within 6 months.

P. cusrine are controlle J n. Australia ar.d widespread dieldrin

resistance has bcen reported. 'wild f lics .cre i;c t imes more resistant

to dicldr.n th-n a susceptible strain and resistance, was also obscrvd

to aldrin, endri., isodrin, cr.:crdC..c,, other :yclodicncs, ar.d B..C (32,

67, 6d). Since th, general us- of chlor;nated hydrocarbons is i'iegal

in Florida these chenmca's were not tcstLJ in 2, stjd.,

A shi-t in ;h. cot.-.r.C of b:., .: L. to c.-z- ic p;.osphLas ra made

in Austrc: iO ..-. :.-.: ,a e ;S 's. i&zia ;cn ..~t :t ?rims ry insecticide


-.-'-I





45

used and according to Shanahan (70, 71, 72, 73) no resistance was found

after 6-8 years of use. He terms a 3-5-fold increase in the LD50 values

of wild fl ies as tolerance. Schuntner and Roulston (65) found resistance

to diazinon in blci flies and identified it as the breakdown of the

in vivo pool of free diaoxon. A perusal of the literature revealed that

resistance to any insecticide by P. cuorina has not been reported in

the United States.















SECTION III


DENSITY AND SEASONAL FLUCTUATIONS OF
HOUSE FLIES AT THE COMPOST PLANT



Observations conducted during 1968 revealed that bla, flies and

house flies were present in large numbers in the receiving area and

around the sorting platform, while house flies predominated in the

digester building. These flies annoyed the workers and posed a possible

public nuisance if the plant proved to be a source of flies to the

surrounding community.

A house fly sampling program was begun in January, 1969, to determine

the density and seasonal fluctuations of the house fly population at the

compost plant. The purpose of this survey was to determine the magnitude

of the house fly population, the necessity of a fly control program, and

seasonal changes that may affect such a program.



Rearing House Flies


All stages of house flies used in this and the following section were

obtained froa the insecticide susceptible or Orlando strain maintained by

the USDA Gainesville Laboratory. These flies were reared in a 10 1 plastic

tub in a mixture of 1 part CSMA fly rearing medium and 2 parts water. A

6.5 x 6.5 x 10 cm sponge saturated with water was placed in the bottom of








the tub to maintain proper moisture. The tub was covered with a black

cloth secured with rubber bands. Pupae were collected 7 days after

egging the medium and placed in 15 x 24 x 50 cm gauze cages. The adults

were provided with fresh water and fly food which consisted of 6 parts

granulated sugar, 6 parts non-fat dry milk, and 1 part dried egg yolk.

The flies were reared at the USDA laboratory in rooms with 16 hr of

artificial light provided by fluorescent lamps. Temperature and humidity

were maintained at approximately 26 C and 70 percent RH.



Seasonal Fluctuations of House Flies


Trapping

The digesters were selected as the primary sampling area for adult

house flies at the compost plant for 2 reasons: (1) initial observations

showed that adult house flies were usually more abundant near the

digesters, and (2) equipment operation in the receiving and sorting

areas made sampling procedures difficult.

The grill method of sampling house flies, developed by Scudder (66),

was initially selected for use in the seasonal fluctuation study. This

sampling procedure results in an index of the population and not an

actual measure of population density (43). The reliability of grill

sampling is debatable. Murvosh and Thaggard (43) reported a high correla-

tion between grill counts and the total number of house flies in kitchens

on the Island of Mayaguana, while Schoof (62) found that grill counts did

not increase linearly with the population sampled. Welch and Schoof (81)

reported chat grill counting was subject to individual error and was no

more accurate than visual estimates.






S40S

Crill counting rq .na effectt ve at the compost plant because of tne

large .evolu'e of attractive mate .-ials present.

One-foot- square (32.4 cm ) masonite boar'.'- ccvercd Ly a th n la'.er

of Stickem (.ictal e1 nd Pelton Co., Emryv.;le, Califorria) .-iLr w;v-l-:cd

for tracp.ing fl -s i tr.o digc stcr. T .se o rJs '.:ei-e ctt-chcd tc stn.es

I m in I r.g:s .'-.ich v\wru then C:.'v,. :r.to :h- ccO-..ost n .h.. di. c t. -s5.

This procedure \v-.s d .scardc: because scL !arg, r.ur.bers of fl i; vw .-e

trapped that -..- beards becs:.- : .r.crfTct.vat v 2' 'O,- 2 ,- hr a h passed. M.SC,

m.or. than 1000 fla:-s per Zoard wIre trapped and a population recuiction

:his gre t n-ay hove significc-'.t1 y r:uced ch. :ctc: pouLlat'.c,.

F ., st icky tap..:s (Ac-c--.o. ?:.duc.. .... .c.. fo. N.'. ) "ras.rir.g :

o: c. '.:.'re .-t. arr cr :ha s c.y U; C %.:C r shc..n .c be ,s .

TO" trapping :,.e f i e .ayo J d (.5-, S, E) resor-2: --at s:.c',' zta.es

were -,or.e acczur- c t.ha, 11 ccu r.:.c ir. ..:. L ..-. .ouse f 'l poj -D.d.

in Africa because they wrc:-e ass depcndn t on hj.-.on 'udc,-ert, took into

acccnrt temporary :l jctu: o;.-,s in oer.slties, an.d allo.-ed for the de: nti-

fication, cf the fl ies. Sticky tapes nave also been sho.in to be More

accura-e than vaacu.um collect ions .nd visJul co-nts at poultry farms (2;,

.nd baits at dairy bar-s (51). T.sts c.ring Decreber, 1963, revealed that

stzcky ta.cps were accc-: p al for tr-pping ..ouse f, s at tne con..post plant.

ric.sc f lis were sc-.ipled in th-. digesters from January, 12 to

DecezT.mcr 31, 19'9, using st ;cky ;apes sLspn.-.ed from 1.2 rr. .ooden StaKus

driven in-o tne cc-' o... Five stakc, were ,Tp' oy.ed d-ily '.d each s :ke

w.;as placed in a diffcr;r.: 3ag of conpcot va.ry.-.j fro-m l- days of CgJ.

. .k;" : .. .. .* r..-::. ca .y cC i. L.,- r.. .-C, c r.cuse :..s CuL .-.: 01

rc acr. ... e o: t'. ca .os :.. .a. t .per.dcZ r.*c

r uc or: c:.






-9

The mear. numoer o. fl 'e ca.-.t- per sticky tape per ue&k .a cacu-

Sated by 'di.'iT r.; t-e r.j.-b~ C f ;.s ,c ugr.t per w.e
st cky rapes. 7rese ca aa e sn,:.-n i. Fig. 14.

Effects of Te-: .-atre

The' m xrr.'-, au-;; c. ..'- .. l u., .T-:' .': .- re rs '.. cr roGce .. Z 1

3 5e sz..-,ace treat e.n racil t,, .ic.I -s c Ioc'n i me "y ce.".

:o the compost plant. T.i es c-ta .- -a m:Zace av.aiab.e :hro t.-.e

c t-rzesy of Mr. C. '.. Lenrat, n najer of t:e treat..er.:t fa :'/. ri.c

.aeekl', .means of the imzic.ar da1 y s.:- Tpera.ures w.ere calculated ar.d

are sh: .-.o n i n -. . .

A co,.par sot, c. tre rca-. : .e.' c:tch of f. s r. .:-. -- :-rs

th.e rme.,n vjc m:.x mu.. a: r :.-:er :Lrcs sr .... an a:pare-nt corre.a: Cr.

betw.'een- these data fro,. J',uary/ tc J-r.e. T.c cc-r.posc plant was closed

to replace the prTimary grinc :rg mill on June 15, 1959. L'her. ope-ations

resumed c.- Jj1 6, a c ':.'ize c.-op .r' r.u:be,-s of trappea flies v.wa

observed. A. check w.':n tne plant foriT-n -rv ,ealed thsa: he operating

procedures were the same as tr.ose before .he plcr.: closed for repairs.

The oly sserv.aole difference was ch.a the ;e:L.se d:sc:a-rged into Lhe

d;gesters was sl ightly snmal ler in size. There was no reason to bel ieve

thaz this would greatly affc: ,zne nu, e. of :l ies in th. area.

1: wa-s ooserv.ed nmat ter..cerZtures in the digester builainS w.,-re

higher than the -..iblent air :e.T.pcra-:Cu.'eLsbecause o.: the heat generated in

the co.T.pozting p-ocec-a and the cons:.'uction of the il-Il digesting

build ing. A .yc ro t-.rcorcaph was p accd on a platforrmI 15 cm abo;e rne

c -.c :he ; r :c : s .er L:e- w.r, .- .cord d for se ,vera

t-. '0 k r.-: '.".. :.- ..:, :ve.-. :.. 7 :. ,-,.C t t tz-.e eajr daily























06 0


I.


-v
L.

Q..






Ic
U









u
a,
a)
4-


(U
-o








IP -


60.
.0 9


0
* go **


23 9 23 6 20 4 18 1


15 13


27 10 24 7 21 5


19 2 16 30 14 28


J F M A M J J A S 0 N

1969 Weeks


Fig. 14. Mean number of adult flies captured per sticky tape
digesters at Gainesville compost plant.


per week during 1969, in


(a Plant closed for repairs June 15-30.


12 26 9


080


foj
35 n-

-o 3
on,
30 1

CO 0

25 3
n X
3
20 c
0-

15 -
-






Table 9. Air temperatures recordeda 15 cm above conpost in digesters at Gainesville c-npost plant.


Mean daily
high


1969 Wcelk of


41.6

37.5

37.3

33.7

33.3


Mean daily
16:1l


34. 1

32.4

31.6

24.2

20. 1


Mean hourly
temperature


37. 1

311.9

34.5

28.5

24.0


Na f ics caught
per sticky tape


9.0

9.9

13.0

77.3

51. 2


Aug. 17

Sept. 21

Oct. 19

Nov. 16

Dec. 21


Degrees Farenhcit recorded on a hydrothermograph converted to degrees Centigrade.

See Fig. 14.









|m.,x:mnum ir temperatu.:c in the dlcj.ster Lu:lding cculc b- expected cc

exceed 37 C during :he SL--.rT r r.on ns. Appcrently/ hthse tg.-ceuraturei

discourageJ the flics frc.m entering the building resulzir.g in a laer

number of flies trapr-d c,.- the cricky,' t p es.

Tna nur.-,br of f; :e tr:,cc :ncre:-c_ n a.l OcLar .wh.

decrease .-- obsc.',v d .n ne c.-ricr.. -. r .T.p:r.._r- cr.d t:- ,.-.7 .ra. r.

in the b ild:r.:. Tn.;Lu bs 'rv/r.::.". c-..d c.r d-r.c. :a :h.e c-: .'.r :.

the fl ies w.:re re l: i bc.aus c, t.-.e h.gra.- :-T J.- Lr .

r, c c.-C ease -. t:-.e r....nber of f ies ard .-na Zi.b:ir.t ai.- tCeT.,m ratu-c

w s o0asuved in Dec-mber.

Th :s invcs :.; ric.-. V s o.-:c!r.a.-', csicr..cd : dert rcr r.3 :.-.3 s L o.-..a,

.jctuct:o.ns of hc e f :es .a t,-. co-.pos p. n.t. Tr.c tciper:~.-cs .r.

the c:gsrer bui:.ing where t.ne t-aps .'ere located affected the njuber of

fl ies caught d r ing the s_:.....c:- mor.ths and this szu-dy failed in i-s

orisinz. goal. r:c.saver, tns-e c.ta do show a general trea-d during the

cooper m.T.cn-s an: d..ons:ratefd thIt ::'. J.u:.ding design rdJucjd tlhe

number of fl ;es present i -.he di.,st :r building during the p.ricd w-hen

fly r.:.-.bers were ajte.-.:.al. L.'e greatest.

T-.e r.L-:ibe" of flias ca& :, : o.- sticKy' t-pcs placed in the differer.:

ages of cor-post .r, shcha-n in TabLe 10. Thc:. data demonstrate thra

flies prefer the f.-ehly ground refuse. Gretzer th-n 53 pe.-cur. of the

f; .cs in the cigusters r.ormaly congregated in the crea of the 1- crd 2-day-

od c Gpos .





Table 10. Number of adult house flies caught on sticky tapes in different ages of ccnposl..


Percent of total
flies caught in
Days compost in digesters 1-Day old 1+2-Day old
1969 *cek of: 1 2 3 4 5 compost compost

Jan. 12 629 417 434 360 367 28.5 47.4
Jan. 26 266 182 173 91 119 30.8 52.1
Feb. 9 241 150 121 94 105 33.9 55.0
Feb. 23 74 65 44 46 51 26.4 49.6
Mar. 9 28 27 21 36 20 21.1 41.7
Mar. 30 154 130 45 51 12 36.5 67.4
Apr. 20 553 321 123 105 52 47.5 74I.9
May 4 1413 501 193 197 179 56.0 76.9
May 18 501 365 193 154 162 40.I1 65.3
June 1 790 347 228 151 198 46.1 66.3
Jul. 13 99 55 40 26 37 38.5 60.0
Jul. 27 85 106 17 46 32 29.7 66.8
Aug. 10 83 46 45 56 16 34.2 51.8
Aug. 24 176 128 '44 .51 37 36:3 62.6
Scpt. 7 123 116 41 49 79 30.2 58.5
Sept. 21 105 81 69 I4 51 30.4 53.8
Oct. 5 86 134 75 59 88 19.5 50.0
Oct. 19 188 92 91 58 61 38.4 57.2
Nov. 2 407 369 226 201 321 26.7 50.9
Nov.. 16 677 533 675 424 297 26.0 46.5
Nov. 30 971 714 542 407 469 31.4 54.4
Dec. 14I 680 461 437 374 217 31.6 53.1







Evdlut!oon o' F 1, St'c'." Tam .


elet'-.od S

A nc:n nL -ibe." o .'.c 7. .-.e.re -el i.ce a : ,'r-e t. -cc

screen c.a e w :h sticky :tpo s to c--U..."-i.a if ..-e r.u;.'.3r c. f ic; cLu jht

co '.u d be correlated wr.: t.. coazl .-._.-.b .- 7 f : .-, n:. t -.- ;-

..* Is located in a. p rtially s.-..dad c behi. r. tr -.',in bull i-, c- ..,f 3A

Cair,esv:1 e l oora:ory. The c-ce -hd a 5 x 5 .n aasa wi\ a ccc:c rc;-.

rof0 3.5 m high. The floo.- c.ns sted of soil and :..s ukept claearne o.:

-:weds and grasses jdring the tests. T ..cr 1.2 .i~ states were driven intc the

ground on th.. center l ine c,, r.e ca2e 1 r. fra.. ecch end. A s. ...
was hing on eac-. stake ar.d .-'.Lcud dl. A I xi 1.0 x 1 2 c.m ]"-helf

metal stand was p-ccd ;n the c.ntei- cf th.e cage to .hC.d the food .nd

water SLup ed cally and to provide shelter for the flies. Tests were

coidjctec dr ng June: July, and rugust of O069.

Test insects were obtained as pupac from the LSDA's insectic~ .

susceptible !o..ose fly color, and were held in cages until adult files

were beginning to c-nerge. At the onset of eclosion approximately 200

pupa3e were placed i, a 15 x 24 x 27 cm, cuz z ca~. After 24 hr the

rerimining pupas %,ere removed. The cagcc we.- provided daily with fresh

fly food and v-.ater and were held in a roori provided with 16 hr of arti-

ficial daylight by f:;.-escent lamps. Temperature and humidity were

rmaint ined at 26Z ar.d 7C percent Rn.

Flies used in the test were removed frc., tne cages, anesthetized

with carbon dioxide and counted. A 1:1 ratio of males to females was

SE.LCt n. t,. f'. s ;C.e.u Z..en rel Esed nto .ne large cou:door a;'L.

Sticky t.p... .... r-sac :r. .: cjtaco-r co-e iMUnTdadziatly aftar rel(asin3






55

the flies. Twenty-four hr later the tapes were collected and the numbers

of flies counted. All flies remaining in the cage following a test run

were killed using a fly swatter. Pupae, 1-, 3-, and 5-day old house flies

were released in the cage in numbers of 100, 250, 500, 1000, and 2000.

Duplicate tests were conducted for all ages and numbers of flies tested.

Ore-day old flies were released in the outdoor cage 24 hr after

placing the Energing adults in the small cages. This procedure provided

flies which were 1/2 24 hr old at the start of each test. Three-day

old flies had emerged 48-72 hr prior to release and 5-day old flies had

ez erged 56-120 hr prior to release.

In one series of tests, mature pupae were counted and placed in the

large outdoor cage. Sticky tapes were hung on the stakes and 24 hr

later the number of adult flies which had emerged during the test was

determined by counting the number of remaining pupae.

Results

The number of flies caught on sticky tapes was linearly correlated

to the total number of flies present in an outdoor cage as shoan in

Fig. 15. A high degree of correlation was noted for flies of the same

age while there was a smaller though acceptable linear relationship in

the combined values of all ages between number caught and number present.

The slope of the correlation was calculated following the procedures

outl ined in Dixon and Massey (16).

The percentage of flies released as pupae, 1-, 3-, and 5-day old

flies caught on the sticky tapes were 11.9, 24.8, 17.1, and 19.2,

respectively (Fig. 15).'













-----o 1-day old, 24.8% capture

--- 5-day old, 19.2% capture

c--- o 3-day old, 18.1% capture

*----* pupae, 11.9% capture


100 250 500 1000 2000
Number of flies released
Fig. 15. Number of house flies captured on sticky tapes within 24 hr after release in
a large outdoor cage.


600


500
-o



U

1 300


o 200
L.
.0
E
n 100
z







57

The small er n-iber cf fli cs trappec wncr. pLpaZ V.aUs zl lc.-.:c tt

e.arge ini the- otdo r cage ve are 7no surprisir.g s r.ce a highe- mcrtal ity

rate w s expected.



C'e err:in:. 'or. f ..'1 1 r1: r. '.TLr f hI- -icjse Fl1 -, O; d Zt ic.-


'. thods

The total nu,-.,ber of hcuse fI cs in ;-.e digester c'uilc:ng I.;-

est: T.r. ted b/ de:e.m r. in t-ic po -ca- S o r' ked flI :aptP .cd c.-

st cky taes that were rel eas-:s :r. *:a: Z- -c. ...ree-dca old .-...se ..S

fri,-, ;th USDA suscet.:' co' C y :.'ere criesth.at:zed by cac. on r io> d -r.d

placed "..:o small scree- :-.oldinc ca-es. Ti-, e- 'lIes wer e .-arked by

..dd:..g or.e-.a teaspzon of DayC o (Si.zer brot;- rs Ir.c., Cle .-lard,

r,.:o) f;jo,-escert djst to ap. -o.; i.-.T el / 00 ,l i and genzly rotcz inc

t..e cage-s. Tr.e 'lls were c. e. tre:aL er.-ed :o 15 x 2 >. 27 g-uze ca:ee .

Folacwlng a 1-hr period to allc. t:he fl'es to rec'.'rr, the fl es wLere

transzorted to nri- cc'-pos: pian:t .-,d released in zhe digester buiidirg.

A. r'eases were mrri- bet'.-er. U0:00 1 1:00 a cm n a S c-urday or -

S-nday when t.ie plant w-s nort n c erat.cn. Al thugh .il1 the doors ;r.

the c -ilding .wre,-e c!osed, f Ics were not confined to the digester buidir.g

because tne sid.-ng d:d r.ot fiz f:us:h -c the bcse of the bLilding caving

a 25 cm. opening.

The flies w.-re captured by 5 sticky tapcp suspend; d fm .tn tket-s :n

the c;gest.r-. n-d were the si--me as iescr ed previously for :" se.sc-ial

flu c:;ut irn survey. The stick/ t:pcs were collcc.cd 24 hr ;-f:er ccch

rc_ eas. 3.-,0 the rsr--r 1 ': 2 c n i d -' us. C i b-.:ora,, p -,'-r

ui-r ,' ct 1. .:. .o .- rdse- ...-. r.-dc :.-.v lvir.g 1530 -' ic; .-:.:

alnd war, .-.,de i .h 50-0 f is ach.









Results

Ar. v.-erase o. 1.S percent of ,he laoror cor-recrud ho-.- fli e

released in the digcsters %a.are captured on sticky capes ablee 1 ;.

The capture of hose f!ies cn st:cky tape- in a large cutdocr c5- was

s.;o.'-n pr. ioJsl y to b- prop!ryo.a. to .n, ._-o':.-.- o .:l is pretc- r.:.

