The striped cucumber beetle (Diabrotica vittata Fab.)

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Material Information

Title:
The striped cucumber beetle (Diabrotica vittata Fab.)
Series Title:
Circular / United States Department of Agriculture, Division of Entomology ;
Physical Description:
8 p. : ill. ; 23 cm.
Language:
English
Creator:
Chittenden, F. H ( Frank Hurlbut ), 1858-1929
Publisher:
United States Dept. of Agriculture, Division of Entomology
Place of Publication:
Washington, D.C
Publication Date:
Edition:
Second rev.

Subjects

Subjects / Keywords:
Agricultural pests   ( lcsh )
Beetles   ( lcsh )
Genre:
federal government publication   ( marcgt )
non-fiction   ( marcgt )

Notes

General Note:
Caption title.
General Note:
"Issued May 22, 1909."
Statement of Responsibility:
by F.H. Chittenden.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029678535
oclc - 27940589
lccn - agr09001490
Classification:
lcc - SB818 .C6 no.31 1909
System ID:
AA00020898:00001

Full Text
79 '3 1--- -._


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I / ? /I
CIRCULAR NO 31 SECOND REVISION. .s.... ij-l ily I n if

United States l)elarthifllel5T iirtft
BUREAU OF ENTOMOLOGY, "
L. 0. HOWARD. Entumololglu and Chie jf Bur-au -Br a.u


THE STRIPED / tttuMi IEE'TIIEl
i tfibrot--'n rittalti l"al).;


lyv 1". II. (C1IIITTENI.N, Sr. 1i.
In chargeg e of Truck-r-rcip ianI .S ', id Iset hii, 'f, 9l1nltiminl
IKNF:RAI. Al'lE.;AICANW': .\NI) N.\Vri 'u: (11' IATT.'K.


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Early in the season, with the lirt aplpearince (of 'iicunilmer. ,qu.'asli,
and melon plants, often before they are abovyr groumn. they are attacked
by a little yellow and black-stripted insect, kni wn as the stripsii
cucumber beetle, striped
bug," "melon bug," etc.
The principal injury is ef-
fected by the mature insects :
at this time, and is also yr
caused later by the larvae -
feeding underground upon -
the roots and stems of the "
sa m e p la n ts. c
The beetle, illustrated at \p .
figure 1. a, is quite small, a a
measuring about two-fifths A d e
of an inch in length and
half as m uch in width. Its Fii I -S.trip. ., tr, t ,,r .,,..thi ,nbr.,r, .' ,flafap
a Be'-tie h laera r pujps 4 'gi -. -'ilpoure itf
color is yellow above, with -ar F I h r Miuth ,ilarged i 1. mire terlricl
black head and a black highly magnifird tAuth,.r PIlcltratin I
stripe running longitudinally on each side of each wing-cover, prodlucing
the effect of a three-striped hack. The under surface is mostly black
and portions of the legs and antenna' are marked with black.
The striped cucumber beetle is indigenims to this country and inhab-
its the entire eastern U'nited States from the Canadian border to Mexico.
It has been reported as injurious in all except a few States east of the
Rocky Mountains and to occur in the State of Washington.
The most apparent form of injury effected is through the first appear-
ing or hibernating generation of beetles burrowing down to meet the
plants before they show above ground and in feeding upon the tender
plants before they have fairly started. The beetles are also destructive
to older plants, by eating the leaves and especially by gnawing around









