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MANUAL OF VEGETABLE-GARDEN INSECTS

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MANUAL OF

VEGETABLE-GARDEN INSECTS

CYRUS RICHARD CROSBY

AND

MORTIMER DEMAREST LEONARD

OF THE NEW YORK STATE COLLEGE OK AGRICULTURE
AT CORNELL I'NIVEKSITV

THE MACMILLAN COMPANY
1918

All rifffiis reserved

COPTRIOHT, 191S,

Bt TIIK MACMILLAN COMl'AXY.

Set up and clcctrotypetl. Published September, iyi8.

Xortoooli t^rrss

J. S. Cu.«hiiiK Ci>. — Hcrwick & Smith Co.

Norwood, Ma.H!)., U.S.A.

JAMES FLETCHER

STUDENT AND TEACHER

FOR A QUAKTKH OF A CENTURY
ENTOMOLOGIST AND I50TANIST TO THE DOMINION OF CANADA,

NOTED

FOR HIS STUDIES IN ECONOMIC ENTOMOLOGY

AND FOR THE CLEARNESS AND ACCURACY OF THE

PRESENTATION OF HIS WORK TO THE PUBLIC

AND ENDEARED TO THE YOUNGER GENERATION OF WORKERS

BY HIS KINDLY INTEREST AND ENCOURAGEMENT,

THIS BOOK IS DEDICATED AS A TOKEN

OF THE authors' ESTEEM

Digitized by tine Internet Arciiive

in 2010 witii funding from

University of Britisii Columbia Library

http://www.archive.org/details/manualofvegetabOOcros

PREFACE

In the present work we have attempted to bring together in
concise and usable form what is known in regard to the habits,
Ufe history and control of the insect enemies of vegetable-garden
crops in the United States and Canada. ]\Iuch of this uifor-
mation has been published in technical journals and in the
bulletins and circulars of the State Experiment Stations and
Federal Government, where it is available only to the special
student who has access to the few large libraries that collect
and preserve this type of literature. We have endeavored
thoroughly to digest this mass of material and present it in a
form adapted to the needs of the gardener and vegetable-
grower.

In regard to methods of control we have tried to eliminate
as far as possible useless and impracticable recommendations
and include only those found to be effecti\e under commercial
conditions or such as would seem to be worthy of trial. It has
seemed better to state frankly that the problem of control in
certain cases has not been solved than to suggest remedies that
would lead to disappointment.

The chapter on cutworms and the accounts of several others
of the lepidoptera wore written in collaboration with Dr.
liobert Mathesoii. Wc arc under great obligation to Dr. \\ . T.
M. Forbes for eritieistii and aid witli the lepidoptera; to Dr.
F. (\ ^'an D\ke for the determination of beetles ; to Mr. (^harles

Vin PREFACE

W. Leiig for the fjift of sj)ccimcns ; to S. W. Frost for thi* use
of photographs ; and to many others for similar fa\ors.

Tlie drawings were made by Anna C. Strykc, Ellen Edmonson,
Nellie H. Grosby and C II. Kennedy. Several of the illustra-
tions are from photograi)hs previously published in bulletins
by the late Prof. M. V. Slingerland, by Prof. G. \\. Ilcrrick and

by H. II. Knight.

C. R. Crosby.

M. I). Lkoxakd.
Cornell University, Ithaca, N. Y.
May 28, 191S.

CONTENTS

CHAPTER I

General Considerations

PAGE
1

CHAPTER II

Insects Injurious to Cabbage and Related Crops
, Imported cabbage worm
Potherb butterfly
Southern cabbage butterfly
Cabbage looper .
Diamond-back moth
Cross-striped cabbage worm
Cabbage webworm
Garden webworm
Purple-backed cabbage
Zebra caterpillar .
Cabbage aphis
Turnip aphis
^ Cabbage root-maggot
Seed-corn Tuaggot
Western radish maggot
Harlequin cabbage bug
Green soldier-bug
Cabbage leaf -miners
False chinch-bug .
Cabbage curculio .
Cabbage seed-stalk weevil
Red turnip beetle .
Other insects injurious to cahbage and related croi)s

4
7
7
9
12
14
10
18
19
21
22
27
29
30
37
38
42
43
47
19
50
50
51

CHAPTER III

Pea and Bean Insects . * . . . . . . .54

Pea wee\il .......... 54

Rean wccxil ......... 57

Broad bean weevil ........ GO

cox TEXTS

Four-spotted boan weevil

Cowpca wceNnl

Bean leaf-beetle .

