الفهرس 
The use of petroleum fractions in the control of the cotton leafworm
assessment of larvae and pupseOnly 14 pages are availabe for public view
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Abstract
ECOLOGICliL STUDIES ON T~ COTT’ON LBAF;;;ORK,
S?ODO?l’ERA LIIIOR.b.LIS (30ISD.)
A s~eaiy increase in ~he pGpulation of the cotton
leafv,orm.. Spodopterc; littoralis bas been observ2d, in
recenc years, in apper Egypt. The increas6 reached an
outbreak level at liatey (El-t.:in;ya G::>varnorate) i:J 1974.
The prese::.t v;:lrk ,;as iedica1:ed, :r,.ainly, to tbe s:udy of
ecological :”accors i::.fluenci:Je cl:e infestc.tion i::. that
art; e.
~::.e studies included the populati::>::. de~sity of this
ins6c~ ;esc i~ c~e ar~a, as ~ell ~s its ac:ivity ~=i bebaviour
i~ r~latiori to s~ne c~e~gescle cJ=~itions. =rials
-.r·:er<= ::lsJ CJ!:C.:..rc::ed for ~;;;ste”clist:i::~ ::: ·:·E.Sis fJr pr.sd.cti:J.g
the size Jf -~be first gs~tra~io~ ~f tt~ ~~s~ct o~ cotton.
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after cotton or after c::rn duri::1g tte> period l~~-,. - :Gee.
were 105.8 ic:! t tle first cc:se and. 64.2 in t tle second.. I·ha
corresponding means dt1ring Jan.- Feb. were 8.9 after
cotton snG. 1.7 after corn. l’he an&1ysis of variance revealed
tbst tbe differences were significant indicating that
clover culoivated after cotton narboured itll’ing tbe
autumn and Win~er a higber level of population than if
cu1..tivate _ afc;er corn. I’bis rE:sult e::1p:~asizes -c;je iUJ.portance
of cbe roles of crop rotation and other agricultural
practices in tbe infestation level.
b) So•.·.ine; ciates:
ste.g;es /OC, sq. ft. Ct.lXint; :·~O\’• - :Jec. in clo .. ver sown O!:l
~ere 5~.2, ~4.7 and 20.8 respectivel:. ~::1alysis o~ vari~
nce a=~ ~.~.:. ~alues intic&t~d that ~~:s insect’s population
~ensity differed, si 0~ificantly 1 ~ccording ”GD tbe
dat6s =~· so~ing. It could t~us be c~ncl~ded that in
early-culti·Jated clover t:::-- inies”tation -... oulC. be expecR..
-·-.---~-
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c) Clover cutting:
Data indicate that cie mean of toe total nu~9er of
larva.;: and pupae du.ring :..:arct, - hley v;e:re 26.1 in .;tanding
clover and 8,4 in cut clove:r. ’2he analysis for each o£
the larvae and pupae separately indicated a significant
difference at 0.1% level in the case sf larvae (F= 35.15)
and au insignificant difference in the c~se ~f ~upae
(F ,_ 3-09).
These resul-cs support tte observatio:ls stowing tte;t cutting
of clover is e; practicel method fer :::educing the
population of the larval stage.
d) Clover irrigati’Jnl
Resul~s i~dicate t~st stc;pi=~ :h~ irri~ati~~ cf
R6s~l~s i~ 1975, r~vealc~ :hat clever receiving its
numbers of larvae and P’..ljjec t:.an tte clover th:Jt C”C·:-:ttin1;.ed
to be irric-&te:i Dn 5t::, l5tt, 2o-th :i:E.y, ~~t:r_ -~d ’r;-1.- T”ne
to • ~- --- -’””’” c ~ •
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Data i~ 1~76 showed, et the end of sampling, G~at
the meen number of i~ature stegcs /60 sg. ft. in tte
clo·;er that had its last irrigetio!l or:. Stt :..:ey wc.s 12.8,
wb.ile i~ clover in wb.ich irrigation c::>ntin:.;ecl tc:J 27th !Lay
tte mea:1 ..,,;as 27.6, end in clover ttst 7.-e.s irri§;eteci up to
17th Ju::~e, the nean was ~.8. l.ll tc;.ree ;neans were sisnifica::
ctl;y different at 5 % level :of prc;oa’::Jilit;.-.