:.'hi.:ner the percent, c capLurea 17 p rc; r.: as s-c..n ;.or f-c c!

fl ies re:'.ase' it. a out-oor cacg as sho.-.-n .i Fi.. 5o5 o, l.c pec- -.

as sho..n in T7bla 11, 1 .Culd depend on the circJ..s::nces. Ad iteaoy,

any '.lue assigr.nd wojld be questionable due to d-eth, di-parsal, &nc

er.\ i.-on.-ental .actor Hc.-cv- r, in the cres.r.t case t.h- va.ue 1.

percr.: is gIven cred.-.ca since :.ur'vc-h :.id Thagg rdc (-3) counted 1.25

percent. of tie houLc i ies preser.t in a sirr.ilar p rt:iaily open s i:;Jaion.

Ti;s fig-re (l.a pc:cent) can be us.d to estimate the total n.umTer

of house fl es preser.: in :he digestars based on tne numbers cajgh n. on

the LtiC~y tap-s. For example, Fig. 15 sho.-is tha: 48.9 fl ies per stake

per day w.are caS-g.t the aeek of Ap-i! 27, 1939. An estimate of the

tozal number of flies present can be calculated b, ICO percent 1.8

percent x 5 stakes per day x L8.9 fl i s per sLake and is equal to 13,569

hose fl;es per d-y present ii the d:gester building during the weer of

April 27, 19S9.





Recapture of 3-day old markeda laboratory reared house fl ies by sticky tapes hung in
digesters for 2i4 hr following release of flies in the same area at the Gainesville
ccmpost plant during 1969.


No. marked flics
released


No. marked flies
recaptured


1500
1500
1500
1500
5000
5000
5000


Average


Percent
recaptured


. 0
1.8
1.0


2.5
1.7
.8
1.3

1.8


NIo. unmarked
flies trapped
on sticky Lapes


42
30
33
396
1058
696
1i50


aDayGlo fluorescent dust.


Table 11.


Date


Oct. 5
Oct. 12
Oct. 18
Nov. 16
flay 10
MIay 17
Dec. 13















SECTION IV


HOUSE FLY BREEDING IN COMPOST



Observations conducted during 1968 and early 1969 revealed that

house fly larvae were present in the compost in the digesters and

along the conveyor belts where spillage had occurred. The ability of

house flies to breed in compost presented the possibility of great

numbers of flies reproducing in the enormous amounts of compost avail-

able.

An investigation began in April, 1969, to determine the extent and

some of the limiting factors of house fly breeding in compost in order

to devise procedures that may be used to prevent or hamper house fly

breeding.



Moisture and Age of Compost


Methods

Composts of various ages and moisture (%) were evaluated to determine

their effects on house fly breeding. Compost 0, 1, 3, 5, and 10 days of

age was tested at 30, 45, 60, 75, and 90 percent moisture. The age of the

compost was determined by the length of time the compost had been in the

digester. The 0 days of age compost was freshly ground refuse taken off

the conveyor belt just prior to discharge into the digester. Compost 10





61

days of age was tested prior to and after it had passed through the final

grinders.

The samples taken from the digesters were removed from a depth of

30-60 cm and placed into a plastic bag. A minimum of 5 areas were

sampled for each bag. The bag was then sealed and the contents thoroughly

mixed. A 10 gm sample was removed from the bag and the moisture content

determined with a moisture determination balance. The moisture content

of the compost in the digesters usually varied from 35 to 55 percent moisture.

Since this was greater than the lowest moisture content tested, a portion

was removed from the bag and placed into a plastic screen mesh bag. The

mesh bag was then placed in an oven maintained at 800C. After a short

drying period, the compost was transferred to a separate plastic bag. A

10 gm sample was taken to determine the remaining percent moisture.

The desired moisture content was obtained by adding tap water. The

amount of water added was calculated by the following equation:


(y) (100-z)
x = z
(100-y) -

x = ml of water added per 100 gm of compost
y = moisture content desired (%)
z = moisture content of sample (%).

After the amount of water needed for each desired moisture content was

calculated, the compost was divided into 100 gm portions and each portion

placed into a separate plastic bag. Tap water was added in the amounts

calculated and the bags were sealed and the contents mixed. Fifty gm dry

weight samples were removed from the bags and placed into waxed paper cups

(0.946 I) which were marked for identification. Either 100 eggs or 100

48-hr old larvae of :. domestic were added to each cup. The cups were

then covered with black cloth and secured with rubber bands. Temperature








-,0
,nd h-,-;c : y .-rc;e ,r; :ntQ.ain-d -: 2- C -.d 70 p-rccit P.h. Seve.)i cL.y

after e ging or 5 ccys after placing t..e lar'vL. in -:h co-..pS .-e c-ps

were emptied ir.to a p.n of water :nd the cl.-_ting rupa-. '..eri cc'. c:1:

ra d co-.n:ed. Each test -.,s real :ca--d t .--. CS'.A fly r.r .- .

conte:r..r.:g 6 pcrccnt .o:s:u.- w3: uL.LC c ; co. :-o.

Fasul :s

;-'o.s:L:e cointer.t a the- 2: o0. t... C3TpI- -: ha tt-1 -!l.- c:.

,-., ,--turatic.-. of 5-,-.." o d ho-u.-- f y l .-v -t-bl 1] ). .o.*. ,.' r, ..-, e

factors c ; r.-l -..-.ce z.-.e a.eve' co.T. .t o.: hcJU -. c frc". ea. -. 1

ages of co.-pos :e:-,.d co.-nta;.-ing j3 -an 75 perce.-.L mc G;tZL r suppc.":ed

hoLS-e f'y development to .c- e:-.tent. i.ne :.'., p,.-cc.-.t -noistur inhkiIt:d

house fl, cac opT. t w.-. 'e 43 percent macis-rc ,..' Ir.surf :cient :o r.a,-

house flecs. Fo.:y-fi.,a perce-. .To;ctur inr. freshly .round rcfise

resulted i.f lass .tn.a 1 pe-cer.: sur ia\ i to ppaL. It should be r.otec

tha: tnese tests uer, sua acted to a.O ientF.,4 (70:1) and moisture

flLctuat:o.-.s duL in t.e tt-. peroc .-ere not r.:;easure.

The zae of tri ccco-,: f-. dect.d ho-s fly development jut ihis was

secondary to moisture as .hc..n ir. Tab!K 12. There was a s:Snificar.:

reduction ;n tne number of eggs that d-vAlopcd o popae .;n 3-cay o.d

ccrr.pos at cj percentt moisture b.t no significant reductions occurred

in tne ages of ccO.post :estica .t 75 pc-'cent moisture.

.he effects o1f Iac.sture Lr, house Pl dIL'I.!opm-ent friom C s .was extended

to cef ir.e more closely h. o : ir,:u.; r.oisture of co,-post for fly oreecir.g.

In this test series 130 M. dcic-st ic e'gs wierc placed .i 3-day old co,-.-os

co:.tc;n :; S5, 6;, 7a3 c tr, d

c;.T.e -.",'.,,.r .. dc, -C; i ,. . L','e. Jic.- .O.; C ..- ,t vwas r: .." T cac?..C:






Table 12. Influence of moisture and age of compost on maturation of immature house flies reared
in compost.


Time conpostedb Percent moisture
(days) 30 45 60 75 90 Control

No. of pupae collected per 100 larvae (48 hr old)
0 82.5 78.0 84.8 81.6 67.0 94. 1
1 54.3 81.3 58.6 33.5 50.3 92.5
3 84.3 74.3 80.3 88.3 80.1 90.1
5 76.0 80.6 84.6 91.6 70.1 92.6
10 81.6 79.6 86.6 90.3 58.5 92.6
10d 82.8 86.6 89.0 90.5 80.3 92.6
No. of pupae collected per 100 eggs
0 0 0.8 16.5 43.3 5.6 80.6
1 0 0 11.3 33.8 .4 87.6
3 0 0 21.2 40.8 .8 78.6
5 0 0 3.1 39.0 .6 64.8
10 0 0 3.1 25.1 .3 80.5
10 0 0 .3 8.5 0 88.3


Mean of 6 replicates.
Length of time in digesters.
dCSMA fly rearing medium containing 66 percent moisture.
Passed through final grind (finished product).








64

10 times. CSMA fly rearing medium containing 66 percent moisture was

used as a control. The optimum moisture content for house fly develop-

ment was 75 percent (Table 13).



Sludqe and Grinding


Methods

A test similar to the preceding experiments was conducted to deter-

mine what effects the addition of raw sewage sludge and the grinding of

refuse had on house fly development. In these tests either tap water

or sludge (approximately 98 percent moisture) was added to various

grinds of refuse to obtain the desired moisture content. The sludge

was obtained from the storage tank at the compost plant which was main-

tained by the city sewage treatment facility. Sixty and 75 percent

moisture contents were chosen to be tested with the various grinds.

The amounts of water and sludge added to achieve these moistures were

calculated as in the previous study.

Four sizes of refuse particles were evaluated in this study. These

were obtained from refuse taken immediately after primary grinding,

refuse taken after secondary grinding, a 1:1 mixture of refuse from the

primary and secondary grinders, and refuse that had passed through a

small laboratory mill with a 0.63 cm grid. These samples were placed

in plastic bags and mixed with water or sludge in the same manner as

described for the previous experiment.

One hundred M. domestic eggs were added to 50 gm dry weight of the

test materials and placed in waxed paper cups (0.946 1). The cups were

covered and the pupag collected by flotation 7 days later. CSMA fly









Table 13. Influence of moisture on maturation of immature house flies
reared in 3-day old ccmpost.


Percent No. of pupae collected per
moisture 100 eggs

55 14.0
60 21.7
65 23.7
70 30.2
75 39.4
80 21.6
Control b 80.3


Mean of 10 replicates.

bCSMA fly rearing medium containing 66 percent moisture.





rearing medium brought to 66 percent moisture by adding either water or

sludge was used as a control. Six replicates were prepared for each

test.

Results

The addition of raw sewage to compost of all size ranges produced

a higher yield of house fly pupae than the addition of an equal amount of

water as sho.n in Table 14. Such an increase is not surprising since the

total organic content was increased and since Olson and Dahms (49) found

se.rage sludge an ideal breeding medium for house flies.

The effects of grinding compost were not clearly demonstrated. The

results shown in Tables 12 and 14 indicate that the larger particles were

more conducive to house fly survival. However, the size of the refuse






Table 14. Influence of sludge and grinding a of refuse on maturation of immature house flies reared
in compost,




50:50 Mixture Refuse after Refuse
Refuse after of refuse from secondary passed
Percent primary grinding primary and grinding through
Moisture ca. 8." x 811 s econ da ry m ilIls ca. 411 x lif ]/A" gridb

a. Water added for desired moisture controlf = 85.2).

60 26.3 20.5 19.0 0
75 33.6 29.1 30.0 0

b. Sludge added for desired moisture controlc =8.)
60 31.9 26.3 28.0 2.8
75 47.o 39.5 35.3 19.8


aGrinding samples taken from grinding millIs at the Gainesvill e coiipost plant operating under
normal conditions.

bRefuse from secondary grinding mill passed through a small laboratory mill.

cCSMA fly rearing medium containing 66 percent moisture.





67

particles varied '..i :h r.e daily \-. ar of -.he grinding m:ils and the exact

size r-nge CL1s difficui: to ascert:. n.







The terTp, r.-'z urL s ocx-.'i:'g :.-.c .. / ra.rinr con. incrs J.;

:inves:igczed to c ter.T;nc tiC t n:,r-t.-r.r .-;-', rf -r.e2 b ir,.-.L.

I.'IuO se J : l as i .ne pr - "-. A "k ..A 51. -:I s i co cL c:... .T. -..

(Atkins Inc., C ..'.svy .1 : .? or. c ) .e.- p acec i;. 1i0 1 ic :.-ea.- n;

tu.. ,c.'. :.z. -,: ;.-.g .:'. :-.c -.: "f:'/ ,' r ": rc : .;: ,.:,. : ,o,? '.-e:.." .': .c."s .:"

,."t p'cb:,es w e e.- p, c cc '. t ...;:, 'i ic... c :,e ..:~ ,. e.' .- a r,--, i tc

The t. .i:,e. -jr ,,.:,- .- : .---:.J c.e r, _. :-,.- for,.- J '-ys. 'c'.-. -

waZs rc l i ca: d 3 t i... L-

The mian ..T. -raLure recorcea ; the -'earing tubs at each pcsiticn

are oreser.tefd i.-. TZbL'e 15. T.-,I b! cckc: cat.- ;r. T b. e 15 reprcsenrt

those probes i. areas OccLpied by ia.-rv.e. The mcx mum tczrm.perat-e

observed :." :;-.e larval region b..s L6.1 C. "."t se data indicate that larvae

develc, :.n a tem.perture range of 23 S-.SJ C.

The .c.-.:i.:.un tc.- era. re in whic.i i a.',ature hojse fl ie. can develop

is not kno..an. T.ere are ma:ny rdfercnces deal ing :Wi tenperazure studies

c.i house flies bu : uite defi:. te info.rmiatiron -.'s found concer.ing this

pa.-ticuLr area. Jest (32) sttcCed tht h-cuse fly eggs car.not su..'vive

a temperature tcove ".. l1C while F.c:bajd (59) repor:cd the: larvae died

in 3 minutes when exposed to SJ L.

Tc determ..-.e if zh- temT.erat_.-es tzcir.cd i., ..c d.d -s- -s 7..'y

tre.c.t hojse ,1' d vele;.:..:. :. t c cCT.o .t r. A.:i.-. H 51-. s.;:. co-d. ctc

t.n-.-..c.LA.cr '.;s CSL '' reton e ur. L.'-. e .-T-c.'- .L res. -.'. protes v.ro






















level of
med ium
1 2. 3 1 2


5




10
sponge86





-7.5


30





F ig. 16. Pos it ion of temperature probes in house f ly rear ing
containers (distances in cm).






1Tbl I T1.. Tcni pr.ltur:s oLscrv'cd iin iho".e 1 *, ri rin cci ita incls.


Decgres Cent iqrcadI rccci dcd b d,s aIfLI r

i" r 1 2 -3 I; r 6

1 3I:.9 35. 7 33.9 3C.3 31. 1.
1i0.7 1.9 37.8 33.6 33.3 29.':
3 I6.3 i 2.7 37. 2 32. 3:.8 8. 1
.; ..8 1 .4 /:3.7 37.i' .... 9 3i.0
r 1"3, 2 1: 9 1:1.7 36..7 35. E. 32.,


7 I5.8 C i9.' ':,4. 1 3 0 36. 3 .5
37.1 39,2 3 2 37.0 3'.1 33,2
347 36.1 31 31:. 37 4. 2 .0


SL ricj 1 2.

IL, In of 3 rcpl icatc.s recorded by, an Atl :ri's sc ij con.rlu- icr tliheiiOncLtcr.
CBlockcd data ii..'icate area oLCLIpied b ,' lrvie.






70

placed in 4-day old ccr.post at depths ranging from 1.27 15.24 cm and

alloIed 10 minutes to equilibrate. The temperatures were then read and

recorded. Twenty-five readings were made at each depth over a period of

several weeks. The temperatures ranged from a mean of 38.20C at a depth

of 1.27 cm to a mean of 59.4 C at 15.24 cm (Table 16). Information on

the temperature in the digesters at greater depths was supplied to the

author by Dr. D. T. Knuth, Environmental Engineering, Inc., Gainesville,

Florida, and is presented in Appendix 4. From these data it can be

concluded that temperature would prevent house fly breeding in the

digester except in the top 2.5 cm of the compost.







Table 16. Temperatures observed in 4-day old compost in digesters.


Depth (cm)


I 5. 24
12. 70
10. 16
7.62
5.08
2.54
1. 27


M i n imum


56. 2
54.3
54.7
48. 4
43.0
40.0
35.8


Degrccs Centigrade
Maax imum


61.5
62.5
59.9
59.7
55.5
66.0
62.5


Mean of 25 Observations


59. 4
58.5
57. 2
53.9
'9. 7
44.9
38. 2


Sewa e sludge added to achieve 50-55'. moisture content in compost and ca. 1.6 ft per hour of
air per ft- of refuse suJppl ied for aeration.


Neno 2 berain
















SECTION V


MIGRATION AND DISPERSAL



Compost plants and other similar types of refuse handling systems

are centrally located to lower the transportation costs. These facilities

are optimally designed to operate in these central locations without

causing a nuisance to the surrounding community. The Gainesville compost

plant has previously been shown to produce approximately one-half million

adult flies per week during the summer months. These flies may disperse

into the surrounding community, thus discounting the value of central

location. An investigation to determine the extent of fly dispersal

from the compost plant was begun in 1969. When the plant closed in

December, 1969, these dispersal studies were completed at the city land-

f ill.



Literature Review


House Flies

There is an undue prominence often attached to the maximum distance

of dispersal of flies (63). Flies released from a central location and

recaptured later at some distance in very limited numbers imply that the

area covered is subject to infestation from the release point. Although

this may be true, it should be noted that those one or two flies





73

rccovarea at some -reat distnr.ce %..ere Xonr thre xcti io.na fe. zat, b,

soe ] c-ient oa c.iaecE, rraqad to Lca. v'e this is -ance. Th: d scE.-al

of th the of the f / pop-'~c.' 7- rat:.e.: zrn.-i that of -- fe. ind v cu:.

is the s i r. ic .'.; cri:e i.- C., o ." a c.:e. Z. .zc rd : n -.*: c:. -. S..'.

(63). T:- d.?p-e:. .l c p::!t' c ..:. i,-s c:p. ctiorn is c :, ;p cec be

ex e., dcd \w::;r.in '/2 2 mi z ccuse o.: -he a:.-;2:..-..g c.-.:r:.- c

hoLSe fl.y rovZT,.-It ( :, 7.E, 5;, 5 6, 6;, SL 75). -T :", m.O/.s f:c.- c-.

;ield of a s:imulurr s c--aus! r.3 a .-opic zaa: :.o. or :, at f cr.oth (3,'.

A fly r..ac/ travel 15 n1 es to r.ch a c s rce I ile :-o it- orig.n (6l).

The attr-ctiveness of the r lease s te may greatly irnflue nce c.spersJ.

Picker.s et a'. (51) recap:uired 1 percent of the liberated house flie

z the .e ezec sit .he...'rr.. r. z:. ., k. a:.

fl ies in an, open area loccrcd at :..e center of a 1 '2 mile circle of L

carns only I..1 pe.rc.in of t..ese fiies were recapTu.-ed. Schoof (63) four.d

that ir. rr. r.y instarn cs flies dispars-d from a location despite tre

presence o n.r. apparent exce-ss oi feeding ar.d breeding areas.

Tnere ae- cCni l ic:;r.g reports of the effects of i o u n rly cIspersal

(25, 40, 52). H.o.-.ever, -he nore com.iiireer.s ive studies of Schoof and

Silverl y (64) four.d th.- ncusu fly movement w.'as not equal in magn;itud in

all directions arnd Pcke.isert c'. (51) r:./alod that fly aispercsl was

ra.-,dc- wner, the w':nc w/as variable and -upw.n:d t.h-n the wind blo.- pre-

cAT, inantl'.' from 1 quartc.-.

C',ata et :1. (.6) demonstrated that hoJse fly d:spersal w.'as not

influenc,- .y hi;n.-iays, rice fields, or rounr air.s. Dispersal is influenced

by tre a;c. snJ : ..; Ti of :h ," .: .,.r, :hc.- no sc."r, i c.-t c '.c..

c,;,.--/ .a ;r. "... .:; : .. .. .. -.:. c ,- .' .., : 2, . f .





74

Schoof and Silverly (64) concludLd :t;t the cc-.non characteristic of

fly d ipoars:,l was a bS'ic rdr.dcannss of movement ir. flucr.ced by 5 conditions:

i1) popLlat;on pressure, (2) differentially attract ..e site-, (1) geographical

barriers, (4) preferen i:i r.ovenent, c. (5) ir..ijrn:t tcncency of fl ies

to disperse.

.he rrA;m...m ".g.'it r.-ang c i. ;- ccorccd i .- ,o L Js di W,

usually :e r.axirc.J d :st-ice of trp??w ng. Tne nzximur. recorded fl;gnt

of no a. flies is 23 miles (S3,.

E1 o. F ies

C:imor- a (2.) f .d t' .a: z . P .- ,-'ael a.d at ce-.tral point

.cre distr;ib5cd .-cndc;nly after 2 Jc/s in open sheep country. MacLcod

c-.d c.-.r-.ey ( 3, 3 ) co.-,clu-e tn:: bhc' f y cispersal was r ar dor-. Lt

:;,o acscreg3aticns .c.-e fc.-...e p.odLcing a clbmpcd distribution. These

qgg-eCgz .ons ".erLe dJ to aiffe-ent d gra3.s of attraction offer&, to tncse

indivic;a;s ir, tne:r ra.dc.n :.iov rt acro-.s the activity, arcs. These

a:t.ncrs later occided on two types of blo: fly 1 i'"t: a sustained

cispersa; flight, ir.d>pende.: of the enviro-tent, and an i.-terspersal

l :.ght wh::h may :r.voiv n n no r dis l ccc..er.t (40).

