99,"7i .' -
I% ' "
R'A )lI N '
CIRCULAR No 6. SEC'tikD SERIES
United States Department of .A riculture,
DIVISION OF ENTOMOLOGY
THE MEXICAN COTTON-BOLL WEEVIL.
i I i ,,,,,,I. Ii l, 1 I ,,i
Il-:N I" ;M, M.'I'I +,l:\s, < I \MN ".l Ill',r "1 \-',l|;h
Tbim inioti'l i- I ,i,-ll. lrra il-i %%utr il..,f lh, .hl ,," .,,,, Al ai ,.il ilii,,;iran
found ill ioltboi lielidm thr,, l.ui,,)i ir Tii, *.I-II. p.IIIi. tiiirli ,.ii ii 1 I VIII'' its eg< s inl tiC
uiluarem t na L Ill 1'. "- l' I.ir' .. il l' I, .].i],. .ii' l .i'|l. rl.i1 -hi." i .1L1 I I 1 i xuL, l
lmieasui ring it litle ,' v i- tr,.e-r ',_,bt-it pi iri 1 i li 1 l IJ-ilh %% In 11 llull .'r,' ji, jivr
within tfliet lniii- .til'
112olli uid i'r'l Il|111 r '
their ittrirnmilm.t.iiir .
Thu siqiuares -irt.licki, / T
tiilmatly droip. hit ,t \/ I [
tar hih daunti az''l 11.111< y 4^ *-^ jaT ^--3
a, il uIp', nu. iltilil , p *Ia.,. t --
il warft,"!. IVIrII 1:r.iiiZ'
tile se~laol. n1 uyl tIlws
cithr dry #,r r,,t i .. -
inall Misivrnii. miil l'6r E 7 c
(''mind in IIa r rr- i. ito -.1h' as ... ri a .mIuIl .,.; e ra
arnin "il M oI ii .. i I in i lii '"r. .1
Staiei> tof ..ulillI d I r.I 1111 i i: ; i 1mi; i' if %. ,11 I ll |T i (I ii Wii iti. 11 t to ll il
ine ii l, iiii .1 It .,pi|| 1[r.'.I i ll \ iii M iNn1-t- -'lia Nv-irs ",
crl ,'-'l Iar r", l r I n l r' n-i ill'. iil n 1i1iiii il l.-i t' i..' \ir- liid. p
nfarili it, t i" r',n ltr n 1 Itlr. sa. I A'l. .li'. l lIr. ,il. I .. in xlirr. i trm r.
to spiriail rhL l ii', i'h i i ht t ih i f.r,? ,,r t l.%r r.li ';' ,,I" [ \ i l ii,' i. other I.".I ,jI-
T hls :;li, ')ltll]> .i ll In.Il- "h ,, 1- it," m ill i'l,. -ri.,l I I[ ll.. I -I- i t I I I t lh, l.h ol <>I li ta.
son of 1I 91, the cro.s-b)arreil portions indivaLing the regions imrc 4ir less severely
d1:iiImit-il. ,aiid thle single-lined portion the region in which it will probably be
iujurios tlhe ciiming season.
II Ml.-T N(r BIE 'ONI.'Ut.E I) \\ [TI THE SIIARiI'Ii Or I'ER.
li 3lp\iio thlie iiUisrt is kLiionii to cotton growers ns the "-icudo,'" and in the
]lrofi ti ille region otton iplauters have inamied it the sharpshooterer." From the
fatt thnt this terim has been ust.l by the Brownsville cotton planters, someconfision
h;is arisen anioing planters living farther north, and nimany of them have supposed
that the iniect is nothing but a species which has beeu kiion fuir niny years in
FIG. 2.-Map showing the present known distribution of the cotton-boll weevil in T.a.i anil Mlexico.
Texas, and to which this same popular name of "sharpshooter" hai been applied.
In general, it may be said that whenever bolls or squares have been pierced bLy any
insect, and wilt in consequence, the work is called "sharpshooter work." not only
in Texas, but in Louisiana, Mississippi, and other portions of the cotton belt.
