The apple-tree tent caterpillar (Malacasoma americana Fab.)


Material Information

The apple-tree tent caterpillar (Malacasoma americana Fab.)
Physical Description:
Quaintance, A. L ( Altus Lacy ), 1870-1958
Gov't. Print. Off. ( Washington )
Publication Date:

Record Information

Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 29651296
oclc - 27980018
System ID:

Full Text

C ,,, ,,,,%,N o., -"i
/ '. "? 1,.

C. I INolt, I

United Status epartwf -'f llu- T,

1,1I F %ii't1i:-THIci: HA I c 'I iii. it,. *
I~~~ ~ ~ f"i" */U I 'ru I I- I If fi~ i~I
IL. O. 0. HOWARD. Entomo]ogist *nd Chief lIf i.,i-. i t I~

T ~ ~ ~ ~~frJ Vll I I ? I l' f t 0,i~cl l 'III, \h ,-
11"1v1f1111'l1l:1',.illl I the l H iAlt- l ll~ .ti l
e p i n c 1 ih lard'1 ii ti 'elll hi cpl I I l, )
|!i A, I, ..1 yiAINT\Nfl-
hi 'harf/f! uf D+ dfh.'riilu rnlt'itf h.'*/ Inrrftufiil'iinio .o

'1'll," ,rii-pii,,ii-. eii-i,..]l nest. ov t er I .s of tois in ect ll,.. )
i 't' f11 11ilriir ,,i'l (i' l n tilee -.1i1ii,,1i ll 'ee :I", L:, lt iV Nliv snliii ,.
fr'l,''-,' ini ii'_'"h' t,', orecharids.. jiI elsewvhere. The Vl,"',i,;ii'i<"i' ;il-
ep'[>ill:ir- constrit tihe tnl for their pwoiection. and tliie-1. ;i( iiriu
..illill. ;ir,. I .iIii1 i: ylll enlari._,ilt as the *.,rva' -,I ,,v, ofteit ht n fJ o
o1" Itin're inl h,.I~i i aii mu dinieiieer, (lhe size .ii niL,, \withi tti liliinln'i



'I,," w ~

"I '.j *-*
, # ,t
" -

"". d


o|1 iIn~l :,tii i'I- in tih c-o hiy. TI:i .' ,l' I I,'- "1 feLd Ai ii tlit fohI
.i-,,. ,,"Ih' th'e tr--, -'!i|lI i:,._' the [ceive.- frcti/i llie lipiic-, ndjucell 1< tih,
iii'-t, silid if ihlierv le ('reai'l '(l(oiiie- in a tuee. a- i fi, ,',, ',iiv lh'
(-lt., 'li i ii. periIli ,.1 idImndatice. hlie 2.. i:lre Ili;iV tM' .. R 1l' dehi4rw'l
I,'.l ii.-< tile l|>t tlt'sPi- 'I 1 bare a-? in nmidvw iix'r.

-'i' '.- N". Is



The tent caterpillar is a native American species occurringg quite
Generally in the IUnited States front Canada south to Florida and
wvestw\ard about to the IRocky MN,,it;iaiim. From the Rockie- to the
Simi,,'ic'o,, lrdinpg to Dyar. the species is replaced by .*[dlawo-oma
faf!;!;.' Si r t, I. which rait,-- front Canada to Mexio, and this lat-
ter form in the Pacific Northwest is replaced 1bYv alacosoma plu-
,;Nl;f )yar.
The tent caterpillar has been a troublesome pest from the earliest
times. As stated by Fitch, its injuries in MIalsaclmitett, in the
years liC W'; and 1649 led the early settlers to term these caterpillar
years." At rather long and it rii'i1;i r intervals the caiterpi]l li r-, have
been excessively abundant in different parts of their range. but more
particularly in the New Etigh: iiil States. This species was among
the first to receive attention by the early American vntomolo-ist.
and the principal features in its life and habits have been known for
many years. Troiit-liotiut its extended distribution the insect is
likely to be abundant each year in one or more localities and often
over a considerable territory. Scattered nests are to be found usu-
ally d(11ingfl any 1ipriiL). though during some seasons these are biut
little in evidence.
The favorite food of the tent caterpillar is the wild cherry, and
this is probably its native food plant. Next to the wild clierr'y the
apple is apparently preferred. In the absence of its favorite food.
or under special conditions, it attacks many other piimt-. as plutm.
peach, thorn, pear, rose. and other members of this ,tnui,: also
beech, witch-i ia/.l, elm, maple, various species of willows, ,ik-. and
]i41;llr-,. etc. D'rine. periods of unusual abundance trees are more
Mr less completely defoliated, and at a time when li.\ i most need the
leaves for their growth or for the development of the fruit, and they
are materially weakened, t'lij rarely killed.