GLrnr.y neo .-oc:h: 1.2) .crnd :hat J. cjpr'.na tended to fly da n or

across a p.-Lvc.ilir.g \.'r.d, while Maccod ar.c Donnelly (40) found no evidence

of wi.nd affecting bl -. fly f ight. ",laenicia spp. has dcTons.rat: d a

seasonal n;g.-aL:oi in autumn from the forest to the cities in F;nlzr,d

47) '-r.. f.-0n tr.c forest to opL.n ter. c in .. i G-.;at Britain (36). Pn: menicia

spp. w:s ,nffiLct:Ld oy step slopes of a val ey ;n upllnd Lheeo cCntry

of Grat ;r;c;in t37) ar.c crossec a C;O-y;rv-w la rive,r jnd a SO-ytrd-wide

c c : .-c s.. : 5 -., .-. o-. d tna: b i fl;iess did not fly

during3 hevy ca c- i.-.c -.. =.- -. ; Jir'r i was ,.n aJ i- in daily









active' ity irn .tr a. P. c cr '-. .cs bir:::-. in JZ an, re..-,g ;,cs

n rero s In h e aft -rr c pc-l. : 7'4). Ii:n- a .:" s recorded -.7. -

fr -i : c r ib.cr a: s' : -.!.: i : .- r .).

CcToprehe.ns i'e r.v : .'s o. refcrc- as on f!l.. .'. oispeirs:1 zna

.migration a.e presar.ted b5 JC-.r..c-. - .. .. r r ).



-1] -r "l' I


Fl ight mill s :rcv';de a C:-.r. ni ui m.cr.. of' c sj....': n c:. ac:e.' .7 :s

of .r.sac. l g-.t L.:.J .- conc"ro i e..vi.c.T....;al c d. 0.s. S ir.:e ?

CuL r..-z '..-s crc f.-c.A..:.f.: .: ',, s -i3 a: ..ne coZ posz p 3 li o.-.:c.,/-

reared spc.me:..._ E.,ro a :..c tC o fV'g .t m t aarT.r.e tn i m:x;
disC.:r.c they ,my LC; V ir. d :spers' fl ich:z.

A ;.mp l ccr.s ruLcrt-c f!i t ri' i i as .s.- by .tk ir.s (3) -.' th the

sco.yt id, Dar. -.cc:cnus pFse. :o s e lc. <. .?.is de. e ,.a .as imy,3-,v J

Sr.i;lh -ad Furn:ss (77) ar.d Rc. le,' .: (CD) by ato.Tiacically recording

th- re. iutiorns of t..e mills by ,-.eans of p..D:onelectr.c ce', s and -l ctr.ic

co. ters. Chcrbers and G'Conncl (1-2) furznsr improve' ths e c ic._e by

reduL.Cng t.ne f:Icoc.' of ,ohe ..i .ls ty suppcrt.:n, the pivot bSarzc..-. 2

rr.,gr, ers.

t- enc-s

ThI f. 'gh. mi I s s,.d ir. .'.. scud. ,'ae an-rc-o'ly p.o'.-idod by

Dr. .. L. Eaiiy, JSA, Ga.'n sv;i; Tnr .-c, c-rs of hecs.e ill u.-.,e

cz. s, zruc J frz .i 0.5f r-..: c-,r o. :i- s;tcn 1 r. 1" c :n nC.1 tn, n eand or

this wi .-e w.a ban: : .to 2 r :gCt a.-rl as sh -i.n n F'g. i7, so t.ac. zir.

ze..T.. -, 1 r.. oc" th. '..'. r ..- er.cnc :- 1 S r t .. c." .... .- o."

c-r.~i. 0 3 an l <-.'. .1 o" 1" \.' rs ^.r.rt "i L. :.. :::;... .,- 1.-..i as:-^ ..a






76

the end of the rotor arm to produce the double end shoxvn in Fig. 17. A

pivot was fastened 16 cm from the end of the arm so that the circle it

described had a c;rcumfrence of I m. The pivot was a No. 0 insect pin

with its head removed which was glued, point upward, to the rotor arm

between two 6 cm circles of paper. The pivot was suspended between two

6 x 25 mm magnets (stirring bars) so that the pin was in contact with

the upper of the 2 magnets and was stabilized by the laoer magnet. The

magnets were supported by 2 wooden doaels connected to a steel rod frame.

The revolutions of the arm were counted and recorded by a method

similar to that described by Smith and Furniss (77). A 6 volt lamp was

attached to the wooden daoel holding the laver magnet as shoan in Fig. 17.

A photoelectric cell was positioned above the lamp so that a 2.54 cm

black paper disc glued on the rotor arm would interupt the beam of light

with each revolution of the arm. This paper disc was 7 cm from the pivot

on the short end of the rotor arm and also functioned as a counterbalance.

The photoelectric cell was connected to a poaer unit which operated an

electric counter.

Flies used in this study were reared on a diet of lean ground beef

in the method described previously. The flies were anesthetized in a cold

room maintained at 2-40C. These flies were then attached to the radius

of the mill with a drop of rubber cement on their pronotum. The rotors

were then immediately mounted on the mills. In one series of tests,

P. cuprina of various ages were placed in constant light provided by

fluorescent lamps for 24 hr and the distances flown recorded. Ten male

and 10 female flies were used for each test.

A second test involved 10 male and 10 female P. cuprina which were

attached to the rotor arm approximately 4 hr after they emerged as adults.









































Fig. 17. Diagram of insect flight mill. a-rotor arm; b-magnet;
c-counter-balance; d-light source; 3-photoelectric cell; f-metal
plate; g-cotton ball.







78

These insects were allayed to fly until death. The flies were allowed

to fly from 8:00 am to 6:00 pm each day under constant light. In the

evening, the rotor arm was fastened to a magnet placed on the metal plate

as shown in Fig.17, and the flies were allowed to feed on a cotton ball

saturated with a 10 percent sugar solution. The lights were turned off

and the flies remained in this position overnight. All tests were

conducted at the USDA laboratory in a room where temperature and humidity

were maintained at 26 C and 70 percent RH.

Results

The mean distances floa n by various ages of P. cuprina attached

to a flight mill for 24 hr are presented in Table 17. The greatest

distance travelled by an individual male was accomplished by a 5-day

old fly that flew 24,129 m. The greatest distance travelled by an

individual female was 19,603 m by a 3-day old fly.

Male and female P. cuprina flew an average of 19,405.4 m and

25,235.2 m and a maximum of 30,127 m and 45,030 m respectively, when

attached to a flight mill until death, as shaown in Table 18. Assuming

these were less than ideal conditions, flies in the field could be

expected to travel these distances and further, especially when taking

advantage of the winds.



Bla Flies Released at Compost Plant


Methods

Four releases of wild flies were conducted at the compost plant

during September, 1S69, to determine their dispersal patterns in this








Table 17. Mean distancesaflown in 24 hr by adult Phaenicia cuprina
attached to an insect flight mill.


Age of fly Males Females
(Days) Meters (Miles) Meters (Miles)


1/2 3,671 (2.28) 2,914 (1.81)
1 8,356 (5.19) 7,725 (4.82;
2 11,335 (7.04) 10,168 (6.32)
3 6,341 (3.94) 8,289 (5.15)
4 5,559 (3.45) 10,776 (6.70)
5 10,273 (6.38) 11,438 (7.11)
6 5,556 (3.45) 7,785 (4.84)
7 5,476 (3.40) 7,849 (4.88)


aMean of 10 repl icates.






area. The wild flies were captured by sweep net from the grassy areas

surrounding the cocnpost plant and placed into a large plastic bag. They

were immediately anesthetized by carbon dioxide supplied fro-n a portable

lecture bottle. One teaspoon of DayGlo fluorescent dust was placed in

the bag and the flies were marked by gently rotating the bag. The flies

were volumetrically counted by pouring them into a 50 ml beaker. This

volume represented approximately 500 flies. The flies were then placed

into gauze cages, alloa.ed 1 hr to recover, and then transported to the

release site. Two releases of 1000 flies each were made at the compost

plant, and 2 releases involving 1500 flies each were liberated at the city

animal shelter. The flies were captured around 9:30 pm and releases were

made about 11:00 pm that same night.










Table 18.


Distance flown until death by adult Phaenicia cuprina attached
to an insect flight mill.


Females Males
Age of Insect Age of Insect
Meters (Miles) At Death (Days) Meters (Miles) At Death (Days)


26,651
16,931
13,283
15,445
45,030
23,386
26,195
13,994
25,599
40,838

X = 25,235.2


(16.6)
(10.5)
( 8.3)
( 9.6)
(28.0)
(14.8)
(16.3)
(1 .3)8)
(15.9)
(25.4)

(15.7)


5
3


4
6
8
9
9
7
7

x 6. 1


29,546
19,892
16,601
6,477
23,658
30,127
21,698
14,361
9,1 26
22,568

x = 19,405.4


A sample of approximately 200 marked flies was taken from each

release and identified. Greater than 99 percent of these flies were

P. cuprina.

The marked fl ies were recaptured by sweep net after they were

identified by examining the blaw fly roosting areas surrounding the

compost plant with a portable battery powered ultraviolet light. Baited

cone traps, described previously, were placed behind the receiving building,

at the city animal shelter, and in the backyard of an apartment 200 m east

of the plant. These traps were checked every 24 hr for 4 days after


(18.4)
(12.4)
(10.3)
( 4.0)
(14.7)
(18.7)
(13.5)
( 8.9)
( 5.6)
(14.0)

(12.1)


5
4


5
3
5
5
3
4

S= 4.0







each release. The trap at the animal shelter was removed for those

releases at that location.

Results

An average of 10.7 percent of the blao flies released at the compost

plant were recaptured in the same area 24 hr after liberation as sho.n

in Table 19. Traps baited with i-day old fish heads at the city animal

shelter and behind the apartment failed to capture any marked flies for

these 2 releases. Flies released at the city animal shelter were

recaptured at the compost plant at an average of 5.65 percent. The trap

behind the apartment failed to trap any marked flies in these releases.



Fly Releases at the City Landfill


The compost plant closed December, 1969, forcing the completion

of the dispersal studies to be conducted at the city landfill. The

landfill presented a situation different from the compost plant but

similar in the large amounts of attractive materials present and the

generation of a large number of flies. It was concluded that dispersal

patterns observed in this area may be interpolated as to general trends

which may be applied to the compost plant.

Location of City Landfill

The landfill was located on a 30-acre tract of land north of the

Gainesville Municipal Airport. This area was surrounded by pine flat-

woods and the closest residence was located 1.2 mi south of the landfill.

The Gainesville Industrial Park was located I mi west of the landfill

and the airport runways began 1/2 mile southwest of the landfill. Three

residences were located 1.5 mi north of the landfill while woodlands

extended for several miles to the east.









Table 19. Recapture of wild marked flies by sweep net and baited traps 24 hr after release.


J1o. marked flies INo. recaptured Percent
Date Release site released at compost plant recaptured

9/11/69 Conpost plant 1000 121 12.1

9/1I/69 Conpost plant 1000 93 9.3

9/17/69 City animal shelter 1500 102 6.8

9/21/69 City animal shelter 1500 67 4.5


DayGlo fluorescent dust.

>99 percent P, cuprina.








Operation of the Landfill

The refuse was brought to the landfill by truck and dumped into

trenches 15 m wide and 5 m deep. A bulldozer was supposed to crush and

pack the refuse into the trenches and then cover it with soil at the

end of the day. Such an operation would be in ccipl iance with the

standards of the American Public -lorks Association for the operation of

a sanitary landfill (1). Unfortunately these procedures were seldcn

co-plied with because of equipment failures. Refuse was observed to

remain uncovered for several days on many occasions.

A separate area of the landfill was used to dispose of dead animals

and the maintenance of this area was poor. Too frequently animals were

not coTpletely covered with soil or else not covered at all for several

days. This resulted in large numbers of flies developing in this area

(Fig. 18).

Fly Behavior Patterns Observed at the Landfill

Before a general discussion of the releases can be undertaken some

observations concerning fly behavior at the landfill should be reported.

Blow flies and house flies were inactive at night, roosting on the

refuse or on vegetation surrounding the refuse until sunrise (Fig. 19

and 20). As the roosting sites were exposed to the sun the flies crawled

about the plant or refuse to position themselves in direct light where

they groomed themselves for 15-90 minutes. The flies then left the

roosting sites, flying as it seemed, an orientation flight. These flights

occurred in all directions, with the majority of the flies finally appearing

at a sunny, sandy area, absent of vegetation. The sunny sides of the

mounds of sand used to cover the refuse were preferred sites. The flies































Fig. 18. Fly larvae in animal disposal area of city landfill.


Fig. 19. P. cuprina roosting on grass tassel at night at city
landfill.
































Fig. 20. Predominantly M. domestic roosting on weed at night at
city landfill.


I


Fig. 21. Predominantly C. macellaria with some M. domestic roosting
on dead brush in refuse at night at city landfill.















sites. House flIies and P. cupr i_,a were both observed to f ol Iow th is

pattern and both occurred in the s;,me mating area s simultaneously.

The roosting sites were centered around the most recently dumped

refuse. M. domestic rested on the refuse, especially brush in the

refuse, and on the surrounding vegetation immediately adjacent to the

refuse. There appeared to be little selection of plant species chosen

as resting sites but there was a preference of height. House flies

appeared most often on plants 1/2 I m in height, House flies have

previously been reported to roost preferably on ceilings, trees, and

shrubs in rural areas (2, 33, 41).

Cochliomyia macellaria were observed to roost on leafless or dead

branches 1-3 m in height. Brush in the refuse and plants immediately

next to the refuse were preferred (Fig. 21).

P. cuorina was seldom observed roosting on the refuse and rested

almost exclusively in grasses and weeds up to I m in height. Green (22)

and Maier et al. (41) observed similar behavior at a slaughterhouse as

well as in urban areas. These flies roosted at a greater distance from,

the refuse than did the house flies. If one walked from the refuse

through the surrounding vegetation, he would first pass through a belt

2-5 m wide of plants containing roosting house flies. This zone would

give way to a mixture of house flies and bcloq flies and finally to an

area where the blow flies were in the majority. The number of flies

decreased rapidly with increasing GistGriCe from the refuse. Flies became

relatively scarce after about 20 m.




Full Text

PAGE 1

Ecology and Control of the Principal Flies Associated with a Compost Plant By CALVIN GALE ALVAREZ A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 1971

PAGE 2

II SSESBL& no* 08552 (IDA Mini 4782

PAGE 3

ACKNOWLEDGMENTS The author wishes to extend his sincere thanks and gratitude to the many persons who have made this endeavor possible: To Dr. F. S. Blanton and Dr. H. D. Putnam for serving as co-chairmen of the supervisory committee, and their assistance and friendship throughout this investigation. To. Dr. G. C. LaBrecque for serving as a committee member, for his assistance, direction, and friendship, and for providing equipment and working space at the United States Department of Agr icul ture's Insects Affecting Man and Animals Laboratory, Gainesville, Florida. To Dr. J. F. Butler for his participation with the committee, for providing equipment and working space at the Medical Entomology Laboratory, and for his tolerance of the odors of rearing blow flies. To Dr. D. H. Habeck for his assistance and work with the committee. To Dr. W. G. Eden for his guidance, encouragement, and assistance. To Dr. D. L. Bailey for providing equipment and advice. To Dr. D. E. Weidhass and all the other members of the Insects Affecting Man and Animals Laboratory for providing counsel and aid on many occas ions. To Mr. Dan Wojcik and Mr. Terry Marable for photographic assistance. To the Department of Environmental Engineering of the University of Florida for financial assistance provided by Contract number 5-701-UI01029-09 from the United States Public Health Service. ii

PAGE 4

To Mr. Herb Houston, project director of the Gainesville Municipal Waste Convers ion Authority, Inc., and Dr. D. T. Knuth, Environmental Engineering, Inc., for furnishing eq and fac " ies as provided by Department of Health, Education, and Welfare Demonstration Grant number 5-D01-U1 -00030-02. Finally, the author wishes to express his deepest gratitude to his wife,Judi, for her patience and constant encouragement during this stuGy. i i i

PAGE 5

TABLE OF CONTENTS Page ACKNOWLEDGMENTS i i LIST OF TABLES vi LIST OF FIGURES viii ABSTRACT x I NTROOUCTI ON 1 Statement of the Problem 3 Location of Compost Plant 4 Operation of Compost Plant 5 Fl ies 9 SECTION I. FLY LARVAL MIGRATION FROM REFUSE 13 Methods 15 Result and Discussion 17 II. CONTROL OF BLOW FLIES 26 Blow Fly Traps 26 Field Tests 29 Rearing Blow Flies 37 Laboratory Screening of Insecticides for Control of _P. cupr ina k\ III. DENSITY AND SEASONAL FLUCTUATIONS OF HOUSE FLIES AT THE COMPOST PLANT k6 Rearing House Flies k6 Seasonal Fluctuations of House Flies kj Evaluation of Fly Sticky Tapes 5*+ Determination of the Magnitude of the House Fly Popul at ion 57 IV. HOUSE FLY BREEDING IN COMPOST 60 Moisture and Age of Compost 60 Sludge and Grinding 6k Temperature 67 IV

PAGE 6

TABLE OF CONTENTS (Continued) Page SECTION V. MIGRATION AND DISPERSAL 72 Literature Review ~]2 Fl ight Mills 75 Blow Flies Released at Compost Plant 78 Fly Releases at the City Landfill 8i SUMMARY, CONCLUSIONS AND RECOMMENDATIONS 100 APPENDIX 1. Test for the precision of the counting technique used to determine total number of larvae collected under the apron conveyor 108 2. Fly larvae trapped under apron conveyor during 1969, at the Gainesville compost plant 109 3. Percent mortal ity of 5-day old Phaen ic ?a cupr ina females 2k hr after exposure to insecticides in a w ind tunnel Ill k. Temperature in digesters 114 L ITERATURE C ITED 115

PAGE 7

LIST OF TABLES TABLE Page 1. Percent abundance of species of fly larvae trapped under apron conveyor during 1969 19 2. Total number of larvae collected under apron conveyor compared to number of larvae trapped the same day.. 20 3. Total number of larvae collected per day under apron conveyor compared to the number caught in the same area during the night 22 4. Sex, species, and abundance (%) of flies caught in cone traps baited with 1-day old fish heads at Gainesville compost plant 29 5. Number of flies caught per day in cone traps baited with fish heads as a monitor of procedures to control adult flies at the Gainesville compost plant 30 6. Sex, species, and abundance (%) of flies caught by sweep net in grass adjacent to receiving area of Gainesville compost plant 34 7. Analysis of several rearing media to determine the most su i table method of rear ing Phaen icia cupr ina 39 8. LC-of 5-day old Phaenicia cuprina females to insecticides in a wind tunnel 43 9. Air temperatures recorded 15 cm above compost in digesters at Gainesville compost plant 51 10. Number of adult house flies caught on sticky tapes in different ages of compost 53 11. Recapture of 3-day old marked laboratory reared house flies by sticky tapes hung in digesters for 24 hr following release of flies in the same area at the Gainesville compost plant during 1969 59 v I

PAGE 8

LIST OF TABLES (Continued) TABLE Page 12. Influence of moisture and age of compost on maturation of immature house flies reared in compost 63 13. Influence of moisture on maturation of immature house flies reared in 3-day old compost 65 14. Influence of sludge and grinding of refuse on maturation of immature house flies reared in compost 66 15. Temperatures observed irr house fly rearing containers.... 69 16. Temperatures observed in 4-day old compost in d ig esters 71 17. Mean distances flown in 24 hr by adult Phaen icia cupr ina attached to an insect flight mill 79 18. Distance flown until death by adult Phaenicia cupr ina attached to an insect flight mill 80 19. Recapture of wild marked flies by sweep net and baited traps 24 hr after release 82 20. Recapture of marked wild flies at Gainesville sanitary landfill by sweep net after release 91 21. Observations of marked wild JP. cupr ina remaining at Gainesville landfill after release 93 22. Observations of marked wild M. domes tica remaining at Gainesville landfill after release 94 23. Average percentage of flies remaining at city landfill under different weather conditions 95 24. Rainfall recorded at Gainesville Municipal Airport during release studies at city landfill 96 25. Observations of 2-day old marked laboratory reared Phaenicia cuprina remaining at Gainesville landfill after release 98 VI 1

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LIST OF FIGURES FIGURE 1. Floor plan of Gainesville municipal compost plant 2. Refuse flow plan of Gainesville compost plant 7 3. Receiving building filled with refuse 3 k. Sorting conveyor carries refuse to sorting platform 5. Composting takes place in concrete digesters 6. The finished product Is discharged to outdoor storage areas. 10 7. Fly larvae and pupae under receiving hopper ]k 8. Fly larvae migrating from refuse to pupation sites under wall of receiving building 14 9. Number of fly larvae caught under apron conveyor per week at Gainesville compost plant during 1969 18 10. Eastern edge of approach ramp 2k 11. Fly larvae aiong base of eastern wall of approach ramp 2k 12. Cone trap baited with 1-day old fish heads to sample fly populations at compost plant 28 13. Rear view of receiving building showing receiving hopper and pavement behind building 28 14. Mean number of adult flies captured per sticky tape per week during 1969, in digesters at Gainesville compost plant 50 15. Number of house flies captured on sticky tapes within 2k hr after release in a large outdoor cage 56 t 16. Position of te srature probes in house fly rearing cor....: srs 33 V I I i

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LIST OF FIGURES (Continued) Page FIGURE 17. Diagram of insect flight mill 77 18. Fly larvae in animal disposal area of city landfill 84 19. _P. cupr ina roosting on grass tassel at night at city 1 andf ill 8k 20. Predominant! y M. domes t ica roosting on weed at night at city landfill 85 21. Predominant! y _C. macel 1 aria with some M. domes t ica roosting or, dead brush in refuse at night at city landfill 85 ix

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Abstract of Dissertation Presented to the Graduate Council of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy r ECOLOGY AND CONTROL OF THE PRINCIPAL FLIES ASSOCIATED .TH A CG'.POST PLANT By Calvin Gale Alvarez March, 1971 Chairman: : Dr. F. S. Blanton Co-chairman: Dr. H. D. Putnam Major Department: Entomology and Nematology Minor Department: Environmental Engineering Seasonal fluctuations of Diptera indigenous to domestic sol id. waste were examined at the Gainesville, Florida, municipal compost plant during 1S68-1S69. Populations of both immature and mature forms were estimated and the efficiency of chemical and physical control procedures was tested. Adult dispersal studies were conducted during 1570 at the city landfill. The major fly source at the compost plant was found to be from larvae-infested incoming refuse. The greenbottle blow fly, Phaen i cupr ina (Shannon), comprised more than 50 percent of the larvae which migrated into protected areas where they developed into adults. Approximately 450,000 adult flies per week were produced during the summer months. This figure could be reduced by more than 63 percent by procedural changes and good housekeeping. The daily application of a dichlorvos su^ar bait reduced the number of flies by 66.7 p<~ ogle application of ite reduced the population by moi and dl sre als< tl rests.