e) 4dding solo.r :.:;_1, with irrigation ·11ar;er, t:. clover
fields:
clover ceueed 2 reduction JD
t~.: yeers, i~ t~~ popul5ti:= Jf ~~~ s:il sts~~s :f ~he
field showed ttet, in 1~?6, adding solar oil ~ irrig2tion
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l&rn;l inst &r s s ec:.p led
contained 42.4 % lst - 3rd l~rvsl instsrs;
ples taken o:::. lOtb. hle.y con:::in-cd. 1.+8.5% f-J.pe.~. ~~eit~cr tb.e
young larvae ~or ~hs pupas ~0re affsc~ed by tt~ a~dition
of solar :oil •
...,.-~ ..,.... .,.- - .,...
”..J.. ....... ~ .....
~ ’ r. ’
tban
s~ ~2ou-£ziz than
::c..:; t·.’;O
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sna so ~t~e the sizes of t~e respective brco~s.
3) I’ he sixtb brooci, occur:Hng sbout Cc-c0ber, p:cedoc.ina:::ltly
tbe lsrgest e~ong ali six or seven an~~al ~;oods
of u:.otbs.
b) J:be inf1u6nce of tbs ;:;.aiu -.;eatber fectors 0n tl::.e
acti -;ity cf ;r.otbs:
:::te direct simple relationships jet-;laen tte activity
of tt8 =otts, as reprcsent~d jy tt~ log. catcc, ani eact
~·.: .. tver, tr_c~,· sr~- :iot~
r~~ in ~ltrs Vio~~t ~i~~t tra~s:
l~u.0 ot 51970 rr..ot:·.s cc.l-’tu.re:. ir: -.::·l-o ”Crjps dur:i.:-_e;
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Effect of ooth aensity (catch size):
A significantly nsgatLe correletion ( r = -0.753)
existed betwssn the total nUiaber of captured moths and
the lllale ratio in the catch. T’hs simple regression value
revealed that as the size of the catch increases by 7.36
moths/trap/ day on the averegs, the mele size in the sex
ratio aecreas.3 by ONE 3Ud vice versa.
Effect of temperature:
.b. significantly negetive correlation (r = -O.S3l) -;;as
C>btaincd. oet,Jeen the :rea=. ”Cemp. in tts area end the :r.ale
ratio in t:t:.e cetch of ot:.e t>Vo ligt.t tr::;:,s. Th·~ regxs csion
velue ir.dicated that ”iJit::: an average i:-_2rco:s;, of l.yc in
th~ i:::.:il~--- :::..ca:J. -cespc:rstc:rs t:.0 ::12-le. rs~io d.Gcrs~scs ·Jy
01\E, c :.-_G. ·.,:ice verse.
:2ffcct ot rcl~ti·.-e ~.. ll::.i.~ty:
:: tJ.~ CE.il:~7 8C&r:. releti ·v·e t:~tiC..itj· ::.:..:1 no .::ppc:.rent
e:fftct o!;, tt2 :12.10 rstic in ”’::”C_t cetct .•
d) The broods of egg-mass.cs i:c. cotton fields in t710
areas in two years;
~irst brQoci: bt::tY . .;en t:--_s first ·1;80:-: of Ju.1e ::..nC t2.e
oiadle of July, lastinc for ~bou~ six ~~eks.
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s~cond brood: from mid-July till tte third week of
.August covering a period of ~bout 4-5 weeks. The peak
of this brood occurred between 29th July and 5tt: .August.
Third brood: from the third week of J;ugust till the
tb;i..rd week of September (4 to 5 weeks long). Tb.e peak
occurred about the end of August end early September.
