The bermudagrass mite Eriophyes cynodoniensis (Sayed) (Acari: Eriophyidae) in Florida with reference to its injury sympt...

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Title:
The bermudagrass mite Eriophyes cynodoniensis (Sayed) (Acari: Eriophyidae) in Florida with reference to its injury symptomology, ecology, and integrated control
Physical Description:
x, 182 leaves : ill. ; 28 cm.
Language:
English
Creator:
Johnson, Freddie Allen, 1938-
Publication Date:

Subjects

Subjects / Keywords:
Eriophyidae   ( lcsh )
Grasses -- Diseases and pests   ( lcsh )
Genre:
bibliography   ( marcgt )
theses   ( marcgt )
non-fiction   ( marcgt )

Notes

Thesis:
Thesis--University of Florida.
Bibliography:
Includes bibliographical references (leaves 169-180).
Statement of Responsibility:
by Freddie Allen Johnson.
General Note:
Typescript.
General Note:
Vita.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 000408124
notis - ACF4538
oclc - 02276501
System ID:
AA00003527:00001

Full Text










THIE [ 0 "'j .AGR.A. S MITE
ER OPI'HY S cvi0';N i (SA'MY ) (WART : ERIOPHYIDA )
I -Ft fiR R!F R.LENC: TO ITS
URY SYMprMOGi' COLOGY. U INTEGRATE COT' OL










By

FREDDI ALLEr JC"NSON


A DISSERTAFON PR1 S! TL TO VOL GROJAE COUNCIL OF
THL UNIVFR TY Ofi FoK! j'A
IW ;'ARTIAL FUbL i- :L ;;NT OF Kl UI RL[: EM ETS FOR THE-





UNIVERS IY y ? o I,,nK1 p^


1975























DEDICATION


I dedicate this dissertation
to my wife, Peggy.














AC KN ( I; L FDG LV. E NT S


My dee:pe t and most sincere ih ik s goe-s to Dr.

i. 1. Cromroy, Chai rma.n of my supervisory conm i ttee for

hI u ; irin eff orts and 9 u i dan ce du r in g my doc.ra

program.

Appreciation is graTcfu!ly extended to Or. Mil-

ledge Murphy for his total concern in n;m and y ovcn:vl

training in pursuit of this degree. I ad also indebted

to the other members of my supervisory committee, Drs.

S. H. Kerr and R. E. "Caldw 1 for th advice r nd training

that I received from them during the puo's-it of this rde-

gree.

A special thanks goes to Dr. W. G. Eden, Chairi m;;n

of the Departrmet of Eintomnol rgy in providing rg me vi tl fi -

nia;,cial help and emprloyment duri,;g this st-dy and f-r his

ccnstan8 interest in me and my devel ope:'t.

Thanks are due Drs G. C. !Hor and 1, A. Reine'

frir tih ir hfelpfuo idei s e:nd for the i ;y aid- tie-y '-n.red

in order to help 'make this research: p) ssib l

Special thfit s o;es s to Mr. Lt'.rv y W..'b i .f Invi ; ,ui

G" f" Co' se for is sp cial Sand p! rs,'al interest rin A.!,is

project and fo'r his providirnl so ;iuc' i thi ay of f; --

i ties fc.r a great deal of this ,'es aT: z.s T. e 'I e 1










extended to tCip supuri ite ,dent ot f c beerwooi G( i and4

Country Club, Pa'l :ain,;r Gc:t Complex, Ro11 ,ing nills Golf

and Country Club, !lel -i n-the--W al Golf and Country Club,

the Bea.chi Club Golf Lourse, Roll inq Greens Golf and Country

Club, and Elmeraal d Hills Go l and Country Clu b.

Thanks and appreciation are extended to Union Car--

bide Corporation, Acri cultura'i Products Division for their

financial assistance to this research project.

Last, bit not Ioest, my love and appreciation goes

to my wife and son whose patience, understanding, and con-

stai;. ercouragzement made this accompli shmont possible.















T/'L F C 'NTLN rs


A Ki; N O IN'L E DG :-11 LNTS ...
ABSTRACT. .. ., .
i NT. f ODUCjOT .. ....
LITERATURE R VIC ..
General iackgrou
Biology and Ecol.
Life Cycle 1 an
E;,vi ;ronme ta;
Habilads rnd s
?hc "ota:&...
TaxCnuoi'c Stts

Descr i pti os
Ga lls and Damage
Disper ion......
Hosts and Vir u:
Control of Eviopl
Che ca ... .

C l tur .



N tri : I' C .... i




1V t-r id1 ard
KResu! l:s and i..
Su in ary .
Mi. tici.en Con ;:r{.
5 i i. ;'odi;citi ii, .


S. .. . ..
nd ... ... ..........


d H bi ts ......... ..
s rns .




a n d D e s c i"i n s ..
d .... .............




of the lP r;-n m





hyi d .
.Pe..ti ns.. i .. .... .
Shyids ............











S.. .. ... ... .

c . .

r.! ;. ..... .. ......
. . .


Page



v i i i
ii
viii


4

4
7




9
9






33

36
39
39
41
4?
46
'8


48
48)

51


'5
5..'













Material and Methods......
Pesults and Discussion....


Summa ry .. ...
Miticide Contro
Introduction
Materials an
Samp!i 1 ng
The Bias
Counts...
Results and
Summary.....
Growth Regulato
Introduce on
Materials anri
Results and
Suimma ry .....
Symptomolo gy...
Some Mistakes B!
Controlling the
Temperatures ..
Introduction
Materials an'
Results and
SumLimary- ......
Mi te Habi tats..
Means of Spread
Asso;cated Ovga
IntrodUctS. on
mate-i al s an
Results and
RECONiEN DA 'O S...


: I: : : : : : :: : :::: : :: :


S Tes t:---Pal!mi r'e .......
. .. .. . .. .. .
SMethods ..................


...... ............. .







SMethods........... .
.15 T s .................
.iscussion..............


Discussion ..............
. ... ..... .. .... .. .... ..
.. .. .. ... .... .. .. .. .. ..
believed Being Made in
Bermudagrass Mite ......




d Methods...............
Discussion................




S .. .. .... .. .. . .
nisms ...................


d Methods ...............
Discussion ..............
. .. .. ..


Control of Other Orgaanisms as a
Control for [Ber udagrass Mite...


109
116
116
116
117
120
120
133
134
134
13C
140
14 4


. ..... .... ... .. 1 5 1


Page

59
67
70
71
71
71
74
75
77
78
80
80
80
80
85
87
87













dc~uctian of Overwintcrivg Habitats ............. 152
CONCLUSYNS ..........~......................... 1511
FUTHER[:i Mi NDP RESEARCH......................... 156
AP? P P L N%............................ 158
LI FFPATUFE CITE ...... ............................. 169
BIO APPUICAi SKETCH :............................ 18'











































vi i








AU"-> tc of n seria"on Pr cntrd to t r- Ldua .o ncv
o lh" Ib *'ee' 4' ,, ,r.-foriJ in Partial Ful"f. i nent o, f tfhe ,equ',irem'ts
for t:c ) ree of DoctAor of Phi ;.... y


T!iE b .' rj'.iAGRASS MITE
ri',C-... W.. : cy:,dw irnD i (SAYED) (ACAR : FRIOPHY10AlF)
-IN 1L U;1DA WiTH REURENNCF 10TS
INJURY SYMPT!..'.GY, ECOLOGY, A l INTEGRATED CGcNT.C




Fr dd i e1 len Johnrsori

June, 1975


Chair-~,II ; !H3rvey L. Cromnroy
.Mjor Dep-jrt.llt: E ntoinooigy o an-i Nematol ogy

Th'e Der,.,idagrass m'it, E-i jhl1ies c:ynodonimnsis (S.vd)

{Ac&-ri Ero'phy"ie). was fir st reported *a3s a pest of Berfmnuds-

,rsCs Ct;r oo C l..ct1lon (L.), n Florida in 1962. This study

' V:s! concerned wvith the ident I fi cation of" mite in.Jury and

.sympi ;'I o '.y under-staind i rng the ecology of the organism, and

devoe:'i c_ ::.:i nt.1 of cont .ro U techn iqu c

Gras s injed .. this ; ite o ee rll p dresses

thrJc'ugh tfh fo'oi 1 oI' 19 symptoms: loss of color, leaf twist-

i;:, aid" s';rtenicing of int o.'no.Jes,, fornmati on of "fan" shaped

::> s.':C by e'.''eme i terncdal horti-ni ng fol lo ed by

.b;cr!;ir1 riowtI tLi; t r sul ;d i n c bba ehadc- 1i ke structures

k ,::.un s rusett intend sif,/ying of rosettiw until individa'al

1:.,v, ; bc -!;e sh- ., th i>pik -i k g ri w t h s andl ul i Ir a tel

.ic-l .th of tih'.: giyra- i1l de s .and s+tolons. SThes syiptoiCIs werel'

d-** ir : i,' it: -.^ ri-n I *; i *j s f '.*r) rCp( I .


V i i










Several vari ie- s of C. drity1 on (L e w.re stuuid

for ihere;.C resistance Lto nite injury. It wdas found un~ier

laboratory and fie d c(i on itions t:At r.-peated i nocul nations

v:wi i; tc s fuied o producer inrjurious s y p to'4 s or to

est-i; i s ii t infe, tstat ons on Tifgreen (328) or Tifway

il''. B th of theb s~ varieties ihad C. t.ransvcs P'rNsis D a'.,y

in their l ine e .

A series of compoui~ds were tested for mite control

under field conditions, and aldicarb and pheri~ariphos gave

significant mite control. A similar series of tests with

arthropod growth regulators yielded no significant control.

Temperature measuremenLs were recorded in differ :,.nt

turf microenvironments on tees, fairways, greens, an d rough

on di ferert golf courses in several areas of the State to

deteri ir.e if a preferred temperature existed for miite in-

festations. Results indicated that E. cvnodonievnsis occurred

in lare, populations between 800 and 111.5F .

Fie'd observ-;tio:,s indicated mites were found to in-

habit certain l oc t' s n Q on golf cor.rses. I If present, mites

cou.! ble dett ~ cted ;i, e o-re or nmore nF the fcllowii9g niches;

1) areas where cl ose nmow'ing wa s not practical such as bunkers,

sand tap lips, or atlon walls of buildings or other structures;

(2) aion', f nc es; (3) slopes leading to bodies of water; (4)

ar;.u~r Lc .-es of Crees, shrubs, or other plants or obstacles;

(5) along ir!'lry ns of the fairways that border roughs; (r) areas










where n-titcides may not be applied due to difficulty in

ma~euvering spray equipment.

A pest management program of cicse mowing, utiliz~-

tion of hand sprayers, bare cultivation, and herbicidal

treat:er:ts Lheloed to destroy the niches preferred by the

mites ain reduce serious injury.

Mites were found ii- large numbers in rosettes and

were believed to be spread by mowing or scattering these

structures by maintenance equipment, golf clientele, wind,

ar.t running watir.

A modified Tullgren apparatus was used in sampling

grass harboring mite infestations from different geographi.-

cal areas of Florida to determine if predatory nite types

could be found in association with the Bermudagrass mite.

The most widely distributed predacious mite found was

Neocunaxoides andrei (Baker and Hoffman) which may be a

gredt help in reducing mite infestations. Based on the

research, a number of suggestions were made regarding an

integrated control program for the Bermudagrass mite.











;i hai rman n














I NTkO rUCTI ON


Tur'fgrass differs from nmot agriculti'1 crops

sin sit is ino consumed but is in a constant state of

rel'en; catir :i wihei properly e;iaintained. There are pre-

sently 94i4,534 acres of maintained turf in the S'c o of

Florida (Meyers 1974). Florida has more than 20 mili ion

annual visitors, and golf plays an important role in at-

tractinr; many of these visitors as well as pI oviding a

source of year-round recreation and in-come to the citi--

zerns of the st ate.

Florida leads the nation in new golf course con-

struction averir'ng approximately 30 new courses per year.

Presently there are 640 active courses (Horne, 'prsonal

con urii cation 1974) Theoretically, if all thI fairways

wer e laid end-to-end, golf could be played around tne

entire coast lin e of F .ori dA, up i 1t length acnd across

the 'arh :nde, total oF oVt 2,000 miles. I!y 1985, 831

cours,-s ari'i, predicted for the state. Golf courses are

almost eitirely planted to some variety of Ber'mu:dagrass.

]n acdditi n, 'man; y h': e lawns ceie"t.;iries, so d product on

f'ar ;S !iotel .s, hotels parks a rporIts, and various rin ti -

tut io,. are partil1y or totally p iantcd in 5 er ;;udagk s,










a rinternance c ostsy for gq1 F cou :.es alone are conserva -

tiveiy estiria -ed at 60 million dollars per year,

According r, to r,,apny worker in tie industry, the

Bermuda grass s.ite is the third most important or;fd nsmi.

the other two hein n the weed Poa annuraL ,- r! trne nematode

comp lex. Eva'uating the m-i t on a more ccrscervati ve

basis, it is stiel easy to see that it is a major problem

and has the potential to Decome even more severe. The

need for this study was brou( ht about by complaints of

extensive daiiiage to turf and particularly to golf courses.

The 'ermudagrass stunt mite Eriophyes cynodoniensis

(Sayed) (Acarii : Eriothyc'ae) w s first reported in ulorida

in 1962, at Petrick Air Force Base, Cocoa (known as the

Cape Canavvre'! Area), It was believed until 1964 to be

concentrated on the eastern Florida seacoast but has since

been found over the entire state and is active 12 months

out of the year in areas approximately south of Palm Beach.

The mite occurrence appear to Le seasonal in the middle and

no-th part of the state with infestations being heaviest

in the spring and summer months .