Cirape eolaspis

Bean Ladybird . . .*

Bean thrips ....

Pea aphis ....

Bean aphis ....

Garden flea-hopper

Pea moth ....

Bean leaf-roller

Striped green bean caterpillar

Graj' hair-streak ..

Green clover worm

Lima bean \ine-borer .

Other pea and bean insects .

CHAI'TKR IV

Beet and Spinach Insect.s
Spinach loaf-miner
Beet leafhopi)er .
Larper sugar-beet leaf-beetle
Western beet leaf- beetle
Sugar-beet webworm .
Hawaiian beet webworm
Spotted beet webwomi .
Southern beet webworm
Sugar-beet root-louse .
S;)inach aphis
Other beel and spinach insects

Cll.M'TKI^ V

iNSEf'T.S iNJURIOrs TO CrCTMHKH. S(irA'^lI ANH MkLON

Striped cucumber beetle
Western cucumber beetle
Twelve-spotted cucumber beetle
Western twehe-spotted cucumber beetle
Belted cucumber beetle

Squash bug

CONTENTS

Horned squash bug

Melon leaf-bug

Southern leaf-footed plant-bug

Northern leaf-footed plant-bug

Squash-vine borer

Pickle worm

Melon worm

Squash ladybird

Melon aphis

Squash aphis

Garden springtail

Other cucumljer, squash and melon insects

CHAPTP]U VI

Potato Insects

Colorado potato beetle
Three-lined potato beetle
Potato aphis
Apple leafhoppcr
Potato stalk-weevil
Common stalk-borer
Burdock borer
Potato scab gnat
Potato tul)er moth
Other potato insects

CHAPTER VII

Tomato Insects
Tomato worms
Tomato stilt-bug .
Eastern field wireworm
Erinose of the tomato .
Other tomato insects .

CHAPTER VIII

EcciPLANT Insects

Eggi)lant tortoise 1)ectle
Eggplant luce-bug
Other egg])laut insects .

177
177
17S
179

Xll

CONTENTS

CHAPTER IX

Insects Injurious to Cakiiot, Celehy, P

\RSM1» AM) IvKl

-ATKD

Crops

. 181

I Carrot rust-fly ....

ISl

Carrot beetle ....

1,S.J

Black swallow-tail butterfly

ISO

Celery leaf-tyer ....

ISO

Celery looper ....

I'.ll

Tarnished plant-bug

V.Y2

Negro-bug .....

!<>(•.

Parsnip web worm

1<>7

Parsnip leaf-miner

lU't

Parsley stalk-wee\'il

!'.»'.»

Other carrot, celery and parsni]) insect

L'lM)

CHAPTKR X

Asi'AKAGUs Insects .

Common as])aragiis beetle .
Twelve-spotted asparagus l)eetle
Asparagus miner
Other asparagus insects

'JOl
•JOl

2()S
'J 10

CIIAPTKK XI

Corn Insects .
Corn ear-worm
Corn root-aphis .
South(Tn corn root-worm
Western corn root-worm
Colorado corn root-worm
Larger corn stalk-borer
Lesser corn stalk-borer
Brown fruit-chafer
Stink-bugs .
Other corn insects