::C·he rela”::ive sizes of tte egg-p1ass broods:
1- The 1fe vel of iniest~tion represented by the nur;:.ber
of collected egg-masses was higher in 1975 than in
1976, and at .bbou-bziz than at Ebwan.
2- The first brood on co~ton was the lergest aconM .~e
tb.ree, --tereas the third wes tte =allest.
e) :r-,e ti::.e - relati·ve r-·orulation trends in tte pOJ(Ulation
of theo ce>tcon leaf-”orc e,;c;c-masses in Sai:ta S!ld in h:atay.
J:te resc.lcs revealed that the t;eneral averagt: of the
cotton leaf~orm population i~ Gakta (re~resentinE lower
:ri;gypt), during nine ye2roc (1969-1917) ’l.’as rather cor:sc;ant.
T’he calculated. slope, of c; he infeststicn line, was almost
zero.
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In ~atay (representing ~pper EgJ~t), the slope of
the infestation line, on log. oasis, was + 0.1659, giving
an indication of a grad~al increase ”in the insect’s population
duxing the last ten years (1968 - 19’77). Should
that increase continues at the same rate, the population
of the insect would be e.xptcted to react, in a few years’
time, double its average in 1968.
PART III
PREDIC1I!’~G .!’HE E:IZE OF _;:_:...::;:; J:.NSEC:r Is :rfiRSl
GR”iEHl,TIOl\ (EGG...l\IASSES) IN COI’TON FIELDS
a) 1he populati0n density of the i2matuxe stages (larvae
& ?upae) of sgodoptera littoralis in clover fields as
a basis f0r prediction:
The partial regression 2nalysis revealed ttst the
monthly recorcis of the soil stages in clovEr fielcis for
:.larch, J;pril ”:10. l.lay werE: respo::tsible f0r 97.52 % of t be
variability in the number )f egg-casses 0:1 cotton duxing
the followin€ June. Individual t values for each month
stowEd that ~~’” population in bpril (t = 2.6’78) bas the
strongEst bearing in this rE:spect.
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b) ~oths csptured in light treps during ~erch-~ay as
a basis for prediction’
The partial regression analysis indicated tha~ the
catch of moths during March, .April and 11ay was responsible,
collectively, for 97.6 % of the variability in the number
of egg-masses during June on cotton.
The ~nQividllal t valilee, for ec.c:-” ::.ontt separetely
indicated that the catch in J”ey (t=4.54E) was strongly
associated wit~ the infestetion level (egg-masses) in
Jllne.
It ·.’.O:.!ld thus epp£ar tte.t s prediction csl=:..:lstion,
based on ttc date of the :nsect’s soil steges in ~pril
end of tne coti cetches i:1 c.:s:;, ::_c;;,c pro:itlce tte neerest
corrt:;ct 11Bxpected.” ege:;-oc.ss ;:·~p~letio:-:. i.::t Ju:lt;.
c) :;:r-.e rGlc:tio:l of tr,e nL.:.::.oer off e::.ale ::10tr”s, c5ptured
in light trc.ps, to the. populc:tio::~ density of the cotton
l~sf~or::. egg-masses ir: cotto” fields:
In the first yesr (1?75) tte percial regression
an[;l;;~sis r€.vee.lcd. thc.t the: :::L:,;.r:.ter 0f GE;g-ma2sss on a
certc.oin date .,.ss strong,ly c..ssoci. t~c. ·.;it:. the mot!:J. catches
., ... ~- -. .. -
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of few D.igtts (3-4) earlier. :te respo!lsibi lH;.· of the
motb-cc:tches o:::. ttes.:, r::i”::.ts for tic- c-gg-r::c:ss :::.u;::Oer on
egg-c.ess generations of 1975. ·
In tte seco~d year (1~76) ths ~ott cstc~s Curing
tbe 3 :::.igtts jefore an~ 3 :::.igbts after a certei:::. dat.:, ~ere
ye er s 1 res u L· s , c:::lls
a ::.or~ iete.ilt=d st~dJ.,. of ttis pci::.t, pr..:;fE:rabl:: 7:it~ ..
severcl y&e.rs