Title: Florida Entomologist
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00098813/00222
 Material Information
Title: Florida Entomologist
Physical Description: Serial
Creator: Florida Entomological Society
Publisher: Florida Entomological Society
Place of Publication: Winter Haven, Fla.
Publication Date: 1952
Copyright Date: 1917
Subject: Florida Entomological Society
Entomology -- Periodicals
Insects -- Florida
Insects -- Florida -- Periodicals
Insects -- Periodicals
General Note: Eigenfactor: Florida Entomologist: http://www.bioone.org/doi/full/10.1653/024.092.0401
 Record Information
Bibliographic ID: UF00098813
Volume ID: VID00222
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: Open Access

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Florida Entomologist
Official Organ of the Florida Entomological Society

MARCH, 1952
Vol. XXXV No. 1

WILSON, J. W.-Corn Earworm Control-Spraying Methods.. 3
SMITH, A. L., and C. C. SKIPPER-Screw-Worm Surveys in the
Southeastern States 1944-1951 ............................................ 10
DIEM, JOHN J.-Manufacturer, Dealer and Grower Responsi-
bilities in Handling Highly Toxic Pesticides ...-..-...-........... 14
NORMAN, PAUL A., and HERBERT SPENCER--Experiments in
1951 on Control of the Citrus Red Mite ................................ 19
KUITERT, L. C., and R. V. CONNIN-Biology of the American
Grasshopper in the Southeastern United States --....--........ 22
Minutes of the 34th Annual Meeting of the Florida Ento-
mological Society (continued) .............................................. 34
Index to Volum e 34 ............................................. .................. 36

Published quarterly by the FLORIDA ENTOMOLOGICAL SOCIETY
Box 2425, University Station, University of Florida, Gainesville

Mailing Date: March 4, 1952



VOL. XXXV MARCH, 1952 No. 1


OFFICERS FOR 1951-1952
President ........_.... ... ....... ............ ......... J. W W ILSON
Vice President ---... .............------- ........-....J. T. GRIFFITHS
Secretary..... ........................... .. MILLEDGE MURPHEY, JR.
Treasurer....-----------..~................................. .... L.C. C. KUITERT
Executive Committee ................ D. 0. WOLFENBARGER
/ J. J. DIEM

LEWIS BERNER ..........................................Editor
W. P. HUNTER .-....--...-..............--...Associate Editor
L. C. KUITERT ....-----....--...........- .... Business Manager

Issued quarterly-March, June, September, and December. Free to
all members of the Society. Subscription price to non-members $2.00 per
year in advance; 50 cents per copy. Application for entry as second class
matter is pending.
Manuscripts and other editorial matter should be sent to the Editor,
Dr. Lewis Berner, Biology Department, University of Florida, Gainesville.
Subscriptions and orders for back numbers are handled by the Business
Manager, Dr. L. C. Kuitert, Box 2425, University Station, University of
Florida, Gainesville. The S&cretary can be reached at the same address.
One zinc etching, not to exceed one-half page in size, or the equivalent
thereof, will be allowed free. The actual cost of all additional illustrations
must be borne by contributors. Reprints of articles may be secured by
authors if they are ordered before, or at the time proofs are received for
correction; 25 copies furnished free to authors.

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50 copies................... 1.6012.00 2.70 4.25 6.70 7.25 9.40 10.40 12.05 12.80
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Add 100 copies................. .75 .751.101.60 2.701 3.10 3.70 4.80 5.85 6.20

Additional for Covers, with Titles and Author's Name
25 copies ..............................3.50 100 copies ..............................$5.00

VOL. XXXV, No. 1 MARCH, 1952

Gentravw Florida xpeTiment Station

The rapid rise in the acreage planted to sweet corn in Florida
began with the growing season of 1947-48. Scruggs (1950)'
reports 6,000 acres for that year, 12,000 acres for the following
season and a doubling of the acreage again during the 1949-50
season. Prior to the 1947-48 season small acreages of various
varieties were planted in many of the vegetable growing areas
of the State. This very rapid increase in sweet corn acreage
is attributed to the introduction of hybrid varieties adapted to
Florida growing conditions and the development of DDT as a
control measure for the corn earworm (Heliothis armigera
Russell, in 1944, reported on the first use in Florida of DDT
dust for the control of Heliothis armigera. In 1945 Blanchard
and Sattherwait reported on their experiments with DDT in oil
solutions and in emulsions, and in June 1949 Blanchard et al.
made recommendations for field applications of a white mineral
oil and 25 percent DDT emulsion for the control of corn ear-
worm on sweet corn. Kelsheimer et al. published, in 1950, re-
sults of their experimental work and recommended the use of a
five percent DDT dust.
During December 1950 Dr. E. G. Kelsheimer, N. C. Hayslip
and the writer decided to devote the coming season to a study
of the use of oil and DDT emulsion. An experimental plan of
procedure was drawn up. The problem was divided into three
phases, with Kelsheimer to study number and timing of spray
applications at Bradenton; Hayslip to study insecticide formula-
tions at Ft. Pierce, and the writer to study spraying methods at
Sanford. Later W. H. Thames was asked to study number and
timing of spray applications at Belle Glade.
This paper reports on the experimental work conducted at
Sanford during the past spring (1951).
METHODS: All of the spray treatments were applied by a
high pressure Myers spray pump with a 25-gallon tank mounted
on a Farmall model A tractor. Agitation was obtained by carry-
ing the overflow to the bottom of the tank by means of a half-
inch pressure hose. This arrangement gave adequate agitation,

1 Florida Agricultural Experiment Station Journal Series, No. 20.


because at no time during the spraying operations was free oil
observed on the top of the spray solution in the tank. A four-
row boom, adjusted to the height of the ears, delivered the
spray to the plants. This spray boom was so constructed that
it was possible to use five nozzles to each row. One nozzle was
placed directly over the row and sprayed straight down, one
on each side of the row about six inches below the top nozzle,
and another on each side of the row and about 18 inches below
the first pair of side nozzles. These side nozzles could be turned
through an arc of 180 degrees. Thus it was possible to direct
the spray at any angle or height required to reach the silks.
Two plantings of corn were made. The first was loana,
planted March 18, and the second was Calumet planted March
26, 1951. The plots were four rows wide, 40 feet long and the
rows 30 inches apart, with about 12-inch spacings between
plants in the row. Alleyways 12 feet wide separated each block
and two rows were skipped between each two plots to allow for
driving the tractor along one side of each plot. Each treatment
was replicated six times. The Ioana corn was treated April 26
and May 2 for budworm control with one quart of 25% DDT
emulsion per 100 gallons of spray, applying about 85 gallons of
spray material per acre. The Calumet corn was similarly
treated for budworm control but the dates of these treatments
were not recorded.
The Ioana corn began to tassel May 2 and the Calumet on
May 21. First silks appeared in the Ioana planting May 7 and
the first spray applications were made May 8. First silks ap-
peared in the Calumet planting May 24 and the first spray ap-
plications followed the next day. Spray applications were spaced
at three-day intervals, with a total of four for the loana and
five for the Calumet plantings. The 25% DDT emulsion was
prepared in the laboratory, using the following formula:
25% DDT (by weight) Setting point 890C.
72% Xylene (by weight)
3% Triton x 155 (by weight)
The mineral oil was Blandol, supplied by L. Sonneborn Sons,
Inc., having the following specifications: water white, U.S.P.,
viscosity 900 to 95' Seyboldt. The basic mixture consisted of
3 quarts of the above described 25% DDT emulsion, 2.5 gal-
lons of Blandol and water to make 100 gallons of spray. Details
of the treatments are given in Table 1.

VOL. XXXV, No. 1 MARCH, 1952 5


Section A. Amount of liquid spray per acre.
Basic formula composed of 3 quarts of 25% DDT emulsion, 2.5 gallons
of Blandol in 100 gallons of water using a pump pressure of 100 pounds
per square inch, and 4 nozzles per row. In each case the plan was to
apply 3 quarts of 25'. DDT emulsion and 2.5 gallons of oil per acre. The
spray solutions were mixed on the assumption that the amount of liquid
applied would be approximately the same as the nozzle rating.

Treatment Number
1. Teejet Nozzle No. 650050, rated at 15 gallons per acre.
2. Teejet Nozzle No. 6501, 25 gallons per acre.
3. Teejet Nozzle No. 6502, 50 gallons per acre.
4. Teejet Nozzle No. 6503, 100 gallons per acre.
5. 5% DDT dust applied by rotary hand duster.

Section B. Kind of nozzles.
All plots treated with spray composed of 3 quarts of 25% DDT emul-
sion, 2.5 gallons of Blandol in 100 gallons of water, pump pressure of 100
pounds per square inch and 4 nozzles per row.
Treatment Number
1. Teejet Hollow Cone Nozzle.
2. Christian Nozzle.
3. Teejet Flat Fan No. 6503.
4. Tiger Nozzle (Manufactured by Field Force Sprayer Co.).
5. Untreated Check.