211

•J 11
•J IS
'J'J'J

227
22S
221 >
2:51
2:i2
233

Sweet Potato Insects
Tortoise lieetles .
Sweet potato weevil

CH.\I'TKi{ Xll

2.3.',
235
239

CONTENTS

Xlll

Sweet potato leaf-roller
Sweet potato white-fly
Other sweet potato insects

CHAPTER XIII

Onion Insects
Onion maggot
Onion tlirips
Barred-winged onion fly
Black onion fly
Other onion insects

PAGE

241
242
242

243
243
245
249
250
250

CHAPTER XIV

Insects Injurious to Minor Vegetable Crops . . . 251

Rhubarb 251

Okra 253

Salsify 255

Pepper .......... 255

Water-cress .......... 257

Lettuce 258

CHAPTER XV

Cutworms and Army-worms
Spotted cutworm
Well-marked cutworm .
Greasy cutworm .
Red-backed cutworm .
Dark-sided cutworm
Striped cutworm .
Dingy (nitwonn .
Shagreened cutworm
Granulated cutworm .
Clay-backed cutworm .
Black army cutworm .
Variegated cutworm
White cutworm .
Glassy cutworm .
Yellow-licaded cut worm

260
262
263
2()5
267
268
270
271
272
273
274
275
276
278
279
281

XIV

rOXTEXTS

Spotted-lepfijed cutworm

Speckled cutworm

Clover cutworm .

Bristly cutworm .

Bronzed cutworm

Army (-utworm

Army- worm .

Fall arm \'- worm .

Beet army-worm .

Yellow-striped army- worm

Semi-tropical army- worm

Other cutworms .

Control of cutworms and armv-worms

PAOE

•JS2
2,S3
2S4
2S5
2S(i
2S7
2S.S
202
204
20r)
297
2«.)S
2<)S

CIIAPTKFJ XVI

Blister-Beetles

Striped blistcr-ln'ctlc .
]Marfi;incd blister-beetle
(Jray blister-beetle
Asli-fjray lilister-beetle
Black blister-beetle
Nuttali's blister-beetle
Spotted blister-beetle .
Two-spotted blister-beetle
Miscellaneous blister-beetles
Cleans of controlliiif;; l)lisler-beetlos

CHAl'TIlK XVil

Flf:a-Beetle.s

Potato flea-beetle
Western potato flea-l)(>etl(>
Tobacco flea-b(>etle
ERfrplii'it flea-beetle
Pale-striped flea-beetle
Red-headed flea-beetle
Smart weed flea-b<>etle .
Striped cabl);itje flea-beetle
Sinuate-striped iltu-beetle
Western cabbai'e flea-l)eelle

302
302

3or>
:iO(>

307
30S
300
300
310
311

313
314
31 S
310
320
321
323
323
324
320
327

CONTENTS

PAGE

Horse-radish flea-beetle 328

Spinach flea-beetle

329

Yellow-necked flea-beetle

331

Three-spotted flea-beetle

331

Larger striped flea-beetle

332

Sweet potato flea-beetle

332

Desert corn flea-beetle .

334

Hop flea-beetle

335

Means of controlling flea-lwetles

336

CHAPTER XVIII

Unclassified Pests 338

Root-knot nematode

. 338

Sugar-beet nematode

. 342

Millipedes

. 342

White grubs .

. 344

Wireworms .

. 347

Grasshoppers

. 350

Red-spider .

. 351

Slugs .

. 354

Yellow bear caterpillar

. 357

Salt-marsh caterpillar

. 359

CHAPTER XIX

Insects and Insecticides 361

Structure of insects 361

Insecticides

368

MANUAL OF VEGETABLE-
GARDEN INSECTS

CHAPTER I
GENERAL CONSIDERATIONS

It was estimated by C. L. Alarlatt in 1909 that the annual
loss caused to vegetable and truck crops in the United States
by insect pests amounts annually to 20 per cent of their value,
or $68,000,000. This sum includes the cost of insecticides and
other expense incurred in fighting vegetable insects.

