The white-pine weevil


Material Information

The white-pine weevil
Physical Description:
Hopkins, A. D ( Andrew Delmar ), 1857-1948
United States -- Bureau of Entomology
United States. Dept. of Agriculture. Bureau of Entomology ( Washington, D.C. )
Publication Date:

Record Information

Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 29651646
oclc - 27941488
System ID:

Full Text

f i f r ' i ,,'* ,

CIRCULAR NO 90 t 'ut4J r 1t t

I'iiif.! AL 5TT-I..
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1 { .'i ",. /,

.i I:.. A Ji\ ll I ,_

T h e. B u. r, :1 1 i I'Fi0 l l, '111[ 11,1'%I, h e ,) ,,i,., ,._ \ -I, III ......
JIlie IHiiri:iii 'it ljiiirjiirl' g liJ$ been *'Tili.' Tlii '\ ~i in ii nT i **'

triii in:il shoots of ,Il i it.r-i in the I li, if "i i, thn result of wih li will :e
pthli'hit.l in the r,.",ii.1r te 1hnical and i.,jI'll Ir bulletins; hut since

!i f" t
Flt ^ r' *. )i r r i in i lr l .A t l,*ullrIK r"Ii ia ir:Il m .I f a
[ i i

these can not be 1 --', I in time to he ha- bee, I to ,.\i the iii i t. i, \lii i it of iniiin diate r. -
ti,.il iiii]),rt.liii in rI,'.ir'l to one ,l the most destruc tive of these weevils.

Tlih "liit, -piiimr weevil is a soiew [hat lii- t',. hrownish snout te il,
4 to 5 m. in I rnl,. ,ii:i\ii,_' the thorax il ':. tr i miarked with irr, 1-
ular :pi it. if brown and white s ale1 ( iI. 1, (). '1!,. winter is passed
in ti, iilialt -t.i evidently in the rlii,.1 1 beetles comiie out 1.f
Ilih ir winter il irt rr l i ny i M iy, an1 ,S1 r fV V 1i L fIor a f, I
dia.vz on the bark f the liviivi w_ lit .pin, i, nIrii i shIoots de-posit their

1' I'II... b r're I'0.,-k ; O rd er I ', T I t .,lrr .. .,'i '. I ,, .. I, .

eggs in punctures in the bark of the shoot of the previous year's growth,
placing ine ,1r two eggs in a pit or cavity in the inner bark inade by
the beak of the riiother beetle. In
If/ from six to ten days the eggs begin
l.. / to hatch into silall white grubs
1\" \ (larva), whiicli .it Iir-t 1,re u,,ua:lly
S' \\/ "found in litn', iiaiili.r- feeding
/ upon the inner I.,rk :alI aniiijium I
.l 2 (se(e fi1 2). 'l'liTh v lu ;Lllly work
S' ^ /// downward and -,iiitiiice extend
Nk \-.\ Itheir work into the hark of tlie
S'' // 2-year-old stei, awtil base of the
; branches. By the time thle larvae
/ have completed l tlir devehlopnient
: \(ig. 1, b) they a-ire greatly' reduced
\ / in numbers by iiat ura I eneni ies and
. \ other causes. The .-uirviv\ors bur-
\ / / row into the wood or pith or the
.\\, l / [/ _.. terminal and excavate individual
\ \ /. t transformation ellsls, which they
line and cover with excelsior-like
1)/ .i / bh ii -,.. Intlfe-, t.-lk theytrani -
\ J' .^* '7 fori to pupaw f'i tig. 1, r) rind
\ i/ idalulnt ., and ,luri'iu .1l]y anI August
V / /of the same y,.ir. wlit-iI tlh- adults
Si / are fully maturedI, Ilit-y I,-,re their
''IW / \.,\ out and serk suitaliIle places
\' // in which to i'a-s tie \\
.^// INOX(N LIFE l.' Till: .. I)l.T.
From recordnihl .-derv.iticins on
., .'' l som e species ,I I',::ii .- or iark
\ weevilss by "11\',-ti,:;it ,r: in Eiirope,
S"!! a1nd( on re'pr',-,iitl:li ,V's it other
:11 llied forms in l :rI)pe indl in this
l country, it apl' thi:il an indi-
vidual adult iiV li\te tiwo or three
||1|pyears and will em.'psirit ..!. each
SEASO' N.\I. 111 'I'- 1IV.
Flo, 2..- Whiil- pine n\iv\vil: Newly hatched larvw The beetles art' .it'li\., f rom ;llltout
at work . vitoro)s terminal "hoot of white tie 1st to the l.'lih ..t .M;I 4-11 later.
I)iIHt'. (Authior's illustraliol.) .
v depending on 1 i. i ii liilii., anl
weather. Eg.s are evidently deposited diniii-- the Irinciiil activity cif
tihe adults, possibly ,ltiiii,, the r,.1,t,.r part of the n,,itli ,f M.lay. Tlhe