Section C. Number of Teejet Flat Fan No. 6503 Nozzles per row.
All plots treated with same formula and pressure as used in Section B.
Treatment Number
1. Two nozzles per row (low and directed downward).
2. Three nozzles per row (2 as in Treatment No. 1 and other over row).
3. Four nozzles per row (1 high and 1 low each side of row).
4. Five nozzles per row (4 as in Treatment No. 3 and 1 over row
directed straight down).

Section Da. Operating pressure.
All plots treated with same formula as used in Section B., with 4 nozzles
per row arranged as in Section C-3. The Teejet Flat Fan No. 6503 was
the nozzle used.
Treatment Number
1. 60 pounds per square inch.
2. 100 pounds per square inch.
3. 200 pounds per square inch.


Section Db. Operating pressure.
All factors same as in Section Da except that the Teejet disc type
nozzle was used.
Treatment Number
1. 60 pounds per square inch.
2. 100 pounds per square inch.
3. 200 pounds per square inch.

Counts of the number of eggs on silks of twenty ears of corn
selected at random from each treatment were made on May 15
in the Ioana planting and on May 26 for Calumet. On these
dates the percent of silks upon which earworm eggs were found
ranged from 20 to 70 in the Ioana planting and from 50 to 90 in
the Calumet planting.
RESULTS AND DISCUSSION: A record was made of the amount
of spray applied to the six plots of each treatment at the time
of the second spraying of the Ioana planting and last spraying
of the Calumet planting. Since the tractor was operated in
the same gear and presumably at the same speed it was assumed
that the amount of liquid applied to the plots of each treatment
would remain constant. A comparison of the data presented
in Table 2 for the Ioana planting and Table 3 for the Calumet
planting shows a wide variation in the amounts of liquid re-
corded for the same treatment in the two plantings. One ex-
planation for this variation is that slight errors in the measure-
ment of the liquid used would be magnified when calculated on
an acre basis.


Liquid Spray Tech.
Treatment Applied, Oil, DDT, Worm Free Ears
Gals. Gals. Lbs. No. %
Section A. Amount of liquid spray per acre.
1. Teejet No. 650050 .-......... 72 12.0 7.20 120 50.0
2. Teejet No. 6501 .............-.. 81 8.1 4.86 216 90.0
3. Teejet No. 6502 ............... 144 5.2 3.12 150 62.5
4. Teejet No. 6503 ......-.....- 144 3.6 2.16 193 80.4
L.S.D. (19-1) ................... 24

VOL. XXXV, No. 1- MARCH, 1952

Section B. Kinds of nozzles.
1. Teejet Hollow Cone --...-
2. Christian .....................
3. Teejet Flat Fan .-.......-...
4. T iger .................................
5. Check .........................-....
L.S.D. (19-1) ................

Section C. Number of Teejet
1. Tw o ................ .............
2. Three ................. ...... ..
3. Four .............. ..........
4. Five .............-...........
L.S.D. (19-1) ................

Section Da. Operating
1. 60 lbs./sq. in. -........
2. 100 Ibs./sq. in. .........
3. 200 lbs./sq. in. ...---

Flat Fan

pressure, 4 flat
-...... 117
.. 146

Nozzles per

fan nozzles.


1.75 192 80.0
2.19 185 77.1
3.10 209 87.1

Section Db. Operating pressure, 4 Teejet disc nozzles.
1. 60 lbs./sq. in. --------------.. 107 44.6
2. 100 lbs./sq. in ............... 72 1.80 1.08 114 47.5
3. 200 lbs./sq. in .................. 90 2.25 1.35 155 64.6
Differences in Sections Da and Db not significant.


Liquid Spray
Treatment Applied, Oil,
Gals. Gals.
Section A. Amount of liquid spray per acre.
1. Teejet No. 650050 ..---....--. 108 2.70
2. Teejet No. 6501 .............. 144 3.60
3. Teejet No. 6502 ................
4. Teejet No. 6503 .....--....-... 135 3.37
L.S.D (19-1) ....................




Worm Free Ears
No. %

Section B. Kinds of nozzles.
1. Teejet Hollow Cone -... .-
2. Christian ....................
3. Teejet Flat Fan ............-...
4. T iger .................................
5. Check .......---..................
L.S.D. (19-1) ............. .








Section C. Number of Teejet Flat Fan
1. Two ....-... ... -....-- ....- 162
2. Three ................. ----......- 162
3. Four .....................-........... 135
4. Five ......... .......... ...... ... 198
L.S.D. (19-1) .... .........

Section Da. Operating pressure, 4 flat
1. 60 lbs./sq. in. .....---.....- --- -..
2. 100 Ibs./sq. in. .........-------135
3. 200 lbs./sq. in. ... --.......---

Section Db. Operating pressure, 4 Teej,
1. 60 lbs./sq. in. .............. 81
2. 100 lbs./sq. in. ~...-- -. 99
3. 200 lbs./sq. in. .................. 108
Differences in Sections Da and Db n

Nozzles per


7 2.9
.9 7.9
!4 10.0
10 37.5

fan nozzles.
..... .. 94 39.2
3.37 2.02 53 22.1
...... 136 56.6

disc nozzles.
2.02 1.21
2.47 1.48
2.70 1.62

An additional treatment consisted of 5%o DDT dust applied
by a rotary type hand duster with the nozzle directed slightly
above the silks of the upper ears of corn. Applications were
started in the early morning of the same day as the first spray
applications and continued at 2-day intervals for a total of six
applications for the Ioana planting and seven applications for
the Calumet planting. It is interesting to note that for the
loana planting 50 percent of the ears harvested were worm-
free, as compared with 3.7 percent from the untreated check,
and for the Calumet planting 8.7 percent worm-free ears were
harvested from the DDT dust plots as compared with 2.1 percent
worm free ears from the check.
CONCLUSIONS: From the data presented it is concluded that
the Teejet nozzle No. 650050 had too small an orifice, breaking
the spray droplets into such small particles that there was an
insufficient deposit of the oil- DDT on the silks. In both the
loana and the Calumet planting the highest number of worm-
free ears was harvested from plots treated with the Teejet Flat
Fan nozzle No. 6501.
In the loana planting the Teejet Hollow Cone nozzle and the
Teejet Flat Fan No. 6503 were equally effective. In the Calumet
planting the Teejet Hollow Cone nozzle was the most effective.
Both of these are wide-angle nozzles. That is, the spray is de-
livered over a wide area, increasing the chances of wetting all
of the silks.

VOL. XXXV, No. 1- MARCH, 1952

There was no significant difference between the number of
worm-free ears harvested from the plots treated with 4 and 5
nozzles to the row in the loana planting. Five nozzles to the
row was the most effective arrangement in the Calumet planting.
Differences between the various pressures used were not
significant in either the loana or the Calumet plantings. How-
ever, the highest number of worm-free ears was harvested from
plots treated with the Teejet Flat Fan nozzle No. 6503 in both
After the third application of spray materials the treated
plots of the Ioana planting were noticeably yellow in color when
compared with the untreated plots. No differences between
treated and untreated plots could be detected after five applica-
tions in the Calumet planting. Total yield figures for both plant-
ings did not indicate a reduction in yield due to the effects of
the oil DDT treatments.

Blanchard, R. A., W. A. Douglas and G. P. Wene. 1949. DDT sprays for
control of the corn earworm and budworm in sweet corn. U. S. Dept.
Agr., Bur. Ent. and P1. Quar. E 780.
Blanchard, R. A., and A. F. Satterthwait. 1945. Tests of DDT and pyre-
thrum in oil solutions and in emulsions against the earworm in sweet
corn. U. S. Dept. Agr., Bur. Ent. and P1. Quar. E 665.
Kelsheimer, E. G., N. C. Tayslip and J. W. Wilson. 1950. Control of bud-
worms, earworms and other insects attacking sweet corn and green
corn in Florida. Fla. Agr. Exp. Sta. Bul. 466.
Russell, J. C. 1944. DDT, a new insecticide for vegetables. Proc. Fla.
State Hort. Soc. 57: 208-210.
Scruggs, F. H. 1950. Florida State Marketing Bureau Annual Fruit and
Vegetable Report 1949-50 Season. Fla. State Marketing Bureau. P. 82.


A few complete sets of the FLORIDA ENTOMOLOGIST are
still available. For information concerning these, or single copies,
please write to Dr. L. C. Kuitert, Business Manager, Box 2425,
University Station, Gainesville, Florida.