While several insects are engaged in this so-called sharpshooter work. the most
abundant one is that shown at fig. 3. This is the so-called "gl.issy-winged sharp-
shooter" (Homalodisca coagulata), belonging to an entirely different group of insects
fri',mi the Mexican cotton-boll weevil.
The glassy-winged sharpshooter has been present iu Texas cotton fields ever since
the cultivation of cotton bean, since it was originally not a cotton insect, but
fed upon the poplar tree. The Mexican cotton-boll weevil is not only quite a dif-
ferent insect, but it is a far more dangerous one. It is much more abundant and its
attacks upon bolls and squares are much more serious, since not only are the bolls
punctured with the beak, as is the case with the glassy-winged -harpishoorer, but
egg. are iui. ited and larvaw hatch, which feed upon the interior sub-taiice.
IA rRAl. 1IsT )t1T ANII IHA ITS.
Tit' ii.ii, rnI l,,irii y ,I, the M-. .111 cottnn.boll we evil is a .%, I iiii wr I I I kIwI
but nm III 11.1 lilt illw 1)\ i iIgsill, it is a tll,>si '
W\ iiI.' tlio iii, i hiti appear tiho ,: are .l,.iiiilt' in tile -,l.,ii ami .,ill-. aim
tinllrv:,- l:mhat i :in1l ir.il on the interior substance ..I the hud1 and bolls. The
larl' it" tlielt 11111 I. ,'i\ l o I the ill-
tiior ft thi" MNeI hi i 1 Il i, ,,t1la
thl' 1 hll, niE i-,'-;lli eat seedt or Ol
lllei I i tfler i',tili. The larva a
gram iilly rin lims Cull .1 1 .11 Iit, II
han uti y h, li til.% in lnif'lmri aeell I
O i lfl'H iirt i-lit 41/1. il i'viitce oin> latc \\ ll0 '^
itself. 1iil,4 inll 0.n it pJilla S. I o the-
The ,','li i-' ,ii.u.lly l;I til,,il next \ n H & \< Y
ihl onier rw:,ll otr ],ri- rii iirthe sI / jI "i\
boll. NlI ttait fl,,. m ,-v il. when l
trliiiw'lirilldi', hi:i.iinli to lake its '
wv iy tlhrolugh I1I, \. all i, va".i1"
In issuiling, itl hlis leaves amnill
hul t i h hl. periearp, wbNi'h I7 1 7
m arki tll,, <11 il lI, inlt .,.,! i f 11A' -'
lI.rk mif till Ir'lI As ninny inas aV
elv.'lii lhir,,:, :ve been ,'ri.,ill it .
oiir Ioll. Jc mf
.1 muliam Irm II i li abits of the I...-- --"
atalu*, ainld ;ill:ow in'Ii fr 1 lnlT-i-
en ,e.( lII slI / :;ind i iliII I ( I Oll
ditionw, tih l it r.,itinii ,i the life-V
Cc 'le i i" rol,.i l 1), abou< t i liri \ jI
davs. i ,.
III the I,'wls l l r-t l i '_'ili
*T- i i ^ A I LT PI .. ii ,-^ ii j',l*l, irli..i,.i,(*r: a. iidnlt 1?^t^Rfromt
in tIheiX. h, ee I ts were tirst .. u
atbovc; b, b Mle. ieVH w ; .5akt,,l s,.r i .,., ,r 1,I [.i. ,1 F -|
ItOl iCt .l ill Ii1 cottt)n fields I ..1i d, i Int A.ilm C, 4.&dti., of iiiid ti ia fI; "l, i..li .- .<.