The n;ite was first found in the U.S. in Arizona

ini "1 59. Soon after this, California, Nevada New Mexico

and Texas reported nites during g the 195 S-1.62 period.

Georoia reported the pest in 1962 but it has not as yet

become Ps tabL ihed Currn t'i report s have it that the mite










has been founu d in Aolat ; ::6 but they are u:!official. Accord d-

ing r, !'eifer- the ;ite is alsu found in Afust "a ia anrid Rhi-

d esi v ith ac r co 1 is : bsliving it to be nati ve to Africa,

There h, !Ieen rmu cih speculation as to why the static between

Arizona nd Florid: horve not reported any problo ; with tili.

p est.

Dr Hervey '.rrm-oy Acarol ogi st-[ntoiaol og ist at

the Univerr-ity c.- -1 or da, cnd myself were asked to initiate

studies ti'it wo'uild u tima tely lead to some new approaches

to co-ntreo i 'easures; of the mite as well as understanding its

behavior ~r nd ecology.

h"ih ; orpi ism is considered a true mite bt differs

fi on mos' t other m-tes in thal it possesses only two pairs

of Ir'; 'S i Cr: T'J ,t the usual four pairs. It belongs to

the fai'; iy Erio:phy id a arid consequeni ty falls in the cate-

lory of or: ;f th sir 1lls t arthropods known. They are

smal le" iia ; ,;ny em tiodes, being only 200 ',icrons in

length in i..e e'utri. stca e. The egg is approximately 1/3

three *si: th' a l t Is ard is cle.r in color with the

fis L/: ,c stw.ge b'i 2?/3 the size of adults and more

it in colr. T;he d~;lts 'e worm -shapcd and creCm

to a lii ',. -vcy 1.lw color














LIl!ERA1UPE REVIEW


neraI B ckiround


T'e eriiphyid nites commonlyy known as al mit;s,

bl ister me r, 'urJt mites and bud m ite s) ar the snmallest

animals hearing an exterior ske eton with which the agri-

culturist has to cointend. They can deformi and russet

leaves and fruit. Tihe. also cause bud b lasting and dis-

tortec growth of plart1 and ;f 7 lowed to go uncontrolled,

frequently :: cause p! art da th.

I:, genre thieve are t,,? typsz of Oe'-iiopi.y'id

(KeiTfer 1952); th wrmr:-'ikc -cft species knnwn as gall

or bud ;ites. w .hichi.do all tincir feeding and breeding under

cov:',"r; rnd t.h. rust nites, which arc broAder, cunkier,

ofter. rctl.r t'l ;. ',i I.;h tergi 's to protect them against

Sthe ic. 1 i i t es i c or: This latter type

ee's c.d b:c. r 1 s ir. c e --1 se.f siirf cecs and.

.i thi few rx:.ptio s, :ornsti.t t the rust writes or l af

Sa r rh r; t .,

Tle s:'all1 si:' of ti.Ihc er'i c.phyids in rel nation to

"the q .' n t.i y of ei oo host a.s p .sible the de Ivelop-

:,',:.;t f vev lar e popul tion C he abi ity of the

in,+l' '; i l n uid.;r *fevo a;-[ n iI ,on tr ha!ch
+. I +AI+ ,4' ,* a,4t coU it-' ,










pass through two nymphal stages, ad l: c co:oe ; g-la .y :

adult in seven to ten day: is another rCesc f r deae

popu a cio ,s of tnis arthropod.

E-iophyvic to a great extent lack control evc;

their :eans of di stlributioni and pust travel y cH 'onc

since they deperd o n wind, in sects, bir ds, a i!d other fio'ms

cf car-iers for their dispersal.

Eriophyids exhibit a very inti:im; .te mit -host r e-l--

tionship, charactri zed by considerate host specificity.

Gall formation is another aspect of this intimacy, but

the majority of the mi ts belonging tc to h fallly depcn d

on natural botanical formations of their hosts and cause

(.o ro tice- blI e injury. They, wi th few excep'ions rema i

in locations where feeding ard breeding can take place

whenever temperatures and conditions permit.

According to Hassan (1928) tn: cecido1ogists con-

sidered galls.and fuzzy spots, novw kno-wn to be formed by

the eriophyid 3ites, as fungi. Re:i ,lur recorded observa-

tions of wor-like animals in galls found on leaves of

lind': n trees in I ;37 and hpI it'ved thles. galls to be caused

by these animals anc thought then:- to e be the larvae of some

small insect.

In 1833, TLmpiln c.,
found mites which were seen iy Iatlrille to be rel:t.d to

.th,. enruis Sarco t s, In 3 F'tee discarded the belief









th t gai!; were caused by funqi and advanced the idea of

a relationship between mi Ls and galls.

D y gs, in 183 1, found mites in the galls of leaves

of in den rand white willow and considered theim. as larvae.

He found eggs inr the gall e but supposed that the adults

laid thei, and subsequently escaped through the opening of

the galls. in 1850, Von Siobohd also considered the mites

as larvae and suggested that they possibly propagated

asexually and the adult form was yet to be found. He gave

the name Eri ophyes to these mites.

Dujardin, in 1851, examined two forms of galls on

linden ana willow that had been studied by Duges; found

the mites and observed eggs within their abdomens. He

concluded that they were adults, contrary to Duges' opinion,

and named them Phytoptus.

Scheutinr in 1857, examined blisters on leaves of a

pear tree and found mites which he declared to be the larvae

of another mite occasionally found on the outside of the

leaves. He confirmed Duges' views and argued that what

Pujardins thought to be ee'gs were nut.ritive organs. Sc,.e'.tin

further described the so-ca!led larvae and regarded the adult

.s an oval Len:der, quiclk-i; oving mite found on the larvae

'leaf s-urface alnd proposed Lhe nae' TyphloJriomus belongin

to the family (Gai,;asidao) Durini th:; same year (1857),

Pagenstecher disagreed with Sch!-utun's vi ,e s and insisted










that the so-called larvae were truly adults -nd gave

names to several of them and placed thpmi in the genus

Phytopitus.

Landoi s in 8 4 s tu ied Phyt! opt. ,i _i i_ Pg t.

and showed the t.re nature of the mite. He gave a de-

scription of its internal anatomy and life history, some

of which turned out to be erroneous in some insLtances.

Many disioutes concerning morplol ogy and taxonomy

continued among the workers of the period. In America,

the true nature of these mites was not known until Shirmar,

in 1869, recorded the species Vasates quadripes.

Walsh, i 1864, working on galls of i'.':i ca failed

to observe the mites and thought the casual agents were

cecidoiiyids. He believed all galls to be caused by gall

gnats or sawflies.

Garman, in 1883, was the first in the United States

to study the 6riophyids ;ore coreiully anni described several

species.

Nalopa began work in 1087 ai;d continued to lead

i nvci stioatiions in the study of the erioFhyids.

Kecfe bieg:an hi s w;or:k in t l 1i30's and has con-

ti sued to clad the field in the ta/,nomy of eriophyids up

to the present ti Ce.

2 3 d nd h>nloj d

li+ssar (1928) di o:ie of the '. -.; th:irouih studies
of the e.iophv ids, His "/~,u k covered irmay 'reas from; history










to internal morphology in which the biology of the

E.lJio ,rhvc s tristr i atus (Nal ) was i ncluti ded. Much of tie
subs quent work of Keifer, Sl'yklhis, ii1 son and rmn'y

others has been based on iassan's o i q i nal study.

Keifer (1933) reported thaws nearly e' l erio.hyids

found in the field were -femals. He also described Ace: '

Ltulipa (i'.) and Tfond that the female would lay from 3 to
25 total eggs and nid so over a ten day period.

Keifer (1942) reported some eriophyids produced

two types of females. ie concluded that a female type

mite-called a protogyne resembled the male and would re-

produce shortly after becon!ing an adult which he referred

to as a sp-ing or summer fsmrm. The second fe:,~ale type

was called a deutogyne and wvas consider-ed to be the over-

winterin'. or vagrant form. The latter type was found to

be morphologicallv unlike the forme.r. In species having

the deutooyne'forms, the male does not overwinter.

According to acarologissts the erioplhyids may or

may not have both deutogynes and protogynes, and univol-

tine species ;.ay have only deutcJ;gye '

Roivairon (194S) ime;ti n.:-d t at eriophyid gad l

producers had more than one stage. He reported that the

two difTfreret stacgcs had often behct ;.is, a ken; f or two dif-

ferert speci :c;. She vtch nk (1 952' r e 1 ;. sex ual d -

morphism in female Tri' _et,_ cc 3 i ..; !e.hi .s .ruI N.!Sp. am. a pest










of juniper seeds. The fynee; were characteri c.ed by

suii r and vinLi'S furm Th i ss species w;: found to be-

lon to the oldest gcnus of erioph. ids whi,:h was t!he be-

(inri .ng stage of plant mite paras"it a .

Shev tc hia enko (1970) found that in vrirkiing with

t!'e older gaq l mite EJr o.ioL.r es S. (Sen-so st:rictus) laevi.

(Iie-pa, s19! ) that the ieutogynes were associated with

the onse t of seasonal pherno: ena i r tne ho'.t plant caused

byadecreasinqg photoperiod. Hall (1967) reported the fol-

lowning three different systems that occurred in Criocphyid

life cycles: (1) simple--one type female; (2) complex--

protogyne and deutogynes; and (3) unnamed--ovovivparous

protogynre. Alam and Wadud (1963) found that sexual de.-

morphism is evident in adults only.


Life Cycle and Habits

There are approximately 1,000 described phytopha-

gous lit es belonging to the Eriophyoidea, and although ecch

spec;e- app,-ears to be highly adapted tc its particular eco-

logical niche there seems to be a great deal of similarity

i i in'ist life cycles.

Ramsey (1950) reported that most eriopiyid life

cycles are similar and relatively simple. Krasirskaya

(1'60) icound thc apple Ja!l mite went through h its entire

!i-e cycle in 30 days with the egg stage lasting 10 day:.

CB '(r' > s (19Y'!) research on eriophyids showed th~.t most









g il makers underwent twIj ge;:erations per season. He

's o reported ihat in studying the ga m'tes of Poland

that the female mite usuiily lays one egg per day and

most of the overwintering; females strtdied appeared to be

fecundated, Boczek compared host plants of 65 eriophyids

front; Poland and 126 from Califorria ancd ,only species of

the following genera Oxypeleurites. P~Lhyn_ a~phtoptus, Di tacus

and Eptinmerus had similar life cycles,

In Aceria, Phytopjtus, Phyl_!ocoptes, and Eriophyes,

there are species causing various types of damage and which

vary distinctly in development, and some of which are free

living. For example, Alam and Wadud (1963) found that tho

litchi mite, Aceria litchi K., lai-J eggs singly at the base

of hairs constituting the erineum >.. the leaf surface.

Incubation of the eggs took 2.5 days, the protonymph stage

lasted 1.5 days. and the deutonymph stage took 6 days in-

cluding 2 instars, Pre-oviposition time of the female was

1.5 days and adults lived only 2-3 days; therefore the total

life cycre wds completed in 13-18 days. This is consider-

ably different from other reported life cycles. Baker and

Neunzig (1970) worked on the biology of the blu .berry bud-

mite and reported it -Look only 15 days to complete the

entire life cycle at 19"C. Rosario and Sill (16l 4) found

that the fem;ei3 wh! at curl nite, Aceria tulipac (K.), "laid

from 3 to 25 eggs over a pe;'iod of 10 days and eggs hatched in 3 to

5 days at 48'5"F, but that little or no hcatchin, ociculired it3 36~l'"F .










Eggs hatched in 2 days at 7-/5+'F. Oldfield et al. (1969)

working on Eriohyes earg1ent _L K. found it laid 50-60 eggs

within the gall caused by the mite.

Stern'licht (1970) reported the citrus bud nmite,

Aceria sheldoni (Ewing), took 12-23 days to go from egg to

egg, with 2-14 days usual ly required for egg hatching at

optimum conditions. The average number of eggs laid per

female was 5 with a range of 4-8. If females were fed on

buds during their larval stage, the egg laying increased

to an average of 8 with a range of 5-19.


Environmental Response

Hassan (1928) found that dryness and heat are the

main stimulating factors of eriophyids. Dryness will

force mites to leave galls and is thus favorable to the

distribution of the mite. Summer heat will cause them to

be active and.excessive humidity will cause them to be

almost motionless. Hassen reported light had little ef-

fect but concluded that since the gall former live inside

the structure that they are probably negatively phototropic

and become positive as they leave their galls. Hassan re-

ported that the mites are hardy, and E. tristriatus can

live 10 days at 20"C in a dessicator without food. Costa

and Gonclaves (1950) reported that the tomato fungus

mite Ace 'ri cladopitilhirus (Nal ,) attacked tomatoes more

frequently i n the dry season, but that the infestation









of mites was nevertheless high in the rainy season.

Kevoc'kian (1951) reported the "white mold" disease of

tomatoes (which is so-called because of the white erineum

produced by the mite) caused by Eriopjyes (Aceria) cladcph..

thirus (Nal.) is particularly active at low temperature

and high humidity.

Dinther (i951) found only female Eriophyes gracilis

Nal. on raspberries at 17-20C. Jeppsen et al. (1958) found

that the citrus bud mite, A. sheldoni, populations increased

in warm weather and declined with low relative humidities

and/or unusually hot weather.

Rosario (1958) fund that high relative humidity

in the micro-environment may be the factor in establishing

large A. tulipae populations in the field but information

of this phenomenon is sparse. Rosario (1964) found that

A. tulipae survived without food and water for 30-40 hours

at 36+5F and.would live for 3 months in petri dishes at

36+55F. It was found that these mites survived temperatures

of 120F in the laboratory.