STATES 1944-1951 1


Surveys in the Southeastern States were begun in 1944 by
the U. S. Bureau of Entomology and Plant Quarantine, to de-
termine the incidence and relative abundance of screw-worms,
Callitroga americana (C. & P.). The primary objective of these
surveys was to keep the livestock industry and the distributors
of screw-worm remedies informed regarding distribution and
abundance of screw-worms. Livestock owners were informed
of available screw-worm remedies and how to use them. Live-
stock-management practices were outlined to reduce the number
of screw-worm cases. Information on the distribution and
abundance of the pest formed the basis for allocation of critical
materials for screw-worm control, and manufacturers and dis-
tributors were in a position to supply remedies where they were
The information on screw-worm distribution and abundance
was obtained by personal contacts with livestock owners, agri-
cultural extension officials, agricultural experiment station per-
sonnel, county agents, vocational agricultural agents, Soil Con-
servation Service field personnel, Bureau of Animal Industry
inspectors, Fish and Wildlife Service biologists, veterinarians,
and merchants.
During the years 1944 to 1948 screw-worms overwintered
only in the peninsular portion of Florida. The northern limit of
overwintering during those years extended in a line across the
State from Fernandina to Perry and to the Gulf, while the
southern limit extended from St. Augustine to Gainesville and
to the Gulf.
During the extremely mild winter of 1948-49 screw-worms
overwintered practically over the entire area infested the pre-
vious summer, or a radius of 200 to 250 miles north and west
of the normal overwintering area. Screw-worms were active
that winter over Florida, except for a few counties in west
Florida, along the Atlantic coast to Charleston, South Carolina,
approximately the southern half of Georgia, and a small area
in southeastern Alabama.

SPresented at the Meeting of the Florida Entomological Society at
Winter Haven, September 14, 1951.

VOL. XXXV, No. 1 MARCH, 1952

Owing to this wide range of overwintering, screw-worms
spread to areas of the Southeast where they had never been
known to occur before. Populations were extremely high in
some areas, and loss to the livestock industry was heavy.
A serious situation then arose, since many stockmen and
farmers in areas where screw-worms normally do not occur were
inexperienced in the control of this pest. In these areas it was
necessary to set up an educational program, which dealt with
methods of prevention and control. News releases to the press,
circular letters to livestock owners, radio-broadcast programs,
and public meetings were handled through the Agricultural Ex-
tension Service.
Once the overwintering areas were established, forecasts
were made of the distribution of screw-worms. Warnings were
sent out from the Bureau to extension officials in all the South-
eastern States. Through county agents and the educational pro-
gram, livestock owners were advised of the danger of a screw-
worm outbreak, were taught to recognize screw-worm cases,
and were given instructions on methods of prevention and control.
Dealers in livestock remedies were requested to stock Smear
62 and other approved treatments. This procedure resulted in
a fairly adequate distribution of materials. Even with this pre-
caution, there were some temporary shortages of remedies, and
ineffective control methods such as gasoline, kerosene, spirits
of turpentine, linaments, and honey were applied. Some farm-
ers in North Carolina used the last-mentioned material to induce
screw-worms to come out of the wounds of animals.
By midsummer of 1949 the shortage of remedies became so
acute at Whiteville, Columbus County, North Carolina, that
McNeill's Drug Store chartered a private airplane to fljy a cargo
of Smear 62 in from Charleston, South Carolina. By the time
the plane returned, it was reported that 50 to 60 people were
standing in line to buy the material. It was estimated that
this one county alone had at least 15,000 cases of screw-worms
during the season. Some of the older veterinarians in North
Carolina reported they had never seen or heard of a case of
screw-worms before 1949.
The unprecedented radius of screw-worm distribution over
the Southeast in 1949 covered the entire states of Florida,
Georgia, Alabama, South Carolina, and North Carolina, also
eastern Mississippi, southwestern Kentucky, southern Virginia,
and most of Tennessee. Most of the outbreaks reported in


Mississippi, Kentucky, and western Tennessee originated through
the medium of infested livestock shipped into these areas.
In addition to those areas, a serious localized outbreak of
screw-worms occurred in New Jersey in 1949 as a result of the
shipment, in the latter part of April, of 704 head of feeder
steers from Polk County, Florida, to the Helius Stock Farm at
Jobstown, New Jersey. In the latter part of June the insects
were identified as screw-worms. By the time the outbreak was
brought under control it was estimated that over 1,000 cases
had occurred in the area surrounding the Helius Stock Farm.
This screw-worm outbreak is the only one ever known to occur
in New Jersey.
The extremely mild winters of 1948-49 and 1949-50 per-
mitted screw-worm survival over a greater radius of the South-
east than ever before. Northern limits of screw-worm survival
for the winter of 1949-50 extended approximately from New
Bern, North Carolina, westward to include the southeastern cor-
ner of North Carolina, the southern two-thirds of South Carolina
and Georgia, and the southern half of Alabama and Mississippi,
or a radius of 150 to 200 miles beyond the limit of the previous
During the season of 1950, screw-worms spread over a larger
area than in 1949, but population build-up was not so heavy in
general, and livestock losses were not so great, because of the
educational work done on preventive and control measures in
In contrast to the two previous years an opposite extreme
condition occurred in the winter of 1950-51 in the Southeast.
On November 24, 1950, a sudden hard freeze, followed by sev-
eral weeks of low temperatures, brought screw-worm activity
to an end over most of the southeastern region. The final over-
wintering area was established at a line extending across the
state of Florida from Tampa to Cocoa-at least 125 miles
farther south than screw-worms had ever been known to over-
winter before. The small area of winter survival, the low win-
ter population, and the late spring followed by a prolonged
drought, all contributed to the slow population build-up and the
northern migratory movement.
By the middle of August 1951 a general infestation was
established in all of Florida east of Leon County. A few iso-
lated cases were reported in west Florida and southern Georgia.
The general population was still low at that time, except for

VOL. XXXV, No. 1- MARCH, 1952

a few localized concentrated outbreaks in areas where woods
hogs were abundant. These animals are important factors in
screw-worm control, as they are not given the same care as
other animals.
The Bureau of Entomology and Plant Quarantine developed
at its Kerrville, Texas, laboratory a new screw-worm remedy
known as EQ-335, the formula of which was released to the
public in the fall of 1950. This smear contains 3 percent of
lindane and 35 percent of pine oil, which accounts for the num-
ber "335."
This remedy has not yet become well established in the South-
east, owing to short demand for remedies this year and a large
carryover of materials on hand from last year. The material
is rapidly gaining favor and is the most effective screw-worm
remedy now known.




Southern Agricultural Insecticides, Palmetto, Florida
The purpose of this paper is to review, for workers in eco-
nomic entomology, some of their responsibilities regarding the
manufacture, sale and use of highly toxic pesticides.
The cataclysmic expansion of our list of economically avail-
able chemicals for use as pesticides has placed economic ento-
mology in a position where, for all practical purposes, the art
precedes the science. That is to say, we are finding and using
many compounds simply because they have been found to do a
job by the trial and error route of investigation. We know
little of why a certain compound is a highly efficient insecticide
while its chemical isomers, much less its chemical first cousins,
are more often than not virtually useless as insecticides. Our
inability to predict toxicity from structure leaves us with a void
that makes us treat almost all pesticidal compounds as separate
entities. The mention of this void is not in criticism of the trade
nor the workers doing basic research on the relationships of
structures to toxicity but merely to point out that this handicap
intensifies our responsibilities to the general public, for where
the building blocks are not too firm we must build with extreme
caution. Recent popular articles and the investigations by the
Delaney Committee all indicate the growing public awareness
of the industries obligations.
A discussion such as this seems to outline itself on the basis
of the chronology of events from the manufacturers production
of a pesticide to its eventual use in the field. Keystone of the
statutory law regulating the sale of pesticides is the Federal
Insecticide Act of 1947 and its state law counterparts. It goes
without saying that distribution of a pesticide on a national
scale means conformity with all the divergent state laws and
the federal law as well. A few years ago this was one of the
difficult problems of the industry, but constructive cooperation
by the industry and the various state legislatures is bringing
about a degree of uniformity which is a credit to the industry.
These laws in general perform two groups of functions, they
assure the farmer as to quality and afford protection to -he
public in general from damage by the use of the product either
directly or indirectly. The quality phase of the law involves