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The number of house flies captured on sticky tapes was shown to be proportional to the number present in a large outdoor cage. Sticky tapes were used to show seasonal fluctuations of house fl I es in the digester building. House flies were the predominant insect breeding in compost. They were limited to the top 2.5cm in the digesters because of temperature. The optimum moisture content for house fly breeding was 75 perc^r.^. to 14 percent of the eggs placed in compost at 45-55 percent moisture (normal operating conditions) developed 'rnto pupae. Egg survival to pupae decreased significantly when placed in refuse after 5-10 days of compost ing. P. cupr Ina males flew an average of 19,405.4 m and a maximum of 30,137 m when attached to a flight mill until death. Females flew an average of 25,235.2 m and a maximum of 45,030 m. Wild _P. cupr ina and M. comestica were marked and released 1 mi from a. landfill and later recaptured at the landfill. An average of 10.17 percent of the wild P. cupr ina and 1.66 percent of wild K. domestica released at the landfill on days followed by 24 hr without rain were recaptured 24 hr after release. An average of 10.7 percent of the wild _P. cupr ina released at the compost plant were recaptured in the same area 24 hr later. An average of 11.3 percent of 1 aboratory-reared P_. cup;ina released at the landfill were recaptured 24 hr later. Baited traps surrounding the landfill recaptured only 2 flies after a total release of 255,000 fl ies. x .

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The demands of our affluent society for more goods and coi items such as r,o deposit and non-returnable materials, ult in tl generation of waste products in gigantic proportions. As the a1 ze and the population increase, the per capita and total amount of waste increase proportionally. The disposal of these tremendous quantities of wastes has primarily been an urban problem. Since the trend in the ited States is toward urbanization the problems of refuse disposal become increasingly more important. This becomes evident when it is noted that in I960 the estimated median waste per capita per year in urban areas was 1,430 pounds. This amounted to *, 80 billion pounds per year and the cost of collecting and disposing of this refuse was more than 1.5 bill ion dollars (1). To combat the rising problem of refuse disposal the "Solid Waste Disposal Act" was enacted in 1965 to support a national program designed to implement and evaluate more efficient methods of coping with the solid waste problems. Under this act the Bureau of Solid Waste Management awarded a contract to the Gainesville Municipal Waste Conversion ority for the construction and operation of a refuse composting facility. T.i^ purpose of this project was to "danonstrate the reliability, ry and nu i of a recc -rat dispc:, ... 1

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2 The primary objective cf composting is to dispose of refuse by biological degradation of the organic mater ials. Modern scientific composting prccecures which are employed in municipal disposal systems involve the rapid partial decompos i of organic matter by the use of aerobic microorganisms under controlled conditions (1). Municipal composting is a fairly common practice in many European countries. It is rarely used in the United States because land for refuse disposal was available in close proximity to urban centers in the past. The increasing demand for land provided the stimulus for municipalities to seek a more acceptable form of refuse disposal. As late as .$p0, there was little scientific information available on municipal composting in the United States. Since then several universities and the United States Public Health Service conducted studies that have as yet yielded only a limited amount of practical information. The capital and operating costs of composting are known to be higher than most other forms of refuse disposal but the specific ecor.cmics involved in municipal composting in the United States are practically unknown. The feasibility of composting must be determined by the major advantage of composting, the recycling of waste products. The sale of marketable compost and salvageable goods would reduce the net cost and may result in a profit. There are 2 general composting processes that appear to be the most efficient and economical under U.S. conditions. The first is mechanical digestion, a process in which refuse is sorted, ground, and mechanically manipulated in order to shorten the biological degradation process. The second method termed windro/.'ing involves the sorting, grinding, and of refuse in windrows allowing the materia', to compost naturally, compost plant constructed at Gainesville used the mechanical uigestion process.

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the P.-cbl cm As with other scientific information concerning composting in the U.S., little is known concerning insect prob] ems that may arise in this type of operation. The original purpose of the present investigation was to search out these problems, determine their magnitude, and suggest possible solutions. Initial observations revealed that large numbers of fly larvae entered the compost plant within the refuse. These larvae seeking a suitable pupation site migrated from the refuse stored in the refuse receiving building. These insects were aesthetically unpleasant to the employees as the larvae were often crushed beneath their shoes and sometimes crawled into the clothing of a resting employee. Many of the immature insects eventually became adults and further tormented the employees at the site by their constant presence whi 1 e others were reputed to invade the surrounding community. Thus, the primary areas of this investigation were as follows: To identify the larvae entering the compost plant with the refuse and to determine their magnitude and seasonal fluctuations. To search out possible processing procedures which may reduce the number of larvae migrating into the plant. To evaluate mechanical and insect icidal control procedures to reduce the larval populations. To screen several commercial insecticides for their effectiveness against the emerging adult flies. To determine the density and seasonal fluctuations of the adult house f] ies a1 :ompost plant.

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k To determine the extent and sane of the limiting factors of house fly breeding in compost. To determine the extent of fly cispersal from the compost pie :o the surrounding community. Laboratory studies were co.-.ducted at the USDA Insects Affec Man and Animals Laboratory in Gainesville, Florida, and at tl >ity of Florida Medical Entomology Laboratory. Field studies conducted at compost plant were begun in June, 1968. Because of a lack of funds, plant was closed on December 31, 1969, ar.c seme of the studies r.ot expanded as the author had intended. Most c. r the dispersal studies v. performed at the C'ty of Gainesville Sanitary Landfill curing the suit of 1970. Locrticn cf C c.r, post Plant The compost plant was constructed on a 5-acre tract of land located in southeast Gainesville at the city's sewage treatment complex. This site was near a sewage treatment plant, an animal shelter, and an abandoned dump. A densely populated region of middle-income apartment complexes inhabited primarily by University of Florida students and a lew-income residential area were located in c'r.e immediate vicinity. A woodland area buffered a middleand high-income residential area located one-half I e from the plant.

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Operation of Comoost Plant The floor pK he c post plant Is .ted in Fig. 1 and . general flow plan of the refuse 2. Refuse w truck and dumped on oor of the receiving building (Fl .3). refuse was then placed into a receiving hopper by a tractor modified wi a front-end loader. The hopper (19-3 m "long, 3.6 m wide, , 6 i de constituted the rear side of the building. An apron conveyor which consisted of a series of overlapping or Interl :ron pans was located at the bottom of this hopper. afuse was transported al the conveyor onto an oscillating table. This table loosened the p< rc. : „s^ in order to assure a unil flow. A sorting conveyor ccrried the refuse from tr.e oscillating tab", e to a platform where 6 lcjo-^rs manually removed sal vageable paper, cardboard, and large bulky items (Fig. k) . The paper and cardboard were dropped into chutes which fed t into a baler and the bulky items were placed in chutes that emptied into a dump truck which carried these materials to a landfill. The sorted refuse then proceeded directly into a crusher-disintegrator grinding mill. 2 ground refuse discharged from the crusher averaged 7.6 cm but varied in size depending upon the type and amount of material fed into the machine (20). Refuse passed from the first grinder into a second grinding unit which 2 reduced the particle size to approximately 5 cm . It was then discharged from the bottom of the secondary grinder into mixing screws where '2 counterrotating ribbon-type screws, placed sid^ by side in a common trough, blended tl terial with or sludge. /eyor ~~. . carried the moistened refuse under a . ic separat, xjs

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Hgestsr aeration blowers tgiloadar v/ unload log shuttle conveyor Vgl loader transfer car rails Hgester unloading conveyor tglloader transfer car .(eg rind loading convayor grind distributing screw convayor tegrlnd sail feeder screw conveyors(2) (•grind kills (2) isgrlnd overflow screw coaveyor tegrlnd discharge screw conveyor Stockpiling belt conveyor Itorsge building w/truck loading reap
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«TOtu t>li_»

PAGE 20

Fig. 1. Floor plan of Gainesville municipal compost plant (20),

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Fig. 2. Refuse flow plan of Gainesville compost plant (20)

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Fig. 3. Receiving building filled with refuse. Fig. k. Sorting conveyor carries refuse to sorting platform.

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metals and tl • onto the 1 ei ndc the ... of .r.e digesters. A shuttle conveyor, w . travelled en a pair of steel rails between the digesters discharged the refuse into these ur.!;s. The digesto.-s or digesting tanks were 2 concrete troughs S9 m long, 6 m wide, and 2.7 m deep (Fig. 5). The digester walls were constructed of concrete blocks and tne floor was converted with perforated galvanized steel places. These plates were above an air plenum into which air was discharged by a centrifugal low pressure fan. River gravel approximately 0.6 cm in diameter covered the perforated plates to a depth of 7-10 cm. This enabled the air to diffuse evenly through the small slots over the entire floor of the tank. The refuse was placed in the digesters to a depth of 1.8-2.4 m and allowed to compost for approximately 6 days (20). (In this investigation "compost" refers to refuse that has remained in the cigesters for a period greater than 24 hours.) Removal of the compost was accomplished by a machine called the Agi-Loader (Metro-Waste Patent No. 3,294,451). This machine removed the >OSt and deposited it back onto the tripper conveyor. A system of conveyor belts transported the compost to a final grinding mill. A finely 2 grOo eriai approximately 1 cm was discharged from this grinder and was transported by conveyor to an outdoor storage area (Fig. 6). es uS species of flies present at ^..e compost plant were n house fly, Musca don-est'ea Linnaeus, (.-.cscidae, Diptera), and greenbottle blow fly, _ „_^_ li _ [Shannon), (Call Iphorldae, ^ ," O J »

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10 Fig. 5. Composting takes place in concrete digesters, Fig. 6. The finished product is discharged to outdoor st orage areas,

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The house fly has been incriminated as a carrier of numerous diseases of man and animals including typhoid fever, cholera, and amoebic dysentary (27, 82); however, these claims have been supported only by circumstantial evidence. House fly associations with diseases need further c. i cat ion as experimental evidence Is s:irsc and contamination of house flies between caged mates has been shewn to be sporadic (l Greenbottle blow flies may be domestic nuisances or carry disease organisms, but in this capacity they are far less important tnan other flies. However, the damage ere suffering which the larvae inflict upon domestic animals in some stock-raising areas is of tr« us consequence. In Australia, this fly Is by far the most important species in fly strike or cutaneous myiasis of sheep (44, 69). Fly strike is a condition produced by the development of blow fly larvae on living sheep which may lead to death or a considerable loss of wool. This is a formidable problem in Australia and amounts to an annual loss of 4,000,000 pounds to sheep raisers (44, 6S) . The common house fly is well established as Musca domes tie;. Linnaeus but the systematics of the greenbottle blow fly are somewhat confused. Australian authors refer to this fly as Lucil ia cupr Ina (Wiedemann) . Hall (26) compared specimens from the United States and Australia and concluded they were not the same species. He described the American species as a new combination, _P. pal 1 escenes (Shannon). Waterhouse and Paramonov (80) later examined numerous specimens from Texas, New York, New Orleans, Washington, and Australia and concluded that there was no difference in species, but a definite pair of subsp^. ,. James (2S) concurred in this vie.-/. Hall later in Stone il . (78) m£ ned h i i -ion of ?,

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12 — s _ (Shannon) but recognized the works of Watcrhouse and aut or uses the species name frcn Waterhouse and Paramonov since their work appeared to be more cc. ..sive than that of Hall.

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SECTION : FLY LARVAL MIC. FROM REFUSE The major source of fly Infestation appeared to be from introdi of larvae i the collected refuse and not from breeding at the co plant. Fly larvae that were br , In refuse containers throughcn t the city were brought to I post plant with the refuse. This infested refuse was stored awaiting processing in the receiving area. Many the larvae were mature and the i.^coc stimulus of the disruptive transfer to the plant caused them to actively seek a pupation site (Figs. 7 and 8). Seme of these larvae migrated Into the working areas where they annoyed the employees while others reached protective areas where they metamorphosed to adults. Such occurrences were not unique to the compost plant. Large numbers of larvae may escape to pupation sites during the handling, transferring, or processing of 1 arvaeinfested refuse. Green and Kane (23) found that 7200 larvae/hr/per car were escaping from railroad cars awaiting dispatch to c rural disposal area. The infestation of refuse by larvae in the Gainesville area was anticipated because in a southern California city, with a climate similar to that of Gainesville, Ecke _et aj_. (18) reported that residential refuse containers can have -s many as 50, GOG . e per c» itainei ovei a 10-week These larv "t feed . 13

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\k Fig. 7. Fly larvae and pupae under receiving hopper. Fig. 8. Fly larvae migrating from refuse to pupation sites under wall of receiving building.

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15 to pupate in the soil and later emerged as adults. During the hot summer months it was reported that the feeding period was completed in k days (79). This observation led to the recommendation and subsequent adoption of a twice-weekly refuse collection system for several California cities (17, 79). The purpose of this investigation was to determine the species of the larvae escaping into pupation sites at the plant, to determine the magnitude and the seasonal fluctuations of this massive influx of insects, and to search out possible processing procedures which would reduce the total number of escaping insects. Methods Seasonal Fluctuations Visual observations indicated that the majority of the larvae escaping from the refuse were confined to the partially enclosed area under the apron conveyor. The larvae reached this area either by crawling through the openings between the metal pans of the conveyor or by falling through the opening between the floor of the receiving building and the edge of the receiving hopper. To determine the species present and the seasonal fluctuations of the larvae entering the plant, a trap was placed in this area. This trap was similar in function to that descr ibed by Roth (58) and 2 consisted of a 30.^*8 cm plywood box.. It was abutted to the wall under the apron conveyor so that larvae falling through the opening between the hopper and the floor would be trapped in the box. The trap was operated from January 12 to December 31, 1969.

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The trap was checked daily and the number of larvae recorded. A minimum of one sample catch per week was preserved in alcohol for identification. Pope ' tor It was desired that the larval population trapped in the sefluctuation survey be used to estimate the total number of larvae e_ into the plant. To accomplish this it was necessary to c total number of larvae that entered the plant, the percentage larvae trapped, and the reliability of the trapping proced. The total number of larvae entering the plant wol'.c figure to accurately define. Since the majority of the larvae migrat under the apror, conveyor it was used to deter.. ire the total number of larvae in that area and to determine the reliability. The larval population under the apron conveyor was determined by sweeping the area for a 10-day period beginnir _. st 29, 1969. These sweepings, which included the debris and larvae that had fallen during the previous 2k hr, were placed into a 55-gallon (208 1) drum. The drum its contents were weighed, sealed, and thoroughly mixed by rolling on the floor for several minutes. Immediately a volume of approximately 0.5 1 was removed and weighed on a laboratory balance (Ohaus, Union, i\.J.) . The larvae in the sail countec and the total number of larvae in the drum or under the apron conveyor was calcula. To deterr.-;..^. the precision of the above method, a sample of approximately 0.5 ] was r I, copied, and replaced ir. the drum. The -are was rep: ica. • in A

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• 7 ffects of Clearinc ing Building Dally of Refuse It was standard operating procedure that a sufficient amount of refuse remain in the receiving building overnight so that operations could begin the following morning and proceed without interruption until the trucks began delivering refuse. To determine the number of larvae escaping into the compost plant as a direct result of this proc t< re, the area under the apron conveyor was swept twice daily; once at 7-"00 z. before daily operations began, and again at c : ". 5 F : ' le plant closed. This was repeated for 6 consecutive days during September, 1969. The larvae collected were enumerated as described previously. Result and Discussion Seasonal Fluctuations The results of a larval sampling program to determine the species present and seasonal fluctuations of the larvae escaping into the compost plant are shown in Fig. 9 and Appendix 2. These data show that relatively few larvae were captured during January, February, and March. The catch '..-.creased in April while a consistently high number of larvae were trapped from June to mid-October. The number c'ecl ined throughout November and larvae became relatively scarce in December. Phoenicia cuprina was the predominant fly species collected in this survey. Table 1 shows that greater than 97 percent of the captured larvae were _P. cuor ina . One percent were M. devest ica while the remainder were comprised of Cochl ic.ry ia a_rla ! ' 1 1 ucens (Linnaeus), •Ibut i on of ... ose reported by other 1 .95

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18 or'" ID CO > CO O CM C ro x: 1/1 t

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19 Table 1. Percent abundance of species of fly larvae trapped under apron conveyor during 1969. Spec ies Percent of total number of larvae examined per week Max imum

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20 TO > o -O E 3 C X> TO Q. O >^ o > c o o c o l_ Q. TO X> c 3 Xt O o o o (0 • > >• lTO TO XI <0 uE O TO I/) l_ O O JQ JZ E +J C XI o — Q. to q. 4-> TO O LV TO 4J XI c +-> 1O TO 0) . O O O a> — TO O> E 1TO TO i/l _ I — 4" — J CA OO 00 -3" -3" oo oo — O rA O 'q-'e S3 to ca ca C7I TO l_ < i — n 4 vD CO LTV — oo j-3— ca r-» CA CM CNJ o co rA CM — O -3" m a\ -3" -3" CM O O O O O O _ cm la o o LA o CO CA o o — — o LTv O rA LA O CM .— I — 00 v£> -3" oo ca ca r»» o ca ca — o vo r^ CM LA LA rA -3" ca — vO O CM Jr-^ O -3" N vO LA CO — CM — rA LA rA rA 00 vO CA LA r~» CA LA CA f — CO 00 CA I — [* CA vO -3" — — — rA vO -3" O CM vO CA r» ca o -3r»» o CA 00 CM vO O O ca CM .— LA r»» vo — oo SO 00 vO oo 1/1

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21 the building and extended the length of the receiving area. It was difficult to sample this area and the larval population was an approximation based on visual observation. It was estimated that the number of larvae escaping behind the east wall was approximately one-third of those escaping under the apron conveyor for any given day. The construction of the receiving area and the practice of handling the refuse greatly reduced larval survival in other directions. Refuse was deposited toward the east wall and as it was moved into the hopper from east to west by the front-end loader, those larvae migrating in a westerly direction were scraped into the receiving hopper. Northerly migration resulted in little survival since the ramp and paved areas provided no protected areas for pupation. Combining the estimates that two-thirds of the larvae migrating into the plant enter the area under the apron conveyor and 1 percent of these are trapped results in a population factor of 133. This factor may be multiplied by the daily larval catch to give an approximation of the number of insects migrating from the refuse into the protected areas of the plant. For example, Appendix 2 shows that 6116 larvae were trapped the week of September 7, 1969. Multiplication by 133 gives an approximation of 813, ^+28 larvae entering the plant during that one-week period. Effect of Clearing Receiving Building Daily Larvae collected under the apron conveyor during plant operation were compared to collections in the same area during off hours. The results are given in Table 3 and indicate that an average of 38.5 percent of the larvae escaping into the compost plant migrated from piles of refuse remaining in the receiving building after the plant was shut down for the

PAGE 39

22 o XI E 3 C <13 Q. o

PAGE 40

23 day. It is obvious from these results that not storing refuse overnight would reduce the number of larvae entering the plant by more than 35 percent and decrease the ensuing adult population. The value of clearing the refuse from the receiving area daily was further demonstrated by observing the large numbers of larvae along the eastern edge of the approach ramp. When refuse remained on the approach ramp for several days numerous larvae migrated from the refuse and fell to the pavement below. On several occasions when this occurred fly larvae were so numerous that the pavement along the edge of the ramp appeared white. On one such occasion the pavement was swept clean and the larvae collected 12 hr later. Their number was estimated to be 30,000 or 60,000 per cay migrating from the ramp (Fig. 10 and 11). ^dult Development from Larvae The majority of the larvae that migrated from the refuse were mature and thus required only a suitable pupation site to develop into adults. This was demonstrated by placing i 00 larvae collected under the apron conveyor into waxed paper cups (0.946 1). Twenty-five gm of refuse debris collected from the same area were added to one-half of the cups. The cups were covered with cloth, secured with a rubber band, and placed under the apron conveyor. Ten. days later the number of adult flies that had emerged were counted. Nine replicates of each test gave an average of 65.3 percent adult emergence from the cups to which only larvae had been added, and an average of 88.8 percent adult emergence from the cups with debris added. Generally there was a considerable amount of debris under the apron conveyor and behind the east retaining wall, the main areas of larval infestation. It was concluded that most of the escaping larvae reached

PAGE 41

Ik Fig. 10. Eastern edge of apporach ramp. Fig. 11. Fly larvae along base of eastern wall of approach ramp.