Reed et al. (1964) found that the optimum tempera-

ture for laboratory rearing of the citrus rust mite Phyl_!o-

copruta cleivora Ashm. was P80F. It was also found that

A- tulije appeared to need high relative humidity within

rolled wheat leaf in order for the mite species to sur-

vive. Stern icit (1970) repo rted A. sheldoni egg hatching










was most successful at 250C and 98% R .I., and that hatch--

ing was greatly reduced and dwarf larvae emerged at 1ow

R.H. 's (35-40%). The minimum threshold for embryonic

development was 9C and for life cycle completions 12 .5C

Barke et al. (1972) found that the peach silver

miit Aculus cornutds (Banks) K., was active at 22-31C,

while nymphs were active up to 32.5C but become sluggish

at 24C and inactive at 21'C.


Habitats and Overwinteri ng

It is a common belief among rite workers that many

plants would yield an unreported mite species if a worker

had time to survey, at the propel' time of the year, the

numerous plant niches where mites dwell.

Smith and Stafford (1948) found ihe grape bud mite,

Eriohyes vitis (Pgsc.), to overwinter under the spur bud

and to migrate to the leaf axil of new buds. Putnam (1939)

maintained that the plum nursery mites, Phyllocoptcs fockeui

Nal ., and TKT were stimulated to hibernate in various pro-

tected plant parts by hardening of the foliage. Dinther

(1951) found E. gracilis to pass the winter on and within

auxiliary buds of raspberries. Stafford and Kido (1952)

found the grape bud mite to occur outside the bud en ne~:

browt.h during late April and early May. After the month

of May, 98% of the mites were found inside the bud. Kido










and Stafford (19:5) reported that grape bud mites were

found in heaviest numbers in the first 10 bas l buds with

the seventh having the largest numbers. As the mite pre-

pared to overwirter, it crawled up the canes to the elongate

shots.

Painter and Schesser (1954) found A. tulipae to

live in the protected folds of wheat. Wilson (1955) found

an unidescribed Eriop hyes adhering to the bud scales, or

and under rudimentary leaves, buds and new growth of p lums

and peaches. Kantack and Knutson (1958) found A. tulioae

living protected deep in the wheat leaf sheaths. May and

Webster (1958) reported the grape bud mites was impossible

to control at certain times due to its habit of living in-

side the bud.

Krasinskaya (1950) found that 70-80% of the female

aople gall mites, Eriophyes (Aceria) mali (Nalepa 1917)

Liro 1951, hibernated in the third to fifth bud scale.

Morgan and Heldin (1960) found the juniper berry mite,

Trisetacus .cucadvisetus (Thormas), livrd within the berry.

Boczek (1961) found free living and gall producing mites

Li b;ernat ng in1 bark rerevices aind species belonging to the

same gcenus were varied in their overwintering habit.

Boczek found doutcgynes overwintering in an inactive state

that could be inl:errupted within the laboratory. Protogyne

female, s w':ref foi'n'J to himern.te more often in the buds.










Shevtchenko (1 S62) found tihe aider gall iiite, E. 1 aev; s,

deutogyne to be associated wi th the onset of decreasing

photoperioris a;nJ the phenomenon it triggered by the mites'

host plant.

Talihouk (1963) found Aceria phi loe corptes (Nal.) to

overwinter as a fertilized adult female inside almond galls.

Baker and Neunzig (1970) found the blueberry bud

mite to have its largest populations in the terminal buds.

Early stages were found only in outer basal scales with

later stages found throughout the bud. Oldfield (1969)

found the prunus finger gall mite, E. emarginate (Nal.),

to overwinter as females in old buds situated at the base

of the branches. Upon breaking hibernation, the female

laid 50-60 eggs within the gall. Zaher and Osman (1971)

found Aceria mangiferae Saved to hide between bud leaf

scales of mangos.


Phototaxis

Hassan (1928) assumed that eriophyids were nega-

tively phototropic based on their nebits of concealment.

Rosario (1958) found indications that A, t!lipae was nega-

tively phototropic under laborLtory conditions. Hall (!967)

found that under certain circumstances other factors counter-

balanced eriophiyid's response to light, and miites would move

to outer leaf surfaces prior to dispersal. Nault and Styer

(1969) proposed that A. tuli'jp ;e was necgatively or positively










phototactic depending on its physiological state. It was

found that the mite w:as negative under plentiful host

tissue and positive if the plant was undergoing tissue

destruction,



Taxonomiic status and Descriptions


Three species of eriophyids have been described

from Bermudagrass: (I) Aceria noecynodonis Keifer (1960);

(2) Aceria cynodoniensis Sayed (1946); and (3) Aceria cyno-

Joni Wiisnp (1959),

A. cyr-,'onis appears to be a valid species since

it has a 7-rayed claw and an obsolete shield design while

A. cy,,odoni ensis and A. neocynodonis have 6-rayed claws and

distinct shield lines (Fig. 1). A. cynodoniensis was de-

scribed as having the dorsal setae pointing forward, whereas

A. neocynodonis haa the dorsal setae pointing backward (Fig.

2). In the 1970 publication "Common Names of Insects ap-

proved by F,S.A. ," the common name for A. cynodoniensis was

Bernmudagrass mite, In 1971, Newkirk and Keifer following

the Zoolo1cical Code redesignated the type for the genus,

iL.Lv S This thPn moved the species A. cynodoniensis
into the :onus Erionhyes. In a letter dated December 13,

1973, to Dr, Crowr-ey Keifer indicated that the species

neoc'vodon`;is is in syrnonv,;y with cynodoniensis which he

ha. ter! c d the er uiiJ grass node miite. therefore, the










correct scientific name for Ithls mite is Erior)hycs cyno-

doniensis (Sayed) and the correct common name is Bermuda-

grass mite and in neither Bermudagrass Stunt Mite (Cromroy

and JFlohnson, i 1972) nor Sermudagrass ride mite (IKeifer, 1973).

Although Keif r and Newkirk have re-designated the

species of the genus Ae genus A geinus ErioFphyes. this

is not the final taxonomic status. Many acarologists, and

in particular the Russians, are dissatisfied with this

arrangement since most of the major pest species are in

the genus Aceris and have had this generic name over the

past 15 years. Lindquist (1974) and others are currently

appealing to the Zoological Board of Nom-enclautre for a rul-

ing on this problem. In addition, there is still some ques-

tion as to whether the mite Sayed described is synonymous

with the mite Keifer described as Keifer has not yet for-

merly published a synonymy.

There'is also confusion about taxons above the

generic level (Lindquist, 1971), The current status, there-

for, of this species is:

Class Arachnida
Subclass Acari
Order Acarif T o; es
Suborder Prostigmata
Supei cohort Prr.i.Iat.
SChort Tet.r1podi lna
Super F 'mily Eriophycidea
Famiily ,ri rT.hyidae
G-inus i 2, .[ ,,)
S'peci'es c,noioniaen: if- (Sayed)










itescri unions of the 8ermuda rass Mite

To further eiiborate on the taxonomic confusion

surrounding this species, the original descriptions of

Stayed (1916) and Keifer (9c60) are presented.

0rig ina description of: Aceria cyno-
donr.tsi s new species. Female: 210.9 p,
i rcl udIi r cppi t l.:n: 43.S broad; colour
whitisi; cylindrical; rostrum 19.1 p long
with two pairs of setae; dorsal shield some-
what conric&l with five longitudinal lines and
fine sculpture. Dorsal setae 30 P, projecting
forward. Leg I 41 p including feather claws
(5.4 Vi) leg 11 40 p, claw not knobbed. Feather
claw 6-rayed, ending distally with a single
medium ray. Thoracic setae I 6.5 v, II 15 ,
III 21 ii; lateral setae 30.5 i; first ventral
setae 36.5 u; second 6.5 p third; 2.4 u; caudal
setae 60 i,; genital setae 10 p; genetalia 24.6
longa ;i 12.3 p broad. Ventral skin structure
the last four posterior, sternal divisions with
elon gated tubercles.

Distribution: The mite is found in lower
EgypL ana around Cairo. Upper Egypt has not
been surveyed. Sayed (1946).

Original description: Aceria neocynodonis,
new species Neocynodonis, with a 6-rayed feather-
claw (Fig. 17 l ay be distinguished from other
known grass investors by the clear shield lines
(Fig 1) the rounded micro-tubercles (Figs. 1 and
2) set ahead of the rear ring margins, and by the
narrow ribs on the genital coverflap.

Female 165 p 210 1 long, 40 p thick, worm-
like, whiLtish-cream color. Rostrum 23 p long,
dow;,curved (Fig. 3). Shield 36 V long, 36 p wide,
semicirciilar anteriorly. Median line in shield
design present on posterior 2/3, admedian lines
siinu.'te diverging to rear; two anterior submedian
lines, the first sinuate, abruptly curving out-
warn'd well ahead of dorsal tubercle, a separate
ii! i running toward rear of admedian line; second
sus:.edi.i1 short curving from anterior margin to










.bout 1/3 on first admedian; line of granula-
tions running to rear margin from second sub-
median; rear part of shield and sides set
with granulations and short dashes. Dorsal
tubercles 23 p apart; dorsal setae 45 p long.
Forelegs 30 p long; tibia 5 p long, with seta
8.5 pi long centrally placed; tarsus 6 p long;
claw 8 p long, tapering, curved down (Fig. 5);
feather claw 6-rayed. Hind-legs 26 p long,
tibia 4.5 u long, tarsus 5 p long, claw 8.5 p
long, caw 8.5 p long. Coxae granular, junc-
tion line between interior coxae paralleled
by lines of granulations; first coxal tuber-
cles a little ahead of lir.e through third
tubercles. Abdomen with about 65 rings, com-
pletely microtuber:uiate, the microtubercles
rounded and ahead of rear ring margin. Lateral
seta 35 p long, on ring 7 behind shield, first
ventral seta 32 u long, on about ring 21; second
ventral seta 7 p long, on ring 38, third ventral
on about ring 4 from rear 27 p long. Accessory
seta 2,5 u long. Female genitalia 18 p wide,
10.5 p long; coverflap with about 10 narrow
longitudinal ribs; seta 8.5 p long. Type local-
ity: Brawley, Imperial County, California. Col-
lected: June 7, 1960, by Vincent D. Roth, Farm
Advisor. Host: Cynodon dactylon (L.) (Graminae-
Chlorideae), Bermudagrass. Relation to host: the
mites live in the terminal leaf sheaths where they
cause stunting, a witches broom effect, and gen-
eral decline of the grass. Type material: as
well as mites in liquid there is a type slide and
three paratypes. Additional localities from which
this Rernudagrass mite has been received are:
California-Westmorland and El centro, coll. by V.
E, Roth, June 7, 1970 Westwood, collected June 13,
1969, by F. S, Morishita. Burback, collected
June 21, 1969, by Morishita. Arizona--Phoenix,
collected September 3, 1959, by J. N. Roney. and
submitted by D. M. Tuttle of the Arizona Ayricul-
tural F;,ieriment Station. Tucson, collected
August 29, 1960, by G. M. Butler (Keifer, i960).


Galls and Damage

Accordi g to Keifer (1952), there are two types of

eriophyids; those that feed on the leaf surface like the
































Fig. 1. Scanning Electron Microscope Photograph of
Eri hyes cynodon iensis (Sayed) Showing
Rounded Microtubercles (1075X)





















































- !E:'.- I %bt
;i- 1L~~


F


...I .*z



I, *
1 l


















Fig. 2, Scanning Electron Microscope Photograph
Showing Backward-Projecting Dcrs!a Setaa
and Dorsal Shield Lines (2100X)





















Fig. 3. Scanning Electron Microscope Photograph
Showing Downcurved Rostrum (2100X)





23













f 4k
t1





















Fig. 4. Scanning Electron Microscope Photograph
of Feather Claw Showing Rays (11,500X)



















Fig. 5. Scanning Electron Microscope Photograph
of Feather Claw (11,500X)





25




Cp





citrus rust mite, Phyl locptrta ol ci voiIra (Ashm,. ), and

those that are bud mites and gallmakers. Only the damage

caused by the latter type will be discussed.

Galls on plants were first noticed more than 2,000

years ago. Neiswander (1954) reported that gall' production

was dependent upon statmuiatiCj of plant cells i r meristLe-

matic zones.

Andre (1954' found that many specific names have

been given to members in the family Eriophyiidae solely on

the basis of the nature of galls formed by the mite. A

gall on a new host often is considered justification for

a new specific name even when the mite causing the gall

had not been seen.

The majority of the work on new species and subse-

quent hosts has been done since the early 1950's. There

appears to be a constantly growing list of new hosts re-

ported. Many.of these host plants are not presently con-

sidered economic species. However,the budmites and gall-

makers do cause a great deal of damage to plants that are

of economic orC aesthetic value to man.

Smith and Stafford (1948) reported that Eriophyes

vitis (Pgst.- the common erineium mite, was associated with

stunted cane growth Kido and Stafford (1955) further

reported the extensive damage on grapes caused by E. vitis

and said the wite was capable of causing severe injury and










even death of the plant. Smith and Stafford (1950) re-

ported the fol owing seven basic injury symptoms of grapes

caused by mite infestations: (1) short basal internodes;

(2) scarification of the tark; (3) flattened canes; (4)

ziczagged shaped shoots; (5) dead overwintering buds;

(6) barren canes; and (7) \:itches broom growth of new

shoots.

Jeppson and dePietritonelli (1353) were the first

to associate abnormalities of lemon frit and foliage with

presence of the citrus bud mite, E. sheldoni,in California

in 1947. However,similarly deformed lemons were known in

Italy in 1646. Numerous articles have appeared since con-

cerning the damage inflicted on citrus by this mite.