VOL. XXXV, No. 1 MARCH, 1952

inspection, sampling, and chemical analysis by the United States
Department of Agriculture and various state governments, thus
insuring against adulterated products. The registration pro-
cedure makes quite certain that the product will do the job for
which it is intended.
I will not dwell further on the quality aspects of the laws
for the needs of performance are obvious, however, it might be
well to point out that even the accidental production of an adul-
trated product might cause serious crop damage, even if it has
no phytotoxic effect on the crop itself, by failure to do the in-
tended job. While such damage is often difficult to prove, negli-
gence is present and the manufacturer can be held liable.
Protection to the public is obtained through the following
labeling restrictions:
1. The directions for usage, where toxic residues are potential
danger, give adequate timing instructions.
2. The instructions for usage with such compounds as para-
thion contain specific instructions to operators handling the
application of the material as to protective equipment and
other safety instructions.
3. Warnings are clearly stated to prevent accidental poisoning.
Antidotes, when available and deemed necessary, are also a
part of the label. Artificial coloration for arsenicals and
some fluorides is also necessary.
4. Most recently, precautions to the user with regard to pos-
sible damage by drift of the pesticide to other property in
the immediate proximity have been required as a part of
the precautionary statements. While it is by no means a
part of the law, most manufacturers also use a non-warranty
clause, the fine print of the label, in an attempt to limit their
liability of the product to the chemical analysis. The validity
of this clause is of doubtful value.
Violation of the federal insecticide act and most of the state
laws is a misdemeanor; however, the liability implications of
civil suit can be far more costly to the manufacturer.
The general rule is that a contractor, manufacturer, or ven-
dor is not liable to third parties who have no contractual re-
lations with him for negligence in the construction, manufacture,
or sale of the articles he handles. However, highly toxic in-
secticides must, by nature, be considered articles which are in-
herently dangerous and as such the manufacturer or vendor
may be liable for damages without proper warning of a danger
which might not be apparent to another.
Assuming that the manufacturer has placed on the market
a properly labeled reputable product for sale, it then becomes


the responsibility of his sales organization to see that the
product is handled and used according to the manufacturer's
recommendations. Sales organizations must be on guard to
prevent the over-zealous sales representative from extenuating
the precautions or extending product claims, for it must be
understood that an agent or employee may do an act or make
a statement that not only is not authorized, but is actually pro-
hibited by his employer. Still if it is within the apparent scope
of his employment and done in course of principals, business
persons dealing with him have the right to depend upon appear-
ance. That is, insofar as the public is concerned, the employees
or agents authority may be real or it may be apparent, and the
public may rely on either, unless in case of apparent authority
the circumstances are such as to put a customer on inquiry.
By accepting benefit of agents act or representations the
employer ratifies.
These are general rules and in any particular situation the
facts must control. Time does not permit a development of this
broad field of law; however, the implications of its application
to salesmen, branch managers and possible liability of manu-
facturers and dealers is obvious.
Of course the employee or agent who does an unauthorized
thing is personally liable for loss resulting to person dealing
with him, and is also liable to the employer or principal for
loss caused by his unauthorized act; however, financial irre-
sponsibility of the employee usually renders this right or in-
demnity of no practical value.
Dealers' responsibilities parallel those of the manufacturer
with respect to sales effort and the same admonitions regarding
the extenuation of precautions and broadening of manufacturers
claims apply here.
There are two other points regarding the merchandising of
highly toxic pesticides with which it is the duty of the dealer
to acquaint himself. First, the personnel should be properly
cautioned as to the dangers inherent in the product. They
should be carefully instructed and protective equipment made
available to them so that they can clean up spillage from broken
containers which is bound to occur when handling these ma-
terials in glass or paper. That this danger to employees hand-
ling these materials exists, can be seen by the exclusion of re-
sponsibility for damage caused by handling that has crept into
most manufacturers non-warranty clauses in the past ten years.

VOL. XXXV, No. 1 MARCH, 1952

Second, the matter of warehousing these materials should be
given more consideration than the average seed, feed and fertil-
izer dealer gives. There is very real danger of storing highly
toxic insecticides with feed or foodstuffs. For, again, breakage
of packages occurs all too easily and the dosages of these ma-
terials in feeds would not have to be very great to cause trouble.
Storage of weed killers also presents a special problem for
contamination of adjacent spray materials or fertilizer packed
in paper, from a leaking drum of liquid weed killer, can pro-
duce damage to a considerable acreage.
From the dealer the product passes to the grower or the
custom applicator. It is this point in the chain of sales that is
one of the most problematical phases of the industry. For the
industry produces a legion of materials, most of them inherently
dangerous, and they must pass in large quantities to as variable
a consumer as the American farmer. We are all aware of the
newness of many of the tools we work with and it takes time
to build up a body of case law; however, there seems to be
enough case law arising from spraying and dusting operations
to give the farmer some basic principles by which to govern
himself when using pesticides.
First, the farmer must choose the right product. This
product must do the job without injury to the crop and without
possibility of leaving a harmful residue on his produce which
would carry through to the consumer. This means that he must
be aware of the timing limitations of his pesticide.
Second, he must see to it that his own personnel are familiar
with the poisonous nature of the materials they are using, that
they are supplied with the proper safety equipment and know
how and do use it. It may be well to add here that while farm
labor is not included under the Florida Workman's Compensa-
tion Law the employer can elect to come under the provisions
of the law with a rate of about $1.92 per $100.00 of payroll.
Third, he must be aware of his rights and obligations with
regard to the effect of his spraying operations on his neighbors
property. There is no doubt that farmers have the right to
use the many beneficial dusts and sprays, in fact their necessity
to efficient production is a fact rather well established by recent
testimony before the Food and Drug Administration hearings
on residue tolerance. However, such preventive measures can-
not be used with absolute impunity. The owner of an area
dusted or sprayed with a pesticide known to be dangerous say


negligently spread the material in such a manner as to endanger
stock or other property of persons in the immediate vicinity
and become liable to damage therefrom. The plaintiff has the
burden of proving that it was the pesticide used that caused
the damage; also that the defendants were guilty of negligence
on account of the manner in which the material reached ad-
jacent fields; and that such negligence was the proximate cause
for the damage. The hiring of independent contractors such as
airplane sprayers and dusters would appear to offer a means of
avoiding liability. Generally, the employer is not liable for the
negligence of an independent contractor; however, this is not
true in this case, for again we must take into account the fact
that we are dealing with an inherently dangerous substance.
The damage due to negligent application should be apparent to
the owner and he cannot delegate the work to avoid the liability.
It is true that lack of previous experience has been the basis
for holding the owners not liable for damage, as in certain cases
involving the use of 2-4-D dust on rice. However, as our use
of dangerous pesticides expands this should become an ever de-
creasing basis for defense for damages caused. When it be-
comes necessary to apply pesticides where there is adjacent
stock, notice to or knowledge of impending operations can affect
the owners liability. It is best that this be handled by cooper-
ation of grower and adjacent land owners. In regard to tres-
passing stock on the owner's land, the plaintiff cannot recover
damages unless the poison was distributed wantonly, maliciously,
or with deliberate intent to said stock.
In summing up these grower problems, it would be safe to
say that almost all of them resolve themselves into reading the
entire label carefully and proceeding with all the precautions
stipulated, and back this with some honest to goodness common
It is a real tribute to the pesticide industry that they have
produced the tremendous dollar and tonnage volume; have mar-
keted this to as mutable a customer as the American farmer;
and in so doing have not built up any great body of case law.
In closing; it may be well to point out that the high ethical
standards of doing business which is the rule with most com-
panies handling highly toxic pesticides is good business. It is
well to understand that neglect of a moral obligation when work-
ing with inherently dangerous products may cost you money in
a court of common law.

VOL. XXXV, No. 1 MARCH, 1952



Control of the citrus red mite (Paratetranychus citri McG.),
also known as the purple mite, has become an important prob-
lem in Florida in recent years. Experiments on control of this
pest were started in 1937 (Spencer et al. 1949, 1951). Oil emul-
sion or emulsive-oil sprays at 12 to 12 gallons per 100 gallons
of water give adequate control, but such applications are in
addition to the regular sprays and accordingly are costly to
growers. Moreover, they may injure the trees in cold weather
or in very dry periods. Dry Mix No. 1 (40-percent dinitro-o-
cyclohexylphenol) is effective, is compatible with wettable sul-
fur, and is used in the cooler months, but may cause injury in
hot weather. Much needed is a miticide that can be added to
the regular sulfur sprays.
In 1951, at Fort Pierce, Florida, an experimental grove of
Temple oranges was set up with 10 blocks and 9 miticide treat-
ments randomized in single-tree plots in each block. Late in
March citrus red mite infestations were high in this grove, an
estimate showing that 61 to 71 percent of the leaves were in-
fested. Only one unhatched egg or crawling stage was enough
to classify a leaf as being infested. Infestations of 20 percent
or less require no control.
The following commercial products were included in the ex-
periments :
Neotran-A wettable powder containing 40 percent of bis(p-chloro-
phenoxy) methane.
Sulphenone (R-242)-A wettable powder containing 35 percent of
p-chlorophenyl phenyl sulfone and 15 percent of related sulfones.
Hypozene 70-A wettable powder containing 70 percent of azobenzene.
EPN-300-A wettable powder containing 27 percent of O-ethyl O-p-
nitrophenyl benzenethiophosphonate.
Metacide-An emulsive liquid containing parathion 6.6 percent, 0,0-
dimethyl O-p-nitrophenyl thiophosphate 24.5 percent, related organic phos-
phates 2.7 percent, emulsifier 66.6 percent.
Genitol 923-An emulsifiable concentrate containing 50 percent of
2,4-dichlorophenyl benzenesulfonate.
No. 883 and Ovotran (K-6451)-Wettable powders containing 50 per-
cent of p-chlorophenyl p-chlorobenzenesulfonate. Ovotran is micronized.