PAGE 42

25 adequate pupation sites and close to 88.8 percent adult eiiergence was expected. Extending the previous example given for the week of September 7, 1969, an approximation of 733,313 adult flies could be expected to emerge within 10 days as a result of larval migration from the refuse. Survival of Larvae Through Grinding Mills Approximately 10,000 mature house fly' 1 arvae were passed through the secondary grinder in May, 1969. The primary grinder was not in operation at that time because of equipment failure. Nine live larvae were recovered in the discharged refuse. In July, 1969, 10,000 mature house fly larvae were passed through the recently installed primary grinder. No surviving larvae were found in the discharged refuse.

PAGE 43

SECTION I I CONTROL OF BLOW FLIES Studies were initiated in June, 1969, to evaluate several procedures such as mechanical control and insecticide baits, fogs, and residues for the control of blow flies emerging from the incoming refuse. The effectiveness of a control measure was determined by the reduction of flies caught in two baited traps located behind the receiving building. These investigations were terminated in October with the advent of cool er weather. Bl ow Fly Traps A suitable method to estimate changes in the number of flies was needed to evaluate the various control procedures. Sticky tapes were ineffective because the large amount of dust created in the receiving area rapidly coated the adhes ive mater ial . Grill counting was ineffective because the counts varied with hourly density fluctuations and positive species ident if icat ion was nearly impossible (42, 45). Norris (45) reported that bait trapping was the only generally useful method available to study blow fly populations and that the bait employed was the most important variable. He reported that animal tissue was the best for blow flies, being mere reliable than some of the more 26

PAGE 44

27 recently developed synthetic attractan:s (14, 45). However carrion is not a uniform bait. Its attractiveness varies with age, moisture, and decomposition (42). Kawai and Suenaga (30) found that fish 1 -day-old was the most attractive to b". '. es. The traps si For use compost plant were two 3C x IZ .% 54 cm inverted cone traps. fere baited with 1-day-olc acquired locally. " ^sa of each trap was enclosed by 0.5 cm screen wire to prevent small ar.imals from stealing the bait. These traps e shown in F ig. 1 2. , The traps were place : . the pavement behind the receiving area, see FIgs.l and 13. The flies were collected from the traps daily by placing the trap and 13 ml of ethyl acetate into a plastic bag. After the flies were anesthetized, they were removed and placed Into a small plastic bag. The catches were then transported to the laboratory For counting and identification. Table 4 gives the identification of flies caught in 15 different daily catcnes. This shews that 89 percent of the flies trapped were -"icia spp., 6.8 percent were Musca domestica , 3.7 percent were Cochliomyia macellaria , and 0.5 percent Sar'coohag \ spp. These figures are close to those percen .ages recorded in Table 1 which gives the relative abundance of the various species of larvae entering the plant from the refuse. The differences that occur may be the result of the .ping method employed, different survival rates of the species involved, or immigration of adults from surrounding areas.

PAGE 45

28 Fig. 12. Cone trap baited with 1-day-old fish heads to sample fly populations at compost plant. Fig. 13. Rear view of receiving building showing receiving hopper and pavement behind building.

PAGE 46

29 Table k. Sex, species, and abur.de.nca (%) cf flies caught in cone tr: b^ited with 1-day old fish heads at Gainesville compost plant. . ; i es Phaer, ?c :a spp. ^usca domes tica Cochl iomy'a macel la~ r a Sarcophaga spp. 39.0 6.8 .

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30 •_

PAGE 48

i I c o o

PAGE 49

32 c o o

PAGE 50

33 Fly Bait, a 0.5 percent dichlorvos sugar bait obtained commercial 1 y from the Fasco Chemical Co., was used prior to this investigation to control the fl ies at the compost plant. This bait was evaluated when appl ied at a rate of 400 gm per day. The bait was distributed along the conveyor belt system for a 7-day period beginning on day 8 of Table 5. Sweeping to remove larvae . — The area under the apron conveyor has previously been shown to contain the majority of the larvae migrating into the compost plant. To determine the effect of collecting and removing these larvae on the total number of adult flies, this area was swept daily for 15 days. Malt bait . — Malathion, diazinon, chlorthion, and dichlorvos in malt or molasses were reported to be highly effective liquid baits for blow fly control around dumps (76, 31, 34). A dichlorvos and malt solution was used to determine the value of liquid baits for the control of flies at the compost plant. Blue Ribbon malt was diluted with distilled water to form a 25 percent malt solution. Technical grade dichlorvos was added to produce a 1 percent dichlorvos solution which was stored at 4 C until used. Fifty ml of this solution were applied daily to each of 4 locations along the conveyor belt system for a 7-day period beginning on day 40. Fogg ing . — Fogging is not a highly recommended procedure for effective control of flies since fogging leaves no residue and a high concentration is necessary to kill flies. However, the effectiveness of fogging was evaluated since it was used to control flies at the Tennessee Val ley Author ity compost plant in Johnson City, Tennessee (6l). It was observed that the adult blow flies, predominantly Phaenicia (Table 6), left the building at dusk and roosted in the grass immed iatel y

PAGE 51

Table 6. -ies, and . ght by In grass i pi ant. i Spec f 1 ies

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Gardona, (2-chl oro-l-2[2,4,5-tr ichl orophenyl J vinyl dimethyl phosphate), a house fly larvicide, was provided by Dr. G. C. LaBrecque, USDA Gainesville laboratory. A 10 percent Gardona in water solution was applied on day 83 in the same manner as described for dimethoate. Resul ts The results of the field tests are presented in Table 5. Sugar bait . -Daily application of a 0.5 percent dichlorvos sugar bait red-jced the number of flies trapped by an average of 66.7 percent when compared to a previous 7-day period of no treatment. This control procedure cost about $3.00 plus 0.5 man-hr per 6-day workweek. Sweeping to remove larvae . — The area under the apron conveyor was swept daily to remove the larvae before they developed into adults. An average of 40.6 percent reduction in the number of flies was noted when compared to a previous 3-day control period. This reduction is considered to be a minimal value. It was significantly lower than expected since previous estimates indicated that 67 percent of the larvae that migrated into the plant escaped under the apron conveyor. The difference between the observed and predicted reduction may have been influenced by the short test period. Since the larvae entering the plant required 8-10 days to become adults the 15-day study period may not have been long enough to ascertain the true results of cleaning the area. Regular cleaning over a longer period should reduce the adult flies by a factor approaching the percentage of larvae escaping into the area. A second factor influencing these results was the operation of the plant during the test period. Mechanical problems prevented regular operation of the plant and refuse remained in the receiving area for

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36 several days. This resulted in larval migration patterns differing from those encountered under normal conditions. Since the larvae entering the plant required 8-10 days to become adults it is reasonable to assume that cleaning the area once a week would produce the same results as daily cleaning at a reduced cost. The effects of cleaning over a long period were not investigated. The area under the apron conveyor could be cleaned once a week at a cost of about 4 man-hr. Mai t bai t . — A 51.2 percent reduction in the number of flies was observed over a 7-day period with the application of a dichlorvos malt solution. This bait was found to have several disadvantages; (1) it is not available commercially, (2) it must be stored under refrigeration, (3) it costs more and was less effective than dry sugar bait, and (k) its syrupy consistency made it inconvenient to use. Fogg ing . -The grassy areas of the compost were fogged for 3 consecutive nights producing an average reduction of 68.9 percent of the number of flies trapped on the following 3 days. The effects of fogging were minimal after 1 day as shown by the post treatment counts in Table 5. Thus, an effective control program would include a minimum of 3 foggings per week. This would cost $15.00 plus 3 man-hr per week. To determine if this fogging procedure was effective on _P. cupr ina , 100 adults were caught at night by a sweep net at the compost plant and placed in a gauze cage. The cage was placed in the center of the grass hill during the fogging operation. After the area was treated the flies were transferred to a clean cage provided with fly food and water and held for 2k hr. A control cage was set up and the fly r,,orta', ity obsc ved

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37 in each. This procedure was 'or e3ch treatment. An average of 97.2 percent of the treated flies were c„ad after 24 hr v-.h i 1 e 6.1 percent mortality was observed in the control cages. Res idua js. —As :ion of dimethoate gave better control e Flies for 1 week and remained e . :tive for 10 days as sho.;n in Table 5. The cost of one appl ication was approximately $7. CO plus 0.5 man-hr. dona was ineffective as a rc^'dual spray for the control of blow flies as shown in Table 5. !_arv icides . — Green (22) demonstrated that 99. 1 percent of the larvae escaping from standing refuse trains could be controlled by dusting the area twice weekly with DDT. However, the application of a larvicide under the apron conveyor to control blew flies was not attempted because '.arge amount of debris falling daily ir.to this area. The effects of the 1 arv'cide would be short-lived since incoming larvae probabl y would not be exposed after 24 hr. Rear inc 51 ow Fl ies Methods To screen Insecticides in the laboratory for their effectiveness against _P. cu. ." ,it w« , first necessary to find a suitable rearing medium so large rs would be available. _P. cupr in a are easily reared the laboratory on a die . ^caying meat but this medium is odoriferous and also ex pens i\ ibers of flies ere required. t igat ion was stai

PAGE 55

38 substituted for meat. Two series of tests were carried out which varied the amount and kinds of test media used. In the first series the. test medium was placed in waxed paper cups (88.8 ml) with 200 _P. cupr ina eggs collected from wild flies captured at the Gainesv i 1 le landfill. Each cup was then placed in a waxed paper cup (0.9^+6 1) containing approximately 20 gm of dry builders sand. The larger cup was then covered with a black cloth and secured with rubber bands. Eight days later the mature larvae had pupated in the sand and the pupae were removed from the medium by sifting the sand through an 18-mesh sieve. The pupae were counted and the number recorded. One hundred of these pupae were randomly selected, washed, dried on paper towels, end weighed on a laboratory balance (Mettler, Evanston, Illinois) to determine differences In the size of the pupae reared on the various test media. Six replicates were prepared for each med ium. The media tested included the following: lean ground beef; Alpo, an all meat dog food; Chunx, a dry dog food; Strongheart, a canned grain base dog food; and Chemical Specialist Manufactures Association house fly rearing medium (CSMA) . Various amounts and combinations of these media were used as shown in Table 7. Meat was added to several test media because _P. serr icata was reared on CSMA fly rearing medium when provided with sufficient meat for the larvae to develop to second instars (35). In the second series of teits 1 ml or approximately 6,500 P. cupr ina eggs collected from wild fl ies were placed with the test medium into k x IS x 30 cm enamel trays. Each tray was placed on approximately 5 1 of dry builders sand in a kO x 55 x 25 cm plastic tub. A piece of one-fourth

PAGE 56

35 en c i_ CO o T3 O 5 -Q <0 3 to O E o o c *I a cj o E en c V L_

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40 inch plywood with a 25 cm diameter circle cut in the center and covered with muslin cloth for vent i 1 at ion was placed over the tub and secured by k bricks. Eight days after egging the medium the pupae were removed by sifting them from the sand and the total number recorded. One hundred pupae were then randomly selected, washed, dried, and weighed. Six replicates were prepared for each test medium. The test media included lean ground beef, Alpo, Chunx plus Alpo, Chunx plus ground beef, CSMA plus ground beef, Chunx, and Chunx plus CSMA and ground beef. Rearing tests were conducted on the screened porch of University of Florida building number 61 8 which is located northwest of the medical entomology laboratory. The porch was screened on 3 sides and covered with a roof with 1 m eaves. Light, temperature, and humidity were ambient. These tests were conducted during May and June of 1S70. Results The results of the rearing tests are presented in Table 7. These data show that immature _P. cupr ina reared on a diet consisting only of meat were larger than those reared on the other diets. When large numbers of larvae were reared, as in the second test series, k of the diets produced more flies than did the all meat diets. The diet of the dry dog food, Chunx, plus water and 50 gm of ground beef was chosen to rear the flies used in the laboratory chemical screening tests. This diet was superior to all other diets tested in the numbers of pupae produced and cost less than the all meat diets without producing offensive odors. Although the pupae were not as large as those reared entirely on meat, these size differences were not

PAGE 58

41 considered great enough to adversely affect the tests or offset the advantages of the dog food diet. Adult blow flies used ' ical screening tests were rec from eggs collected : the flies were re :ion on th diet cc 400 gm Zr.^r.s., 400 ml tap water, and 50 gm lean ground beef in described above for the second test serie Adult flies were helc 1 5 x 24 x 50 cm gauze— covered caces and provided with fres -er and fly food daily. The fly food consisted of 6 parts granulated sugar, 6 parts non-fat dry milk, and 1 part cried egg yolk. The cages were held in the University of Florida medical entomology laboratory environmental control chamber with 16 hr of artificial day light provided by incandescent lights. Temperature and humidity were maintained at 26 C and 70 percent R Laboratory Screening of Insecticides for Control of ?. cuprina Methods Five-day-old female _P. cuor ina adults were exposed to space sprays of 12 commercially available insecticides in the wind tunnel described by Davis and Gahan (15). The insecticide solutions were prepared by dissolving each chemical in acetone to attain the desired concentrations (w/v) . The original range of concentrations ror each chemical was based on the LC-„ values obtained for an insecticide susceptible strain of

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42 The tests followed the procedures outlined by Bai 1 ey _et aj_. (7, 8). Twenty adult females were confined in test cages made of metal sleeves closed with screen wire at each end. These cages were placed in tne wind tunnel. One-fourth ml of the insecticide solution was atomized at 1 ps i into the mouth of the machine, and drawn through the cages by a 4 mph air current. Duplicate cages of flies were treated with each concentration, immediately after treatment the flies were transferred to clean holding cages and a cotton pad saturated with a 10 percent sugar water solution was placed on top of each cage as a source of food and water. The treated flies were held under constant light at 25°C and at 70 percent RH for 24 hr when mortality was recorded. If the concentrations of the chemical tested produced greater than 90 or less than 10 percent mortality these data were discarded and other concentrations selected until a minimum of 4 concentrations were used that produced mortalities within the acceptable range. These data were used to calculate LC 's by the probit analysis technique described by Finney (19). Twelve compounds were evaluated in 13 tests, each of which included from 4-7 insecticides, acetone, a dimethoate standard, and an untreated check. The chemicals tested were as follows: dimethoate, parathion, naled, diazinon, fenthion, ronnel , propoxur, carbaryl , malathion, Dursban [0,_0-diethyl 0(3 ,5 ,6-tr ichl oro-2-pry idyl ) phosphoroth ioate ], Gardona [2-chloro-l(2,4,5-tr ichl orophenyl) vinyl dimethyl phosphate], and Bayer 41831 [Sumithion] [0,0-d imethyl 0(4-n i tro-m-tol yl) phosphorothioate]. Resul ts The insecticides tested as space sprays are listed in Table 8 in ascending order of the LC-g values obtained by probit analysis. The fiducial limits (P=0.05) are also listed. Dimethoate was the most effective

PAGE 60

43 Table 8. LC co of 5-day old Phaenicia cuprina females to insecticides in'

PAGE 61

kk The LC cn values obt JSDA Goinc-v; the Orlando suscepi tested are listed !n lese \ lues when compared to t -„'s obtained wit . -n of the cr. -at . ss for he blow flies within a factor of 2. The tolerance ase insecti ~ared to t s those of the sus house fly strain colonize ago. sir.ee the blew . been generally exposed to insect icidal press over a /idespread area in the United States. The ineffectiveness of malthion to kill JP. cupr ir.a was unexpect as rnalathion resprays . recommended to control blew flies ."lorida dumps (3^, 79). This becomes less startling, ho/tfc r,en one considers that n r.c control _P. cupr ;na on shtep in Australia (57) and that lion has induced a very specific resistar in the house fly, in Cul 1 is Coq. , and in the blow fly, C. putoria Wie< II). In the case of the blow fly, complete resistance was induced within 6 months. JP, cupr ina are controlled in Australia and widespread dieldrin resistance has been reported. Wild flies .. _s more resistant to dieldrin than a susceptible strain and resistance was also ob: to aldrln, endrln, isodrin, chlordane, cyclodlenes, and BHC (32, 67, 63). Since the general use of chlorinated hydrocarbons is illegal in Florida these chemicals were not te A shi t c phos| in Austral ia 1

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45 used and according to Shanahan (70, 71, 72, 73) no resistance was found after 6-8 years of use. He terms a 3-5-fold increase in the L n rn values of wild flies as tolerance. Schuntner and Roulston (65) found resistance to diazinon in blow flies and identified it as the breakdown of the in vivo pool of free diaoxon. A perusal of the literature revealed that resistance to any insecticide by _P. cupr ina has not been reported in the United States.

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SECTION I I I DENSITY AND SEASONAL FLUCTUATIONS OF HOUSE FLIES AT THE COMPOST PLANT Observations conducted during 1968 revealed that blow flies and house flies were present in large numbers in the receiving area and around the sorting platform, while house flies predominated in the digester building. These flies annoyed the workers and posed a possible public nuisance if the plant proved to be a source of flies to the surrounding community. A house fly sampling program was begun in January, 1969, to determine the density and seasonal fluctuations of the house fly population at the compost plant. The purpose of this survey was to determine the magnitude of the house fly population, the necessity of a fly control program, and seasonal changes that may affect such a program. Rearing House Fl ies All stages of house flies used in this and the following section were obtained from the insecticide susceptible or Orlando strain maintained by the USDA Gainesville Laboratory. These flies were reared in a 10 1 plastic tub in a mixture of 1 part CSMA fly rearing medium and 2 parts water. A 6.5 x 6.5 x 10 cm sponge saturated with water was placed in the bottom of k6

PAGE 64

47 the tub to maintain proper moisture. The tub was covered with a black cloth secured with rubber bands. Pupae were collected 7 days after egging the medium and placed in 1 5 x 24 x 50 cm gauze cages. The adults were provided with fresh water and fly food which consisted of 6 parts granulated sugar, 6 parts non-fat dry milk, and 1 part dried egg yolk. The flies were reared at the USDA laboratory in rooms with 16 hr of artificial light provided by fluorescent lamps. Temperature and humidity were maintained at approximately 26 C and 70 percent RH. Seasonal Fluctuations of House Flies Trapping The digesters were selected as the primary sampling area for adult house flies at the compost plant for 2 reasons: (l) initial observations showed that adult house flies were usually more abundant near the digesters, and (2) equipment operation in the receiving and sorting areas made sampling procedures difficult. The grill method of sampling house flies, developed by Scudder (66), was initially selected for use in the seasonal fluctuation study. This sampling procedure results in an index of the population and not an actual measure of population density (43). The reliability of grill sampling is debatable. Murvosh and Thaggard (43) reported a high correlation between grill counts and the total number of house flies in kitchens on the Island of Mayaguana, while Schoof (62) found that grill counts did not increase linearly with the population sampled. Welch and Schoof (Si) reported that grill counting was subject to individual error and was no more accurate than visual estimates.