Another eriophyid of economic importance is the

blueberry bud mite. Darrow et a!. (1944) found that the

scales on blueberry buds infested with mites maintained a

persistent rosette appearance. Bailey and Bourne (1946)

found the feeding by the blueberry mite, Eriophyes vaccinii

K., caused buds to be gall-like and often reddened and swol-

len at the base of the buo scales and on the stems. This

mite has created severe problems to the blueberry industry.

A. tulipae was named by Keifer in 1938 when it was

fond on tulip bulbs. It also attacks onion and garlic

bulbs and causes them to dehydrate. The mite moves into

the protected leaf folds of these three hosts and causes









twisting, curling, stunting, and subsequent yellow mottini .

In severe infestations, this species causes permanent dis -

figurement of plants,

A great deal of research has been done on A. tuligae

since it was later proven to vector wheat streak virus, and

red streak kernel virus of corn, The mite was given the com-

mon name of wheat curl rite. This mite will be discussed

under Hosts and Virus Relati Lonship.

Aceria ficus (Cotte) was reported by Ebeling and

Prince (1950) as causing an uncommon type of injury to figs.

ihe terminal buds were bleached. and abcission of immature

terminal leaves coupled with stunting of growing shoots

resulted from mi te i :festations,

Collingwood and Broc. (1959) reported a gall mite,

Phytopt.,us (Erioohyes) ribis Nal attacked black currants

and caused foliage distortion and prol feration of side

shoots at the expense of terminal growth. The mite was

found to invade the buds and suppress flower development.

Phi illp (! 963) reported Eriophyes (Phytoptus) ribis (Nal.)

to cause thick rouid galls on black currant branches and leaf

spots, as well as cortical galls (at the point where the

shoot. branches from the stems), on several species of plums.

Thresh (1963) reported that the malformation on black cur-

rants was c li ed "false reversion." E. ribis has caused

a great dea 1of damage on currants (especially in Europe) and

a great deal of research has been done there on this mite.










Sakscna (1942) reported Erioghyyes prosopidis (Nal.)

caused galls on Prosopis spjici ra I.

Burkhill (194,8) reported witchesbroom on willows

as being caused by Eriophyes trir :dictus (Nal.); he also

reporLed that jals had been reported as far back as 1907

and noted 11hat o',ly mi;ale trees were attacked.

Eriophyids cause the growth of erinea on many

plants. Lamb (1953) found that Aceria (Eriophyes) lyco-

persici (Wolfensterrn) caused the production of the white

hairy patches on stems and leaf stalks. Sheffield (1954)

reported excessive "hairiness" on stems and leaves of sweet

potato was widespread in parts of Africa. The plants also

exhibited stunted growth, thickening of the stem,and

auxiliary bud death when attacked by a species of Aceria.

Numerous eriophyids attack the bud and early

flowering stages of plants. Muhle and Konigsmann (1954)

found Aceria 'carvi (Nal.) to cause flower deformation in

caraway. When the mite attacked the blossom, no fruit was

set. The leaves also showed deformations under severe at-

tack. Tripathi (1955) reported that eriophyid mites were

the reason for mal formation disease of mangos rather than

deficiency of mineral nutrients as previously believed.

Snetsinger and Himelack (1957) observed mites to

case witchesbroom of blackberry and reported little work

has bpen done on this phenomenon since 1888. Gibson and










Painter (1957) found A, ttlipae to cause ;.heat plants to

become weakened and chiorotic. The wheat leaves curl

and foidedsimilar to the description of the common witches-

broom.

Vereshchagind and Makailyak (1959) reported E.

phloeco-ptes to 6amage plums via galls. Mature female mites

were round to overwinter in galls formed on new growth.

The female would be found in numbers of 100-580 per gall

and would deposit eggs within the gall. All stages of the

mite were found within the gall. Krasinskaya (1960) re-

ported the apple gall mite E. mali te cause a normal leaf

of 250-280 u thick to increase to 350-450 p thick when in-

fested. The mite also caused severe leaf drop.

Agarwal ar:d Kandarami (195P) found that a eriophyid

mite caused gall-like blisters on the inner surface of the

leaf sheath in sugarcane. Severe injury was confined to

the area near-the actual infestation and damage could be

identified externally by leaf scars.

Kuitert (1962) reported distortion on young cedars

caused by Triseteus cupressi (K.). He found the mite to

feed on tissue between the leaf and the stem. Feeding in

this area caused distortion under light infestations and

the needles became shortened and thickened. Severe infes-

tations caused browning and death. Under mite attack, the

internodes did not elongate, terminal growth failed to










develop, and young plants became "bushy" and ro.inrded-i in shape

due t the failure of a "leader" to develop.

Alam and Wadud (1963) found A. litchi attac!ced

young litchi leaves, shoots, and ye.;ng fruit causing erinea

on their surfaces. The leaves were also found to curl,

dry Lp, and drup; and flow:ev" buds would fail to develop, and

the plant would be stunted. Talhouk (1963) reported simi-

lar damage to almonds by A. phloeocoptes. The mite caused

irregular galls around buds and prevented fruit formai.ion.

Mite infestations reduced vigor of trees so that death

occurred within five to six years.

Arnold (1965) reported that eriophyids that origi-

nated in flower buds and occasionally on leaves caused

galls on Hoheria sexstylosa Colenso. Galls over one year

old had weell-developed vascular systems radiating from

original flower stalks. Colonies of mites and eggs were

found in sac-like cavities within the shelter of galls.

Arnold (1968) found mites were responsible for transforming

flowers into galls oi Melic't,,s ramiflora J. R. and G. Forst.

Malior-irations ranged from callus-like or tumor-like assem-

blies to leafy clusters resembling witchesbroom.

Stubbs and Meacher (1965) found that a virosis like

proliferation (w.itchesbroo.m) on lucerne, Medicagi stiva L.,

was caused by an eriophyid mite, Aceria media coqinis K. The

symptoms we-i similar to those attributed to a leafhopper









trans m itted virus. A. medicaginis also caused leaf and

foliage proliferations in lucerne.

Lavender et al. (1967) found that an eriophyid

mite caused Douglas fir trees to have deformed growing

tips. Arnold (1970) reported that galls were formed in

6 days on two species of Calystegra sp. after mite infesta-

tion. In some galls, there was no leaf tissue present as a

result of the powerful morphogenic influence of the gall

mite on the shoot apical meristem. This influence, accord-

ing to Arnold, may depend on the gall mite removing materials

from the host cells rather than adding secretary or excretory

products.

DiStefano (1971) found that Phyllocoptes triflorae

DiStephano formed galls on "Shiro" plums. The cortical

galls were formed on twigs. The mite overwintered princi-

pally in the adult stage but was also found to do so in the

larval and nymphal stages. The galls produced were large

enough to contain 350-400 individuals. The mites caused

early petal fall, slow growth, and death of lateral twigs.

Kant and Arya (1971) found that gall development

on Salvadora persica L. induced by Eriophyes mites was

initiated with the laying of eggs. The tissue structure

of the gall differed from that of normal leaf tissue par-

ticularly in the stomata and mesophyll cells. During the

enclosure process, a cup-like structure was formed by the









mite. Several cells of inner ep id.ermis along the neighbor-

ing cells develop into nm l i inuciecate hair cells. The ad-

joining walls of tie cells surrcundirgc the grow4 : heir

cells disappeared into the cytop!asma. Nuclear 'm igrations

into the bedy of the hair ce'll resulted in a mu1tinucleate

state, The hair cells also contained numerous starch

grains.

Tuttle and Butler (1961) reported that A. neocvvno-

doni s caused damage on Bermudagrass in the spring. The grass

displayed a typical resetting and tufting, i.e. a growth

caused by ah shortening of the internodes and the apparent

stimulationr of excessive plant growth. Heavy infestations

caused the grass to turn brown and die. Eventually, infested

lawns became thinned out which allowed weed growth.



Dispersion


Most workers have agreed that one, if not the major,

means of dissemination of eriophyids is by wind dispersal.

Pzdy (1955) capture A. tulipae at a height of 150

feet and for a range of 1.5-2 miles from the nearest popula--

tion source, This was the first time this species had been

found airborne,

Freeman (1946) found mites in insect bodies at

aitii:udei up to 300 feet, Most mites were found at temp-

erat'.i'ees above 6"'F and at relative humidity readings










below 60L, with wind speeds below 12 miles per hour.

According to Freeman,wind was the most important single

factor in dispersion.

Staples and Allington (1956) reported wind alone

affects A. tulioae dispersal and temperature was not im-

portant. However, the research of Nault and Styers

(1969) indicated temperature had a profound Pffect. Dis-

persal initiation by mites in tests showed when winds were

greater than 15 miles per hour coupled with temperature in

excess of 18C accounted for more than 80% of the number

of mites trapped. The researchers further found under

laboratory conditions that temperature and light affected

dispersal.

Gibson and Painter (1957) found that dispersal was

actively initiated by adult behavior since li 1C0,000 mitts

captured by them were adults. At the same time, all mite

stages were present on the plants and it was concluded that

if passive dispersal occurred it would be expected tnat

some immatures would have been trapped. Further study

showed that mites were not accidentally dislodged from

plants even at wind speeds of 20-30 mph. The researchers

found that wind, temperature, and light affected dispersal.

An increase in temperature from 12-24C resulted in an

eight-*foId increase in numbers trapped. More mites were

also trappoid in light than in darkness. However, photoperiol










effect decreased in magnitude with an increase in tempera-

ture.

Siykhuis (1965) and Staoles and Allington (1956)

mentioned that the eriophyid dispersal by wind was promoted

by use of 1the anal suckers. Gibson and Painter (1957)

found that eriophyids apparently control their dispersal

by a kind of behavior observed in nearly all species.

Eriophyids are capable of holding their bodies perpendicu-

lar to the leaf surface and adhering to the plant surface

by a pair of anatomical appendages found on and within the

anus and called anal suckers. In this perpendicular posi-

tion, they are likely to be blown from the leaf surface.

In addition, A. tulipae will migrate upward and on heavily

infested plants will form "swarms of fuzzy appearing masses"

of mites on the uppermost tips of leaves. There they will

crowd upon one another forming chains of several individuals

attached one to another by their anal suckers. These chains

break apart from the mite mass and they disperse in a cluster.

Gibson and Painter observed that air movement over leaf sur-

faces stimulates:perpendicular standing and chain formation,

a factor which could enahnce wind dispersal. It was also

observed that only adults move to exposed surfaces on the

plant and exhibited "dispersal" behavior except in cases

of extreme and :apid plant deterioration when immature forms

would also move to cuter surfaces.










Holy (1957) fuund that the citrus bud mite, A.

sheldor-i, may be carried froMi tree to tree by various in-

sects.

Gibsotl and Painter (1957) Found that aphids moved

the wheat curl mit2,A. to_'ipae, but that this was of second-

ary importance. They found that aphids often placed mi.es

into volunteer wheat and other host plants. It was found

that the aphids would move into the masses of mites pre-

viously mentioned and the mite chains would break and be-

come attached to the aphid. Upon flying away,the aphid

then transfers the mites to other plants. The greenbug

was the most successful in transporting the mite but the

cc'n leaf, English grainand apple grain aphids all were

found to transport A, tulipae.

Butler (1963) mentioned that it could be possible

that the Bermudagrass mite,A. neocynodonis,could be car-

ried by the wind as well as by insects such as thysonap-

terons, homopterons, and coleopterans.



Hosts and Virus Relationship.


Recent studies have classified approximately i,000

described species of eriophyids as phytochagous (Whitmoyer,

1972). Liro (1940) found 98 species of eriophyids in Fin-

land, In 1947,Liro reported 178 species and Roivainen










('94/ ) added another 53 species to the eriophyiyds of Fin-

land. Roivainen (1950) reported 183 s pe e s of gall makers

in Sweden. Keifer (!952) reprort.ed 186 species from Ca i-



Species of eriophyids that are economical iy damag-

ing, however, are not res;'rictcd to any one geographic

region. Hamilton (1949) reported che blackberry mite,

MAeria essigi (Hassan), to cause the redberi y disease in

New Zealand. Borgman (1950) reported the same disease

and mite as a pest of fruit in Queensland. Lamb (1953a)

reported the tomato erineumr mite to be found worldwide with

the exception of Australia and New Zeala.nd. Zeck (1955)

-ound the dreaded pest of grapes, E. vitis, in New South

Wales. Connin (1956) found A. tulipae able to reproduce

on all varieties of wheat, barley, corn, sorghum, Sudan

grass, and 12 varieties of wild grasses. This led to exam-

ination and discovery of the mite in many previously unre--

ported areas. Wilson (1965) found the pear blister form-

ing mite, Eriophes pseud ainsidiosis Wilson, from the Pacific

coast of the U.S. to Wisconsin.

Several species of important eriophyids occur in

Florida. The citrus rust mite, P. o1eivco:: is presently

considered the number one economic arthropod pest of citrus

in Florida. Bailey and Bourne (1946) reported the blue-

berry bud mite, E, vaccinii, as a serious pest ini N. C. and










Mass, and now Florida has been added (Cromroy and Kuitert,

1973) to the growing list of states where this pest is

found. Attiah (1959) reported finding A. m.ang~iferae a

pest of mango and A, sheldoni, the citrus bud mite, in

the Miami', Florida area. Within the last few years, the

eriophyids have been found to be responsible for more

plant damage than just blisters, galls, witchesbroom,and

other distorted growths.

Slyk:huis (1953) while ,working with A. tultipae as

a pest of wheat reported a close association between its

feeding and transmission of wheat streak mosiac, a viral

disease, and subsequently proved it to be a vector.