wridi ,f i ,i-v 1,ii ., ,t .. the larw varie I'I" I Il'y. .I.-.I mnore I II. -
110 0te ilf.),: i lr l -, 1 ,' ; 111tin ul,0 f )1, -1n11 1 i- i+ f,\ll '. l n p~f'l 1
i,,.fl', gome of thie I's I.E*lIliat1 lieS ill tllic OF IN 5 -lit lIs I i 11 I-1I 1 Pl*t Oli-
folrth as I =1, all!.i"il,1 tIn w 11r Hl w1hirh 1 -1tl aite itti\y hilyIV l10,11
d,' ....iti.l ;t alo it tIhn sat r ti e. Thlfn'. is ;i ls a 'I 1idh Ii.' in th1,
l).rii,,l ,F traIlnformltati>li to tl< iI,, i atndl adl lts- :itIl i. ,1 it thl' +lIter-
grnt ,. ,,I the lattrt T hIuIII i I hf t I1 -1 -, -,- ;ir<> .I .I 1... ;- 1Ht I hl lt tle j Stl
f, M ,y :at M. ill.i.I. lI'i.. li, titud -i I t' 2 1 -ltituih' 1 2.'1" (u ,I '"" tfiI1t, t1)I
lirH -t f will 6,,.zij to 10ti h :h1 it thi f H C ltl l f It I'.. tli<+ i;,-i larva* w ill
be full ..r, ii h a out Inly 1 he 14 '11-1 tr1tfrnaitio's t, te pui mpa will
take I1,11 i ;a i-,lt th about Jtho 2., unld ailts- will continue to cone' ouil iilil thei i -I i;irt
of S1pti it11 ,r. J'l i, I. ,lly aill w ill lt ut 1.% Si l)tltiiiber 1F l ii prill-
Vi'i l l 1ri,,l of ,, ,-. i,,, L H vcrA W is 11.. I, .h-ut thn 25th l f July to
tlit middle of Alu-'l-I

Thi. white ipii, is the tree normally itta iked, huit tfl- wevil is lcca-
si,,nilly found in the terminal o ttopnio't ra'Iches, ot tlie native a;1d
cultivated tliir,'-. the jack pine., and '- '. i. i i in the pitch pine or
oitlir eastern pines. T'he attack is riiii i .t tho t i small to I sap-
tiln- and |I,,1' -t I-' in tie dev eloplwint of the tre.I

DI- I I:1I"r ION.

Our records indicate that this weevil tIllw tihe natural r ii._' of tlhe
whlite pii6. fr',, s:ithwetstern North Carolina into New 8rtoswiuck and ;an'l westward into Wisconsi-n.

\I:DENri+ OtF ATTAx K.

Tit' lir-i evidence of attack on thoe li',i, terminals is the I 1xudationi
I*f I'r-li. clear, and 1-1 iIi tI. ,1r, I '- of resin. 1''III, closer exam iniIIation1
fr,'-hi l 1in l,,.-Ik, pIi, I n, es are b found in thte lark (11_ 2), and am t tihe
same time tilte i, ,ii-l. ii' i,- heetles may lt-e ,iiiI on thle t!ernintal but
uip',i the ipprr'>., ,i .41 thle observer tle beetles will -liten let a',, their
I',, ,1111911, and f.ill to the -r','I,. where l,, y ,',l 1f. i- ,* .1 l, In a few
l.y- after the Iir-1 attack the i, .i tl iern ini tls w ill have thle resin
more or less abundant and *i-pi, i'1,1- over the greater part of the sur-
face. The 1i.1 evidence that the terminals are infested within larva- is
the stunted, unhealthy appearance of the ,,,iii,_ -22,'.il, at the tip.
which I 1i I die, the i,,.,l, ,iJriii,;' r' I I.,wisl I and Ilater
Tl' time if development of the broods to lIlIt "iil he indicated Ihy
the Iir.-t .11ip.Ir.i i ,i of dead lIp-
Mld work ,', the weevil is evidenced iv the presence of ,.1 ,1 i.1 ter-