PAGE 65

48 Grill counting was ineffective at the ccmpost plant because of the large volume of attractive materials present. 2 One-footsquare (32.4 cm ) masonite boards covered by a thin layer of St I (Michal and Pelton Co., Emryville, California' :ed for trapping fl ies i s attached 1 m in nere then driven ir.co t pest i This procedure was discarded because such large numbers of flics were trapped that the boards became ineff -fore 2.d passed. Also, more than 1000 flies per board were trapped and a population reduction this great may have significantly reduced the total populati :ky capes (Aeroxon Produc :« 5 for trapping t ies. Raybould (54, $5, 56) n .at sticky tapes were more accurate than counts in s. house ions in Africa because they were less depend_.it on human judgment, took Into account temporary Fluctuations in densities, and allowed for the identification of the fl ies. Sticky tapes have also been shown to be more accurate than vacuum collections and v counts at poultry farms (2), and baits at dairy barns (51). Tests during December, 1963, revealed that sticky tapes were acceptable for tr-pping house files at tne ccmpost plant. se flies were sampled in the digesters from January 12 to December 31, 1969, using sticky tapes sus . from 1.2m wooden stakes driven Into ..ployed daily and each stake placed in a v age of compost v ) from 1-5 days o. G.I

PAGE 66

The mean number of flies caught per sticky tape per week was ca', . :ed by i ng the numbe.' of caught per week by the n of sticky tapes. These data are shown in Fig. 14. Eff Jj razors m inimum ir ratur at t -age treatment facility ch . as Iocat -lately ad. to the compost plant. These cata were made av£ easy of Mr. C. R. . , manager of the treatment fac'. Ity. The weekly means of the maxir. daily air temperatures were calculated and are shewn ir. Fig. I A comparison c. ; mean weekly catch of fl ies in the di ss ters ; imum air temperatures showsan apparent correlat betwec. tl jse d from January to June. The compost plant was closed to replace the primary grinding mill on June 15, 1969. When operations resumed on July 6, : finite numbers of trapped flies was observe.. check with tne plant foreman .^vealed that the operating procedures were the same as those before the plant closed for repairs. The only observable difference was th< t the refuse discharged into the digesters was slightly smaller in size. There was no reason to believe that this would greatly affect the number of flies in the area. It was observed that temperatures in the digester buile jre higher than the ambient air temperatures because of the heat generated in composting process and the construction of the metal digesting building. A ^raph was placed on a platform 15 cm above the compost in the dig« perat I icr sever I iods. how that the ..-,ean da i ly

PAGE 67

Weekly mean of maximum daily air temperature °C 50 LA O

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51 c to 10 o (J TO > TO C TO o (0 in to +j in TO en a c o Q. o u a > o -Q (0 U LA TO -o 1_ o o to l/> to o Q. E to TO TO -Q

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52 maximum air temper;. . n the digester ouilding could be expected exceed 37 C during the summer months. Apparently these discouraged the f 1 i . m entering the bu i Id ing > resul t ing in a jer of flies trap he sticky tapes. The number ^ -.-ease was observ in t f 1 i es repel 1 ! .-ease in the number was ob. in December. This inv. on was or ctuatlons of house files at :ompost The temper the .cr building where the traps were located affected the number of flies caught d^r ths and this study railed 1 . original goal. However, these eata do show a general trend during the cooler months an; .strated that the building design reduced the number of flies present in iter building during the period when fly r i were potentially the greatest. The number of flies ca~_..>: or, sticky tapes placed in the dif st are shewn in Tab": a 10. These data demonstrate .hat flies prefer -eshly ground refuse. Greater nt of the in the ...ally congregated in the area of the -dayold compost.

PAGE 70

53 ru o c u Q. CO o 1/1 o +-> 1/1 >» o CM O XI *-> — in O O Q. Q O Q O I 1/1 i_ o I/, 0) o c. a LT\ O O o crv cr-OvOI^CCn^ffM^OOOOOvOLAOOONCAin-JI — CM LA O^ — h>C^O WvO OvO^ CM 00 c\ o I^O^C4ro -3" LA LA -3" -3" MD r~-r^vO\X3vD\D trwO LA LA LA LA LA -3" LA LA LA 00 CX\-3" — LA LA O -3" •— LAr^-.CMrACM-3"LA-3"r^»0-3"VO CM ^ cv-> CM CM A CM CM ir\ o^ rv(riLn>-oN(M(r\Ncoi — cvivot^cn — oo — — r-^c^i — U3 -O u"i M 4" UMvvfl CA rr\(v-i^ coMACO vO — — (v^ N C N O — -3" vovo — la ! d"— vOvDvO — CPiQ 00 — -3" r-^-3" ommc^^omiAiANc uma-?-J(t»won o n cr\ . — . — . — . — -v LA CM -3" .3r>A -3" pa . J-, — U\c^MMCOOI^Ln4-^-CTiLA — vOLANN CM vO LA-3" ^T r_ — .— .— CM M^OIANO^-UM — LAvQ vO 00 MD — -J N 0\ c^4" — 00 lavO CM. rA CM OvO -J LA O -3" CM — OO f*-v CT\ vO r«~\ — M3 -3" >— — — 0A LA rA 0A — , — — _ 0A LA f^»-3" CT\ vD — 4"CO-J CA CA — O OMa Mv£ ivmA^OCO r-r^-..— o CMvO-3"r««.CMLALA — O (A• ____ _ -3" vO CJ\ MD CM v£) rA O O — CM CT> CM C7\ CA CM rA r>» o -3" r*» cm O0 — — CM _ CM CA \0 O -3" LA — cm ,_ oa — c ru Q tt> i> ro ro a. < ro ro d — i — oi oi a o. +j -.J _ ) _ >< > >
PAGE 71

Evaluation o~ Fly St'c'-. ' pels A known number screen cage with sticky tapes to dete could be correlated wltl The c ge was located in a partially sha< 3d 1 in bu i '. Gainesville laboratory. The c a 5 x 5 m base roof 3.5 m high. The floe.c .ed of soil and was kept cleaned weeds and grasses during the tests. Two*' 1 . 2 m stakes were driven into the ground on the center 1 ine of the cage 1 m from each end. A = as hung on each stake and ed daily. A 30 x 120 x 120 en 3 -shelf etal stand was pieced in the center of the c t ge to hold the food and ater supplied daily and to provide shelter for the flies. Tests were Ing June. July, and August of 1369. Test insects were obtained as pupae from the LSDA's insect ic. susv. e house fly colony and were held in cages until ac es ere beginning to emerge. At the onset of eclosion approximately 200 pupae were placed in a 1 5 x 2k x 27 cm gauze cage. After 24 hr the remaining pupae were removed. The a ire proviced daily with fresh fly food and water and were held in a room provided with 16 hr of artificial daylight by fluorescent lamps. Temperature and humidity were maintained at 26 C and 70 percent R. . Fl les used in the test were removed from th« d with carbon dioxide and counted. A 1:1 ratio of males to females was ha lar.g V. m '.-. w

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55 the flies. Twenty-four hr later the tapes were collected and the numbers of flies counted. All flies regaining in the cage following a test run were killed using a fly swatter. Pupae, 1-, 3-, and 5-day old house flies were released in the cage in numbers of 100, 250, 500, 1000, and 2000. Duplicate tests were conducted for all ages and numbers of flies tested. One-day old flies were released in the outdoor cage 2k hr after placing the emerging adults in the small cages. This procedure provided flies which were 1/2 2k hr old at the start of each test. Three-day old flies had emerged 48-72 hr prior to release and 5-day old flies had emerged 96-120 hr prior to release. In one series of tests, mature pupae were counted and placed in the large outdoor cage. Sticky tapes were hung on the stakes and 2k hr later the number of adult flies which had emerged during the test was determined by counting the number of remaining pupae. Resul ts The number of flies caught on sticky tapes was linearly correlated to the total number of flies present in an outdoor cage as shown in Fig. 15. A high degree of correlation was noted for flies of the same age while there was a smaller though acceptable linear relationship in the combined values of all ages between number caught and number present. The slope of the correlation was calculated following the procedures outl ined in Dixon and Massey (16). The percentage of flies released as pupae, 1-, 3~, and 5-day old flies caught on the sticky tapes were 11.9, 24.8, 17.1, and 19.2, respectively (Fig. 15).'

PAGE 73

56

PAGE 74

57 The smaller number of flies trapped when pupae was allowec ,-ge in the outdoor cage were not surprising since a higher mortality rate was expected. Deterr: ' . ^ier r.~ ... c ;___-_ :se F": y ?c--ui at ion ( i pds The total number of house flies in the digester building was estimated by determining tne p; ge or marked flies captured sticky tapes that were released in that area, Three-day ole from the USDA susceptible colony were anesthetized by carbon diox. placed into smal '. screer holding cages. These flies were marked by .^_ing one-half teaspoon of DayGio (Switzer Brothers Inc., Cleveland, irescent djst to apenately £00 flies ar.d gently rotating cages. The flies wer. t tr< — : erred to ox Ik x 27 g^uze cages. Following a 1-hr period to allow the flies :o recover, the flies were transported to the compost it and released in the digester buildin releases warmad« 10:00 11:00 am on a Saturday or a Sunday when the plant was not in operation. Although all the doors in the building were closed, flies were not confined to the digester building because the siding did not fit \ to the base of the building leaving a 25 cm opening. ie flies were ... by 5 sticky tapes suspended from stakes in the digesters and were the same as described previously for the seasonal flue >n survey. The sticky t vere collected 2k hr aftei rel e id the marked . -Iving i 500 fl ie. and 3 '•• f 1 ies each.

PAGE 75

Results An average c. T 1.8 percent of the laboratory-reared house flies released in the digesters v. ere captured on sticky tape. le 11). The capture of house flies on sticky tapes in a large outdoor cage was /lously to be ... , ies preserver the per. r^~ is 1 ? flies released ir. an outdoor cage as shown in Fig. 15 or 1.8 perce t as shown in Table 11, would en the ci." -nces. Admittedly, any value assign jld be questionable due to -sal, and sntal factors. Hew ever, in t percent is given cr^^. nee sin id Thaggard (43) counted 1.25 percent of the house flies present in a similar partially open situation, re (1.8 percent) can be used to estimate the total number of house flies present in the digesters based on the numbers caught on the ->.;c.sy tapes. For example, Fig. 15 shows that 48.9 flies per stake per day were caught the week of April 27, 1959. An estimate of the total number of flies present can be calculated by ICO percent t 1.8 percent x 5 stakes per day x 48.9 flies per stake and is equal to 13,569 -se flies per day present in the digester building during the week of April 27, 1S69.

PAGE 76

59 -

PAGE 77

SECTION IV HOUSE FLY BREEDING IN COMPOST Observations conducted during 1968 and early 1969 revealed that house fly larvae were present in the compost in the digesters and along the conveyor belts where spillage had occurred. The ability of house flies to breed in compost presented the possibility of great numbers of flies reproducing in the enormous amounts of compost availabl e. An investigation began in April, 1969, to determine the extent and some of the limiting factors of house fly breeding in compost in order to devise procedures that may be used to prevent or hamper house fly breeding. Moisture and Age of Compost Methods Composts of various ages and moisture (%) were evaluated to determine their effects on house fly breeding. Compost 0, 1,3, 5, and 10 days of age was tested at 30, k5, 60, 75, and 90 percent moisture. The age of the compost was determined by the length of time the compost had been in the digester. The days of age compost was freshly ground refuse taken off the conveyor belt just prior to discharge into the digester. Compost 10 60

PAGE 78

61 days of age was tested prior to and after it had passed through the final grinders. The samples taken from the digesters were removed from a depth of 30-60 cm and placed into a plastic bag. A minimum of 5 areas were sampled for each bag. The bag was then sealed and the contents thoroughly mixed. A 10 gm sample was removed from the bag and the moisture content determined with a moisture determination balance. The moisture content of the compost in the digesters usually varied from 35 to 55 percent moisture. Since this was greater than the lowest moisture content tested, a portion was removed from the bag and placed into a plastic screen mesh bag. The mesh bag was then placed in an oven maintained at 80 C. After a short drying period, the compost was transferred to a separate plastic bag. A 10 gm sample was taken to determine the remaining percent moisture. The desired moisture content was obtained by adding tap water. The amount of water added was calculated by the following equation: x = (v) noo-z) X (100-y) x = ml of water added per 100 gm of compost y = moisture content desired (%) z = moisture content of sample (%) . After the amount of water needed for each desired moisture content was calculated, the compost was divided into 100 gm portions and each portion placed into a separate plastic bag. Tap water was added in the amounts calculated and the bags were sealed and the contents mixed. Fifty gm dry weight samples were removed from the bags and placed into waxed paper cups (0.9^6 1) which were marked for identification. Either 100 eggs or 100 ^8-hr old larvae of M. domest ica were added to each cup. The cups were then covered with black cloth and secured with rubber bands. Temperature

PAGE 79

62 and humid: .ained at 26 C and 70 percent RH. Sevc after egginr or 5 cays after placing the larvae in the cc jps e emptied into a pen of water and th ting pup£. ted! Each test was repl icated 6 cor. j 66 perc>. -"; . Resul ts Moisture content and t th« turat J house fly larv (Tal le 12). I _e snee the deve ages of compost tested contain 3 znd 75 percent moisture supported house fly development to some extent. Ninety -.loisture inh house fly development while kS percent moisture isuf 1 ic 3 roar house flies. Forty-five percent moisture in freshly ground refuse resulted in 1 . percent survival to pupae. It should be noted that these tests were s :ted to ambient RH (70%) and moisture fluctuations dur . t period were not measured. age of the compost -. : . T v-^_ .-elopment but this was secondary to moisture in Tabl There was a significa. reduction in the number of eggs that developed to pupae in 3-day o compost at 6j percent moisture but no significant reduction occurre the ages of compost tested at 75 percent moisture. :ts of moisture on hous^ opment from eggs was extended to define more clos_ sture of compost for fly b rig. In this test series 100 M. d ernes t ica ergs were placed in 3-day old compost cor..

PAGE 80

63 c o c OJ o 0) Q. o lT\ o LA -4" o u

PAGE 81

Gk 10 times. CSMA fly rearing medium containing 66 percent moisture was used as a control. The optimum moisture content for house fly development was 75 percent (Table 13). Sludge and Grinding Methods A test similar to the preceding experiments was conducted to determine what effects the addition of raw sewage sludge and the grinding of refuse had on house fly development. In these tests either tap water or sludge (approximately 98 percent moisture) was added to various grinds of refuse to obtain the desired moisture content. The sludge was obtained from the storage tank at the compost plant which was maintained by the city sewage treatment facility. Sixty and 75 percent moisture contents were chosen to be tested with the various grinds. The amounts of water and sludge added to achieve these moistures were calculated as in the previous study. Four sizes of refuse particles were evaluated in this study. These were obtained from refuse taken immediately after primary grinding, refuse taken after secondary grinding, a 1:1 mixture of refuse from the primary and secondary grinders, and refuse that had passed through a small laboratory mill with a 0.63 cm grid. These samples were placed in plastic bags and mixed with water or sludge in the same manner as described for the previous experiment. One hundred M. domes t ica eggs were added to 50 gm dry weight of the test materials and placed in waxed paper cups (0.5^+6 1). The cups were covered and the pupae collected by flotation 7 days later. CSMA fly

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65 Table 13. Influence of moisture on maturation of immature house flies reared in 3-day old compost. Percent No. of pupae collected per moisture 100 eggs 55 1^.0 60 21.7 65 23.7 70 30.2 75 39.4 80 21.6 Control b 80.3 Mean of 10 replicates. CSKA fly rearing medium containing 66 percent moisture. rearing medium brought to 66 percent moisture by adding either water or sludge was used as a control. Six replicates were prepared for each test. Resul ts The addition of raw sewage to compost of all size ranges produced a higher yield of house fly pupae than the addition of an equal amount of water as shown in Table 1 k. Such an increase is not surprising since the total organic content was increased and since Olson and Dahms (kS) found sewage sludge an ideal breeding medium for house flies. The effects of grinding compost were not clearly demonstrated. The results shown in Tables 12 and ]k indicate that the larger particles were more conducive to house fly survival. However, the size of the refuse

PAGE 83

66 o rO in 01 W 3 O -C 0) i_ 3 C o (0 u 3 ro E C o 0) I/) 3 V0) CD c X C x c Q O CD XI 3 J

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67 particles varied with the daily wear of the grinding mills and the exact size range was difficult to ascc re The temperatures occurring in house fly rearing containers investigated to determine the tem| srature preferred by line prot is H 51 -X semiconductor . (Atkins Inc., Gainesvill placed in a 10 1 p tic r< "i ng CSMA he cent probes were placed in sositic in 7 . c . 16. 3 temperatures were recorded every 2k'. r 6 Jays, was replicated 3 times. The mean temper recorded in the rearing tubs at each positic are presented in Tab . e . 5 . The bl cc.;cd data in Tab. e 15 represent those probes in areas occupied by larvae. The maximum tempei observed ii larval region was ko.] C. These data indicate that larvae develop in a temperature range of 28 ko. 1 C. The maximum temperature in which immature house flies can develop is not known. There are many references dealing with temperature studies on house flies but little definite information was found concerning this particular area. West (82) stated that house fly eggs cannot survive a temperature above 46.1 C while Roubaud (59) reported that larvae died in 3 minutes when exposed to 50 C. To determine if the temperatures attained in tl t house fly deve compos:. is H 51 -X s

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68 level of med ium Fig. 16. Position of temperature probes in house fly rearing containers (distances in cm).

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o ro "O Q O •u o o O en ~ cr. G o (0 C •_ (5 en — — . c •— U cj r 01 u Q LO no — u u

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70 placed in 4-day old ccmpost at depths ranging from 1 . 27 15.24 cm and allowed 10 minutes to equilibrate. The temperatures were then read and recorded. Twenty-five readings were made at each depth over a period of several weeks. The temperatures ranged from a mean of 38.2 C at a depth of 1.27 cm to a mean of 59.4 C at 15.24 cm (Table 1 6) . Information on the temperature in the digesters at greater depths was supplied to the author by Dr. D. T. Knuth, Environmental Engineering, Inc., Gainesville, Florida, and is presented in Appendix 4. From these data it can be concluded that temperature woul d prevent house fly breeding in the digester except in the top 2.5 cm of the compost.