Painter and Schesser (1S54) reported wheat grass as a host

of the virus and of A. tulipae. Flock and Wallace (1955)

proved fig mosiac to be transmitted by the eriophyid A.

ficus and further showed the disease was not due to toxi-

genic feeding; Slykhuis (1955) found A. tulipae to carry

the wheat streak virus in all life stages with the excep-

tion of the egg, Wilson (1355) found an undescribed

Eriopljyes and showed it to be a vector of peach mosiac
virus. Slykhius (1956) found A. tulipae to transmit wheat

spot mosiac, a viral disease associated with the wheat

streak type. Seth (1963) found an eriophyid mite to trans-

mit a sterility type virus to pigeon peas. Stubbs and

Meacher (19065) found a virosis like proliferation (witchesbroom)










in luce ne to be caused by A. mecdicaginis. Williams et

1l. (1396 ) found the 3A strain of wheat streak virus to

be tratismiitted to corn by A. tuliip'e. Nault et al. (1967)

found kernC.i red streak of corn, a virus, to be caused by

the u heavy v ct;l mite, A. tuli. re. Slykhuis et al. (1968)

also conFirmed A. tulipae as a vector. Proeseler (1968)

reported damage caused by gall mites and symptoms of virus

to occur together.. Whitmoyer et al. (1972) reported erio-

phyids vector 10 known plant viruses.



Control of Eriophvids


Chejm cai

The his .iry of chemical control of eriophyids has

run the gamut of materials or compounds as has the history

of control of other arthropod pests. Keifer (1946), in re-

viewing the e'co"..," c eriopi;yiGo of North America, stated

that sulfur was effective since it blocked the consumption

of oxygen by ti. .-n.ite.

Daily a.:C Bnourtn (i 94F) obtained control over the

bL1uebe!y bud ; E. vaccinia, with, the dinitro compounds.

Jeppson ( I 17) ." 7 und that DDT. dinitrophenol compounds,

ai-d di-2-et hyl ; .y 1 .Fthalate controlled the citrus bud mite,

A. shel ch I ni 'r ".bbi ng (1947) reported that control of the

pear bud i:iite; :; iopl hye' s py Vrl Pag., centered arc(und critical










timing of spray applications. He found sulfur a better

control than the lime-sulfur combination and the wettahb e

type to be the most effective source. Borgman (1950)

treated the blackberry pest, E. essini, successfully with

sulfur-mineral oil combinations. Roy and De (1950) found

DDT sprays to give good control of Frioi vyes species in

India.

Kevorkian (1951) founa sulfur dust or spray to be

a good control of E. ciadophthirus, the casual agent of the

"white mold" disease of tomatoes in Cuba. Dinther (1952)

controlled Eriop yes aveilanae (Nal.) and E. gracili with

tar-oil plus mineral oil sprays and reported wettable sul-

fer as well as dusting sulfur to give good control.

Lange (1955) controlled A. tui pae on stored garlic

with methyl bromide and sulfur. Zeck (1955) controlled E.

vitis on grapes in New Zealand with lime-sulfur. Mansfield

(1956) used lime-sulfur to control the citrus bud mite, A.

sheldoni, in Australia. Shchegoclva (1958) found iime-

sulfur to control E. ribis on currants. Butler and

Stroehiein (1965) found it was necessary to use diazincn

plus fertilizer to obtain control of the erpmudagrass mite

A. nrijcvnodopris on turf. Either fertilizer or diazinon

alor was not1 sigrificad t over conti ols. Thomas (1960)

found chlorpyrifos to control the Rermudagrass mite in

nine locations in Florida.










Varma and Yvcow (1971) reported the systemics,

aldicarb and phorate, to be effective for 75 and 50 days

respectively in control of the mango bud mite, A. manqi -

ferae, on mangoes. Bindra and Bakhetia (1971) found

demeton-methyl and dicrotophos to control A. mangiferae

for 110 days when applied to the trunk of mangoes, but

found diazinon and aldicerb ineffective. Dimethoate,

phosphamidon,and- demeton-methyl which had once shown good

control proved ITess effective in later tests. Sternlicht

(1971) found 'bebinmyl and mancozeb (two basic fungicides)

to control the citrus bud mite, E. sheldoni. Wafa and

Osman (1972) found phosalone plus triona oil to give good

control when used on A. mangiferae and that acaricide

useage stati.ti->.l 1y decreased the number of stunted buds

and malformed inflorescences on mangoes. Bharadivaj and

Banerjec (1973) found aluminum phosphide controlled Eriophyes

manciferae (Say'cd) on mangoes when shoots and samplings were

exposed within-a sealed chamber.


Cultural

There appears to be cultural methods that have a

rceat deal of` effect not only in controlling eriophyid mites

but also in pr.-.-venting them friom reaching population poten-

tials.
Griffiths and Fisher (1949) found copper-zinc-lime

sprays to cause an increase in rus t mite populations on citrus










in Florida, It has become common knowledge among citrus

growers that refraining from use of certain sprayable

metals and other compounds which leave long term resi-

dues on the leaves helps to prevent mite buildup. Barns

and McCormack (1951) in preliminary experiments found

that the date of pruning effected the severity of injury

caused by a physiological strain of the grape erineum

mite, E. vitis.

Kuenen (1952) found that submersion of black cur-

rant plants in water for 10, 16, or 35 minutes at 45, 43,

and 41.50C,respectively,would control E. ribis, the mite

causing "big bud" disease. Slykhuis (1955) reduced A.

tulipae populations by destroying infested plants by culti-

vation, the mites perishing when the plant were destroyed.

Hamstead and Gould (1957) found mite populations in apple

orchards to be greater in plots of highest leaf nitrogen

counts. High nitrogen was found to enable a benign popu-

lation to become destructive.

Das and Cloudhury (1958) found that thorough prun-

ing of leaves and twigs of eriophyid-affected litchi trees

following spraying kept the mites off during flowering and

fruiting. Shchegoleva (1958) found that clipping infested

buds of the black currant, Ribis nigrum L,, helps control

the mite E. ribis. He also found pruning of root sprouts

on young seedling plus intensive nourishment of the plants

aided in control.










Thresh (196-) found that dipping of black currants

in water for 40, 30-40, 15-20, and 5 minLtes at 40, 4!.5,

45, and 41 ,5"C, respectively, killed all E. ribis gall mi tes

without hurting plant growth.

Wafa and Osman (1972) found that pruning old stunted

and ei-alformed mango iuds, and inflorescence in ,:inter before

newr buds 6r d inflorescence occurred resulted in decreased

A. Manraij'e rae populations and prevented migrations to other

inificescence. This operation was considered an acceptable

agricultural control method since it decreases infestation

levels and gave appreciable yield increases.

Bindra and Bakhetia (1973) also found that pruning

of malformed mango twigs and pIart p.rts reduced A. man-i-

ferae popu nations.


Natural

The literature is quite sparse where the effects

of natural control agents stch as fungi and arthropods on

eriophyid populations are concerned. Keifer (1946) men-

tioned that the eriophyid populations were reduced by

predaceous mites, thrips, various species of maggcts, and

possibly fungi. Painter and Schesser (1954) found thrips,

leafhoppers, and thie iite Parattranychus pratenis Ranks

associ .ted w. ith A, tul ipal on western wheat grass.

Vereshchi ngina and Mikailyal; (1959) reported that

Thysanope e ra an d p rledac ,ot s mites belonging to t ic: family i .ic









Phytoseid:,, and Anystidae play a significant role in con-

trol of .'. Iph!eL c coptes on PLaums. Boczek (1961) in studies

of the eriophyid mites of Poland found the mites of the

family lTydeidae to destroy .ll1 stages of the criophyid;.

Gonzalez-B;chi i (1904) found Lhat organic insec-

tici'des caused death to predators, appreciably in the

Erythraeidae, a ni te family. It was found that huge dif--

ferences occurred in the populations oF the cotton blister

mite, Eriophyes o.ss ypi i, Banks depending on presence or ab-

sence of erythraeids, Alai and Wadud (1963) found preda-

ceous mites to have strong effects on decreasing the popu-

lations of the litchi mite, A. litchi, Muma (1955) reported

that in Florida citrus groves the mites belonging to the

genus Cunaxa were predaceous and the family Tarsonemidae

contained considerable scavenger species.

Baker and Neunzig (1970) while working on the biology

of the blueberry budmites found the predaceous mites Asca

citri Huri hurt, _lyphlod romy is dilbri s (DeLeon) Cheletolnes

berlesci (Oudemans), and three genera of tydeids: Tvdeus,

Micr'otyd.eus, and Triophytydeus. They also found three species

of non-predaceous mites, Daidalotarsonemus jamebakeri Smiley,

Tarsonemls suimimersi Smiley and Tarsonemus adamsi Smiley.

The tarsonemids were found to be the most abundant of all

the associated organi sins. They appeared to he miycopha,'ous

in the field and plant tissues injured by the blueberry mi te










provided necrotic material on which the tarsonemids fed.

Baker and Neunzig also found three species of thrips and

a cEcidomiyid larvae that could be predators.

Zaher and Osman (1972) reported predaceous mites

did not olay a great role in controlling A. mangifera on

mangoes probably Lecause the eriophyid pest hides between

the bud scales. Alford (1972) found a new species of

tarsonemid mite,Tarsonenius aculeus in association with

Eriophyes qallarumtiliae (Turp in) on limes, The tarsonem-id

utilized the irregular growths structures as a food source

and the eriophyids abandoned the galls as their number in-

creased. Bharadivaj and Barterjec (1973) reported that

predatory mites of mangoes were killed along with E. mangi-

ferae when the saplings were treated with aluminum phosphide.

Spears and Yothers (1924) found an unidentified fungus as

a parasite of the citrus rust mite in Florida. Fisher et

al. (1949) reported an epizootic of P. oleivora on citrus

and suspected a fungus as the casual agent of mite death.

Fisher (1950) reported the fungus Hirsutella thompsonii

Fisher may be parasitic on the rust mite. Burditt et al.

(196') further described and verified the relationship of

H, thornpsconii of the citrus rust mite. Leatherdale (1965)
reported that several fungal agents attacked the family

Eriophyidae. -Baker (1968) reported H. thompsonii as a

fungal parasite of the blueberry bud mite. He found









-infected mites to turn greenish-gray, becoming inactive

with death following. Hypha were found to extend fro: the

legs, genital, and anal openings as well as from the body

wall. Baker found the population of the blueberry budmites

and seasonal mortality of bud mites infected with H. tho;np-

sonii to show an inverse correlation. The bud mite and the

citrus rust mite showed the same symptoms in becoming dark

and exhibiting non-natural color when infected with the

fungus. High populations of the blueberry bud mite, coupled

with increasing rainfall and high temperatures provided

suitable conditions for fungus growth. As mite populations

and/or rainfall decreased, fungus counts would decrease.

McCoy (personal communication, 1974) has developed an exper-

imental control program for citrus rust mite that combined

the proper timing of acaricide with fungal outbreaks.



Resistance of Plants to Eriophyids


There has been a limited amount of research dealing

with host plant resistance to attack by the eriophyid mites.

Philiip (1953) found E. rihis to attack both black and red

currants. The mites caused galls in the former but not

the latter type. Talhouk (1963) reported a strain of almond

in Lebanon that was totally immune from attack by A. phioe-

coptes.










Aqar wal and Bia-ia (1965') found that the genus.

Aceria sp., showed a prefei'cerce for somec varieties of

sugarcane over others under ienti czal conditions. They

also found that in the same variety where the i intensity of

attack was highest in the eighth leafth sheath from the top,

the Iower sheaths, one through four, were free from attack.

Nault and Briones (1968) found on a specific variety of

hybrid corn that A. tul i aec caused no symptomsc without any

increase in population;wh;le on a particular inbred line,

the mites increased 25 fold in two weeks and the corn re-

acted severely with leaf spotting, rolling, and trapping.

Sokolov (1967) reported that pear varieties with

long shoots, smooth bark without down at the ends,1eaves

smooth on both sidesand sparse crown appeared to be mite

resistant. Plants with tender skin, leaves with thin

epidermal layers and with hairy coverings were susceptible.

Bindra and Bakhetia (1969) found numerous mango

varieties were infested with the mango bud mite A. mangqi-

ferae, but degree of damage varied between and within vari-

eties.













RESEARCH


Bermudarass Inoculation l tests


Introduction

Several varieties of Sermudagrass were inoculated

with E. cynodoniensis under laboratory conditions. The

information sought in this test was first to obtain infor-

mation on symptomology and second to determine visably the

mite response to the varieties tested.


Materials and Methods

New six inch diameter black plastic pots werc filled

to within approximately two inches of the lip with soil which

had previously been sterilized with methyl bromide. The pots

were placed inside the laboratory with controlled temperature

which was kept at 85+80F. The photoperiod was controlled at

12 hours light.

NoMow, Common, Ormond, St. Lucie, Tifgreen (328),

Tiflar: (T-57) and Tifway (419) varieties vere tested. The

qrass samples were obtained from the University of Florida

Horticultural Farmn Unit. Healt.iy plots of each grass var -

ety were selected and circular plug were removed .:ith a

standard golf greens cup cutter. Thic cutter te-asuired 4 1/4










inches in diameter. Each plug contained the grass roots

and some soil. This unit ineasured approximately six

inches from the top of the grass to the bottom of the

soil and root zone. The prepzc.ar excess soil was sliced

off the sample just below the area of heavy root develop-

ment. The gras. sample was reduced to approximately four

inches by removing the excess scil be'lo the root zone.

The samples were labeled as to variety and placed inside

polyethylene bags and individually sealed. The bags kept

the samples moist until they were planted.