Insects affect vegetable crops in various ways. They feed
on the leaves, devour the roots, tunnel the stems and infest
the seeds and fruits. In many cases their injuries to succulent
parts of the plant give entrance to decay-producing organisms
which greatly augment the damage. Insects also act as carriers
of specific diseases, the most remarkable instances of this kind
being the transmission of the curly-leaf disease of the beet by
the beet leaf-hopper and the carrying over winter of the bacterial
wilt of cucurbits by the striped cucumber beetle.

The enemies of vegetables here treated are, with five excep-
tions, members of that class of animals known as insects. These
exceptions are : the red-spider and the mite producing erinose
of the tomato, which are Arachnids ; snails or slugs, belonging
to the molluscs ; millipedes belonging to the Myriapoda and
the root-knot nematode, one of the true worms.

Some vegetable insects are general feeders, attacking a great
variety of plants, but the greater number are more or less
B 1

2 MANUAL OF VECETA BLE-CARDEX IXSECTS

restricted to a single family or other closely related group of
plants, both wild and cultivated. Thus many beet insects
also feed on weeds belonging to the goosefoot family, cabbage
insects on weeds of the mustard family, potato insects on wild
solanaceous plants and sweet potato insects on wild morning-
glories. This fact, that certain insects form more or less
definite associations with certain groups of plants, is of great
practical importance and must be kept in mind when considering
methods of preventing injury. It also explains why clean farm-
ing is one of the most important factors in preventing insect
injuries to vegetable crops. In fact, clean farming together
with proper cultural practices often makes it unnecessary to re-
sort to special remedial measures, or at least renders it possible
to obtain more effective results from the use of insecticides.

About 250 species of insects have been recorded as .serious
enemies of vegetable crops in the United States and Canada l)ut
a much larger number may occasionally become injurious.
Only the mt)re important species are treated in the following
chapters, arranged under the crops to which they are most
injurious. Flea-beetles, blister-beetles, cutworms and other
general feeders are discussed in separate chapters.

CHAPTER II

INSECTS INJURIOUS TO CABBAGE AND RELATED

CROPS

In this chapter are treated the more important insect enemies
of cabbage, cauliflower, brussels sprouts, kohlrabi, kale, col-
lards, radish, turnip, mustard and horse-radish. With the
exception of horse-radish, these form a natural group of food
plants that serves as the common host for a large number of
insects, which, although showing a preference for certain crops,
can also thrive on the others. Many cruciferous weeds are
also food plants of these pests and may serve as centers of in-
festation from which the insects spread to cultivated crops.
The most important enemies of cabbage and related crops in
this country have been imported from the Old World but some
of the native insects have found in these succulent vegetables
satisfactory food plants. Of European origin are the cabbage
root-maggot, the common cabbage worm, the diamond-back
moth, the cabbage aphis, the cabbage curculio and the cabbage
seed-stalk weevil. The cabbage webworm had its original
home in the Old World tropics and the harlequin cabbage bug
spread into the ITnited States from Central America during the
last half century.

Horse-radish has relatively few insect enemies, the most
important being the harlequin cabbage bug and the horse-
radish flea-beetle.

Cabbage and related crops are often seriously injured by cut-
worms and flca-bcetlcs. These insects are treated in Chapters
XV and XVn.

MANUAL OF VEGETABLE-GARDES IXSECTS

The Imported Cabbace Worm

Pordia rnp/i Linnaeus

The common white cabbage butterfl\- of the T'nited States
and Canada is a native of the Old World. It was first intro-
duced into America at Quebec about 1860. Later independent
introductions occurred at Xew York in 1SG8, at Charleston,
South Carolina, in IST'-i and at Apalachicola. Florida, at about
the same date. From these points as centers the insect spread
rapidly and by ISSo it occupied practically the whole territory
east of the Pacific slope. The favorite food plant of the im-
ported cabbage worm is cabbage, but it also attacks cauli-
flower, turnip, horse-radish, radish, mustard, gillyflower,
nasturtium and sweet alyssum and it also feeds on a number of
wild plants belonging to the mustard family. The cater-
pillars are sometimes found abundantly on mignonette.