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71 to i_ o +J in 03 en -a c in o a. u -a o 03 "O I -a03 > l_ O l/l J3 O 10 o !_ 3 4-1 TO l_ O a. £ o vD J3 (0 in c 03 > o IS) o la CM c CO a) -u ra i_ C 03 o 1/1 0) o a a) o E 3 X to 5 E IA N (T> ca cm en LA CO LA LA ca LA CA -3-3" -3 CO CA LA LA CA — CM vO vO en LA en LA LA LA vO LA vO LA CM CM (A t»"» -3" CO LA -3" -S CO CA O LA LA -3" -3" -3" LA CA o Q. O O jo o CM I — — LA CM CM CO O -3 LA I — CM i. o 03 Q. -3" TO O o c (0 in O O o c 03 4-J o o o

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SECTION V MIGRATION AND DISPERSAL Compost plants and other similar types of refuse handling systems are centrally located to lower the transportation costs. These facilities are optimally designed to operate in these central locations without causing a nuisance to the surrounding community. The Gainesville compost plant has previously been shov;n to produce approximately one-half million adult flies per week during the summer months. These flies may disperse into the surrounding community, thus discounting the value of central location. An investigation to determine the extent of fly dispersal from the compost plant was begun in 1969. When the plant closed in December, 1969, these dispersal studies were completed at the city landfill. L i terature Review House Fl i es There is an undue prominence often attached to the maximum distance of dispersal of flies (63). Flies released from a central location and recaptured later at some distance in very limited numbers imply that the area covered is subject to infestation from the release point. Although this may be true, it should be noted that those one or two flies 72

PAGE 90

73 recovered at some great distance were among the except ic, ie element of chance, managed to /e this distance. The dis of the mass of the fly pc than that of a few indivicuis the s ignif leant criteri gard to (&3) . The c 1 at ion is expected to expended '.. 1/2 2 miles : house fly movement (13, 48, 50, 53 , 63, 64, 75). /moves -id of a stimulus causing a : F another (33). A fly may travel 15 miles to reach a distance 1 mile from its origin (63 r tr ctiveness of the release site may greatly influence disper! Pickens et al. (50 recaptured 13 percent of the liberated house at the rel ease s ite ' flies in an open area located a center of a 1/2 mile circle c ns only 4.1 percent of t .^_e flies were recaptured. Schoof (63) found that in many instances flies dispersed from a location despite the presence of an apparent excess of feeding and breeding areas. There are confl ictl _ports of the effects of wind on fly dispersal (25, 40, 52). However, the more comprehensive studies of Schoof and Silverly (64) found that house fly movement was not equal in magnitude in all directions and Plckensjet _ _. (51) revealed that fly dispersal was random when the wine was variable and upv. the wind blew predominantly from 1 quarter. Ogata _et _aj_. (46) demonstrated that house fly dispersal was not influenceoy h;,_,nways, rice fields, or mountains. Dispersal is influenced by the t_v_ a of the fly. rer.ee ay old fl ies w

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Schoof and Silverly (64) concU at the i characteristic of fly di. sic randomness of movement influenced by 5 conditions: (1) population pressure, (2) differentially attr, (3) geograpr barriers, (4) prefer it tendency of fl to d isperse. ax i mum flight range of usually the maximum distance >ping. The maximum record [ght Fl ies is 20 mi 1 es (83) . Fi ies r I more et al. (21) fc at £. cjpr '.: . released at ."al point •e distr ily after 2 days in open sheep country. Kzc~. y (3^, 39) conclude . cw fly dispersal was random t that aggregat i _."e formed producing a c id distribution. These aggregations were due to d jnt degrees of attraction offeree' to those individuals in their rar.dc.-n movement across the activity areas. These hors later decided on two types c ..a sustained dispersal flight, independent of the envi. ., and an interspersal Ight which may ir.voive no net dis D) . Gurney a. 1 (25) . : c. . c u p r . ,i a tended to fly down or across while MacLeod and Donnelly (kO) found no evider.of wind affecting blow fly fl ight. ^haen icia spp. has de d a seasonal n on in -est to the cities in FinL (47) and from the fc .1 Great Britain (36). . : spp. was un sp slopes of a valle ..pland ! try and a . ide t fly daily

PAGE 92

75 activity in Australia. _P. c Jal in Japan, being mos numerous in the afternoon peak (7~0 . £. cuor ina was recorded -.-.7 mil — frc ir "iberati-n site with I). Comprehensive reviews of re ^s on blow fly dispersal and migration are p;-„. ted .-St. -r iis Fl ight mills provi ;harac .;s^c,: :'. ght under controlled environ : ..-._. Since _ c _a was the domir.-.".. Fly sp ~ . .3 at le mpost plant, laboratoryreared specim^.-.. were ... iched .c ^ flight r c determii I : aximum distance they may ..ravel in disperse'; flights. A simply constrLc:_c f 1 ighl mill was used by Atkins (3) with the sco";ytid, Der.ii.'OCucnus p ae H . ... This devirewas improved : th and Furniss (77) and Rowley __ aj_. (60) by automatically recorc . .-.ions of the mills by means of phecoel ectr i c cells and electric counters. Chambers and O'Connel (1-2) further improved this tec s by oir.g the friction of t Is by .he pivot between 2 mills uScd in ... are onerously provided by Dr. i. L. Bailey, JSJA, G.. arms of these mill constructed fr~.vi 0.52 mm chr^ teel . '.n length. One envthis wire ^as .s as si 17, so that .he 1 1 l . 5 mm of 1 1 'p€ t h « t o .A3 r and soldered t

PAGE 93

76 the end of the rotor arm to produce the double end shown In Fig. 17. A pivot was fastened 16 cm from the end of the arm so that the circle it described had a circumfrence of 1 m. The pivot was a No. insect pin with its head removed which was glued, point upward, to the rotor arm between two 6 cm circles of paper. The pivot was suspended between two 6 x 25 mm magnets (stirring bars) so that the pin was in contact with the upper of the 2 magnets and was stabilized by the lower magnet. The magnets were supported by 2 wooden dowels connected to a steel rod frame. The revolutions of the arm were counted and recorded by a method similar to that described by Smith and Furniss (77). A 6 volt lamp was attached to the wooden dowel holding the lower magnet as shown in Fig. 17. A photoelectric cell was positioned above the lamp so that a 2.54 cm black paper disc glued on the rotor arm would interupt the beam of light with each revolution of the arm. This paper disc was 7 cm from the pivot on the short end of the rotor arm and also functioned as a counterbalance. The photoelectric cell was connected to a power unit which operated an electric counter. Flies used in this study were reared on a diet of lean ground beef in the method described previously. The flies were anesthetized in a cold room maintained at 2-4 C. These flies were then attached to the radius of the mill with a drop of rubber cement on their pronotum. The rotors were then immediately mounted on the mills. In one series of tests, P. cupr ina of various ages were placed in constant light provided by fluorescent lamps for 2k hr and the distances flown recorded. Ten male and 10 female flies were used for each test. A second test involved 10 male and 10 f emal e P. cupr ina which were attached to the rotor arm approximately 4 hr after they emerged as adults.

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77 Fig. 17. Diagram of insect flight mill, a-rotor arm; b-magnet; c-counter-balance; d-1 ight source; 3-photoel ectr ic cell; f-metal plate; g-cotton bal 1.

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73 These insects were allowed to fly until death. The flies were allowed to fly from 8:00 am to 6:00 pm each day under constant light. In the evening, the rotor arm was fastened to a magnet placed on the metal plate as shown in Fig. 17, and the flies were allowed to feed on a cotton ball saturated with a 10 percent sugar solution. The lights were turned off and the flies remained in this position overnight. All tests were conducted at the USDA laboratory in a room where temperature and humidity were maintained at 26 C and 70 percent RH. Resul ts The mean distances flown by various ages of _P. cupr ina attached to a flight mill for 2k hr are presented in Table 17. The greatest distance travelled by an individual male was accomplished by a 5-day old fly that flew 24,129 m. The greatest distance travelled by an individual female was 19,603 m by a 3-day old fly. Male and female _P. cupr ina flew an average of 19,405.4 m and 25,235.2 m and a maximum of 30,127 m and 45,030 m respectively, when attached to a flight mill until death, as shown in Table 18. Assuming these were less than ideal conditions, flies in the field could be expected to travel these distances and further, especial 1 y when taking advantage of the winds. Blow Flies Released at Compost Plant Methods Four releases of wild flies were conducted at the compost plant during September, 1969, to determine their dispersal patterns in this

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79 Table 17. Mean distances a f 1 own in 2k hr by adult Phaenicia cuprina attached to an insect flight mill. Aae f fi Y Males Females r (Days) 1/2

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80 Table 18. Distance flown until death by adult Phaen ic ia cupr ina attached to an insect flight mill. Females Mai es Age of Insect Age of Insect Meters (Miles) At Death (Days) Meters (Miles) At Death (Days) 26,651 (16.6) 5 16,931 (10.5) 3 13,283 ( 8.3) 3 15,445 ( 9.6) 4 45,030 (28.0) 6 23,386 (14.8) 8 26,195 (16.3) 9 13,994 (11.8) 9 25,599 (15.9) 7 40,838 (25.4) 7 29,546

PAGE 98

81 each release. The trap at the animal shelter was removed for those releases at that location. Resul ts An average of 10.7 percent of the blow flies released at the compost plant were recaptured in the same area 2k hr after liberation as shown in Table 19. Traps baited with 1-day old fish heads at the city animal shelter and behind the apartment failed to capture any marked flies for these 2 releases. Flies released at the city animal shelter were recaptured at the compost plant at an average of 5.65 percent. The trap behind the apartment failed to trap any marked flies in these releases. Fly Releases at the City Landfill The compost plant closed December, 1969, forcing the completion of the dispersal studies to be conducted at the city landfill. The landfill presented a situation different from the compost plant but similar in the large amounts of attractive materials present and the generation of a large number of flies. It was concluded that dispersal patterns observed in this area may be interpolated as to general trends which may be applied to the compost plant. Location of City Landfill The landfill was located on a 30-acre tract of land north of the Gainesville Municipal Airport. This area was surrounded by pine flatwoods and the closest residence was located 1.2 mi south of the landfill. The Gainesville Industrial Park was located 1 mi west of the landfill and the airport runways began 1/2 mile southwest of the landfill. Three residences were located 1.5 mi north of the landfill whi 1 e woodl ands extended for several miles to the east.

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82 o i/i ns o 1u 0) -3" CM in a. .a (0 a o V 1_ C 4-" CJ Cl o ro lo CJ 0) 0. L. c to n cj .— ia. 3 Dol

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83 Operation of the Landfill The refuse was brought to the landfill by truck and dumped into trenches 15 m wide and 5 m deep. A bulldozer was supposed to crush and pack the refuse into the trenches and then cover it with soil at the end of the day. Such an operation would be in compl iance with the standards of the American Public Works Association for the operation of a sanitary landfill (l). Unfortunately these procedures were seldom complied with because of equipment failures. Refuse was observed to remain uncovered for several days on many occasions. A separate area of the landfill was used to dispose of dead animals and the maintenance of this area was poor. Too frequently animals were not completely covered with soil or else not covered at all for several days. This resulted in large numbers of flies developing in this area (Fig. 18). Fly Behavior Patterns Observed at the Landfill Before a general discussion of the releases can be undertaken some observations concerning fly behavior at the landfill should be reported. Blow flies and house flies were inactive at night, roosting on the refuse or on vegetation surrounding the refuse until sunrise (Fig. .13 and 20). As the roosting sites were exposed to the sun the fl ies crawl ed about the plant or refuse to position themselves in direct light where they groomed themselves for 15-90 minutes. The flies then left the roosting sites, flying as it seemed, an orientation flight. These flights occurred in all directions, with the majority of the flies finally appearing at a sunny, sandy area, absent of vegetation. The sunny sides of the mounds of sand used to cover the refuse were preferred sites. The flies

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8k Fig. 18. Fly larvae in arums' disposal area of city landfill Fig. 19. P. cupr ina roosting on grass tassel at night at city landfill.

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85 Fig. 20. Predominantly M. domest ica roosting on weed at night at city 1 andf i 1 1 . Fig. 21 . Predominantly _C. macel lar ia with some M. domest ica roosting on dead brush in refuse at night at city landfill.

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86 remained in these areas 45-60 minutes and mating was widespread during this period. The activity diminished and flies began appearing on the refuse where they remained until dusk when they returned to the roosting sites. House flies and _P. cupri.-.a were both observed to follow this pattern and both occurred in the same mating area simultaneously. The roosting sites were centered around the most recently dumped refuse. M. domestica rested on the refuse, especially brush in the refuse, and on the surrounding vegetation immediately adjacent to the refuse. There appeared to be little selection of plant species chosen as resting sites but there was a preference of height. House flies appeared most often on plants 1/2 1 m in height. House flies have previously been reported to roost preferably on ceilings, trees, and shrubs in rural areas (2, 33, 41). Cochl iomy ia macel lar ia were observed to roost on leafless or dead branches 1-3 m in height. Brush in the refuse and plants immediately next to the refuse were preferred (Fig. 21). P. cupr ina was seldom observed roosting on the refuse and rested almost exclusively in grasses and weeds up to 1 m in height. Green (22) and Maier _et aj_. (41) observed similar behavior at a slaughterhouse as well as in urban areas. These flies roosted at a greater distance from the refuse than did the house flies. If one walked from the refuse through the surrounding vegetation, he would first pass through a belt 2-5 m wide of plants containing roosting house fl ies. This zone would give way to a mixture of house f 1 ies and blew f 1 ies and f inal ly to an area where the blow flies were in the majority. The number of flies decreased rapidly with increasing distance from the refuse. Flies became relatively scarce after about 20 m.

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87 Mortal i ty The determination of the natural rate of fly mortality in field populations is almost impossible since flies are such mobile insects. The determination of mortality rates of marked flies released in the field is even more difficult. Some observations on the effects of environmental factors and predation of marked and wild flies which may provide some information for the estimation of fly mortality are given in this section. Flies at the landfill were preyed upon extensively by toads, spiders, ants, beetles, earwigs, dragonflies, and birds. Flocks of cattle egrets were observed feeding on adult flies and blackbirds were often seen feeding on the larvae in the refuse. Numerous toads inhabited the area and appeared to have little difficulty in acquiring a meal of flies in the grass and weeds at night. Earwigs hunted the fly roosting sites at night. These insects would grasp a resting fly with its pinchers and then feed on its struggling prey. Numerous spiders and ants patrolled the weeds and attacked the roosting flies. Ants were especially numerous in the early morning hours. Dragonflies hunted the area catching flies in flight during the day. It appeared that different species hunted at different hours of the day with tremendous numbers of dragonflies appearing at dusk. To determine the effects the marking procedure had on the flies samplesof approximately 500 flies from several releases were taken to the laboratory. The flies were anesthetized in a cold room (2-k C) and 50 male and 50 female _P. cupr ina and M. dar.es t lea were placed into a gauze cage. Fresh fly food and water were supplied each day. The dead flies

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88 were removed daily and the number and species recorded. A control cage was also set up which contained wild flies that had not been marked. The marked flies suffered mortalities of 10-15 percent within the first 2k hr, 15-25 percent within 48 hr, and 33-^0 percent within 7 days. The control mortalities were 2-k percent, k-G percent, and 10-25 percent respectively. These results were similar to those of Murvosh and Thaggard (43) where 25-30 percent mortality was recorded for marking flies by shaking anesthetized flies with a dust. The above data show that the largest percentage of flies were killed within the first 48 hr, indicating that the marking procedure killed or mortally injured 15-25 percent of the flies marked. It should be noted that these results were under laboratory conditions and a greater loss could be expected in the field. This becomes more apparent since it was observed that the marked flies released at the landfill often groomed themselves approximately 2 hr longer than the unmarked flies in the area. These marked fl ies were physically weakened and more subject to predation. Ants were particularly injuriousat this time as they were observed to attack roosting flies by grasping their legs and the weakened flies were less likely to shake free. The physical operation of the landfill also contributed to fly deaths. Fiies in their search for food and breeding sites in the refuse would crawl into every available opening in the refuse. The crushing of the refuse by the bulldozer and the covering of the refuse with soil trapped and killed numerous flies.

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89 Flies Released Around the City Landfill Methods . -Four releases were made at sites 1 mi or more from the center of the landfill. The purpose of these releases was to determine if fl ies would travel that distance to the landfill. Flies were captured by sweep net at night on the vegetation surrounding the landfill. These fl ies were placed in 15 x 24 x 27 cm gauze cages with approximately 3>000 flies in each cage. After a sufficient number of flies were captured, they were transferred to a large plastic bag by placing the sleeve of the cage in the bag and rapping sharply on the aluminum bottom of the cage. Because of the large number of flies in the cage and dampness of their wings, the flies tumbled into the bag. DayGlo fluorescent dust was placed in the bag at a rate of approximately 1 teaspoon per 2,000 flies, and the bag gently agitated. These marked flies then were counted by volumetric approximation in which a waxed paper cup (0.946 1) filled with flies was equal to 12,000 flies and a 50 ml beaker was equal to 500 flies. Approximately 8,000 flies were then placed in one of several 45 x 45 x 50 cm release cages. These cages were designed for fly release studies as the rear panel of the cage was hinged to facilitate removal of the flies. These cages were transported to the release sites and the flies released. Capture usually began around 9:30 pm and the releases were made about 1:00 am the following morning. A sample of approximately 500 marked specimens was removed from the release cages and taken to the laboratory for identification. The percentage of each species in that sample was taken as representative of all the flies in that release and was used in conjunction with the total number of flies released to calculate the number of each species released.

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90 The marked flies were recaptured at the landfill by sweep net after they were located by systematically examining the refuse and the surrounding vegetation with a portable battery powered ultraviolet light. These areas were examined for 7 nights following the release. Each release employed a different colored marking dust. The sites, dates of release, and numbers and species of flies released are given in Table 20. Resul ts . — Flies were recaptured at the landfill from 3 of the k release sites as shown in Table 20. These data show that an average of 0.097 percent of the _P. cupr ina and 0.07 percent of the M. d cm est ica released at the last 3 sites were recaptured. The flies released at the 39th Avenue location were subjected to several attractive loci and this may explain why no fl ies were recaptured from this area. A cow pasture was located immediately across the road from the release point and 10-15 residences were in the area as well as a hog farm. A direct line of flight from this release point to the landfill would require a fly to pass 3 residences, the hog farm, and 1.1 mi of woodland. The remaining release points were at least 0.1 mi from any residences and a direct line of flight passed only through woodlands. The results of these tests agree with other published reports that these 2 fly species can travel and infest areas over 1 mi from the release or breeding site. Releases at greater distances were not attempted. Flies Released at Landfill Methods . — Wild flies were captured, marked, and released at the center of the landfill in the manner described previously. Baited traps

PAGE 108

a a. v a — o o a) en cc in O O — « — < I/I o — N "O 0) Q. to o o a: c o ro.*b — -.O O cv-v O ,z —

PAGE 109

92 were used in addition to the sweep net capture method described above to recapture the marked flies. The traps were modified cone traps consisting of two 1 quart (0.946 1) plastic freezer jars taped together at the mouths. The bottoms were removed and replaced by an inverted screen cone. A putrified fish head was placed inside each trap as an attractant. The traps were placed at the 4 points of the compass in concentric circles 1.5, 1.0, and 0.5 mi from the center of the landfill for the first 2 releases. The outer circle was moved to 0.25 mi from the center for the remaining 5 releases. Captured flies were removed and fresh bait added daily. Resul ts . -The results of the marked flies released at the landfill and later recaptured in the same area are given in Tables 21 and 22. An average of 8.26 percent of the _P. cupr ina and 1.89 percent of the !',. d on est ica released were observed at the landfill 24 hr after liberation and these numbers decreased with each suceeding observation. In Table 23 these data are divided into the average percentages of flies observed for releases followed within 24 hr by rainfall and those where no rainfall was recorded (Table 24). These data show that releases followed by dry days resulted in 10.17 percent recapture of _P. cupr ina and this number decreased s ign if icant ly with each suceeding observation. Those releases followed by rain resulted in an average of 6.84 percent recapture of P_. cupr ina and this number had a significantly lower rate of decrease. Norris (43) reported that rainfall inhibits dispersal of _?. cupr ina and these data support that observat ion. The majority of the flies released were not .-^covered. This was because of recovery error, mortality, and dispersal. The method of locating and counting the marked flies was exhaustive but it could not

PAGE 110

93 10 fO o -a c CO > l/l 0) to (0 3 C a O TO o u ro E c o Q > !_ O CM C +J o CO O 1-o o o o 1/1 10 O vD LA (O CJ. 14o! to h(0 E ifl >J "0 O — s_ — O 14-O TO S c 3 (D a a> 10 to 4) *o l_ r— o o M0 O la CO CA VO CO O — o ex o MO M0 O 00 CM CM CO -4" — CO • CA CM CO \T) — . ,— r--. . ,— CM . ^o en ca r>~ CO -3" r». MO LA co LA LA CA CM LA .— CA CM CM rO CO o LA o vO O0 CM r~ en — — o CO CM CO CM .— LA LA CO CM •— fO O CO CA f"^ — mo -c la en r-~ r--d" -3" CO — -4" -4" MO — ^-^ LA LA CO *~* ^— » y—~ ^O CO • • LA LA VO • o «Cj* -J" • • • CA CO • — — CO LA MO _ _ _ vD vO vO — co cm la P» r-» O O O O O O O O — r~r-. co ro LA CM CO \Q — — — co — CA O u

PAGE 111

9*t o l/l ra 0) o c ra > c O +-> f0 CD = ra u o -I a i/i c o ra > o in XI O cm CM Q o ra Lft c o u I-o -— _ (U o (/) _q ra O o o l_ <4a -3" T

PAGE 112

95 c o X) c o u TO o 3 +> c o _ 4) U o x> c 3 x> c TO o en c to e l/l a) c o o l_ o Q. o en ID L. 0) > < CM X> a

PAGE 113

c CO Ifl O XI 3 LA oa C7\ -3" — O S6 o ID o vO (0 1) en CN en O — o LA -4cn c o 1_ 1_ o Q. (3 D. 3 > LO o c CO o x> o X) l_ o o o L. •1 CO -3" CM CD LA i/i > X) CO o O c LL. c CO vO CA vO O oo en CN CN -3" LA I — 00 CN Cn CN CN o cn LA CA cn cn oa -a P-. LA — -3I — — cn ca cn CN cn o — o o i — o oa vO CN CN CO o o I — 1-^. CN o oo o o o o o o o i — ca r»— — — CN vO — CN oA I^> csj — CN o VO CN f^ oo oo co oo oo oo cncncn c o o o LO 1/1 < c o > < 3 o t_> LA CN XI c CO CN CN o CN LO 0) -Q CO I— CO I10 O o X) L0
PAGE 114

97 be expected to identify all of the flies present. Marked flies resting on the underside of leaves were difficult to locate and isolated patches of vegetation used as roosting sites may have been overlooked. Marked house flies roosting on the refuse were particularly difficult to find because of the tremendous quantities of refuse present. Mortality from marking was previously discussed and could be expected to amount to 15-25 percent of the released flies. Mortality from predatation and the natural death rate of the flies and dispersal accounted for the remaining flies. The assignment of any figure to each of these factors would be conjecture. Information concerning dispersal patterns was minimal. Only 2 marked flies were captured in the traps surrounding the landfill. These were both _P. cupr ina females captured in the same trap on the same day 1/2 mi from the release site. Release of Laboratory Reared _P. cupr ina Wild _P. cupr ina caught at the landfill were reared to the F„ generation in the laboratory on a diet consisting of Chunx and ground beef in a manner described previously. Two-day old adult flies were anesthetized in a cold room maintained at 2-k C and marked with DayGlo fluorescent dust as described previously. The flies were counted volumetr ical ly and placed into 45 x 45 x 50 cm release cages supplied with fly food and water and allowed to recover about 8 hr. The flies were transported to the landfill and released about 10:00 pm. Flies were recaptured with sweep nets and baited traps as described previously. Laboratory reared releases were followed by 2k hr periods of no rainfall (Table 2k). The results of these releases are shown in Table 25

PAGE 115

98 > in c CO u c o -Z a. "D

PAGE 116

99 and are similar to those recorded for wild _P. cupr ina 1 iberated during a dry period (Table 23). No laboratory reared flies were captured in the baited traps.