The grass discs were placed in the plastic pots

and the soil was addedd and firmly packed around the disc

so that it was level with the top of the grass. This was

done in order to promote vertical as well as lateral grass

growth. The grass was maintained within the laboratory

for six weeks in order for it to overcome the shock of

transplantation and become well established. It was watered

on a regular basis and fertilized once every four weeks by

watering with a plant nutrient solution made by adding 1

level teaspoon of Millers 20-20-20 nutrileaf complete Fer-

tilizer per 1000 ml of water. The fertilizer contained

the ingredients shown in Appendix A.

At the end of six weeks the pots containing grass

that showed poor growth were discarded. The remaining pots

were rando;mized according to variety and marked to become a










control or test pot. Each variety to be tested ,ws repli-

cated 10 tifMes, The controls were replicated five times

and were kept on a bench at the opposite side of the labora-

tory and a vaseline barrier was placed between tst and con-

trol areas.

The inoculum was taken from a know; heavy infesta-

tion of Tmites on NoMow variety. Nodules 3f NoMow were re-

moved and placed within plastic bags. The mites were

placed on the potted samples by tearing the infested ro-

settes apart and placing the parts into the thatch of the

grass that war to be inroci ,ated. Two varieties, Tifgreen

(328) and Tifway (419), were reinocL:lated a second time

by the same procedure 33 days later.

The varieties were observed daily to determine

when the first syraptoms ef mite injury would be expressed.

Whcii the symptoms become evident, a portion of the grass

was removed and the presence of mites was ascertained by

examining the tissue under a microscope.

Field-established TiFqre n (328) and Tifway (419)

were iroc ul atccd by the ;same procedure every week for seven

weeks at the University uf Florida Horticul tural Farm.

These supposedly nonsusceptible varieties were the only

two tested since the farm has a history of not having

known mite infestations. The known; susceptible varieties

were purposely not tested to :vceid the risk of infesting

the far !.










The first inoculation was done when the grass

reached the standard maintained grass height of approxi-

mately 3/8 to 1/2 inch. The subsequent weekly incula-

tions were mide as the grcss grew taller since the plots

were not mowed during the test, This was done to see if

the two varieties would show symptomologyif allowed to

grow. Under normal golf course maintainence, fairways,

tees and greens the areas where these two varieties are

utilized are kept at a height of less than one inch. In

this study susceptible varieties Ormond and common in

particular showed little mite damage if kept mowed close.

Tifgreer (328) and Tifway (419) which are normally not

allowed to grow to a 2-3 inch height (a common height

for grass found in golf roughs), were allowed to grow

to this height during this test to see if mites would

attack (Fig, 7). The test was run on three different

occasions according to procedures explained and weekly

observations made. Samples were taken of random sprigs

of test grass and examined under the microscope. The

tests ran for 20 weeks s after the first inoculation and

numerous smaplei were observed under the microscope.


Results anr Discussion

The first symptoms to occur in the laboratory were

on the NoMow variety. This symptom was a shortening of










intetnodes and observed 13 days after the original inocu-

lation was made (Fig. 61, The NoMow variety first exhibited

the -flat fan type, symptom (discussed under Symptomology)

and upon microscopic exa.minnation revealed that mites were

established.

The varieties were observed daily and as the symp-

toms become evident thcy were recorded. The data are shown

in Table 1.




Table 1. Number of Pots with Grass Showing Bermudagrass
Mite Feeding Symptoms after Inoculation with
the M Le,

Days after # of Pots of
Inoculation
Grass Surviving
Grass Variety 13 20 27 30 after 6 months

NoMow 1 4 7 10 9
Ormond 1 4 9 4
Common 2 8 2
St. Lucie 1 3 7 6
Tifla'wn (T-57) 3 5 sod webworm
damage
Tifgreen (328) 10
Tifway (419) 10






NoMow was the first variety to begin mite symptoms

and all pots in this variety had symptoms to some degree









within 34 ddys of inoculation. This variety continued

to hold its color better than did al- other varieties

including Tifgreen and Tifway. The classic sequence of

symptoms were shown. by the NcMcw variety more strongly

thl!il any of the other varieties.

Tiflawn (T-57) and St. Lucie showed symptoms later

than did NoMow. It was not known if the mites established

themselves as soon as they did on NoMow: since microscopic

examination was not done until visable symptoms appeared.

It is possible the mites were established equally at the

same time on all the aforem-entioned susceptible varieties

but that symptcirs were not expressed as quickly on some

varieties as others due to differi;ig physiological responses.

Another reason for the apparent delay could have

been that NoMow developed a closer more compact thatch and

did not grow as tall prior to inoculation. The mites from

the inoculum could have had a better chance to survive since

they were probably in closer contact with the grass in NoMow

variety than in the other thinner growing varieties such as

Tiflawn (T-57), common, and Ormond.

The symptoms appeared later on other varieties and

this could be explained by the fact that all pots were

placed side by side and that the original inoculum didn't

take on soice of the thin grasses variety. As the grasses

grew and their foliage touched, the mites could have migrated










from one pot to another and thus symptoms could have been

delayed due to late arrival of the mite.

It is not known how the mite finds its way to its

niche between the leaf sheath and stem. It can be seen

from this test that the grass taken from the Horticultural

Unit was free of mites since no symptoms were ever seen at

field unit and also the fact that none of the pots showed

any symptoms during the first six weeks they were in the

laboratory prior to inoculation. However, one fact that

cannot be overlooked is that later field observations showed

that close mowing of susceptible varieties (with exception

of NoMow) kept the mites from forming rosettes and thus

building up large numbers. Close cut grass expressing no

symptoms would occasionally yield low numbers of mites.

Therefore,it would have been possible to bring the mites

into the laboratory on a disc of short cut grass taken from

the field with symptoms that would be expressed some 7-10

weeks later. However, the controls did not show symptoms

during this test as they did under a similar replication

of this test which will be discussed later in this chapter.

Tifgreen (.28) and Tifway (419) did not show any

signs of mite infestation in these tests. These varieties

were reinoculated a second time in order assure their ex-

posure to the mites. After six months, these two varieties

still showed no symptoms of mite infestation.










Even though NoMow: had the first symptoms and dur-

ing the sequence of attack the symptoms were more promin, ent,

the grass in only 1 pot died within 6 months. NoMow variety

seemed to be able to live and outgrow symptoms better than

did the Ormond, common, and St. Lucie varieties.

Although Table 1 shows the number of pots with sur-

viving grass, it camot be said that deaths were due strictly

to mites since sod webworms got into the laboratory and

damaged the Tiflawn (T-57) beyond recovery. The sod web-

worms also damaged some of the other varieties. At the

close of the test period, water was withheld from the pots

to see if the mite damaged grass could withstand the stress.

The results showed NoMow, Tifgreen (328), and Tifway (419)

could stand this condition the best, the latter two of course

had not been under any stress caused by mite infestations.

The test was repeated six months later with the

following exceptions: (1) only 3 varieties were tested,

NoMow, Tifgreen (328), and Tifway (419); (2) the pots were

kept in a non-air conditioned greenhouse under normal light

conditions; (3) they were replicated 6 times. Tifgreen and

Tifway were inoculated weekly for 6 weeks. The results

are shown in Table 2.

The NoMow responded the same as it had in the previ-

ous laboratory test. All pots of grass were alive at the

end of 6 months (Figs. 8 and 9). The control pots were kept










Table 2. Numbers of Pots with Grass Showing Bermudagrass
Mite Feeding Symptoms after Inoculation with
the Mites.


Days after Inoculation
Grass Variety 14 21 28 35 42 49

NoMow 1 6 6 6 6 5

328 8 -

419 -

Control NoMow 2 6 6 5 6


on a separate bench. It is not known how the controls

became infested. It is possible that due to wind move-ent

through the open greenhouse that the mites were bicwn to

the control pots. A. neocynodonis has been observed during

this study to exhibit the perpendicular erection on its

body via anal -suckers that precedes wind distribution char-

acteristic in the eriophyids.

No symptoms were expressed by Tifgreen (328) or

Tifway (419) and no mites were microscopically observed as

a result of field testing.

Golf courses were inspected from Jacksonville to

Miami, Florida for over two years. Over 200 different

greens were examined, samples removed, and microscopically

examined; many of them more than once. The greens examined










were plnrted in Tifgreen (328) variety. No A. neocvnodonis

or any damage known to be caused by them were found on any

of these greens.

An equal number of fairways were examined and

samples handled the same way as the ones collected from

the greens. Fairways planted in common, Ormond, and St.

Lucic were almost always found to have one or more areas

infested with mites during the early spring to late fall.

Golf courses in the Ft. Lauderdale area had mites the year

round on these varieties.

Only one sample of Tifway (419) ever yielded any

Bermudagrass mites. This sample was found on a slope be-

tween a tee and a small lake. The grass was approximately

1 1/2 inches in height. The superintendent, Mr. Larry

Weber (personal communication, 1973), said the grass was

positively Tifway (419), variety. The sample had only a

few mites and would have been considered to be an extremely

low infestation. Intensive sampling was taken within this

area on Tifway (419) and no other samples yielded any mites

or showed any intermodal shortening. On this golf complex

which had 3 separate courses, Tifway (419) variety was

used for fairways exclusively and the roughs were planted

in common variety. Bermudagrass mites were found constantly

in the roughs and damage often was extremely heavy with

patches cf grass being killed as the result of infestation.










The fairways were kept cut at 1/2 to 3/4 inches in height

and the roughs at 1 1/2 to 2 inches. However from time

to time the contour mowing patterns would change and

roughs of common would be cut short or Tifway (419) (fair-

ways) left unmowed thus serving a a a rough.

Even where severe infestations of mites were found

on the Common variety, damage stopped with the onset of

the Titway (419) variety. In the aforementioned transi-

tion zones where Tifway (419) was found to be 1 1/2 to 2

inches in I!eight, there were no mites or damage observed.

Lines of damage were so obvious in these zones of transi-

tion that Tifway (419) growth margins could be picked out

between the varieties from a distance of 50 feet or more.


Sunime ry

This study showed under laboratory and field condi-

tions that NoMow, common, Ormond, and St. Lucie varieties

were highly susceptible to Bermudagrass mite attack and

symptoms became evident as early as 13 days after inocula-

tion.

Tifgreen (328) and Tifay (419) were found to be

resistant to attack from the mite. These varieties yielded

no mites under microscopic examination iand exhibited no symp-

toms from attack by them. This work verified Butler's (1965)

that Bermudagrass varieties with parentage of Cynodon










transva eensis Davy appears to beres instant to E. cynodoni ensis.

According to Hanson (1965), TirFgreer. (3?2 ) and Tifway (419)

have C. transvalecnsis as parentage w iile St. Lucie, common,

and Ormond do not.



Miticide Control Tests---Deerwood


Introduction

The Deerwood golf course, located at Jacksonville,

Florida, had a history of Bermudagrass mite infestations

particularly on its tees and fairways which were planted

in Ormond variety. Greens were planted in Tifgreen (328)

variety.


Materials and Methods

The course was inspected in June and Bermudagrass

mites were found to infest many areas on the fairways.

The infestation was sporadic and dead spots followed a

circular or irregular patterns. Certain tees were also

infested with mites and one was almost bare of grass.

Weeds and non-Bermudagrass varieties were beginning to

establish themselves where the original Bermudagrass had

been.

The sixteenth fairway was chosen for pesticide

tests since it had a history of being the most heavily

infested area on the course for mites. Inspection showed






















Fig. 6. Beginning of Internodal Shortening of Grass
13 Days after Inoculation under Laboratory
Conditions




















Fig, 7. Field Plot of Unmowed Grass that Underwent
Weekly Inoculations of Bermudagrass Mites














































































.- ,w -NOR
nowir.ir
























Fig. 8. Pots of Grass Grown in the Laboratory
Showing Vertical Growth Seven Weeks
after Inoculation



















Fig, 9. Pots of Grass Grown in the Laboratory
Showing Lateral Growth Seven Weeks
after Inoculation







63


f-a Sm~_1.._,., .


TIFWAY










mites infesting the fairway which was discolored and had

numerous bare spots.

The sixteenth fairway was surveyed and a random-

ized complete block experimental design was used. Each

block was 10 feet wide and 70 feet long and was set to

cut across t.e fairway and through the area of damage as

much as possible. The blocks were marked by driving

cornerposts of wooden stakes into the thatch so that only

1/4 inch of the stake was above the soil layer. This was

done because-play on the course was to continue throughout

the tests and it was imperative that plots not interfere

with golf play or the normal mowing-and maintenance opera-

tions. The test was replicated four times since adding

more blocks would not encompass the damaged grass areas

evenly. Each block was divided into seven 10 x 10 ft plots

in order to accommodate the six pesticide tests and a con-

trol.

The following pesticide formulations and their rates

of application were used:
Amount of Fonrmulation
Pesticides* e Formulations Broadcast/Acre
Phienam. i Phos __ 15% qranuLlar 66.67 Ibs.
Adica_ rb_ ____ 10. granula r 60.00 lbs.
Tr i ch rfon-4 v- 0.375 + 0.125
C T 1 S i f 21.78 aal s.
d_ -,., t., ,1 crii:lsifial e', li l 'id 21.78 oals.
duP j -.i, o- .i .. I 'l al 1, AI______ -22.L 1 bs.
Sul,/_-... __,__ ,.,' .I-__,,:-',.___ _t_____ __ .______
r {Ooxur 7r"l -'-;er 11. U0 lbs.____

Further ini. oi&tion available in Appendix D










The rates of application for cach pesticide were

selected as the most likely amount the Environmental Pro-

tection Agency (EPA) would register for future use on turf.

The pesticides to be used on individual plots

were measured and weighed in the laboratory prior to ap-

plication. They were placed in glass containers, labeled,

and sealed. The granulated materials were placed inside

a glass jar with a lid perforated by nail holes. This

allowed the granules to be shaken out evenly over the plot.