and consuming the epidermis of the stems, and the larva, are often the
cause of injury through their unseen but none the less pernicious work
at the roots. Another form of mischief is caused by the beetles acting
as carriers of the bacterial wilt' of cucurbits, cotton, and cowpea.
The subterranean habit of the larva? makes it certain that they are
more often than not at the roots of cucurbits without the knowledge of
the farmer or gardener, the outward manifestation of their presence
being the wilting of the leaves and the failure of the plants to develop
perfect fruit. Far too often the debility or death of the vines through
the presence of this insect is attributed to dry' weather or some similar
natural cause. Injury, then, is threefold, due (1) to direct attack by
the beetles to the plant above the roots; (2) indirectly to the beetles
as transmitters of disease germs; and (3) to the work of the larvae
upon the roots underground.
FOOD PLANTS.
The striped cucumber beetle is rarely absent from the farm and
garden, occurs over an area which embraces nearly our whole country,
and is by far more common and more destructive than any other cucurbit
pest with which we have to deal. Hubbard and marrow squashes are
favorite host plants, followed by cucumbers and cantaloupes. Other
cucurbits, such as pumpkins and watermelons, are also subject to
injury by the beetles and larve. It is not alone in the field and garden
that this species is troublesome, as serious injury is sometimes done in
greenhouses in midwinter, both by larvaw and beetles. So far as we
know, the larv.T are restricted to the Cucurbitacew,, but the beetles attack
other plants. They are flower feeders naturally, but eat also nearly
every other portion of a plant, and even cause injury to cucurbits by
gnawing the rinds of the fruit. Among other cultivated crops, beans
are favorites, and the beetles often congregate in numbers upon bunches
of these plants, killing the leaves and rendering the pods so unsightly
that they are useless for market. Peas are similarly attacked, as also
ripe apples, apple blossoms, and the leaves, silk, pollen, and unripe
kernels of corn.
Of wild plants the beetles evince a partiality for the flowers of golden-
rod, aster, and sunflower, devouring the colored portions, stamens,
pistils, and ray flowers. They also frequent the flowers of chokeberry,
Junelierry, cherry, and related plants, and they feed freely upon the
prickly cucumber or wild balsam apple (Echiuiory.tis lob tfa), which is
probably a natural food plant.
LIFE HISTORY AND) HARBITS.
The beetles make their appearance in April or May, earlier or later
according to locality and climate, feed upon such flowers as may be in
I' 'iOru.%,iosio's]ir' cisitfevta Atk. (Btacillus Irn liciphilhs Erw. Sm.).










season or on either 'g4ttati,,n. and when cucurbits are set out attack
and injure them in the manner prIviiusly described.
The egg wails unknown until lP 9, a singula"r fact'. i-insidthriing that
this is tie o(if tlie ,ommonest and best known ,if injurious insects. It
imeiisures I; ll nin. in lngtiih, and varies in color from ,rig)it lemon yel-
low to orange, the length Il iing about twice the width (fig. 1, di). Ti'.
surface, ias viewed under a I ig -pn\\,r ,i,.ri-c',., is i,.I5ily sculptured,
arranged I in lixiagoiial pits (e).
Eggs tire dleposited. either singly or in gr,,mii,. in the soil about the
roots an,[ stems, tihe fn.lIle frei untly l 1ai6g1 themi in a crack or crevice.
In experiments iminluceted in New Hampshire at an :n tt-ragi temperature


of 7-1'" F., the eggs hatched in about nine 1l.i.w. TI,,
numl)er deposited by a single fni.hil vane.-. 117
being the highest number observed.'
The larva (tig. 1, b) is a v,.ry slender, white.
worimlike creature. ith dark-brown head and anal
plate and lighter brown th,,racic plate.o-
The larval period I is pas.-.d in the moist earth,
about thlt b;ase of the stalks, and larvw may.v be
found within the stems as also ulnmi the Irmi where
this comes in crintact with the earth. This period
lasts about a month, and there is an active salgge of
this duration in which the larvae working in num-
bers have ample time for injuring the vines. When
full grown, just lhefire tranfnrm.ntiion, the larva
contracts, having the ; ppeir;ni'e 'If 1,,ing much
stouter. L.arva l observed in July remained fir three
days in this contr:tted position,. aInd this is proldi,ly
the usual warinm weather iiuiesctint peril lih-fo-re
assuming thIe pup;lal stage. The ppipa (fig. 1, C) is of
nearly thir samli' cl4bor as the larva. and its surface is
sparsely beset with long spinelike Ihairs, tho,-;e on
the dorsal surf;a.e risingng fri i siiiall but piminvi-int


I,

(1

I,
7
I -


V..
r
i ____ ~I


c f
PF If 2.- Diairoti.a ri a
tats: a. Head o( larVa;
it git o(f ame. anal
segment from l idt ; e.
tnal prole r All
greatly enltargie (Au-
thor's ilustration.)


piliferous warts. The pupal period will vary with climate and sea.-'iii,
from six or sve'n lays in warm weather to two weeks when colder.
In experiments in N.w Hampshire the entire lif, cy, le consumed
between forty-.ight and lifty-six days in a t'mperamture of 7li F.
Between twenty-six anil thirty-eight days were reiiiired in the larval