alroilt thit(' 1iilshl I 1 AI A ughil to enlarg t d ;p i ttina ,I ovipoailor- ti:11t ii r i.:di .. ,I
lih, Ihl.t oif Siplantil-ir: in the
i.'sl> I l fe-til r,.siii 'I t'.i.ilhiii il a month earlier ; in ti : il tl dI r inillC teil r, .i.-I-I of
Tt'x:i- i B im' it-; ill~ and( ,,.,lml, ]., (l 111,1.11:: 1 .. as arly as M ay to lie. \li ,i]- i. ,tr
ditrts of)I ilin tiirt .ili<'.,111:. 'P in ll ,\I infested reUi4ns have te li received aS
follow -" (',riil l Ir l \l ., .i r ,l.r i-iI), i'liili ofAugust: I, ,* ill, last of \II,, I-
allil ,i"'l t' ,, l lr r. S.i',l I l r, Ir-t ,.I Ppi, nili,.
N Iliiir, 1, I known ..-i.. i 4 1,y 11,111 ,i tl ite number of ainnmial brools, Imt there
'i' ire idrI.ily two liroods in the newly infested s .irii ani in tio older 1 district,
"hlur, iIh.r r.ivils :]>li'.:ir in Ma and June, there must be> ftor lir more broods
iii I i% tii '1 .
At ".ili .izu-' lirnlut,. Coahuila, two \.I v small larv e wer, frime1d ii ll d, Novem-
lii -'3. :iil .t I r. n another was tiun1d1 illn a r,, 11 1ud, l ecemlMl r 12. I', is
Preisl, i- t milii'.,tea .-.I late brood if, indeed. the 1lrt ..- are ;t :111 ,n I'I.r. I,,.
layi 11g pr, ,;11%i. -,e-. on at all tliis. so that the broods are lli re or le' s ;1 r. ridl.ar
li',mi plant an.m. hbhit, t, j iiil, s,. 'A| doalt.-The iill\ food plant s- far as known
is (.,itttin. Tlihe adults seem to I.I-. liotli on thile buds alnd hills, and ..t h'u,.,iilf the
se.asli ais long as tIh. ','e..iih.r is warm. Ity nii, .,, If th ,l. i.1l i.i, .ii theend of its
beak. the w.'\inl eats tIhroluii.li theskin of tlO budor lslIl.l i. u.,Ill hide tlrmii
SptecinipenS M'erc fii1nd as late as December l1. :;,; i.li-, north of I r.,wn.-i illv, with
their be:;tk-4 sunk to full Itiioith in h >.l ,o:rwn i,. ,. i'olll lip[ .irtinly Ilth'iui u on the
Exterildil iniquiiiry show that the weevils ;lways r.inain withiu the squares or on
the bolls, and never je.il on the leaves, nor are they ever seen on the latter.
Tlii' weevils were fiIudl at San Tomas, and j. it norli of Brownsville, infesting
fields of sea-island cotton as badly as the upland variety. There seems no hope,
lihr Ilor'.. of tindling a variety of cotton that will not be attacked by it.
If the weevil has another looil plant, it will probably be found in the Monclova
region of Coahuila. No wild malvaceous plant could be found in the regions visited,
and the insect was not found on any other plant than cotton. Information obtained
froii Monclova states that the insect has never been known there on any other plant.
Oviposition.-The weevils deposit their eggs liret in iht. bluds, which are to be
found within the squares. WVhen the buds art all intfested, the lemiiiales oviposit in
the smallest bolls, then in tihe next largest, until all ar, attacked that arc still green.
Judging from the egg.laying habits of the genus, the feJuale makes the hole in the
bud or boll with her beak, and then turning around, applies the ti p of the abdomen
to the hole and deposits an egg therein. The Lame female may deposit a consider-
able number of eggs.