SUnited States Department of Agriculture, Agricultural Research Ad-
ministration, Bureau of Entomology and Plant Quarantine.


Aramite-15W-A wettable powder containing 15 percent of 2-(p-tert-
butylphenoxy)-l-methylethyl 2-chloroethyl sulfite.
An emulsive oil-Standard No. 345 spray oil with 38 ml. of Triton
B-1956 (a glycerol phthalic alkyd resin) emulsifier per gallon. Viscosity
of oil 114 seconds Saybolt at 100F.; unsulfonatable residue (A.O.A.C.)
73.5 percent.
These miticides were used in combination with other ma-
terials. Except when otherwise indicated in the table, all plots
received 3 pounds of basic copper sulfate, 5 pounds of wettable
sulfur, and 1 pound of 15 percent parathion wettable powder
per 100 gallons.
The first sprays were applied on April 4, 1951. A pre-spray
estimate of infestation by red mites was taken on March 28,
and post-spray estimates were made on May 8 and June 12.
The results are shown in Table 1.


Quantity of the cor- Percentage of Leaves
Miticide mercial product per Infested on-
100 gallons March 28 May 8 June 12
Neotran ................ 1 lb. 66 40 58
Sulphenone ......... 2 lb. 71 89
Hypozene 70 ---........ /2 lb. 70 96
EPN-300 ....--....-. 1/ lb. 66 70
Metacide* ................. 1 pt. 71 98.
Genitol 923 ............. 1 qt. 64 37 67
No. 883 ............ ..... 2 Ib. 62 31 60
Ovotran (K-6451) .. % lb. 68 34 64
Emulsive oil** ....... 1 gal. 61 21 15

Parathion omitted.
** Wettable sulfur and parathion omitted.

The high infestation on March 28 was probably favored by
the dry weather that had prevailed for about 3 months (January
had 0.69 inch of rainfall, February 2.98 inches, and March 0.73
inch), and by the application in February of a nutritional spray
containing zinc, copper, and manganese.
Between April 4 and May 9, 9.9 inches of rain fell, nearly
half of it the first five days after spraying. Emulsive oil gave
the best control under these wet conditions. Neotran, No. 883,
Genitol 923, and Ovotran gave 40 to 50 percent reductions in
infestations in spite of heavy rains. Sulphenone, Hypozene 70,
and EPN-300 were used at half the concentrations at which the

VOL. XXXV, No. 1 MARCH, 1952

same materials were used in our experiments in 1950, when
they looked very promising. Apparently the concentrations were
too low for good control in this year's rainy season.
Since the infestations in the trees treated with the three
last-named materials and with Metacide were so high on May 8,
these trees were eliminated from this experiment and were set
up in a second experiment. They were resprayed on May 9, as
shown in Table 2, which also gives the results of the tests.
Metacide was not used after the first experiment, because it
showed no value for control of citrus red mites.
MAY 9, 1951.

Quantity of the com- Percentage of Leaves
Miticide mercial product per Infested on-
100 gallons May 8 June 12
Sulphenone ....- 4 lb. 89 18
Hypozene 70 .........-. 1 lb. 96 59
EPN-300 ..........-.. 1 lb. 70 12
Aramite-15W --... 21% lb. 98 11

At the concentrations used Aramite-15W and EPN-300 gave
excellent control. Between May 9 and June 13 only 3.91 inches
of rain fell, and 2.82 inches of this fell the third week after
spraying. In our mite experiment last season azobenzene (Hypo-
zene 70), at the concentration used, gave the best control of all
the new miticides used, but this year it reduced the infestation
to only 59 percent.
This season emulsive oil gave immediate and the most last-
ing control of the citrus red mite of any of the materials used.

Spencer, Herbert, and Max R. Osburn. 1949. Experiments on control of
the citrus red mite. Fla. State Hort. Soc. Proc. (1948) 61: 95-101.
Spencer, Herbert, and Paul A. Norman. 1951. Experiments on control of
the citrus red mite (purple mite). Second report. Fla. Ent. 34(1): 3-5.





The American grasshopper, Schistocerca americana (Drury),
commonly referred to as the bird grasshopper, has been present
for a long time in most areas throughout the South but only
rarely in damaging numbers. Injurious outbreaks have been
restricted to the sandy upland localities extending from southern
Florida northward along the ridge and fanning out into northern
Florida, southern Georgia and Alabama.
Occasional reports of grasshopper damage have been received
from Florida and Georgia for many years past but injury was
usually restricted to widely scattered areas and to small portions
of fields. Numerous reports of serious destruction of corn and
other crops in north central Florida and south central Georgia
by American grasshoppers were received by agricultural workers
in June of 1950. Surveys of the affected area in Alachua and
surrounding counties in Florida by representatives of the Agri-
cultural Experiment Station and Extension Service at once re-
vealed that the grasshoppers were much more widespread than
in former years, the insects were extremely numerous over
relatively large areas, and they had caused material damage to
late corn and peanuts.
The causes of this extraordinary abundance of S. americana
in south-central Georgia and north-central Florida during 1950-
51 are difficult to ascertain. Popular local opinion attributes
the unusual numbers to the mild winters of 1948-49 and 1949-50.
Some credence can be placed in this belief, as the official Weather
Bureau Station at Gainesville, Florida, did not record a minimum
temperature of freezing, or lower, during the winter of 1949-50
and there were only two minimum readings of 32 or lower for
the winter of 1948-49. Although the authors did not evaluate
the importance of parasitism, it appeared to be a very significant
factor in some areas. Since the several areas of highest parasite
abundance were located in low-ground situations, and since

'Florida Agricultural Experiment Station Journal Series, No. 56.
Associate Entomologist, Florida Agricultural Experiment Station.
SEntomologist, U.S.D.A., Agr. Res. Adm., Bureau of Entomology and
Plant Quarantine.

VOL. XXXV, No. 1 MARCH, 1952

temperatures are usually 3 to 5 degrees colder than on high-
ground, we wonder if the previous mild winters could have been
a deterrent to the development of parasites.
Another factor which could well be of some importance is
the tremendous increase in acreage of winter cover crops grown
in the area. Oviposition occurs most frequently in fields which
were under cultivation the preceding year. There is but little
tendency to oviposit in pastures but early instars are found in
these areas; however, such fields have always been situated close
to a "laid-out" cover crop field.
The grasshoppers were considered of sufficient importance to
warrant study and investigation. Two main phases of investiga-
tions were explored; namely, biology and control. The informa-
tion in this paper is restricted to results of the studies and
observations made on biology.
This insect has a life history somewhat different from the
majority of grasshoppers. It overwinters as an adult and lays
its eggs in March and April, while most other species lay their
eggs in the fall and overwinter in the egg stage. There are two
generations a year. Hereinafter, to avoid confusion, when refer-
ence is made to the first or spring generation, it concerns those
individuals which hatch during April and May from eggs de-
posited by females which live through the fall and winter
months. The second or summer generation consists of indi-
viduals which hatch during August and September. Adults
developing from these nymphs are present during the fall and
winter months and are occasionally referred to as the overwinter-
ing generation.

The eggs of S. americana are light orange in color, smooth,
widest in the middle and tapering uniformly to both ends.
Measurement of a series of 25 eggs gave a range in length from
7.14 to 7.59 mm., with an average of 7.56 mm.
Since these biological studies were made incidental to control
investigations time did not permit us to rear individual speci-
mens to determine the number of nymphal instars. It is the
opinion of the writers that there are six instars. This is based
on measurements and morphological differences, such as the
number of antennal segments and the size and shape of the wing
pads. In addition, several first instar "clusters" or "groups"


found in a peanut field were caged in the field and observations
made involving development, type of damage, and habits.
The first-instar nymphs when newly hatched are 6-7 mm.
in length. They have a slender, fragile looking body and a large
head. They are pale green in color with a distinct black mid-
dorsal line extending the length of the thorax and abdomen.
The antennae have 13 segments and the eighth segment is long-
est. The eyes are large and dark reddish-brown in color. The
posterior femora are usually faintly marked on the exterior side
with three black horizontal bars. No trace of wing pads is
present in this instar.
The second-instar nymphs average 12-13 mm. in length. The
head continues to be relatively large and bears prominent dark
eyes. The antennae usually have 17 segments but on occasion
there may be 18. Wing pads are now present as small but in-
distinct lobes. In this and succeeding instars there are two
general body colors. One is predominantly black and the other is
predominantly green. The dark individuals, while not totally
black, are heavily marked with black or dark red lightly inter-
spersed with yellow or green. The green forms are light green
in color with one prominent black mid-dorsal line extending the
length of the head, thorax and abdomen. Specimens of both
colors usually have the horizonal black stripes on the exterior
side of the posterior femora, although it is more pronounced in
the dark individuals.
Third-instar nymphs average 16-18 mm. in length. The
antennal segments vary in number from 19 to 20, with the latter
number occurring most often. Wing pads are present as distinct
triangular flaps or lobes with the point of the triangle directed
obliquely ventrad. The color pattern of the third instar is the
same as in the second.
The fourth-instar nymphs have an average length of 22-25
mm. and the antennae have 22 segments. The tegmina and
wing pads are inverted in this instar (see Shotwell). The point
of the triangular pad is now directed obliquely dorsad. The
pads are appreciably larger and the venation is now distinct.
Fifth-instar nymphs average 27-30 mm. in length and have
23 or 24 segments in the antennae. No changes in the color
pattern take place.
The sixth-instar nymphs range in length from 35-45 mm.
The antennal segments number 26 in this instar.