'See account ,if T. .1. .1 adlh, Journal of Econoimic dei'niiiilr,.y, Vol. I, 'ip.
*l-tl3--0), iios.
SWhen fully maturrmil it measures about ilirue-itiiiths of an inch in Irigl, I, thus
being about ten times its width, amnd priseit tl i| app .ar:azcf illuiitratel in figure
1 at b. It is provided mitli three pairs of thoracic lI.g- and an anal priileg
Figure 2 illustrates thie heal antil thoracic plate a a true l.g /.i, and the anal
proleg and plate in profile ().









period, which has previously been considered to last about a month.
In a warmer climate, as, for example, in the District of Columbia,
where the summer temperature usually ranges between 80 and 90 F.,
the life cycle might be passed in a much shorter period, which may be
estimated as at least as low as forty-two days.
SThe entire life history of this insect has evidently never been ascer-
tained. Considering its long season and the fact that newly transformed
beetles have been observed from the second week of July till the first
week of October, there is, as generally admitted, comparative certainty
of two generations each year in the northernmost locality inhabited by
the species, and it is safe to assume the possibility of three genera-
tions annually for, the District of Columbia and southward.
SToward the end of the season the beetles congregate under the stems,
prostrate portions of plants, and withered leaves of cucurbits, often as
many as fifty or sixty individuals assembling about a single plant, and
later they seek other places of shelter. The beetles begin to disappear
near Washington during the first cold nights of October, though hiber-
nation may commence earlier.

NATURAL ENEMIES.
The beetle is parasitized by a tachina fly (Celatoria diabrotice Shim.)
which develops in the abdomen of its host and sometimes kills consid-
erable numbers.
METHODS OF CONTROL.
Direct applications of poisons will destroy the beetles when they
occur in moderate numbers, but have not proved entirely efficacious
when the insects are most abundant; hence recourse must be had to
(1) preventive, (2) repellents, (3) cultural methods, and (4) insecti-
cidal and other methods. Living as the larvie do, underground, it is
more difficult to reach them than the beetles. Their destruction could
be effected by saturating the surface soil about the roots of infested
plants with kerosene emulsion.

PREVENTIVE.
Corering young plants.-To prevent injury to young plants early in
the season, coverings are used. A cheap frame may be made by cutting
a barrel hoop in two so as to form two semicircles, which are then placed
at right angles to each other, and the lower ends inserted in the ground
with the curve uppermost. Two strong wires bent in the form of cro-
quet arches can also be used. The frame is covered with gauze or
similar material, held in place with earth packed about the edges, to
prevent the beetles working under it. It is necessary to keep the
plants covered only while they are young, and the same covering may
be used year after year.










F
5

Wire-gauze covers. such as are used fir prltt.cting plates of food frirm
house tlie.s, would also answer the puirp,.-,' of pr,,tet,,'cti L cucumbers
against the ralvages of this cucumber beetle. T'lly can be pun rlins-.,
at about S cents apiece, aind pro1i:illy cheaper at wliulr.-Ic, and will
be found useful in the case o)f choice pl:ints
Various fornis of covers have been ipr ip,.st,1 by Mr. I,. C. Corbett, of
the Bureau of I'lant Industry, and by Mr. lfeadlee and ,ith.r-. but the
two forms described above appear to be the most easily iirii..ir'l or most
available and are, moreover, certainly more serviceable than others of
which the writer has positive kiIwlt'.lge.

CULTURAL METHODS.

Early plantiing, etc.-Where no rovering is used it is advisable to
start the plants in frames or in hothouses, or to plant the earliest varie-
ties and set them out as soon as possilihl so as to (-t the plants %ell
established before the appearance of the beetles. In v',ii,l1in.ition with
this, the setting out of the late varieties should be ,potiiinedl until after
the first appearing beetles have laid their ergs and 'lisp.r,.,1.
Planting an '.rc'.ss of seed.-In lieu ,of the above pir:ItiIc.s a certain
degree of relief can be secured by planting an excess of seed so as to
distribute attack. After the first danger is passed the lills are thinned
out to the desired number.
A method which has furnished! good reuiilt: in some localities con-
sists in planting the seeds in square-. one each week as shown in the
diagram. The first planting. "'1 ," is freluntly kill,1l.and may f 2
be followed by the second, and sometimes the third. .\ lohng Ti
as the insects are seen they are poisoneidl. and this is continued
until a stand of plants is obtained, as it is sellmi that all four pl.aiting,
are destroyed.
Clean culture and trip plants --Mn.-h injury froit this as wvll ;,
other cucurbit enemies would be prevc'ntid ]I closer attention to clean
ipethods of cultivation. As soon as a crp, q) is harvested the vines should
be covered with straw or other intlaninmiable material and 1iurnird. and
it would be a wise precaution to have certain plants (e. g., such as
might be desired for seed) left standing here and there ltiri,._liitul the
fields, so that such insects as may not have been reached by the tir-
will concentrate on then where they can be easily dletroyel with a
spray of strong kerosene emulsion or Paris grven. .As traps fr the last
or hibernating generation, it would be % ell to plant later or to use later
varieties. By destroying the beetles at this time the numbers for the
ensuing year will be greatly diminished.
Some exemption from injury, it is l.iinicd. nity be attained Iy grow-
ing beans in connection with cucumbers, for example, in alternate
rows. The beans are planted before the cucumbers and the beetles con-