Fii. 3.-Work of white-pine weevil, showing (haraett r ..f ;i r v chip eci nomiim iipiil andl<
a, Vigorous teartiinl shoot, -in.'.'ill.: co ditiou of !i4% i 'r .%lii at time I-'ir.r art iran-forminh
to( ahduh b. :; \-year-old top, -h- imw ho]w Nlarva ho %' iiiiera!.-.I friin iCrnIiil To Ti he j u.d 3
year old internodes; c, chip cocoon and pupal iL-1i, nalura l *ize (iriKinal )

finals in the forks
,,f the .,,iii.;, trees
(fil 4), and thei re-
suill of their work 'k
will be evident in the
,lfiirnl, growth, *I
lar-W, forks, and
hroail, low crowns of1
both vmllg and oldh
trf.: (tiL' 5). ,t
< ,I'I.1.\> 'I' I O THE
I.\M \'.I
Thr. l:11,.i, alndt
loss. as ,itTr, iii.. the
commercial trr. con- ,,.
sist: not only in the I
dea:itli of the terminal
sl,, s, but in subse- ,
lIvI'nt abnormal de-
v\', in iiift of the
tr'e- so injured. The "
,lyins ,f the h..i'1iiit
shoot throws the next
yeair- i.grm 'tl, into the "
upper lateral -li, o ,I-
whi h res ults in a
fork, I and iin a n y -
branche i,. Each
branch ]Irclii a
vigirpn- ter in l, 11;1
;ild All i', lp,'r for .'
Ir1iiurshlipin fii ,,
the crown. In suce-
ctdilig years t I he
more viL 3,ir1 l' termIi-
nals ,f the tplii' f 1
branches are at- ';
tacked and killed, .
c:iusing ii or+ branch- ;ll
eC. and thus ,tT.1 -
tually pr,,',ntill.l the i; i tr na1
Fl I. Wrk t,!whiteqiTe w ,*i~~ zr~~i f ~tria
dleveloipn to'i f f the i yarold t

n rnorm.1 t raii glit trunk
and symiietrit il crown necessary to a tree of commercial value.

Tlie extent of di;iiagrg-, as ,ifTe-wt'in natural rfp1niilu.tiin. planla-
tinn~s, .'iinl tini-
l"'r of comnwtr-
;" riia1 ,iz(e in the
tirest, is difficult
/ to estiniate but
i t is an impor-
L tLint item to be
Sch.airgedl to the
losses iII C oln-
'il-r(i:al growvt h
.1- u-t%%I l Ie pine an,
,' is therefore a for-
..nstr problems
wh~i.i, must de-

:. .. riiand special at-
't "ititi- tin il ti e
future manage-
g iI11mlt of rood-
-hlutis and forests,
Wherever tie tree
predoi inlates.

1N F A VC] R .% N I)


The most fa-
vt'rabhe condii-
tion for serious
injury by this
weevil consists
in a scattering or
,pi-n pure stand
^1if imig white
iiy w-Ihere the
growth is healthy
:and! rapid, such
as is found in
Oipei planta-
tions, in ahan-
dhneil fiehls, and
Fiw. 5.-Work of white-pine weevil, showing result of killed terminal
shoot in 8-year-old top of large .aphng (Original.) around the bor-

ders of dense stands w he-rever the soil and other ci editions are most
f,i\,,r llr,, i'ni r ili ,l *r,," th .
'l'li., cinditioIns for injllr are sl v r -,r Iti, fe se pI ure
st.iiil-. and mixe+1d st:ulds of pihe mitid hardwoodil.
lII'I, r the foriaer Ionditin I tte IIIii1 vi' Ii I- termhi als are espt-
Si.,ll\ ,,,,',l !IH *.ii ,llir: places t[rt tih' weevil ;l-I where tliesI areI
killt 1. thn' vital i, i-'. of the trey iH thiroxx inhto tin+ liitt'rc l ltraiut'hl-s.
()|'>i staiuds, tueretfore, favor tlit' uiuv' lojiiuut t 1' !,i -' l u!tcl'Ht a;nd a
. 1i,;. ili i,'. crown, whi il' ii, r co1,1itioii' uni iv rabhl, to wi'-vil hijii'.
lc' termiiiun is r< siiialler akndl t v it Ii ... aare killed, tIhi closa stand a or
lateral shade will teIndi to 1ili. II, sI up- a ward or vertical ,,,l of the
topinI.-t branches, the -itI. i onlle 1L, l1 -_ the leadl d ; Oa I ro f I i-.-

NA I I ; Xl, 1 ENI+IES. %I

N. in ,'luiii 11.i.I1-it ir alld 'i ili ',i iu-sect t'iertuin e attack the ld evelop-
ing broods in the terminals. Woodlpeckers, :lhf, feed on the matured

... {.. ..