VOL. XXXV, No. 1 MARCH, 1952

This is a large, rather slender-bodied species. The body
length of the females is often 2.3 inches and of the males 1.5
to 1.7 inches.. The overall length of the females measured from
the tip of the head to the tip of the tegmina when closed is often
2.7 inches, while that of the males is 2.1 inches. Adult speci-
mens when freshly molted are very handsome creatures. The
general body color is a reddish-brown with a slight vermilion
tint. The tegmina, thorax, and abdomen have numerous brown
patches. A prominent light yellowish mid-dorsal line is present
on the head and pronotum and extends posteriorly to midway
of the length of the closed tegmina. The basal half to three-
quarters of the posterior or anal margin of the tegmina is a light
yellowish color. This light band is broadest just beyond the
point of attachment of the tegmen to the body, begins to narrow
gently about midway of the posterior margin and fades out com-
pletely on the distal third of the tegmina. When the tegmina
are closed these light margins form a continuous stripe with the
mid-dorsal stripe on the head and pronotum.
It was noticed that collections of adults made during August
and September 1950 always included specimens of two general
body colors. In addition to that described above the general
body color of some specimens was a light straw-yellow with the
darker area being brown. Considerable speculation existed re-
garding the reasons for the two color forms. As the season
progressed it was noticed that the reddish-brown forms were
present in increasing numbers. With the approach of winter
the yellowish colored individuals began to disappear. A collect-
ing trip made on February 10, 1951, in Alachua County, Florida,
netted an estimated 8000 specimens and all were of the dark
reddish-brown color. About the first of March it became appar-
ent that the adults, especially the males, were changing in color
from the maroon reddish-brown to a bright yellow interspersed
with brownish areas. The color change in the females became
noticeable a short time later. As these individuals grew older
the yellow color became brighter and all traces of the reddish
color were lost. The times of the color change correlated with
the development of the gonads and it is believed to be associated
with the maturation of the testes and ovaries. In general, the
changes in coloration found in S. americana are similar to those
found by Uvarov in S. gregaria. The presence of both color


forms at the same time in the adult population during August,
September, and October is due to an overlapping of generations,
while that in the spring is due to the variation in time of the
occurrence of the color change in different individuals.

FOOD PREFERENCES.-One of the most astonishing features
observed in this grasshopper is the relatively small amount of
food eaten by the adults. Evidence of their feeding could be
found wherever the grasshoppers occurred, but this was sur-
prisingly light in view of the enormous numbers of the insects
present in some areas. Evidence of feeding was observed in
corn, oats, peanuts, rye, and lupine fields and they have been
reported damaging tobacco and small vegetable plantings. It
was found that much of the damage to rye and oats attributed
to the American grasshopper was actually caused by certain
small, ground-inhabiting species. In tests where young tobacco
plants were offered as food to caged S. americana specimens the
plants were fed on sparingly. Other crops injured by American
grasshoppers include hairy indigo, sugarcane, hegari, and other
grain sorghums. In addition to these cultivated crops, feeding
by these grasshoppers was observed on the foliage of oaks, wild
cherry, holly, myrtle, ground oak, guinea grass, ragweed, and
dog fennel.
HABITS AND BEHAVIOR.-The overwintering adults prefer
"laid out" or idle fields with a good weedy undergrowth inter-
spersed with numerous tall weeds or bush type trees. In numer-
ous instances adults were found in large numbers along the
margins of wooded areas in which the stand was light enough
to allow considerable sunlight to penetrate to the ground. Ob-
servations indicated that the insects never penetrated densely
wooded tracts.
Adults move freely, but aside from the movement from the
breeding areas to cultivated fields there has been no indication
of migration. Although rather short flights of about 20 to 50
yards appear to be the rule, the grasshoppers may fly consider-
able distances when disturbed. During the winter months there
is a regular daily movement of the insects from the trees and
shrubs in the tree line to the open fields in the morning and a re-
turn to the trees and shrubs in the afternoon. Sunlight and
temperature are probably the most important factors in this

VOL. XXXV, No. 1 MARCH, 1952

movement. Although the reason for this movement has not been
determined, it appears that the insects might be seeking a warmer
or drier situation than is found near the ground. It has not been
learned what proportion of the grasshopper population makes the
daily journey from trees to field and return but it appears to be
The activity of these insects can be correlated with tempera-
ture and sunlight. It was found that on bright sunny mornings
the grasshoppers could be flushed readily at temperatures of
45-50 degrees F., while on cloudy mornings they did not flush at
temperatures of 62 degrees F.
It was observed on a number of occasions during the fall
and winter that the grasshoppers might be extremely numerous
in a field or other localized area one day and several days later
it might be almost impossible to find any of the insects there.
When first observed it was believed that this might be due to
movement from place to place resulting in a fluctuation in the
population from day to day. Although some type of migration
has not been ruled out, there is reason to believe that the grass-
hoppers were present all the time but were simply being over-
looked. The coloration of these insects presents an excellent
camouflage and readily permits them to go unnoticed on cool,
overcast days when they remain quiet. These insects also have
the habit of moving to the far side of branches, twigs, stems of
grasses and weeds or other resting material so that they face
their pursuer. Invariably, as the observer moves the grass-
hoppers move so as to keep on the opposite side of the object on
which they are resting.
When disturbed the adults take to flight. The flight is
initiated with a coarse rustling sound and it is usually down-
wind. If the disturbance is downwind, a grasshopper may make
a short flight into the wind but after a short distance it usually
turns and then flies with the wind. When the insect comes to
rest on an object it immediately moves to the far side of the
twig and draws its posterior legs into a jumping position.
The American grasshopper is a sun-loving creature. All
stages of nymphs and adults in cages located so as to be shaded
during a part of the day were usually found resting on the sunny
side of the cage. The tendency to congregate in sunny areas was
most evident in the field. In areas with heavy cover the grass-
hoppers tended to congregate by the thousands along the roads
and in open plowed areas. On numerous occasions hundreds of


individuals were observed on the sunny side of a single tele-
phone pole.
Early instar nymphs of both generations are gregarious and
invariably group together on plants in the immediate vicinity
of the hatching area. Often more than 100 first-instar nymphs
were taken with a single sweep of an insect net. When dis-
turbed they dispersed quickly but regrouped in a cluster usually
within 30-40 minutes. As the season progressed it was noticed
that some individuals remained in clusters until the third and
fourth instar, while others dispersed over the field in the first
and second instars. For a time it was believed that the dark
forms mentioned in the description of the immature stages were
the individuals remaining in groups while the green forms
tended to scatter. Later, however, both color forms were found
in the groups and among the dispersed forms.
HATCHING.-The first hatching of eggs in 1951 was observed
on April 23; however, numerous second-instar nymphs were
observed on April 26, which suggests an earlier hatch, prob-
ably about April 20. On April 25 hatching of twelve egg masses
was observed, the majority of these occurring between 9 and 11
A.M. Close examination of several of these hatching masses
disclosed that the upper eggs hatch first. The chamber in which
the eggs were deposited was cylindrical with firmly packed sides.
It was nearly perpendicular to the surface, approximately two
inches deep, and extended to within about one-fourth inch of
the surface. The first nymphs to hatch break through the sur-
face crust and the remaining nymphs emerge through the same
opening. When the nymphs appear at the surface they have
already shed the amnion from the anterior portion of the body
and after emerging they complete the task by shedding the
amnion from the posterior portion of the body. The hatching
areas and emergence holes are readily located by the accumu-
lated cast amniotic skins.
With but a few exceptions all hatching of first generation
nymphs occurred in areas that had been out of cultivation since
the previous summer. Infested areas were not uniformly popu-
lated. In some instances restricted spots in a field or around
abandoned homestead sites literally would be alive with grass-
hoppers, while adjacent areas were relatively free of nymphs.
Most of the areas in which first generation nymphs were found
in largest numbers were on relatively high sandy ridges having