The ......./.Eg are deposited in masses or belts enciircliniii the
smaller twigs, as shown in fig. 2, and at a, fig. 1. Different 111g mases
may vary from one-half to three-fourths of an inch in length anl
contain from 150 to 250 e'",. The average number of 4-,1s in several
,.-. masses counted by Prof. V. 1I. Lowe on peach and apple was
ibot 2-21 each. Each -i, belt is deposited by an individual female
;nId ordinarily represents the entire number which she will deposit.
I'l-_. are placed on end. cemented closely i,.getlier, the whole oval-
slhaped mass ,.it,- finally covered with a layer of liriht-brown frothy
.I|',. which soon becomes tough, brittle. and g,_i tuning.
Ic (ir. 98]

/ >) ,,



tf,,11,,i,_' -ir ri.. \W l, the ,.,, f w rm ll tJ h r
es .ial by ,_.I,., II^ l ll their -1'-1t- N\oll~. ften (If Ire t1h-1 1 is
.'Or S 1Ml


-I, ~

\3 .~

In t. m tlt. ll' "'i [*luruf I'""' tirn llv, full ._',, 'n._ illlh .iiifi rfisiitiinL_ w ithli tn i ,,i_ ititil tln'

04 T '

F-n I >. -A 101) ten ra pllla..L i .l fn- 'i'' '1< 1, 'Ii' '1
knl n x att i ~ et *N a -isdri.. r nritl ~~~ I' I ~ua. L

f,,li.,-v out for food, and under these circumstances they may feed
upon the L-l0iiui'ii-m ', ,-friii,, of the -g_- mass.
7Th liia.- IIn the presence of food the lairve ,,egii the formation
of their nest in about two days from 1li;ilriii, usually .v.,iitir the
crotch formed by two limbs an(l ordinarily one that is not far from
the < mass. The caterpillars are ,,,i:,l'l.. those from one egg
mass ilnhabil iI,- one nest and r,..dli,, to'-,.r,.llir upon the ;ladjatreil
leaves. If two ,.',22 masses happen to be deposited close totlher, as
oil tlie same or adjacent twi-,. the resultii, caterpillars may unite
inii one nest. Wherever they go each larva spins a thread of silk, the
'. ,,g individuals i,:iigiii, suspended from a silken thread when
they drop), as do the (canlkerworms and many other larva'. Thle ne-tk,
it first small and iltl',li11g bult little -I''Iher, ire gradually iidirgi,'dl
as (lie caterpillars ir,,n\ and soon furnish ample protection. I 'lipn
close exaiiiination the nests of this species will be found to be made
up) of layers of silk, with room for the larva? between the layers.
Ac(cor i 11 '' to Fitch these layers are the result of the .t ,.lrpi -lir-'
habit of lyii,2 on thle outside of the nest duhiii: bright weather, tilhe
few restless individuals crax li2^' back and forth over thle re-'(iir
illass, spinning silk as they ,-,. soon foi millw a new layer. Diriniiii'
rainy and cloudyv weather thle larva? remain mostly withiin thie i'-t.
lbunt when the weather is favorable they feed at 1''ar intervals;
ai. li ,,riii to Fitch, in the nmlorniiii, in thie afternoon, and a._,iii -idur-
ing the night. Upon 1)0 .1iii nearly full _,','ir l the larva' wander
singly away front the nest, feed, i', upon snclhi pits as come to hand.
This waidl1riig habit preparatory to pupl)ation results in the scatter-
i1,.' of tlhe pul)pa' and greatly increases the chianices (of their escape
from destructiion froini their inulierous natllral enlnemies.
When full gi.,wil the caterpillars are about 2 inches ioz'.. cylin-
dri('al, deel) black in color, with a white stripe ;nil-" the back and
lateral ia1rking-. as shown in fi2. 1. b. On each side is a row of oval
i):ile-blue spots, one on the middle of each -,_.iiiit. and on the ante-
rior side of each is a broader, deep velvety-black spot. Ti".,, 1body- is
sparselv clothed with fine soft yellowish hairs (of v:ir\ i'ii- length.
thickest perhaps toward thle anterior -iid. where th,.y project forward
over thle black-colored lheadl. In about six weeks from hatclhiin,_ the
larva' become full grown and wander away from the iwet. as .tated1.
in search of suitable plac('es for pulp)ation.
Ti7 c(ooo.-Tlie larva' select for pupation :it\ convenient, more
or less secluded place, as under loose bark, in grass or brush under
trees, ,i,'II fences, etc. If close to outbuildings the larvae often make
their cocoons in the : ;ilr,-- 1 .I.l,,g the sides, in window c:liiiL,.-. etc.
The cocoon, shown at d. fig. 1. is oval in -hli:pe, about 1 inch lii.
Iand composed exteriorly of ,.,:r-e. loose, whitish threads of silk
[ C('ir. 9]