gregate on these plants, and having an abundance of food are not forced
by hunger to attack the young cucurbits.
Gourds planted in the vicinity of other cucurbits are claimed to act
successfully as a trap, and wild cucumber might produce good results.
ISSECTICIDAI. AND OTHER METHODS.
1 rset ica Is, irith ashes., dust, or plaster.-A remedy frequently advised,
when insects occur on low-growing plants, is to dust the majority of
them with sifted wood ashes, road dust, or land plaster, and cover the
remaining plants with aI solution of Paris green or other arsenical, in
the proportion of one-fourth of a pound to about 60 gallons of water.
The beetles will concentrate on the clean plants, where they will be
killed by the poison, not always, however, before they have fed to such
an extent that the plants will be more or less damaged.
Dry ar.,enicals.-Paris green and other arsenicals, alone or mixed
with plaster in the proportion of 1 to from 20 to 50 by weight and dusted
over the plants, will effectually protect them in many cases.
Arsemnte of lead.-This insecticide, which has recently come into
general use as the best remedy for the Colorado potato beetle, should
be given thorough tests against the striped cucumber beetle under dif-
ferent local and other conditions.' Arsenate of lead, as is well known,
is more adhesive than Paris green; hence more useful where rain is to
be feared at the time that it is applied. Where cucumbers are trans-
planted, as is d(lone in some States, tests should be made of the value
of this combined insecticide and fungicide, and of arsenate of lead
alone, as a dip for the plants before setting out. It should be used
at the weaker strength at first and afterward, if found desirable, at a
greater strength, not, however, in excess of 1 pound in 10 to 20 gal-
lons of water. Arsenate of lead was used in 1907 at the New Hamp-
shire Experiment Station by Mr. T. J. Headlee, who reports that it
gave the most efficient protection and injured the plants of cucumber
and squash least of any of several preparations tried, and that 3 pounds
seemed almost as successful as 6 pounds to .50 gallons of water. In
connection with this remedy he advises the employment of trap crops,
and, after the plants begin to run, spraying them with Bordeaux mix-
ture, prepared according to the 3-4-50 formula.
All poisonous preparations must be frequently applied, particularly
when rainfall necessitates their renewal, until the plants have obtained
a good start or the insects have dispersed, and they are not generally to
'During June, 1908, Mr. C. H. Popenoe, while working under Lhe writer's
direction at Diamond Springs, Va., made a practical test of this remedy with
complete success, the beetles being treated on a large patch of cucumbers.
Arsenate of lead was used at the rate of 2 pounds in the 4-h-710 (4 pounds cop-
per sulphate, 6 pounds lime, and 50 gallons water) solution of Bordeaux
mixture.