The imported cabbage worm hibernates in the i)upal state
and the white butterflies emerge in early spring, being among
the first to ai)pear in our fields and
meadows. Their flight is low and
unsteady and they alight at fre(|uent
iiiter\ ids. The female deposits her eggs
singly on tlie mider surface of the lea\'es
of the food plant. The egg (Fig. 1) is
lemon yellow in color, nearly ^ inch
in length and attached to the leaf at
one end. It is broadest two tliinls
of the distance from the base, and
then tapers to the to)>, which is flattened. The surface is beau-
tifully ridged lengthwise and crosswise. The egg hatches in
about a week and the pale greenish yellow caterpillar begins
feeding on the under surface of the leaf, which it skeletonizes.
A little later the caterpillars are able to eat out holes in the
leaves, only the larger veins remaining. When the plants are

Fi(i. 1. — K«(;^ of tlic im-
ported fiihbage huttcr-
fly (X 15).

INJURIOUS TO CABBAGE AND RELATED CROPS

headinji;, the caterpillars often burrow rather deeply into the

head in search of the tenderest leaves. They beconit> full

grown in ten to fourteen days.

The mature caterpillar (Fig. 2) is

about an inch in length, velvety

green in color and marked with a

greenish yellow stripe down the

back and an interrupted one on

each side. When ready to pupate, J i' - - i uh-rMwn imp

•, 1 .„ 1 I4- 1 1 cabbage worm (X IV).

it seeks some sheltered place — ■ ^ ^ -^

under a cabbage leaf or on the underside of fence boards

in which to transform to

Fli;. '.i. — Iinpiirtccl cabliaL'c worm
suspended for pupation (X I5).

the chrysalis. ^Yhen a cabbage
patch is near a house, these
chrysalids are often found in
great numbers under the edge of
the clapboards. When about to
transform, the caterpillar first
spins a carpet of silk over the
surface chosen and fastens a deli-
cate silken girdle around its
body at the first abdominal seg-
in position (Fig. 3). After the
chrysalis is held in place by

ment, holding itself tightly

transformation is complete the

this girth. The pupa (Fig. 4)

is about f inch in length and

of a pale green or yellowish

brown color. Fxcept in the

case of those chrysalids which

winter over, transformation to

the butterfly takes place in a

week to twelve days. The

butterfly has an expanse of

about If inches. The wings are nearly white in ground color

often more or less suffused with yellowish. The tip of the

Fi(

4. — Chrj^salis of imported
cabbage worm ( X 2 J) .

MANUAL OF VEGET ABLE-GARDEN INSECTS

frcnit wingj is gfrayisli ; tluTc arc two
Mack spots on the front win^' of the
female and one in the male and in
both sexes there is a black spot near
the front marijin of the hind winj;
<Fig. 5). Spring males are smaller
and sometimes mispotted. In New
England the cabbage butterfly has
three broods annually and in the
South there are said to l)e six.

Coufrol.

^'bai.-.i;','hu";X'^;t .f^^hbase worm, may be easily
above, female below (X l>. killed by spraying with paris green,
1 pound in oO gallons of water, or
arsenate of lead (paste), 4 pounds in oO gallons of water.
The first aj)pli<ati()n should be made soon after the plants
are set out and repeated wheneNcr the worms become luimer-
ous. The poison may be applied in the form of a dust diluted
with sf)me inert material, such as Hour. i)laster or hydrated
lime, but is not so effective when used in this way. Chemical
analysis of sprayed plants has shown that there is practically
no danger from eating cabbages that ha\e been treated with
an arsenical. In the home garden inrethrum, hellebore or hot
water (1.30° F.) will be found convenient remedies. When only
a few plants are grown, hand-picking is often the cheapest and
easiest wav of destrovini: the worms.

References

Soudder. Buttorflios of Eastern U. S., 2, pp. 117.')-1100; 120.''>-1218.