VOL. XXXV, No. 1 MARCH, 1952

a moderately heavy cover of weeds. These areas were, for the
most part, the same fields in which large numbers of overwinter-
ing adults had been found.
COURTSHIP AND COPULATION.-Copulation of overwintering
adults was first observed on January 24, 1951, at Gainesville,
Florida. On March 1, 2, and 3 numerous copulating pairs of
adults were observed in Alachua County, Florida. Mating con-
tinued throughout the Georgia-Florida area as late as June 1.
Courtship-like actions were observed with both males and fe-
males appearing very excited. The action is usually initiated
by the males at a distance of approximately two feet from the
female. The male rustles its wings and darts forward about
one-fourth of the distance to the female and then remains quiet
for several minutes. This is repeated three or four times before
the male finally takes position on the back of the female. The
female usually does not move from the original position but does
flutter the wings in response to the male's actions. Frequently
other males were present and these were observed jostling the
mating pairs in what appeared to be an attempt to dislodge the
male. Most of the mating females collected had distended
abdomens and well developed eggs.
OVIPOSITION.-The first evidence of oviposition in the over-
wintering generation was observed on March 16, 1951, when
a female was found with the tip of the abdomen in the ground
apparently laying eggs. Three days later female grasshoppers
were observed ovipositing in one of the rearing cages. On
March 19 seventeen egg masses were found along the margin
of a winter wheat field in Alachua County, Florida. Of the
seventeen masses found, eight were recovered whole and exam-
ined. The eggs were placed in cavities about two inches deep
and were loosely held together by a gummy, frothy material and
the top of the hole was plugged with this material. The eggs
were not placed in any sort of a pod and the outer eggs were
in direct contact with the soil. The eggs are deposited in the
lower 11/2 inches of the hole. The number of eggs per mass
varied from 76 to 100, with an average of 85.
Oviposition continued in the overwintering generation until
May 7 but became increasingly rarer after the first week of
April. The peak of egg deposition probably occurred during the
last two weeks of March.
Oviposition by a first or spring generation female was ob-


served first on July 23, 1951. Examination of several egg
masses showed that the range in number of eggs was similar
to that found in the overwintering or second generation. The
average number of eggs was 83.7 per mass. Oviposition of first
generation females was last observed on September 1; however,
it is assumed that oviposition took place at later dates, since
mating pairs were observed as late as September 17, 1951. The
peak of egg deposition probably occurred during the first two
weeks of August.
NYMPHAL DEVELOPMENT:-First or Spring Generation.-As
mentioned earlier, the first first-instar nymphs were observed
on April 23 and the first second-instar nymphs on April 26.
Third-, fourth-, fifth-, and sixth-instar nymphs were first ob-
served May 3, 9, 15, and 21, respectively. Adults of the spring
generation were first observed on June 7 and at this time oc-
casional first-instar nymphs were still present. Adults of the
second or overwintering generation were still relatively numer-
ous at the time when sixth-instar nymphs of the spring genera-
tion were first observed. After that the number of second
generation adults decreased rapidly, although some overwinter-
ing adults were noted as late as June 26. Observations during
the spring and summer indicated that there is a definite over-
lapping of generations. On June 26 it was estimated that 50
percent of the first generation had reached the adult stage and
by July 30 approximately 95 percent were adults. Sixth-instar
first generation nymphs were last observed on August 27.
Copulation of first generation adults was observed first on
July 13. On July 23 and 24 large numbers of copulating pairs
were observed in the Alachua County area and mating was last
observed on August 27.
NYMPHAL DEVELOPMENT :-Second or Summer Generation.-
Hatching of the second generation began the latter part of July.
First-instar nymphs were first collected July 30 in 1951 and
July 31 in 1950. First-instar nymphs of the first generation were
last observed on June 13. Thus, it seems reasonable to assume
that any first-instar nymphs observed July 30 would necessarily
have to be of the second generation. In addition, the assump-
tion that these first-instar nymphs belonged to the second gener-
ation becomes more valid when one considers the large number
of mating pairs and ovipositing females observed several weeks
earlier. Second-, third-, fourth-, fifth-, and six-instar nymphs

VOL. XXXV, No. 1- MARCH, 1952

were first observed August 8, 13, 21, 27 and September 5, re-
spectively. On August 21, when the first fourth-instar nymphs
were collected, it was believed that the peak of hatch had oc-
curred. Adults of the second generation were first collected on
September 12. At the time the first second-generation adults
were collected individuals of all instars were present but the
majority were in the fourth instar. Some adults of the first
generation were also presefft, so that again adults of both gener-
ations were present at the same time.

During the last 10 days of January and the first two weeks
of February 1951 robins in large flocks were observed feeding
on the overwintering adult grasshoppers in several areas in
Alachua County, Florida. The robins congregated in extremely
large numbers in pastures and fields which were heavily infested.
Observations indicated that the robins broke off the wings and
legs before eating the insects and this observation was sub-
stantiated by finding large numbers of these remains in the areas
where the birds were numerous. Other birds observed feeding
on grasshoppers included mocking birds, crows, and red-headed
woodpeckers. Similar observations were also made in Georgia
during this same period. In several fields where the hoppers
were extremely numerous balls of regurgitated material were
found which consisted almost exclusively of grasshopper remains.
The material was characteristic of the hawks but the species
could not be determined.
On April 5, 1951, numerous overwintering adults collected
in Florida were dissected and found to contain from 3 to 10
dipterous larvae. Specimens of the larvae sent to the U. S.
National Museum were identified by W. W. Wirth as Sarcophaga
sp. (probably lambdens) of the family Sarcophagidae. On July
23 and 24 observations made in Brooks County, Georgia, disclosed
that nearly all adult American grasshoppers leaving the ground
were pursued by from 6 to 12 or more flies. Specimens of these
flies were collected and sent to the U. S. National Museum for
identification. The flies were identified by C. W. Sabrosky as
Sarcophaga sp., of the general group Acridrophaga, which are
parasitic on grasshoppers. A specific determination could not
be made as all of the specimens collected were females and males
are required for identification.


On March 20, 1951, a coleopterous larva was collected on a
grasshopper egg mass in Alachua County, Florida. This larva
was fed on S. americana eggs in the laboratory until April 21
and during this period eight eggs were consumed. Since the
egg supply was exhausted the larva was killed and sent to the
U. S. National Museum for identification. The specimen was
determined by O. L. Cartwright as Conoderus sp. of the family
Early in May 1951 blister beetles, identified by W. H. Ander-
son as Epicauta sp. (probably floridensis Werner) and bee flies,
identified by W. W. Wirth as Systocebus vulgaris Lw. of the
family Bombyliidae, were collected in areas where nymphs of
S. americana were abundant. In several instances it was felt
that colonies of grasshoppers could be located by the presence
of these insects in their vicinity. No larvae of either of these
species were observed feeding on the eggs, but since it is known
that they do feed on grasshopper eggs it is considered very likely
that the eggs of S. americana constituted a large proportion of
their diet. This belief is strengthened by the fact that both
blister beetles and bee flies were reported more numerous this
year than usual.
During August and September second generation nymphs
were observed to fall prey to several species of web-spinning
spiders. Also during this period several species of mantids were
observed to capture and feed on nymphs.

To Drs. A. N. Tissot, Florida Agricultural Experiment
Station, and J. R. Parker, Bureau of Entomology and Plant
Quarantine, for reviewing the manuscript and offering valuable
suggestions; to Messrs. G. W. Dekle and H. S. McClanahan,
Florida State Plant Board, and Andrew Fraser, Bureau of Ento-
mology and Plant Quarantine, for bringing to our attention
interesting developments in the field, informing us as to centers
of infestation and for confirming many of our observations.

Blatchley, W. S. Orthoptera of Northeastern America. Nature Publishing
Co., Indianapolis. 1920.
Criddle, Norman. The Life-History of Schistocerca lineata Scud., Can. Ent.
1932, Vol. 64, pp. 98-102.

VOL. XXXV, No. 1- MARCH, 1952

Duck, L. C. The Bionomics of Schistocerca obscura (Fabr.), Jour. Kans.
Ent. Soc. 1944, Vol. 17, No. 3, pp. 105-118.
Griffiths, James T., and W. L. Thompson. Grasshopper Control in Citrus
Groves in Florida. Proceedings Fla. State Hort. Soc., 1947, pp. 80-86.
Howard, L. O. Damage by the American Locust. Insect Life, Vol. VII., pp.
Shotwell, Robert L. Life Histories and Habits of Some Grasshoppers of
Economic Importance on the Great Plains. U.S.D.A. Tech Bull. 774.
Uvarov, B. P. Recent Advances in Acridology-Anatomy and Physiology of
Acrididae. Anti-Locust Bull. No. 1. Anti-Locust Research Centre.