,ir ., ,,i.l~ l ." lij i ,,xt.i ia | .,Ilin ,n l -lib liain r,_. Ix. xa* ilk I ,f i li

r:ruo|| is)( iltli\)'d l ;1r il( i-(llii\\ ]||>()o)) |i'r )())l|l l ;lti i'f| u lr ''l-l
Ir ar_ rI f liil tt f u a It i t1 i1 Hia 1 Ii- x, rt I a ll

itlCOhHW, alil i hilh litlt'a t frhi I o l 1f tb lc I ,I +. ,> A a illI,,P
lho f,, r, (i, e l ; t'il q n hll'' a ; lllI i l llli 1t IiIl-I loll' J V lo -

uiIs ;lI Illli'e .ini I' ill 1it 1 fo> l I witII i n xi ,l I. ha' alli- will ix a

T/K' ini r a.ii-,tl' i n1 hre.. t._, <, l 'u, "I li r '2 iii i ; i7 1 liort: Ill i rin il, ;, t t lif 1 I'- Il i 'r l.Il 1 ;i l l l i

tt \it l-.x|a
1" lI 1 It I!\, W hII I

hllthil Iw' lo lIl- I lii'i s!1 es of lt n th ,\ i' H iilijr i i \ -

..... 1 ,,. it r,'l;llr ' lera I ii e f;. ir< aila ',l r ,, I lylol l pito a tlt, l w it>i n ii iu r ( .\| 11 i wit (InI f i h' I. l i lb a I'r in *lr
(li h l* i I I i l f Ir la i xX ir< I ii i t l e -i- llr i t, 1 h II IKi-.;i

1*_*L ir ;in' (laI)j( llit iI'( ''l', i it lit1 i l,' ,,1 a ix l ir!ai'H n i hal r Ii l I '.1,rI '

inli'rj~ii ir.h,1 I, rilll~iiv plara'il+ a 1 11 1 1w\+ a' l a 1 ii, i I+ lFI, eII 111 lhIi'v
ml1,' hi er l f iiar : ltf ''na lia; .. i lAw u i !'-e r'd j wi 1 r' -
.NATUlAII. EN:ME'1llnx.

Th'in fp cic isffl A t tll H ladh I;,s I Iic .1 /

I tr| a' .lii: l u it l "i a' .N'(li' h f.',,tp f /iir-w iiii,.. in i'-~. o1 /l i -iic
I lyi.'iote(!ltio~ 113 l.rii Ttir>W F'. Iwl-lnn rtlicM ol' ilc til *:,t'-,|ill,, n',,lt i. tn*r. s l ]h itn:l' l~ nirv l{lr or ."'. i- *li n .*i hi. *< 1,i~ t", '"oI *l for, i i liei
ll f (Il Iod d i II1 ." t I. %' 7 ., Ix i 'n i i l 1 '.
.... i I' S 1' |. / I f l r I I .I ,.
i ln ,,'!I d.1" I"re- ord l '<' H ", I *, p-; 1 lVtihl t ,t kio <',>t s inct .

r 't 1 ' 1A
;!ill I[.l\ rp, i' i Thliin \\. F. F'^-".' :

.',,..n 1' 1 :' -11' 1 s I~v. H iil ( r '-. \ 'tn i i ilr / fi '/ '

K':r No96 1 L

'l,'oai ioelatnl,( IphIl( BIr. il!' ( ), andl thle dipteron Frontina
hi, t,(4 "Will.
Among plredaccous insects are several species of .,_iill I eetetle,
which are saidt to feed upon the larvae, ; ii ,iti. then ('alosoma scruta-
tor Fab. A\iiiii-" the IIeiniptera Mr. A. II. KilLailI has observed
several species of Podisus attacking the larva (P.',,;. ,,4eplidus 'hl..
P. wmodestus Dall., and P. Uhlw'nr Tl.) and the rudiviid 1;-
p/oits 1,rdUtts Stal. Also. ;gi.,i ,ili.-- to Professor Bruner, Podi.'s
vpioioffN I)all. and IPenbll,. (.itlds .;\iv are enemies of the caterpil-
ia rs.
XWhile most iini-. as a rule, do not feed on h;iirv larva, such as
the tent caterpillar, yet several species are known to iictlude this
insect in their diet, as thlie )black-billed an(d yeliow-billed ,iik.,i,. the
bluejay, and, accord'lini to M'. EItE. '. l'orbush, the crow, clhickladee.