p ,, relied upoln %% Ieni.i lit- Iw.o :nrn. '\e t.,ilIIn) Iemnieroul. Inll (
BoIrletuIx iiixtiirv i .-pilr;i'd 1iptnl, li, il.l l- .1- .i protection .et niti1
disease, l'Paris Lretii shlilu le :il'l a lI. ..1- it iie--it.ate8 no additional
labur and the ii nxttur. iill priii rv,,r" etir, ti., :it:;i ni- the beetles than
would r either Ilien usei'I I al ,ie.
N4imn hitl i ;i, yrm fith.--.\ A i.t'isi ,.rilI t d .r t, if I \,',,,Ii ,,iii from innjur%
tucrues from l ti' .timuIlaliuin hf a t rip li, Ibr:,\ ni.tnuriniz aind frequent
cUltiv.iLtilon. Fertiliivrs t ijmil b. irilp iii vi f ti,' samne results. In
parts of tlie Souiiti, grotinlI li.-ti i, -.zi,1 .a4- a firtili,'r .And is reported by
somie as being a Utlefutl dlterrt'nt iif iin'rti- ait:a,'king; euurbits.
h'iriny within ir-s tak, d hi,,, .-In the n.r i'in .tnli -id uash gri,,%iing sec-
tions (If Ne% .Jersey (Iriving is ri-ir1i, I, .t.s .1 ii eeae- of t iiiri11 in i this
pest. In tlie tnorning, wn' n.t thirt Iet!i's tr'' :;t tiiv, t.dr-slaked lime is
dusted ovur the pla.ints i ith Ili, 'i i "i[ :ani id li, ri.t,.-. Iiy with it to the
next patch. heree simiilar inetlii.ls i11t hil, viiployu'il or the crtip i ill
stiffer the ri'ins.eque'nces.
I~yreth run.- I'vrcthrninjie nmler d us!te' l ,,i the iil.int- with a powder
bellows is repeirte'd .mce'sfill if appliedd varly irt tle1. inie'liinei when the
dew is on. This reninily. hoim'ver, is illn e xjiil.li..iv' for use on a large
scaiile
IftK. 'F.I 1 I-.

Kerinsen'" sd i e rpen/li,,'.- I.:ti plt1istr., or ivgy )-inii, tliiirtiirtL'h.nly satu-
rated with ken.'.ene or turpentine ii etili tnust'e, :;is a repillriit. Tlih
vapor of turpentine is reported ti> lIl ]idrlieiul.arlvy di-ta-,teful to this
insect.
Tivirvef, diu.l.-Oine of the ,lie-t remnnedi.- still illn v2ill,' consists in
sprinkling the hills. particularly %i tii t ilt -.il is 1teoi-, with refuse
tobacco dust. It h:Is ies' adt\vantagli f f it-i eg like turpentine and plas-
ter .1a good repelleint. and it also act-. a.is ,i ftrtili.er .ind mulch.
3np/lthla'aln,.-Niphti'tlt.n,. alind cinmplietr Ihalls lI.veheen iproiqos,,l as
a deterrent for this species, but sinm e rep',rt: a;- to r,.sutlts diitTir, nii;plilha-
lene can scartvly le reremneniiedle i Mr I) IK. McMillan. vtngagetil in
truck-crop iniestiin;itiins in B is ii-nreai, r'jpi-rts it as having produced
negative results in pr.iti>-al experience ag:iliist the stripidl cucumber
beetle in PInn- yvlvania. (On tlhe ottler lhanl. Mr. F. M. I'.tlinii'ton,
Scipioville. N. Y.. reports h.viing planted ; :;r avrs Pf cucumbers, using-,
50 pounds of niotth ba.lls. pl.aciing .1 ft'i on every iitln'r row, 3 feet apart.
with the result that the cut tuimltar est'c:-pei injury.
si MI \% I.Y.
Of the rnnedlies wliich h;iV, been itli.ct-ta:eiI in previu- i'.'is.ir, arsenate
of lead is deserving of more exteusive exp,'rinienrittion that a eI-',1hpl't.
At tlihait tinie the balls c,,sl '24 cents .t pe)oin d, Il olt..alt. in lot of to lI'M1
pounds. Mr. P'atfingttiuin clainedl that thev% s.rve as a deirerrtrit also for the
squash bug and for rnot-niaggiot in c.'abiage lielda.





UNIVERSITY OF FLORIDA

be 8
S3 1262 09216 45311
test may be made of its effectiveness under all possible conditions. Of
other remedies which give the greatest promise of success and which
have been reported on, more or less favorably, by various competent
persons, preventive, repellents, and farm practice take a prominent
place. To summarize, the principal of these are as follows:
1. Protection of young and choice plants with coverings.
2. Planting an excess of seed to distribute attack.
3,. Clean cultural practice, in connection with trap plants, beans,
gourds, etc.
4. Driving with the wind by dusting air-slaked lime on the plants.
5. Dusting the majority of the plants with ashes or dust and covering
the remainder with an arsenical.
6. Arsenate of lead, alone and in combination with Bordeaux mixture.
7. Stimulation of growth of plants by manures or other fertilizers.
With the exercise of good judgment in planting, and combined effort
among growers of curcubits over a considerable tract of country in the
use of such of the above-mentioned remedies as may be best adapted
to local conditions, the total damage from the striped cucumber beetle
should be greatly lessened.

Approved:
JAMES WILSON,
i Secretary of Agriculture.

WASHINGTON, D. C., April 28, 1909.