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SUMMARY, CONCLUSIONS AND RECOMMENDATIONS Investigations revealed that fly breeding at the compost plant was minimal under normal operating conditions. The major fly source was from larvae migrating from the refuse in the receiving building to protected areas where they developed into adults. This situation is not unique to composting facilities. Other disposal systems as central incineration or refuse transfer stations have similar problems. Any time refuse is centralized, transferred, or remains standing for any length of time, insects in the refuse may escape into the holding area. Thus, the results of the present investigation could be applied to other similar refuse handling operations. The number of insects escaping from the 1 arvaeinfested refuse stored in the receiving building often exceeded 500,000 larvae per week during the summer months. As high as 88.8 percent of these larvae may become adults resulting in approximately 450,000 adult flies per week released into the environs. These flies were predominantly the greenbottle blow fly, Phaenicia cuprina . The reduction of these large numbers of flies can be accomplished by procedural changes in the handling of refuse and application of the axiom that good sanitation is the most effective method of fly control. Greater than 35 percent of the larvae escaping into the compost plant could be eliminated by not storing refuse overnight in the 100

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101 receiving building. Such a procedure may involve increasing the capacity of the equipment at the Gainesville plant. Although impractical in this case, this should be considered in the construction of new facilities. The problem of having insufficient refuse to begin operations in the morning could be eliminated by starting the working day at a later time. The construction of the receiving building greatly influences larval survival. Refuse falls behind the wooden retaining walls and provides food and harborage to rodents, roaches, and fly larvae. The construction of a solid retaining wall that would prevent the accumulation of such wastes or one that provides access for easy cleaning would be more des i rable. The construction of a fly larvae trap behind the retaining wall would reduce the number of escaping larvae. Such a trap could be made by the construction of a sunken trough in the floor between the retaining wall and the building wall. This trough filled with water would drown migrating larvae. The trough could be cleaned by flushing. The concrete floor of the receiving building has been chipped by the loading tractor at the edge of the receiving hopper producing an opening between the hopper and the floor. The construction of a lip over the edge of the hopper would reduce the debris and number of larvae escaping into this area. This lip could be either metal or several inches of re-enforced concrete. it was shown that a 40.6 percent reduction in the number of adult flies occurred when the area under the apron conveyor was cleaned and a possible reduction of 67 percent was predicted. This demonstrates the value of good housekeeping. Not only are the number of fl ies reduced by

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cleaning but the dangers c ;ng with poisons and the potent:, of insect resistar.ee and pollution are ei :d. A combination of cleaning the . apron conveyor . eliminating the pre in the r building would r. the ensuing adult pop. ies by snt The application of a ,ecticie_ would reduce the number cf the remaining fl The daily applicati~r bait re flies caught ited traps at the compost plant by £5.7 percent. gging were 1 ei :ive and not recommended, ication of a residual insecticide to che night-time rcos; . .es -d the number cf fl ies at re than S9 percent. better than SO percent control for one week. Gardona was ineffective as a residual. The laboratory screening of 12 commercial insecticides re. .. parat Dursban, nalee, azlnon were effective against female J?. _c It! posed in a wind tunnel. These results -icate that parathion, Dursban, naled, and diezir.cn may also be or the 1 of P. cuor ina . A diet consisting c ry dog food, and ground beef was ind superior to the o„s!y been used to eg food d i _ in total iess, and it produced less offensive odors th the et. r of he

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. indicates that the fly population may be estimated by the number tr When a known number of marked house flies was released in the digester building an average of 1.8 percent were recaptured on sticky tapes. .he total number of flies present in the digester building may be estimated by the multiplication of 1 . & percent times the number c ; f 1 ies trapped. A one-year study of house files in the digesters revealed the. . number of house flies fluctuated seasonally and that high t -es in the digester building during the sun :ouragec entering that area. abilit compos : oduction of sects presents the ial problem that a great method of refuse disposal. Observations re id that house ;es were the predominant capable c. ig in compost ar.d th« were limited by several factors. Temperature was the primary factor limiting house fly Ing in compost. Temperatures in the digesters prevented house fly development except in the top 2.5 cm of compost. The moisture content of the compost was a major factor affecting adult development from eggs in compost. Seventy-five percent moisture was the optimum moisture content. It should be noted that cc moistures above 65 percent could not oe processed because of equipment limitations. The moisture content of the compost in normal operations ranged from nt which gave 1-14 percent survival of eggs to pupae in laboratory t r The length < tec a1 Surviv cc. :ent.

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104 The addition of raw e sludge to th refuse ses the ability of compost to support he. effects of th of the refuse par on survival . adults produc. . oistur^ ad r.o e maturation of 48-hr ol e fly larv in the refuse that survived the grinding pro. to areas wher.. tempere es were ... .develop to £.. was demonstrat . survive normal gr inding. Fly larvae were .he co:. .iters dur April, May, June, Cctober, November, and December of 1969, and mc than S9 percent of 'chose insects identified v. sre _. .lestica . flies may be controlled by removing and grinding the compost before the house fly can complete its life cycle. Th i also be controlled by mixing the compost in the digester by the Agi-Loader so th-. larvae are exposed to lethal temperatures. Flight and dispersal studies were conducted to determine d patterns from an attractive si P. ci-or ir.a males average of 19,405.4 m (12.. and a maximum of 30,127 m (13.7 mi) attached to a f 1 .-, average 25,235.2 m (15."; of 45,030 .0 mi). e data ght distanc ow fly under t i ons . their r. char

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105 displacement may exceed the laboratory distances when flies are blown with the winds. Wild P. cupr ina and M. domes t lea released 1 mi or more frc, city landfill were recaptured .. i of w!',c j'.c. -la, _?. 'city animal recaptured at the c. Thase i cte th< attracted from the surrounding areas. An average of 10.7 d £• i .'ia.nt were recaptur. :er. An c of 10.17 p< Ina and '. . ~i percent c : v '. . ^ _. released at the landfill on days . / 2k hr without rain we rec-;^ tured 2k hr a 11.3 ; reared _?. cinr '. r,a r^'iasac at the landfill were recaptur < 2k hr after rel easu. Baited traps located at an apa.: 200 m east of the compost plant and at the city animal sh....: .-II ed to re any marked release at the compost plant. Baited traps surrounding the city landfill captured only 2 flies after the release of 255,000 marked specimens. th were _P. cj::in:i females captured 1/2 m m the landfill the same day in the same trap. data appear to indicate that the flies do not disperse greatly from these very attractive loci. Th«_ j are .~. r or composting: 1. ^st be J the same day it is delivered. 2. The refuse receiving area must be constructed to preclude t mk 3.

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the .3 hopp^ id be : per we. The daily ap "vos sl weekl y ap:: 5 beca 5. The moisture level St. for a ;ed by the breed inc . ich increases as moisture approaches 75 pe r 6. The grl ng of th« ..se must be thorough to insure X.\ death of larvincoming refuse, 7. Lar .-ceding in the digesters s .royed oy either re-grinding or t -he compost in the digesters. Aani should be centrally located to lover costs preferably in an area at least oi ile from residences to reduce the nuisc. ..-used by flies migrating into the surrounding crea. Furth *eas of fly dispersal from a composting plant and fiy b.-eeding in compost should be conducted.

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APPENDIX

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108 Appendix J. -Test for the precision of the counting technique used to determine total number of larvae collected under the apron conveyor. Weight of sample Number of Larvae. per (gm) larvae gram 514 3064 566 3279 708 4217 430 2720 642 3842 5.96

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109 Append ix

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110 Appendix 2 (Continued) Week of Species present Number caught Phoenicia Hermetia Cochl iomyia Musca cu p r ina il lucens macellaria domestica spp Sarcophaga Sept. 7

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Ill 3 in O a. X ro -3" CM in a U o .— c o 10 -C -a

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112 c

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113 c O TO o CM o o 00 CM I LA CO CO >.

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]]k
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LITERATURE CITED 1. American Public Works Association. 1966. Municipal Refuse Disposal. Public Administration Service, Chicago. 528 p. 2. Anderson, J. R. , and J. H. Poorbaugh. 1964. Observations on the ethology and ecology of various Diptera associated with northern California poultry ranches. J. Med. Entomol. 2:131-1^7. 3. Atkins, M. D. 1961. A study of the flight of the Dougl as-f ir beetle, Dendroctonus pseudotsugae Hopk. (Coleoptera: Scolytidae). Ill Flight capacity. Can. Entomol. 61 \kG~]-k~lk. k. Bailey, D. L. 1969. (Personal communication). 5. Bailey, D. L. , G. C. LaBrecque, and P. M. Bishop. 1967. Residual sprays for the control of house flies, Musca domestica , in dairy barns. Fla. Entomol. 50:161-163. 6. Bailey, D. L. , G. C. LaBrecque, D. W. Meifert, and P. M. Bishop. 1968. Insecticides in dry sugar baits against two strains of house flies. J. Econ. Entomol. 61:7^3-7^7. 7. Bailey, D. L. , G. C. LaBrecque, and T. L. Whitfield. 1970. Laboratory evaluation of insecticides as contact sprays against adult house flies. J. Econ. Entomol. 63:275-276. 8. . 1970. Resistance of house flies (D iptera:Muscidae) to dimethoate and ronnel in Florida. Fla. Entomol. 53:1-5. 9. Bailey, D. L. , D. W. Meifert, and P. M. Bishop. 1968. Control of house flies in poultry houses with larvicides. Fla. Entomol. 51 :107-111. 10. Brady, U. E. , Jr., D. W. Meifert, and G. C. LaBrecque. 1966. Residual sprays for the control of house flies in field tests. J. Econ. Entomol. 59:1522-1523. 11. Busvine, J. R. , J. D. Bell, and A. M. Guneidy. 1963. Toxicology and genetics of two types of insecticide resistance in Chrysomy ia putor ia Weid. Bull. Entomol. Res. 5^:589-600. 12. Chambers, D. L. , and T. B. 0'ConneJ. 1969. A flight mill for studies with the Mexican fruit fly. Ann. Entomol. Soc. Amer. 62:917-920. 115

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13. Cragg, J. E. J. B. , and G. 75. 15. Davis, A. N. , < : Oixo.-,, , and F. J. Massey. 1963. In p. I 7. Ecke, D. H. , and and c . H. , D. ... . Vector V 19. Fii D. J. :S : -7. • Analys! tment of t id Resc lurve. University .-.-ess, Cambridge. p. 20. Gainesville 2rs ion Authority. 1959. .ville .post Plant. . U.S. Dep. Health and We 39 p. 21. Gilmcur, D. , D. F. W :yre. I< i account n to dc :ural p^ density of the sheep b. , Luc:l ia cuprii. ull. Cc Sci. ... . 195. 35 p. , A. A. 135'. Th ;ting s :erJ observ is of ti jlow flies >pl. Biol. 38:475-494. . Green, A. A., and J. Kane. control of blew flies ing slaugl Ml. Largeat a domestic• onel 1 a Hies tc J. HygT 156.

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27. Howard, L. 0. IS 1 . 2. The House Fly Disease Carrier, an Account Its Dangerous Activities and the Means of Destroying It. John , London. 31 2 p. James, M. T. 1 otes on the distribution, syste position, and varie. th particular reference to the species of west err. North ica (Diptera, Callipher Entomol. Soc. Wash. Proc. 55 : ". -.-3-1 48. Johnson, C. G. 1969. Migration and Dispersal of Insects by Flight. jn and Co., London, 763 P« 30. -I, S. , and 0. Suenaga. I960. Studies of the methods of collect flies. III. On the effect of ^faction of baits (fish). Enc^ . ". iv. 2: 3 . Keller, J. C. , H. G. Wilson, and C. N. Smith. 1955. Poison baits for the control of blow flies and house flies. J. Econ. al . 48^563-565. 3 2. \\err, R. W. 1964. Notes or. arthropoc resistance to chemicals used in their control in Australia. J. Ajst. Agr. Sci. 30:33-3^. 33. Kil patrick, J. \1. , and K. D. Q.uarterman. 1952. Field studies, on resting habits of flies in relation to chemical control. P. II. in rural area::. r. J. Trcp. Med. Hyg. 1:1C26-1031. 3^. LaBrecque, G. C. ":95o. Application of insecticides at dumps. Public ..or.v3. : 2:92-9] . 35. . '. -.. •".) . 36. MacLeod, J., and J. Donnelly. 1957. ical relationships of natural populations of calliphorina blow flies. J. Anim. Ecc", . 5-170. 37. . 1953. Local distribution e paths of bl flies in hill country. J. Anim. Ecol . i:7:5 i .-3-3. _ . .960. Natural features of blow fly movement. J. Anim. Ecol. 29:85-93. . 1962. Microgeographic aggregation in blow fly populations. Ecoi. 40. . 19o3. Disperse sal of blow fly popuK. J. Anim. -.0.. .-. I: . -32. 41 . M •. J. 1

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118 42. Muirhead-Thomson, R. C. 1968. Ecology of Insect Vector Populations. Academic Press, New York. 174 p. 43. Murvosh, C. M. , and C. W. Thaggard. 1966. Ecological studies of the house fly. Ann. Entomol . Soc. Amer. 59:533-547. 44. Norris, K. R. 1959. The ecology of sheep blow flies in Australia. Monogr. Biol. 8:514-544. 45. . 1965. The bionomics of blow flies. Annu. Rev. Entomol. 10:47-68. **6* . 1966. Daily pattern of flight activity of blow flies (Cal 1 iphor idae:Diptera) in the Canberra district as indicated by trap catches. Aust. J. Zool . 14:835-853. 47. Nuorteva, P. 1966. Local distribution of blow flies in relation to human settlement in an area around the town of Forssa in South Finland. Ann. Entomol. Finland. 32:128-137. 48. Ogata, K. , N. Nagai, N. Koshimizu, M. Kato, and A. Wada. I960. Release studies on the dispersion of the house flies and the blow flies in the suburban area of Kawasake City, Japan. Jap. J. Sanit. Zool. 11 :l8l-l88. 49. Olson, T. A., and R. G. Dahms. 1945. Control of house fly breeding in partly digested sludge. J. Econ. Entomol. 38:602-604. 50. Parker, R. R. 1916. Dispersion of Musca domest ica (L.) under city conditions in Montana. J. Econ. Entomol. 9:325-354. 51. Pickens, L. G. , N. 0. Morgan, J. G. Hartsock, and J. W. Smith. 1967. Dispersal patterns and populations of the house fly affected by sanitation and weather in rural Maryland. J. Econ. Entomol. 60:1250-1255. 52. Quarterman, K. D. , J. W. Kilpatrick, and W. Mathis. 1954. Fly dispersal in a rural area near Savannah, Georgia. J. Econ. Entomol. 47:413-419. 53. Quarterman, K. D. , W. Mathis, and J. W. Kilpatrick. 1954. Urban fly dispersal in the area of Savannah, Georgia. J. Econ. Entomol. 47:405-412. 54. Raybould, J. N. 1964. An improved technique for sampling the indoor density of African house fly populations. J. Econ. Entomol. 57: 445-447. 55. . 1966. Techniques for sampling the density of African house fly populations: I. A field comparison of the use of the Schudder Grill and the Sticky fly-trap method for sampling the indoor density of African house flies. J. Econ. Entomol. 59:639-644.

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115 56. . 1966. Techniques for -ling the density of African house fly populations: II. A field cc ;on of the Schudder Grill and the Sticky -pi ing the outdoor density of African house Flies. ol . 59:644-648. 57. F.iches, J. H. , end P. J. 0' . ' value of t organic phospho the protection c strike. Vet. 34-j Roth, D. L. ";. : ". y • cans. Cal if. Vector V . — 6. 59. Rouband, E. 1915. P.: -•" de cheval .as. Compt. Rend. Acad. Sci. Par. . 161 :325-327. 60. Rowley, W. / I R. E. Williams. 1968. A flight n system for the 1 at ..tory study -, : -. itc ol . Sec. -.61:15 ••61 . Rul ) . 62. Schoof, H. F. 1951. on ~ ip bet rill counts, elation levels sce.-,s . iary . iealth, t ion, and . . 1959. How far go flies fly? Pest Control. 27:16-18, 20, 22, . 5c., cov, H. ?., end R. E. Silverly. 195**. Multiple release studies on the dispersion of Musca domes tica at rv.oenix, Ari-cr.e. ^. 2 con . Ent c.v.o 1 . 47 : 33 .. -^. Schuntner, C. A., and V.'. J. RoLiszon. ,568. A resistance mechanism in organophoschorus-res istant strains of sheep blow fly (Llc I '. i i cuor ' -st. J. Biol. Sci. 21:173-176. 66. Scudder, H. i. 1947. A new technique ie density of house fly populations. Public Health Rep. 62:631-. \, G. J. 1958. Resist:. and aldrin in Luc il ia c_ ... it. Inst. Agr. Sci. 24:15?. . d i el d r i n cupr ina 17 i ec . , Australian sheep blow fly. . 361. . 1965. A re\p in Al ;tr 70. . . 1st

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71. . 1366. Developr. in Luci 1 ia cupr ina fed.) to organophosphorus insecticides I Bull. Entomol. Res. 57:93-1 0( 72. . 1966. Crganophcs nee in blow flies. . *cz. New Soi 73. Shi . i, G. J. , and R. J. Hart. 1! of L i.i z i 1 i c cupr ina Wied. to orgai in Austral la sh -7. Shinoda, 0., and 7. Ando. 1935 . Bot. Zool. 3:117-121. 75. Shi ra, B. L. , E. V. 3va, and A. D. Shaikov. >f fly c of mass b 76. Smith, C. N. , and J. rol for Cities. PuL. . 77. Smith, / record ing ight mill. 'ooze, and J. ~:ca North of C . C . D. L . Fly la containers in the city of r .-^_.-.:. Cal if. /ector .. Water iov. 1350. The status o two (Diptera, Cai 1 iphor idae) att. eep in Austral ia. . J. Sci. Res., : Eiol. Sci. 3:31 0-2 Welch, S. F. , i oof. 1. ility of "visual survey" in evaluating fly densities for cc ity con. Br. J. Trc . /g. 2:1131-11. 82. West, L. S. 1951. The He. ;tock Publ : Co., Ithaca, N.Y. 584 p. , S. Butts. 1352. Furth :ies of dispersion o. phosphoric acid. J. Econ. E

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sle Alvarez was : /ll le, Florida, t and s gradua. School in June, 1961. In August, , h« was an active reservist until his d -7. antere th ity of Flori -y, 196: received < r of Science cz^-raa with ology in April, i$5C, and a Master f Science degree a major in entomology 1968, to the pre he ited States Public th Service Trainee worl d i\ decree of Doctor of Philosophy. He is . slogical Society of America and t Florida Society. former Judith Gaynell Marable of Newport News, ^inia, on May 7, IS

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I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. Dr, F. S. Blanton, Co-chairman Professor of Entomology and Nematology 1 certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. Dr. H. D. Putnam, Co-chairman Professor of Environmental Engineering I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. °)