C ej 61yv
Fi(;. "..-P'iniplo (conquiitor, an important pairaiiite -of the tent caterpillar: a, Larva.
enlarged: b, head of same, still more i, l, '.-; c. pupa; d, adult female, enlarged.
c, f. end of abdomen of adult male. still more enlarged. (From Fourth Rept. I'. .
Entom. Comm.)
Baltimore oriole, red-eyed vireo, (chipping, sparrow, and yellow war-
bler. Kirkland states that the common toad feeds glreelily on tent
caterpillars, he haviiig found in their stomachs the remains of froim
15 to 20, and in one instance 37 of these larva,.
The caterpillars are also subi,'t to destruction by a bacterial di--
ease, especially when they become grown or nearly so, and -ick. slug-
gish individuals nimay oft ., be ol)bserved lyviitr,, outside at fill] lengti
on the nest. Larva, killed Iy this disease are soft-liodlieil. the skin
easily ruiii rilg and permit ii.- thle escape of the liquid decoiupoe'ld
body contents.
Reior'ul of utxess. trfee.-As hias been stated, the unsightly nests
of tlie tent caterpillars are especially apt to be found on wild cherry.
apple. and other trees gni. i,._ :il,,ii, r,:ld-ilr-.- fences, and elsewhere.
I (Cir. 9S]

Id uiiot rawe suclh tree.- could ,FilI~il d le h eIemoved with( iout I i-:ii
v.i, i .e, a ld (heir reIino, l tF u iil .I, ill rIIr Ii Iif' in I I IrII < f tl i-
pest by ; le s n ii:' teir] |'a\,iuiril f+t)i~ -uplyI .
( /Irt' * I -iI V ii ti 1 i r nii~i )i t period of 1 r e1 oflrh i
the leaves arc ',,i th -._ nii ces airc faii ly 'oisp oi'uo.s. ;ind witli :i
litith practice maI I be recudilv fliiml: i it i llarii tli;l tlFi'V ].Floii l I.I
cut off II I t I firiit* rt
f (i, \ ,.Ir, ot lii.M- iii lie i ilie I iiniy a1, | rl |t 111r1
likely to I Ii clioscn lx tI in' Iilr ut Iui Itli fIr ,(hIF < 'p .i i<> f I 'r 'I.- .'
xi l su ht ree- it least l(nlhl I)". >,*irlnil if it i 1t |ir;<'t( i ;ill, i,[
extenl tl Ie work to tie (r(l;rd l s :i I I iou I i i- i ai 1 111' It Ii, I, -
hi~led w ithl lU'n,, iL';,.' to .. ....l ariv:n tl ,:..*. ;++i n l h) lo ko+ut shl ,uiltl t,(' l ljtt
not ,'inl for the ..':- of tlii i i-(lt
b ili ',, ti t' -* ;li l (a(n', )( I t I /I
other injuriotIs SJMT'ei whih x m-- r / .Fil '
tht winter olu' the11 1 i r ve-.+
D, -;STB
\,'-l,'e(t to s(airc'i oiltt tl r. .-.:' ,,
lashes ,],.liii,:i the winter will r'-ii y
inr tile ;i '"'.iraiee of l I' ltir ;> /
aloIt It the ,tilie til treeI ;Iv III) tit I -A '
f',i It fI I ._,. I. TIhIe I ie-S-, at -i
.small, are so1t s ilc1ereatd i- 1iz+ i, aopted