1plitt'ruiant of an infesfedfield.-As the weevils attack first of all the buds within
the squares, these usually die and drop off. Therefolbre, ;s -oon ais a field becomes
well infested, the presence of the insect can be toll at on, e by the Ifact that few or
no blooms are to be seen on the plants. A field imay be in full bloom, but as soon an
the insect gets well spread over it and accomplishes its work hardly .1 bloom will
be seen. Soon after the squares are attacked they mostly turn yellow and fall to
MIctlliod of hibernation.-A considerable percentage of' the weevils winter over in
the bolls, in the cells which they have formed therein, either as transformed weevils
or as pupa-, or perhaps even as larva!. That the miay sometimes winter as larvae
seems proven from the finding, as above mentioned, of very small larva- from the
last of November to the middle of December. They probably winter more fre-
quently as pupa-, the latter having been found in the bolls up to the middle of
December. Newly transforined adults werefound plentifully in the bolls alsoduriug
late fall and early winter.
But there are many other individuals belonging to eail hr broods which have
issued and certainly will not reenter the bolls to hibernate. The.i question is, Where
do these hibernates In San Juan Allende, where the fields arte irrigated, there are
many cracks in the earth, caused by the rapid dr% ing of the soil after irrigating.
On a cold day there it was found that soIme of the %%ee\ ils had crawled into these
cracks, and many weevils hibernate in such cracks and under clods of earth, under
leaves, and other refuse.
W<.e\ ils were also found in Allende on the cold day aliuove referred to (November
23) around the base of plants, under dr% fallen leaves.
In fields where neither cracks, clod., nor fallrun Ical % exist, ais happens often in
southern Texas, where the plants remain green until late in winter, niany weevils
probably winter in the squares and under the It-aves :t tlio base of the bolls. At
Alice and Beiiavide.,, Tex., the plants were perfectly gieen IDeceimber 12, there
li;, ihj-. been no frost. Ina field there, on that dit.ii ninny weevils were found inside
the squares, as many as four in one square ; alko at the bas-es of the bolls. Many
were iiitht -r tfccdiiignoruovipo'.itiiig. but were pet ft.'tly inactive. Thesquaresaftlord
excellent protection to the weevils in cold or in rainy wr'atlier. During rainy
weather in San Juan Al lii.d (No\ enimber 28) w ee\ ils were fund nunmerously huddled
in the squares 1ih this and fours.
Live '-.,\ il were found at Br.wnsville inside old bulls in March, showing that
the insect can -iu.,e'-sf'lly withstand quitese ere cold. TheWeatherBureau records
show that twice d,,,inm- the past winter severe frosts were experienced all over the
iilhi-. Il region. Up to April 1, although diligent search was inade. no hiiernating
beetles were found under leaves or in cracks in the ground around lrownsville.
lt(W Til IIsEU Ii1itlAiit.
I t iv t il to 1 1 .1% .t ra N 1, 11.1 oI Ih i I gI t Iy I IlI I it I o w 4w 1t 1 1|14f ..iii.-w f l
ialoim N ,li, tihi t. ,toil l lv, i .I r., i.i. are widely eparated %.% rli-trict ,1 in I I hih
Di, .maK,,li i" zr',." n It may have other food plants. ,Imu. .ha.. aa previously iitatV'l,
nil lin. It v %@ I|nti disovTered. "lh,,ii1.1 it be foundII that it i contfined It cotton, it
ban iar..lyll. Imeo carried from one o lii I, Viirm z 11 *.ilii to another iI I loads f
tniogiuiiim,,I ,,ioii 1 when 1i riig takenI to the aiI It i ll 1 l 1h iu artitlIetl I" 1.1. I thi t a
large s.luili're In' 111 future spread will Ie !i ItolIl abo-'t, 1 ,,itIjI whIn it ha' onMce
eut'ereld 1i ri-i',i of more or less cotinuou rotten ii, 1.1-. it (till spread 1.'. I i-l li I I n
ono tiell ti alot lnulir. seasti a -'i'fl season.
IVVESTI1 AT I IIY Til: II'A ITFM KENT t o A.tli1t1 LILU(IR.