1889.
U. S. Bur. Ent. Circ. 60. 190.5.
U. S. Farm. Bull. 7()(). 1916.

INJURIOUS TO CABBAGE AND RELATED CROPS 7
The Potherb Butterfly

Pontia oleracea Harris

Before the introduction of the imported cabbage butterfly,
this species was abundant in the northern Fnited States and
Canada east of the Rocky Moun-
tains but soon became rare
throughout the greater part of its
range. The caterpillar of this
species closely resembles that of
the imported form but lacks the
yellowish dorsal stripe. The
butterfly has the upper surface
of both pairs of wings and the
under surface of the front wings
nearly pure white. The hind wings are usually marked on
the underside with gray stripes extending along the veins.
Rarely the under surface is pure white (Fig. 6).

References

Riley, U. S. Ent. Kept, for 1883, pp. 115-117.

Scudder, Butterflies of Eastern U. S., 2, pp. 1191-1204. 1889.

Fig. G.

The i)otlioi

fly (X I).

The Southern Cabbage Butterfly
Pontia protodice Boisduval and Le Conte

This cabbage-feeding caterpillar is widely distributed through-
out the Tnited States but is more connnon southward, where it
often causes serious injury to cruciferous crops. As in the
case of the potherb butterfly, this species has decTcased in
numbers and imi)()rtaiice since the introduction of its iMirojiean
relative. The butterfly is known as the {hcckt red white. The
ground color of the wings is white in the niali' and dirty white in

MAM'AL OF VECETABLE-GAIWES INSECTS

the femal? and the upper side of
tlie fore wings in both sexes is
marked with several black spots
(Imjj;. 7). The caterpiUar is about
an inch in length, purplish green
in color marked with four longi-
tudinal greenish yellow stripes and
covered with small black dots.

The last two species may be con-
trolled by the same . measures as
recommended for use against the imported cabbage worm.

I'lG. 7. — Thf souiluTii cab-
bage butterfly, male (X I).

References

Rilrv. IT. S. Enl. Ropt. for l.SS:^, pp. 114-115.

ScucldLT, BiitUTlIios of Eastoni U. S., 2, pp. 11(13-1170. IS89.

TiiK Carrage Looper

Aulographa brnssicfr Riley

This well-known cabbage pest is a nati\e American insect
widely distributed throughout the United States and occurring
as far south as ^Mexico. In some localities, especially in the
South, it is the most serious insect with which the grower
of late cabbage and cauliflower has to contend. In addition to
cruciferous plants such as cabbage, kale, cauliflower and
turnip, the cabbage loo])er may also occasionally cause serious
injury to lettuce, celery, beet, pea and i)arslev. It also feeds
on tomato, j^otato, as])aragus, dandelion and dock and some-
times attacks carnation and mignoiu-tte in greenhouses. On
Long Island it is especiall.x injurious to late cauliflower and to
lettuce that has been traiis|)lantt'd fnmi culdframes into the
forcing houses.

The insect as a rnle passes the winter in the pupal stage,
although it is not improbal)le that occasionallx some of the

INJURIOUS TO CABBAGE AND RELATED CROPS 9

Fig. «. — Egg of
the cabbage looper
(X 10).

later emerging moths may hibernate. In any case, only a
relatively small number survive the winter and consequently
the first brood of the season is small and causes comparatively
little injury. The female moth deposits her small whitish
eggs singly or in small groups usually on the
upper side of the leaves. The egg (Fig. 8)
is about -g^ inch in diameter, pale greenish
yellow or nearly white in color, nearly
circular in outline and rounded above. The
surface is beautifully marked with a series
of ridges radiating from the apex. The
length of the egg stage has not been deter-
mined but it is probably not far from a week
or ten days. The young larvje are pale green
in color and feed at first on the outer leaves of the cabbage ;
as they grow older, they become darker green and are marked
with distinct white longitudinal lines. At this time they work
in toward the center of the plant, and often bore into the form-
ing head. The full-grown caterpillar (Fig. 9) is about Ij
inches in length. It is pale green in color with a white stig-
matal stripe and two dorsal stripes extending the whole length