ofI'Il tle i(T li. I I fti' *lV' 11:111"I or+._.+
pillars are destroy ell as soti 1 hI.'..I I I(l II r
small ests afet detected i I tie wile i.. ri + .> ',+.r,,
p re + v e n t I' ,l itl ,,r d e fo )lia t io )n o )f t lie *" + +' ++"**" **" *+ "' *i'+"t+ '+' -+ + s +,," ,-
tre es, and tlhe rille should be+ ashdlptetu ++;t+) F,++I++l'+ltee
to destroy tNhem I)ro tl it sooi ;1 dis'ored. II tis woI 1 itr
Fof tWO ii' ts li le esoted t. inamele 1 I ,-tr' citio l hx \va d cIr
with a tor-ch.
Vhein {It tcn n ie irea f. llie Iiii+il li out with a CArIIish. ,
wrilh 7hve1 halinl o)r oitierx ise. ;lil i i lhi -x I vl irlil-iedi on tie
lroin d, ca re i *ii ,,i 1Iii to) ih-tIFoxv inv iit ill erliI I i- li ixch l it i ;iy hifax
rtniainedl oli the I tee.
The ns-e of a torcl to olii )il1thie lie-it wxili often ihe foXundlll
convenieu it, (estlpein:tlly wh ni these occ'-1 in 1he i '-.i.,, i9rif ri f ilf' of
An ii~sl(itos tiirchii. siilhi iis advei't isedt !x *'eiL-liii. xx will Ier -a;itf~irfiorx.
or one may h)e inade siniply lv ty i ." ri',- to tli, ei d o f ;i a pole. F1,.
asb)estos o1" r;:i- ;ire sat llr;ltil d with keros'(enie :i lign F ]hited altil tint'
caterpillars as i'.,r F iS possihT-l-iiie 1li l'ii. Somii(ie c;ate'rlnillai's-. iiowx evr.
are likely to escapie, fallh ",- l'i'',r the '-t )iu iou i e ;1' |p)|li t(.iiiioui of (lit
torch. In ii-i,-1, thle tiltli ,i.* ii V are is I ecs;iry tihat lno inilnlrt~ii i
tri- n',i

I I11IlBB I III1IIIII)IDltII 1111111l11
8 3 1262 09216 5454
injury be d(lone the tree, it should i,-A be used in burning out nes-.
except in the smaller lbinii-hei.- and twig-. the killilg of wvIi.h AwIld
be of Ino special importance. Nests in the larg',Ler limb, -Iihil I e
destr,,-,,l by Iaidil. as the use of the torch may kill the bark. re-lultilng
in perlmarent iiijiiry.
S,/..,,,',/ with (r.sernwals.-Tent caterpillars are readily Ldestroyed
by arsenicals sprayed oni foliage 'of trees iiinfelel by them. )Dr. II. 'T.
Feriinald's careful experiments atmd those of Professor Lowe iii deter-
I iiig- the amount of poison necessary to kill the caterpillar- show
that thie latter are very sensitive and are killed in from twot'o to tlree
days by the use of Paris green at the rate of 1 pound to 300 or 400
gallons of water.
(O)rchards or trees sprayed with arsenicals in the .,priing for the
(Tohli. moth, cankerwormnis, or similar insects will be Ikept practi-
cally free from tent caterpillar-, and this species rnirelv rcqiiire- at-
tention at the hands of the up-to-date commercial fruit _'row\ve. It
will be troublesome in the scattered trees around the liuiv ort in the
mall orchard which is not I,.' ,lILirly sprayed. On sulli trees thlie
nests will likely be in evidence ,v'.V -iring. and liirillg -, Occ'a-ionll
years the caterpillars may be excessiverly alndiilan(. ollipletely de-
foli.itingu the trees.
Even in the small home orchard of a dozen or more tree- it will
be found highly *profitable to adopt a -\ tcrii of -pravin. I whlilh will
control not only tent caterpillars but such serious pests a. thie oillint
motlhi. (;iiikci,'iriii-. various bud and leaf feeinur ii-,ect-. ;i]d will
.ireatly red(luce injury from the curculio.
Any of tihe arsenical insecticides may be ,i-dl. as Pari, green.
Scheele's ,reen, arsenate of lead, etc. The former two are 11'4(I at
Ilie raIte of 1 pound to 150 or 2'11) 'llons of water, and ie latwitr ;It
the rate of 2 pounds to 50) gallons of water, tihe milk of lime fro,',i an
equal amount by weight of stone liiim. as 1)0poison eItd. leinL',. adldle:d to
neutralize any caustic effect of thle arsenical on the f, ia-e. Pref-
erably, however, the poisons should be used in Bordealix mixture.
thulls eff, ,il'i a combination treatment for insects uand I'Iiiiii di~-
ease+. On stone fruits, such as cherry, .I Il,, and plum. .ir-elic iel-
;ire likely to cause injury to fli:w,, and must be used with caution if
at all. (n siuchI trees the arsenate of lead is pIrif'r;dhii. a- it i- I.-
injurious to filiaig. anid on all trees- sticks much better. III -Iprv.iing
for thle tent caterpillar only, appl)lications should be ma, h\ %IhIil thi.
calterpillars are Yet small, as these succlmll)b more ,iiiidi I) o Ii-,'i-
tihar when more nearly full grown, and prompt 'tI en lIlet -top- fill-
thler defoliation of the trees.
Approved :
Sc WV ASmIrN'TON, D). C.. Dec.emr ., I''"".
I Cir. 9S]j