The holes in the lids on the shakers were designed prior to

actual application so that the flow of the granules would

not be too rapid. Several size lid holes were used since

the various granules were of different size and texture

and the flow rate varied In order to insure uniform spread

of granules, each plot was covered using a broadcast pattern

from 4 to 6 times with the shaker or until the specific

amount of granular material had been applied as evenly as

possible. The standard procedure was to start on one corner

of the plot and go from that point to the opposite side and

then return. This continued until the plot had been crossed

from either a north to south or south to north pattern. The

procedure then consisted of an east to west or west to east

movement, The procedure then rotated back to the north-

south; then to east-west pattern until the supply of granules

were distributed.










The premeasured and weighed liquid and wettable

powder pesticides were carefully emptied into a 2 1/2 gal-

lon garden sprinkler can from their respective glass con-

tainers. The container was then rinsed several times into

the sprinkling can to insure that all of the chemicals was

used. Water was then added until the can contained approx-

imately 2 gallons of the finished mix. This amount was

equivalent to approximately 880 gallons per acre which is

more than is applied to most golf courses in normal spray

application. However with the sprinkler can delivery system,

this amount was thought to be necessary in order to reduce

the error in application.

In order to insure a good mix of water and materials,

the contents of the can were stirred vigorously with a clean

wooden paint stirring paddle.

Liquids were applied with the same criss-cross pro-

cedure as on the granular application plots. The cans were

rinsed several times before adding the material for a new

plot. To reduce chances of contamination, a different

sprinkling can was used to apply each pesticide.

Approximately 4 hours after the application of all

chemicals, the irrigation system was turned on and 1/4 inch

of water applied to the test area. Another 1/4 inch of

water was applied at dawn on the following morning. This

was one to wash off any remaining residue of toxic materials










and to wash in the granulated materials. The addition of

water was also used as a safety factor for the golfers

who would be playing the following day. The reason for

the four hour lapse period between application and irri-

gation was that Deerwcod closes play every Monday for

maintenance and thiis was when the treatments were applied.

After the applications, the sixteenth fairway was

treated the same as was the rest of the course grass and

was kept cut at standard fairway length of approximately

3/4 inch. The plot ratings were based on Butler's (1963)

procedures where overall grass growth, color,and general

vigor of a plot was scaled from 0 to 10, with zero being

bare soil and 10 being a perfect plot showing no damage.

In order to reduce error,the ratings were made by two indi-

viduals and the results averaged, Cooperators were Drs.

H. L. Cromroy and David Bowers. Rating observations of

each plot were confined, as much as possible, to the six

by six foot middle section. This allowed a two foot border

of grass in each plot and helped reduce human bias. The

grass plots were rated on the day of pesticide application

to establish a beginning reference baseline and ratings

were made every 14 days thereafter for 6 weeks.


Results and Discussion

The results of the test are presented in Table 3.

Statistical analysis using Dunnett's Test (Cornell, personal










Table 3. Visual Rating with Six Pesticides at Deerwood
Golf Course.

Days after
s DaySter Net Change in
Treatment ,
Treatmt- rating after
Treatmecnt** Pre-application* 14 28 42 Treatment
Phenamiphos 6.125 7.000 7.125 7.250 (+)1.125
Aldicarb 5.125 5.625 6.825 6.825 (+)1.700
Trichlorfon + 3.125 3.500 4.500 3.875 (+)0.750
oxydemeton-
methyl
Disulfoton 7.375 8.125 6.625 6.500 (-)0.875
Fensulfothion 6.125 6.875 6.750 6.625 (+)0.500
Propoxur 7.625 7.875 7.125 6.625 (-)1.000

Control 6.750 7.000 7.250 7.000 (+)0.250


* Each plot is the average result of combining two ratings
on four plots
**For further information on pesticides, see Appendix D




communication, 1975) showed that plots treated with aldicarb

were significantly better in appearance at the 0.05 level

than the controls during the range of time the test was run.

Aldicarb plots were not however significantly better in ap-

pearance than plots treated with phenamiphos, fensulfothion,

or trichlorfon+oxydemeton-methyl, Plots treated with these

four materials were significantly better at the 0.05 level

than these treated with disulfoton or propoxur. The turf

treated with the latter two materials regressed in appear-

ance but regression was not significant when compared to










the control. It is not known why regression occurred

since variables too numerous to list could have been the

reason. However,there is a possibility that the chemi-

.als could have had an effect on beneficial turf arthropod

cumplexes.

Although a great deal of information was obtained

from this test, a follow-up or continuation would not be

recommendeded because of the following problems and criti-

Si sms.

Although this was the most realistic field research,

it is difficult to work in the main area of traffic on a

golf course. Setting up plots in the flow of play constantly

creates problems between golfers and researchers. Another

problem encountered was the marking of plot layout so that

it can always be found days or weeks later. The marking

was difficult and remeasurement must be precise in order

t.n.re-estabiish block corners or other orientation points.

ih1is procedure must be repeated each time the plots are

-rfd or observed. In a case where fairways, tees, greens,

:.- .other playable areas are utilized, it is imperative to

i~i markers that do not project more than 1/4 inch above

thLo soil s; rffa:e. If stakes or other devices are used and

tfi;,s heig' i is -xceeded, mowing and other maintenance

c;-: pmient will often destroy the markers and will become

d. e! oed themselves in the processes.










Another criticism for not ,'Wng these areas for

testing was the mowing process. It was later learned

that mowing hinders the normal popul aion development of

the Beriludagrass mite. Thus, as a test w:as developing

with mowing being mandatory, the rosettes, fans,or other

nodular growth portions which harbor the majority of the

mite population was cut, mulched, and scattered over a

wide area. Counts taken after these operations could be

misleading as to the actual control that was being obtained

by a pesticide at a given time.

The most severe criticism is in the area of plot

layout and sampling technique. A plot layout that contains

a relatively uniform mite population is mandatory. It

should be pointed out that at the time this test was initi-

ated little was known of the mite population or their habits.

Therefore the large 10 x 70 ft blocks were adopted. Popu-

lations were never found to exist uniformly in areas this

large over the 2 1/2 year period covered by this study.

Extreme populations of mites were found in later observa-

tions but many times their damage was confined to small

isolated spots.


S um nmar y

Ormond Bermudagrass infested with A. cynodoniensis

(Sayed) was treated with six different pesticides. Ratings










of control consisted of a visual classification technique

where plots were scored from G (no grass) to 10 (perfect)

grass.

The plots were raied at 14, 28, and 42 days after

treatment. Plots treated with 60 ibs. of 10'0 61dicarb

granules ,. ere significant over the controls in appearance

at the 0.05 level.



Miticide Control Tests--Palmaire


Introduction

Palmaire is a golf and condominium complex located

at Pompano Beach, Florida, and consists of four par 72

professional type 18 hole golf courses that lie among.

a vast layout of living facilities. The fairways are

planted in Ormond variety Bermudagrass and complaints of

mite attack on them had been numerous.


Materials and Methods

The four courses were thoroughly inspected in order

to establish an area that was uniform as possible in mite

infestation and large enough to accommodate sufficient plots

to test several pesticides. The courses had spots of mite

outbreak on numerous fairways and roughs. A great majority

of the infested areas were too small for the plot area

required to run pesticide tests.










A general infestation followed the slopes along

a stream that ,meandered through the Palmaire courses; but

due to slope tid sparseness of grass, it was decided not

to select a test area along the stream.

A randon-ized complete block design was set up in

the areas that" contained the largest and most even popu-

lation of mites found in the preliminary survey. This

area also had a history of having constant mite problems.

The blocks were replicated three times and the treatments

were five by five feet in size.

The original plans were to replicate the test a

minimum of four times and for the treatment plots to con-

tain 100 square feet rather than 25. However, the overall

infestation was not sufficient for a test of this size

so less replication and smaller areas of treatment were

made. Two blocks five feet wide and 50 feet long were laid

out and cornvo stakes used for markers the same as was dis-

cussed under Deerwood Control Tests. Due to the irregular-

ity of the miO-te infestation, the third block had to be made

L shaped. Th-t plots that were to be tested had a reasonable

equal growth grass and about the same topography with

little or no slApe, In order to be able to find the plots

more easily a: i: 11 amount of herbicide was used to kill

the grass, in a circle approximately two inches in diameter

surrounding the' corner stakes.










The herbicide was also used on the corners of

each 5 x 5 ft plot. This allowed for future sampling

without having to re-establish block and plot boundaries.

This herbicidal procedure was used in this test since the

infested area was located between the rough and the tee

and the dead spots were not detrimental to the appearance

of the course. This procedure also eliminated the exces-

sive use of stakes used in relocating plots. Palmaire

management had requested that no test was to Le visible

to the clientele,and mowing maintenance had to continue

during the testing period.

The following nine materials, rates per acre, and

formulations were used;


Common Name
Aldicarb
Phenami phos
Fensulfothion
Disulfoton
Diazinon
Dialifor

Trichlorfon oxy-
deretonmethyl

Oxamy1

Fentine Hydroxide


Formulation
10% granules
15% granules
15% granules
15% granules
4 emulsifiable liquid
4 emulsifiable
liquid
0.375 + 0.125
emu 1sifiabi e
liquid
2 emulsifiable
liquid
50% wettable powder


Amount of Formulation
Broadcast/Acre
60 1bs.
66.67 Ibs.
66.67 lbs.
22.00 tbs.
1.00 gal.
1 qt.

2..78 gals.


1 gal.


1/2 Ib.









The materials used were previously weighed under

laboratory conditions, placed in glass containers and

properly labeled.

The application of granules, wettable powders

and emulsifiable materials were done as described in the

Deerwood Tests. The weather was usually windy in the

Pompano Beach areas. In order to avoid granules or liquids

from being blown away, the applications were made to the

plots from a height of approximately 1 to 1 1/2 feet. Ap-

plication was made only when there was either no wind or

a very slight breeze. If wind speed increased beyond a

very soft breeze or if there was any indication that the

wind was causing granules or liquids to be blown away

from the plots, treatments were stopped until permissable

conditions occurred. Fentine hydroxide and oxamyl were

not available from the manufacturers at the time of treat-

ment. They were applied 14 days after the other materials.

The statistical analysis was designed in order to consider

this alteration and will be discussed further under Results.

Sampling. Grass samples were taken from the test

plots 2 and 4 weeks after the application of pesticides.

According to Reinert (personal communication, 1973), counts

taken sooner than 14 days could be misleading since deteri-

oration of dead mite bodies appeared to be slow and could

be deceptive if readings were taken prematurely.










Before sampling, care was taken to re-establish

all plot boundaries. The sample was taken from the center

of each plot. This allowed approximately a 1 1/2 to 2 foot

buffer zone in each plot. Since plots were ncL separated

by nontreated boundaries, samples taken from any two adjoin-

ing plots were a minimum of 3-4 feet apart. The sample con-

sisted of approximately 500 cc of individual rosettes, fans,

or other damaged appearing grass. The samples were placed

in a plastic bag, sealed,and put in a shaded area. As

soon as all samples were collected, they were held for micro-

scopic examination in air-conditioned rooms where the temper-

ature was maintained at 680-75F.

The Bias Sample. The bias sample technique was

developed by necessity and can be explained by data in

Table 4. An attempt was made to sample known mite infested

areas on Palmaire courses. The technique used was to ran-

domly remove an approximate 10-20 gram portion of grass

within an infested plot. These samples usually did not

contain any rosettes, fans,or other symptomology indicative

of mite damage. When actual microscopic counts of these

samples were made, mites were found in insufficient numbers

to work with. When a random sample contained a rosette the

numbers of mites found and compared it with a random sample

where rosettes did not occur were so extreme that the over

balance discouraged even the remotest conclusion.










Table 4. Comparisons of Mite Counts from Random Grass
Samples and Biased Samples.



Total Numbers of Mites
Sample No. R__ Random Sample* Biased Sample*

Al 5 935
B2 4 323
C3 2 290
D4 8 725
E5 2 704
F6 3 78
G7 9 565
H8 3 226
19 2 347

*Each sample is composed of the average of 5 subsamples





From this experience,it was decided that samples

would be used from both treated and control plots made

up of grass portions (rosettes, etc.) which contained

abnormal growth caused by the mites. It was felt that

a better comparison could made using this sampling tech-

nique. The bias sample is in need of modification because

this method also yielded large differences in populations

even when it was highly suspected that none exists. This

error could probably be reduced by extracting mites from

larger numbers of samples from a larger area. Time was

not available for the person doing the counts to increase

the number of samples.










Counts, Actual counts wyre usually made within

18-24 hours after sampling. It would take about 48 hours

to examine the samples. As much as 72 hours often elapsed

from the actual time the sample was taken and subsequent

counts made. In order to reduce any bias, the plot samples

were examined on a random basis.

A subcount was begun by taking the sheaths at ran-

dom from a mite infested rosette with a pair of jewelers

forceps. The sheaths were then carefully placed inside

up and all stages counted except egg. A subcount con-

sisted of the total mites found under a 16 X lensfield

of an A, 0. Spencer dissecting microscope,

In order to reduce error, five rosettes were ran-

domly selected from the composite sample and a separate

subcount made on the sheaths as previously explained. The

final total count of a recorded sample was composed of the

average nur.ibercf mites found in the five subcounts.

In order to obtain useful and working data, it was

decided to use the bias method of sampling. A comparison

of the two methods of sampling is given in Table 4. It

was found that a total of only 94 mites were found in 125

random type grass samples compared with a total of 7,528

mites found in 110 bias type samples.