6 tinrr I f aiH' it i >i rB t<, lu i t tirc-ciity u ,<' it ] ,,,' fit it tt er'Otnd hin
en It Ul,

l1arva, iLI, anl adults. SonIc of the larv' .. i.i, Illy die from
Ii:,.t,. and when .ii .I n.iult rs of them ;1rt' crowIded I ,'' II,, r tihe
.ir..Ir nres pi" I, to feed on the staller ,i11 -, so that on the I',.r A ',
not more than front n to 5 per cent of the h1tc1he 1 larva' ever reach
n.tiIt'ity and i Ii from the intf'-i, terminals. low ever, each
fi,:ile is capta le of ,I ... -iti,, more than o e' hundred i 'i- each \,..1
for several vears; thus the 1. i"' d,.ti,,- are continuous. l)irin, some
y -a' the ,1.11, u',' will be -ligl i. while in other years it will be ,.rv
-,\ ,.r,. the amount of iujiiry ,rtpii,'iiiL on the number of adults that
survive and the conditions presented for their attack and I 1 \1 liii ,t.
It "ill be seenI that in the successful control of this -- as in the
control of forest insects in FI 1.i 1.d. much depends on special features in


8 3 1262 09216 4630

the general methods of forest management which will bring about
unfav-orable -'.ornlitinns fir injury :in(l thus prevent loss.
It %%ill ieaIi, le seen how important it is to know the principal facts
in elg;ird to the life history and habits of the insect, in order to secure
the Icst rt.-ults fro' li i-metlhocd. it ii management and of direct control.
Hlert-,, liref this ,lrivve-r l:IH l.tIen (,nfuseil with another species with
x'vPry lilHiitiit li.ilit. :nl ,'niie cit tlijti piulilishedl data and recommen-
l.ilit'Iiis I,.-I .il nI I i, Ii roilt n-i i ,n ;Ir' ol r o n V;Llue.
T"i"1 \"lilte- piii. w- ''il i.iarelvy, if efver, t lie winter in the termi-
li,:l. 'l'll ie... evidhl-n e inii,-;Lt thalitl it never breeds in the thick
Ihi.rk -in tlie t trunk, Mid -t.1 .t, p ti. lie ii te pine or other pines; thus
it ain ,it lie trap;edl in tlie trunks of flled, and girdled pine.


T'hlie ,rily pra:tic:il nietliid. r-if destroying the weevil appears to be the
treaitniont iif thle inlftetld teriinals, and to secure the best results spe-
'i'al iatteiti'oin nmu t I' ,iv en to ert.ain important details.
Ift' the infesltdl terniili.ils nre cut or broken during June and July and
liiurned. thc. Ihnl'd. 'Ai thie \%ee\il will 1ie effectuallyv destroyed, but vast
lnulliber, i" iilatuiral citie-niijs %ill ailsco be destroyed. A better method
is to :,olIe. t lle lerniiin:i]s idulr-inlg the tirst half of July before the beetles
lI,_,in tI eiergt :indI to plhi. llthiemn in tight Ibarrels securely covered
\\itli wire tln-:(.r-en (ittin l on i1, or bothli ends (see fig. 6). The bar-
rels should bie l]t in tlie groves, so that the parasites and other
riii-,is iieia v ,iplt.. wltilfe tle Ivetles peihlih. After the 1st of October
thlie %%ril. iill ,ll ho 'lend. ;iiil the netting may then lie removed,
.iltiitugh thle barIIls. w\itl their contents should be left until the follow-
iu-,i .Ilnet- til illh,% illi (e,,i-'pe il' the later developing and larger parasites.
T're li:irtel -liultil I,,t lie prlace-l in a position to collect rain. It is
Ii -.;irv, 1i.wiir, il this imetliold ie ad',llpted, that it he repeated two
1i ll11i"ret \1 ;i- in ..Il,' t:-ii'n in th li sanil Incalit.y, in order to catch the
.' .-i\' 1irqi"ils rriiin tli il ld parenlit beetles thait live over from pre-
ci.d ing ,ri -.

Thi- il.i,,iiiil- .inil rt'e, ,eiiiln-dl;ioiin in thilis circular are based on recent.
.,,I, %'l iln ;iiil iri .'-;iiriii 'i lS il uI.%t e iiihor aind hLy lield A .:.istunt \W F. Fiske,
.Iij -e-t ; .1 i p:iri i .\ (ilil ," \I liH lih I- hlhiithieri t'o II i publiislied.
A proved :
].\AIES \\VII,,iN,
&,;t- Ivur i .ni Agjri<'rlf tre.

\\' -.IIINWI' N. D ) _'.. .1111 I21, l'.1 07.