Carefully Executed

Delivered on Time





(Continued from last issue)

Mr. Bruce called for a report on the Auditing Committee.
The Auditing Committee composed of the Secretary and C. R.
Stearns, Jr. recommended the treasurer's report be accepted.
Motion passed.
The Resolutions Committee, consisting of L. A. Hetrick,
Chairman, George Merrill and L. S. Maxwell, submitted the
following resolutions:
1. That the Society extend its thanks to Mayor L. H. Reeker and the
City of Winter Haven for extending their hospitality to visiting ento-
2. That the Society extend its thanks to Hon. Nathan Mayo, Mr. Phil
Lucie, and Mr. L. C. Hughes for making the facilities of the Citrus Building
available for the meeting.
3. That the Society express its appreciation to the local committee on
arrangements for the many hours of work that contributed to the success
of the meeting. This local committee consisted of the following members:
J. T. Griffiths, Chairman, W. L. Thompson, Miss Francenia E. Fisher, R. M.
Pratt, C. R. Stearns, Wayne Dean, and William Simanton.
4. That the Society express its appreciation to the various manufacturers
of insecticides and application equipment for their excellent exhibits.
5. That the Society express its thanks to the Polk Packing Co. and the
Citrus Experiment Station for contributing delicious orange juice.
6. That the Society express its appreciation to the members of industry
who contributed to the success of the hospitality hour. Contributions were
made by the following companies. American Cyanamid Corp., California
Spray Chemical Corp., Flag Chemical Corp., Geigy Co., Niagara Sprayer
& Chemical Co., Pennsylvania Salt Mfg. Co., Rohm & Haas Co., Shell Oil
Co., Stauffer Chemical Co., Superior Fertilizer Co., Swift & Co., U. S.
Phosphoric Acid Co., and Velsicol Corp.
7. That the Society express its appreciation to the men who have served
so efficiently as officers during 1950-51.
President Bruce called for a report of the Nominating Com-
mittee consisting of W. L. Thompson, Chairman, M. C. Van Horn,
and W. C. McDuffie:
President -..---......--.-..--..---.....-....... -John W. Wilson
Vice President .--..-.--.......- ----------- .. J. T. Griffiths
Secretary .....-- --------....... Milledge Murphey, Jr.
Editor --..-- --....------..... ..--................Lewis Berner
Asst. Editor -..-.......-..........................-. W. P. Hunter
Executive Committee --..-----..... D. O. Wolfenbarger

VOL. XXXV, No. 1 MARCH, 1952 35

President Bruce then turned the chair over to the incoming
president, Dr. John W. Wilson. Dr. Wilson thanked the society
for the honor that had been bestowed on him.
President Wilson then appointed a committee to work on in-
creasing the membership of the society. This committee consists
of: Wayne Dean, Chairman, W. G. McDuffie and G. W. Dekle.
The business meeting was adjourned.

September 5, 1951
Balance on Hand, December 2, 1950 .........................$. 98.83
From Registration fees (Sanford) ............................. 77.00
From barbecue ticket sales (Sanford) .......--........---- 103.50
From subscriptions to The Florida Entomologist ...... 71.00
From membership dues ..................-------..........--- 250.50
From authors for reprints, etc ...........................------------ 179.70
From sale of back issues --..--------...........---..... ...------------ 63.25
From advertisements in The Florida Entomologist .. 457.75

Total .....--........------- ........-------- -- --- ...------- $1301.53
To Pepper Printing Company ..........................-....-- ......$ 877.16
For barbecue (Sanford meeting) .-.....--.................... 92.84
To U. of Fla. Duplicating Department, Programs,
Letterheads, etc. ......---.-- ...-..-..........------- 33.39
Postage .--... ...-------.------------............. 32.23
Envelopes U. S. Postoffice ......-........... ...........------ 36.32
Addressograph slugs ..........--.......... .......... 4.97
Bank Service Charges ..........-- ......-.........--...--- 5.50
Miscellaneous, P. O. Box rent, etc ....................-----------..... 8.40

Total .....--..........---.. ---------....----$1090.81
Balance on Hand, September 5, 1951
Cash ....---------......... ..........--.......... -$ 2.68
Florida National Bank ......-----.. ..------................ 208.04

Total ..----------................. ------ -----$ 210.72
$ 210.72

Assets not shown page ad ................--........---...- $ 10.00
Liabilities ...........--- ......-.. ----. ........................- N one
Respectfully submitted,
Business Manager



Abedus immaculatus, 21
Aedes sollicitans, 48, 52-53
taeniorhynchus, 48-53
Anopheles quadrimaculatus, 131
Aphid trap records, 6-8
Argia ulmeca, 116

Bacca, list of species, 93-95
Beck, Elizabeth C., article by, 135-
Belostomatidae, 19-21
key to, 157
Belostoma, 20-21
Benacus griseus, 19-20
Bueonoa, 23-24
Burrowing mayfly, reproduction of,

Cerioides signifera, 95
Chamberlin, F. S., article by, 6-8
Cheilosia prima, 95
Chrysogaster nitida, 95-96
Chrysomphalus dictyospermi, 54
Citrus red mite, 83-88
control of, 3-5
damage by, 83
Corixidae, 24-29
key to, 158
Culicoides floridensis n. sp., 135-136
Cynorhi'na notata, 96

Dictyospermum scale, control of, 54-
Drake, C. J., article by, 137-145

Empusa, 84
Entomology, Florida State Board of
Health, Division of, 46
opportunities in, 71-74
Entomophthora, 83-88
fumosa, 84
grylli, 84
method of infection, 84-85
muscae, 84
Epistrophe, list of species, 96-97
Eristalis, list of species, 97-99

Erythrodiplax umbrata, 116

Fisher, Fran. E., article by, 83-88

Gerridae, Key to, 154-155

Heliophilus, list of species, 99-100
Ifemiptera, aquatic and semiaquatic,
17-29; 146-161
habitats, 146-153
key to families, 153-154
Herring, Jon L., article by, 17-29;
Hesperocorixa, 25-26
Hexagenia limbata, egg deposition
of, 62-65
egg, rate of fertilization, 65-66
egg, incubation of, 66-69
egg, production of, 60-62
reproduction of, 59-70
Hoffman, R. L., article by, 15-16
Hunt, Burton P., article by, 59-70
Hussey, R. F., article by, 137-145

Johannsen, O. A., article by, 116-117
Julus americae borealis, 15
americanus, 16

Lepthemia, 116-117
Lethocerus uhleri, 20

Malaria, 43, 44
Malaria control, responsibilities of
engineer, 134-135
responsibilities of entomologist,
responsibilities of epidemiologist,
Malaria in Florida, 131-135
Mallota, 100
Medical entomology in Florida, 43-47
Membership list, 118-122
Mermacrus ruficrus, 101
Meromacrus acutus, 100-101
Mesogramma, list of species, 101-103
Mesoveliidae, key to, 156

Metasyrphus, 103
Microdon, list of species, 104-105
Microvelia, 137-145
braziliensis, 143-144
costaiana, n. sp., 142-143
fasciculifera, 140-141
marginata, 139-140
mimula, 144-145
pexa, n. sp., 141-142
summers, 138
venustatis, 138-139
Milesia, 105-106
Milliped, name of eastern spirobolid,
Minutes of 33rd annual meeting, 30-
Minutes of 34th annual meeting, 162-
Mixogaster breviventris, 106
Monoceromyia tricolor, 106
Mosquitoes, 43
control of, 45
salt marsh, 48-53
Mulrennan, J. A., article by, 43-47
Musca domestic, 84
Myiolepta varipes, 106
Myzus persicae, 6

Nepidae, 17-19
key to, 156-157
Norman, Paul A., article by, 3-5
Notonecta, 21-22
Notonectidae, 21-24
key to, 157-158

Palmacorixa bueonoi, 27-28
Paragus, 106
Paratetranychus citri, 83-88
Parhelophilus, 106-107
laetus, 107
species, 107
Pipiza, 107
Plea striola, 24
Pleidae, 24
key to, 158
Polybiomyia pedicellata, 107
Provost, Maurice W., article by, 48-
Pseudococcus citri, 84
Psilota, 107

Psorophora confinnis, 48
Pterobosca floridana, 117
fuscicornis, 117
incubans, 116
macfiei, 117
mollipes, 117
species, 117
Purple mite, control of, 3-5

Ranatra, 17-19

Shade-grown tobacco, green peach
aphid infestations of, 6-8
Sigara, 26-27
Spencer, Herbert, article by, 3-5
Sphaerophoria cylindrica, 107
Spilomyia hamifera, 107-108
Spirobolus dolleyi, 16
marginatus, 15-16
spinigerus, 15
Spray machines, comparative costs
in use, 114-115
Syritta pipiens, 108
Syrphidae of Florida, 89-113

Temnostoma, 108
Tenthredomyia abbreviata, 108
Tegragoneuria sepia, description of,
notes on, 9-14
Thullbery, H. A., article by, 114-115
Trichocorixa, 28-29
Tropidia albistylum, 108-109
Tubifera, 97
Turner, Frank N., 34
Typhus fever, 46

Van Horn, M. C., article by, 71-74
Veliidae, key to, 155, 156
Volucella, list of species, 109-111

Weems, Howard V., article by, 89-
Westfall, Minter J., article by, 9-14
Wolfenbarger, D. O., article by, 54-

Xylota, list of species, 111-112

Yellow fever, 43, 44

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