Twelvei yviit.4 :-,1 a I'\% slWeiniene of this weevil were sn|it to the I1epartneint of
Agriullnir' I ron Mexieo, with the bare stateiiient tliut it waki known to feed iupoll
rottiol. N idltala were gii, 11. however, wlhieh indit ated that an iiim.ti..it i Nl, w4s
nec"s.ir' In ti iit.' sNummer of 18it it wad stnt to tohe I apartment by several eottoni
growers 1i1 lI'.;>i, atd it was at onee realized that uIless eheeklk the insect would
beeoimeo %m r.ry -rions eletni y to il., cotton '*r.-p of the I rill, 'I -i.iv, An ii,%.-i i..i-
lion wto1 i i11iiiidlately legni A special .m:2rill i'rot4 I l T% .I d I, i 1I, o Il. wI as
appiinu ti whu or1 1 ,1.I. tlil rouil the i l ier io.'.-I 1 411 of Ioti Texas and Mexico, and
galhierd ih t iii litun:m -iii11 11 iii w which tlhi circiltiar is aIsed, iost of the niatter
iutiKi tlir iialt iral history andi hablits of the inseIt h'.iTi ._i 11 iln his own words,
1h" hilm been ,'iiinporaril stationed at Brown sv ille, Iv\ for the |iirI ...- of -I il I i,,
the lil hislor% of the insect fli yel r ihi-iiifl., in the lhi., that 'sch an i .-FiL..
tiou will rexi .il some in-lit in the habitsI ,I the species whiic\li iiI render th.in ,.
tioio l' fliimif al iKr'il.. remedy possible. I'e, attention of the Texaas: .tlitiiuthoritic
has ipema encal'l lu hi, importance of the inect, amind to the .*p ip ,.ii danger of :il,, il,,
it to intf'reas .andl spread. I'h, lgi-I tur, *lui it- present session- ill nmsider
the 1divL ig- llmh ( i' o i ;thi ,tin,,_ ii ir I nl iiln-' .,iii ro-trictiv e tiK nre a .nd o if r,,'r. i..Fr
It is eirly .is \Vt to .i r.il remiedies. sinle the I, ,- Ii.p.Lrtm ii(, hi not hal. a;t o)ppmO-
tunityi tn i'illdUi t any extensive cxperiiitlntt. So illili y<1 t rteilailis to b1e twoiid oilt
aboh ut lilt- lift- 11 'i-ti %I' of thIe inseet tha :i.% K ii,,- which l a1il b1 e said in this di r,'tion
at prucmaiit ini-f be largely theoretical. I ia i,- as th la rv a does, in tihe inte rior of
the uiid ir lill. it cannot be reached 1, % rditHinary ineti, des. illI. ii, i an 'l li. It -
tioll of | 1:il- 1 (K'mit or london tipurple, as for tILe 'Ottoll[ wor, inmade wnhen the 1.,. 1
begio I i ilit;. 111aIv kill a certain I" r i', l I, I- ,I the adult 1,* i.. sin' e these '1..,.
to ,in,. e\TI.iii. lil the outside of)tII bolls.
1-i.11ii il, il ,if L.1.1l. howev er. e:;It be done, and the inars t can Ih la rgely red l'el
iU iiainlmh r-. 1'iy Iiekilia all 1ii. t b,-.I, ,ll.at tile time of th'eeottol pi'eking and hill I-
ing themn,. It .. eli cotton picker he provided with a il .1tr l|a1 in \vhl% to .I 1.1 i
the inf'ei4tl Imllk. it would not involve a great amount of extra labor to Oi aI. r
lithise as tt- iI. >tion is picked. Ill ri ,'ii, where other crops I al t>e groiw 1 it will he
well -i pr.nitl i.e rotation i'l' r.',,- anid inot L ,."'. eotntol t wo seiiN o in It -;csIitn i Hi i 1 1i
the 1.1, l.nI.
III.' Sal~ln I. to rl.
A pp r, cI:
'.I,- WV DAisNiY, Jr., EtlmhoalogiwL
Assistanitl 'er, i,,,-,.
\VA~-I II |,I\. D. !'.. April .'. 18S9'.
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