Data is presented in Table 5 concerning the miti-


cide tests,










Table 5. Mite Counts Resulting from Application of Pesti-
cides at Palmaire Golf Course


Trea trme
Control
Aldicar
Dial ifo
Diazino
Trichlo


Days after Treatment
14 28

nt Rep 1 Re Rep R Rep 1 ReD 2 Rep 3
(A) 226 555 41 220 30 5
b 79 3 41 0 0 0
r 2 204 5 160 43 1025
n 2 347 140 0 0 0
rfon + 249 34 290 460 795 473


oxydemeton-
methyl
Phenamiphos
Disulfoton
Fensulfothion
Oxamyl
Fentine
Hydroxide
Control (B)


323
36
935
85
925


4
303
856
255
425


760 795


277
725
486
490
174

420


0
385
0
12
848

536


0
30
5
160
512

915


300
0
1280
120
325

286


Results and Discussion

It was decided after discussion with an IFAS stati-

stician to combine the data obtained from not only the two

periods of sampling but to also combine the data from the

oxamyl and fentine hydroxide treatments, since separate

controls were added to the test to compensate for delay of

application of these two materials. The data vwre examined









and analyzed by acceptable statistical techniques so

that all treatments could be compared to the control and

all treatments could be compared with one another. Tables

showing statistical methods and calculation are shown in

Appendix C.

Standard A. 0. V. Tables indicated that signifi-

cance existed when the sampling data was transposed using

the log (1 + y) or /1 + y. These tables are presented in

Appendix C, This transportation was necessary since the

range between samples were so large.

Dunnett's test showed aldicarb, diazinon, and phena-

miphos to be significant over the controls at the 0.05 level.

Duncan's multiple range test was used in order to

compare significance to treatments with each other and the

results are presented in the following table:


Table 6. Overall Results of Bermudagrass Mite Control; a
Statistical Comparison Using Duncan's Multiple
Range Test.

Pesticide Level of Comparison*

Aldicarb a
Diazinon ab
Phenamiphos abc
Dialifor bcd
Disulfoton bcd
Oxamyl cd
Fensulfothion cd
Trichlorfon + oxydemeton-methyl d
Fentine Hydroxide d
*Pesticides followed by the same letter were not significantly dif-
ferent at the 0.05 level.









Summary

It was found that aldicarb, diazinon and phena-

miphos had significantly fewer Bermudagrass mites than

controls 28 days after application. There was no signifi-

cant difference between the miticides when compared with

each other.


Growth Regulators Tests

Introduction

The liiverrary golf and condominium complex, located

at Lauderhill, Florida, is composed of two professional par

72 and one par 60 executive courses. The tees and fairways

are planted in Tifway (419) and the greens in Tifgreen (328).

The roughs are planted in common Bermudagrass and landscaped

with subtropical type plants and trees. The roughs are

delineated from the fairway strictly by mowing. Fairways

are kept cut 't. /8 to 3/4 inch in height and the roughs

at approximately 1 1/2 to 2 inches. Changes in mowing pat--

terns will oc.:a.ionally produce the margins of the rough

with Tifway (419) and the fairways with common variety.

The course management reported sporadic outbreaks of mites

on the compl;A and complained that mites could be found

the entire y: ar.

Materials anld Methods

The entire turf complex was thoroughly surveyed.

Mites were found in isolated spots along the roughs or










where common variety was found. The infeEted areas were

too small and isolated to attempt to try and set up a

statistically acceptable pesticide test.

The course was kept under surveillance for almost

a year. During the spring of 1974 an area along the rough

of "number 2" fairway on the West Course was found to be

infested with mites. The infestation extended for ap-

proximately 100 feet in length aitd from 15-20 feet wide.

The area was intensely surveyed and although infestations

were sufficient to support a test there were breaks within

the area that had few mites and little damage.

The Bermudagrass in this area was approximately

1 1/2 inches in height. The entire area was flat and

moisture conditions were considered to be somewhat minimal.

The fertility program in this area was considered to be

excellent.

Previous correspondence with Zoecon Corporation

of Palo Alto, California had led to the investigation of

using several growth regulators in attempting to control

the Bermudagrass mite. Zoecon had reported that six

numbered compounds had shown miticidal and ovicidal activity

against the two spotted, the European red and the brown al-

mond mite. The materials were recommended as foliar treat-

ments and supposedly showed no systemic action. All ma-

terials were 25% wettable powder formulations and were t,
be applied as a 0.1 finished spray.










The area to be tested was examined and seven sub

areas that appeared to show equal symptoms, grass color

and growth characteristics were selected. The seven

plots were randomized as to what treatment they would

receive, A 10 x 10 ft aluminum pipe template was made

and each side'wds marked at the halfway point so when it

was laid flat on the turf a 100 square feet section was

marked off, This area within the template could then be

divided into 4 subsections by lining up the midpoints

marked on the-sfiGes of the template. Each of the four

five by five sections within the template was to serve

as a replication of the same treatment,

The area within the template was delineated by

using an inverted spray paint golf course marking apparatus

containing magenta colored paint, This apparatus is com-

monly used to make boundaries on golf courses during tourn-

ament play. "

The growth regulators to be used were weighed out

prior to test in- and placed in glass containers. The

weight of the test material was precalculated so that

when mixed wi 'i cuart of water it would yield a 0.1%

spray,

A contai':er was premarked so that when it was so

filled it contai:.ed a quart of water. This amount was

selected to be i ed since most spray machines on golf










courses apply approximately 100 (ailons of water per acre

in spraying for disease or mites. One quart of finished

spray per 100 square feet is equivalent to 108.9 gallons

per acre.

The materials used were as follows:


Material Form Rate A1/A Lbs. Fornulation/A

ZR 793 25% WP .908705 Ibs. 3.6351 Ibs.

ZR 856 25% WP .908705 lbs. 3.6351 lbs.

ZR 918 25% WP .908705 Ibs. 3.6351 lbs.

ZR 1829 25% WP ,908705 Ibs. 3.6351 lbs.

ZR 1859 25% WP ,908705 Ibs. 3.6351 lbs.

ZR 1888 25% WP ,908705 lbs. 3.6351 Ibs.



Mite precounts were made prior to applying the

growth regulators. The bias system of sampling was used.

Since the material applied was considered to be an ovicide,

a ratio of all stages of mites to eggs were established.

A sheet of paper with a small rectangle was constructed

and a section of the infested leaf was placed on the rec-

tangle. Observations were made at 45 X power using an

A.O Spencer dissecting microscope and the mite eggs were

counted and compared with the nymiphs and adults found

within the confines of the rectangle. Results of the

count ratios shown in Table 8.










Two applications of the growth regulators were

.iid ,. the second !8 days after the first. The material

was' appliedd to each 100 square feet areas by using a 1 1/2

r"-.lon compressed air sprayers. The wettable powder hor-

m-one.was added to the tank from the glass container. The

containers weLre then rinsed using water from the premea-

sured quart that was to be applied to each 100 square feet

p -,ot and the rinse water added to the sprayer. When the

glass contain-er no longer showed any visible residue from

.-c, wettable -powder, the rinsing operation was stopped and

the remainder of the quart of water was added to the tank.

The tank was closed and the spray mixture was shaken vigor-

ously to aid"mixing.

A different, clean compressed air sprayer was used

to spray each individual material. The procedure for

spraying each block followed the pattern as described under

the Deerwood tests. The compressed air sprayer was chosen

for this test. because it would deliver small amounts of

spray more e.;\enly than the sprinkling can method. In order

tc reduce spray drift the sprayers were operated at low

p~rssure so that droplet size was too large to be blown

;way by s. i oht air movement. Using this procedure it took

from 8 "L 'O '"Limes over" the plot before the spray was

exhausted.

Counts were made on April 18 using the system pre-
viously described on May 6 just prior to the second application










and then on May 30 as a follow up to the second treatment

with the results shown in Table 7.




Table 7. Mite Counts in Total Numbers at the End of 18 and
42 Days after Treatment, Ineverrary Golf Course


Block
I II --11-- 1V
I II V level
___Days___ of
Treatment 18 42 18 42 42 comparison*
ZR 793 496 577 716 432 1080 756 1350 703 ab

ZR 856 592 399 980 137 640 417 1200 960 a

ZR 918 556 1082 380 1344 708 1062 580 1080 c

ZR 1829 336 565 140 784 1500 530 1280 552 ab

ZR 1859 800 744 384 404 460 624 1070 1338 a

ZR 1888 480 420 884 376 732 274 743 768 a

Control 476 628 290 710 700 555 555 600 ab


*Dunnett's test at 0.05 level

There appeared to be no significant changes in mite popula-
tion during the test.


Results and Discussicn

No significant differences were observed between

any treatments at the end of 18 days. Significance was

obtained between treatments at the .01% level at the end

of 42 dr'ys using the standard A.0,V. table. Uunnett's










test was applied to the data and it was found that the

reason for significance lay in the fact that the growth

regulator ZR-918 had tremendously high mite populations

when compared to the other compounds and the control.

There was no significant difference between the other

compounds when compared to the control at the .05 level.

Compound ZR 856 and ZR 1888 however did prove signifi-

cantly better than compounds 7Z 1859 and ZR 918 at the

.05 level. A.O.V. tables and Dunnett's test are included

in Appendix D.

The results of the adult plus nymphs to egg ratio

are presented in the following table.




Table 8. Ratio of Nymphs Plus Adults to Eggs at 18 and
42 Days after Treatments


Treatment
Totals
Days Control ZR 793 ZR 856 ZR 918 ZR 1829 ZR1859 ZR 1888 (T)

18 1:4,591 1:2.649 1:5.296 1:3.195 1:1.365 1:5.857 1:2.857 25.81

42 1:0.385 1:0.673 1:0.783 1:0.419 1:0.418 1:0.983 1:0.415 4.076
Total 29.886

@ 18 days E = 3.687 = 4.21
@ 42 days r = 0.582 X2 = 0.541



It was found and can be supported by the above date

that the variation in the adult + nymph : e; ratios ranged

from 3 to over 11 fold.











However the chi-square values in comparing the

treatmeriit nd control ratios with each other at the 18-

day interval and with each other at the 42 day interval

showed that the variations that existed were not signifi-

cant.

The reason for the sharp drop in ratios is unex-

plained and could be due to many known and unknown environ-

mental factors.

It is possible that predatory mite forms could have

been the reason for part or all of the ratio changes, since

it is known that some cf the mites found during this re-

search are predaceous on mite eggs.


Suin ma ry

No positive significance was found between six

growth regulators and the control when tested against the

Beri-udagrass 'mil, infesting common variety Bermudagrass.

The materials were also being tested for ovicidal

properties and .f- significance was found between the com-

pounds and the control.



Sympt oiiol9_y


The first symptom of the Bermudagrass mite feedings

is not always easy to detect. The patterns are not always

the same and the sequence of injury that can lead to grass










death appears to vary from one plot to another. This ob-

servation is not unexpected and can partially be explained

by the fact that management programs of grass differ widely

from golf course to golf course.

There is a general pattern of attack by the mites

and subsequent symptoms do follow a sequence. The first

stage is a slight yellowing (particularly in Ormond and

Common varieties) of the very tips of the blades of grass

on which the mites are feeding. The yellowing can be more

or less pronounced and probably depends upon variables

such as fertility, moisture and other associated factors

in a turf complex. No Mow variety does not exhibit the

pronounced yellowing characteristic as do the previously

mentioned varieties.

The second stage is characterized by twisting of

the leaves and shortening of the internodes especially

under moisture stress. The leaf twisting alone is com-

monly referred to incorrectly by many lay observers as

"witchbrooming." Leaf twisting is expressed by the fact

that the margins of the leaf role upward and inward and

thus each individual leaflet appears in a tight rolled

position (Fig, 10), A plot of grass if observed as an

entity takes on a darker appearance which begins at the

tip of the blade and proceeds back to the point of its

insertion at the node. As this condition progresses from










leaf to leaf then that particular sprig of grass takes

on a thin spindly appearance. This phenomenon is a condi-

tion of wilt and has probably been termed "witchbroom" be-

cause the blades actually look "stringy" as would the tips

of a worn-out broom. This condition is only a response

by the grass to reduce the loss of water when it is under

moisture stress or comes about when conditions exist where

water is in a short supply. Many times it was observed

that the leaf twisting never appeared in mite-infested

Bermudagrass which was heavily watered.

As this study began it seemed to be the opinion of

many turf workers that when they observed "witchbrooming"

(leaf twisting) during the season for mites, especially

when they had been reported in the area, then the diagnosis

was commonly made as mites. Often mites were the reason

but this overall observation proved to be very misleading.

Literally hundreds of these witchbroomed areas were

observed and taken apart. Samples were brought into the

laboratory and each sheath stripped and observed under the

microscope. An occasional mite was found and a small

colony would also be observed from time to time. However

a great majority of the time mites were not found. When

the leaf twisting did occur the pattern would be found as

irregular spots from a few inches in diameter to one that

would cover several hundred feet. This pattern did resemble










one that would occur when a pest organism establishes a

population in turf, however thinking that the numerous

leaf twisted spots meant mite infestations proved to be

wrong. Many environmental stresses were found to cause

the described condition in one instance or another and

many times an answer didn't appear to be available. Often

observation led to the fact that nematodes were the cul-

prits and the grass responded quickly to nematicide treat-

ments. Root disease and damage often were the reasons for

the symptoms. The aforementioned reasons were many times

associated with the leaf twisting even though the overall

moisture conditions of a golf course were considered ade-

quate or even good, and this often would further lead the

casual observer to think that a heavy infestation of mites

was present.

During this study it was found that several vari-

eties of grasses other than Bermudagrass would show the

leaf twisting symptoms. All Bermudagrass varieties did

appear to show the symptoms far earlier than did other

grasses.

Further investigations often resulted in finding

irregularities of the top soil on which the grass was

established. Many golf courses have top soil hauled in

to provide a media for the vigorous crop of grass de-

sired, In spite of all efforts, often a spot of rock or