of the body. On each side
of the dorsal stripe there is
a fine white line. The
caterpillar is narrower in
front and has the body en-
larged toward the posterior
end which is bluntly trun-
cate. Although the cater-
pillars are close relatives of the cutworms, they crawl with a
peculiar looping motion like the measuring-worms, due to no
prolegs being present on the third and fourth abdominal
segments. The catcrijillars attain tiieir growth in from
two weeks to a montli, depending on the tenii)erature.

Fig. 9.

Full-growu cabbage looper
(X If).

MAXi'AL OF VEGETABLE GARDEX INSECTS

When mature the caterpiUar spins a Hjjht flimsy semi-
transparent cocoon (V'\g. 10) of white silk ahout 1} inches in
length, usually on the underside of the leaf. It consists of
two filmy layers, an inner one close to
the ])upa and an outer one coimected
with the other by many fine threads.
Soon after com])letin<j its cocoon, the
larva transforms to a dark brown or
i)Iackish pupa (FifX- 11) about f inch
in len<i:th. The moth (Fipj. 12) emerjjes
1,1,;. 10. — c'ucuou of the ill ten days to two weeks; it has an
cahiKiw loopor frotii expausc of Ij to U iuchcs. The front

whifh the moth h;is . i i i ~ ■ ^ i vi

enicrRcd (X I). wuit^s are (lark hrown varie<;ate(l with

li<lhter brown and bear near the center
two silver spots, one oval and the other shape(l like a con-
stricted I'. Sometimes these spots are united and resemble
an imperfect figure S. The hind wings are mouse-colored
with bronze reflections in certain lights.

There are said to l)e three broods of the insect amuially on
Long Island, Xew York, and four at Washington, I). ('. As
only a relatively small inunber
of pupa> survive the winter, the
first brood cateri)illars are gen-
erally not abundant enough to
cause much injur\- and are
usually overlooked entirel.w
The succeeding broods increase
rapidly in inunlx-rs and inipur-
tance, the last being the most
destructix'c. Towards the end
of the season, the l)r()o(ls over-
laj) so that all stages of the insect are present on the cabbage
plants at the same time.

Tlic cablcigc |(Mi|)cr i> held in clicck by scNcral parasites and

11. — Pui>a,' of till- (•:il)l)aKC
loopcr (X 2J).

INJURIOUS TO CABBAGE AND RELATED CROPS 11

by a disease. Diseased caterpillars at first turn yellowisli and
later take on an ashy hue {V\. 13). They become inactive,
stop feeding and soon die. After death the skin breaks open
and the body contents
which have become
liquid oozes out and
becomes smeared on
the leaves. Sometimes
a large proportion of
the caterpillars are de-
stroyed by this disease
late in the season.

12. — Moth of the cabbage looper ( X Ij)-

Control.

The cabbage looper
is a difficult insect to
poison because the caterpillars refuse to eat leaves coated
with an insecticide and move quickly to some part of the
plant that has been missed in spraying. Furthermore, it is
not easy to spray a cabbage plant so as to cover all parts

of the leaves, especially the
underside of the outer leaves
and those in the forming
head. Experiments on Long
Island have shown that good
results may be obtained by
thorough spraying with paris
green, 1 pound in <S0 gallons
of water to which the resin-
lime mixture has been added. Some growers dust the plants
lightly with pure ])aris green and have reported satisfactory
results from this treatment.

12 MANUAL OF VECET ABLE-GARDEN INSECTS

Hi;i'i:ui:nc'i;s

Riley, U. S. Ent. Repf. for iss:^. i)p. 119-122.

N. Y. (Geneva) Agr. Exp. Stu. Bull. s:i, pp. G67-671. 1894.

N. Y. (Geneva) A^'r. Exp. Sta. Bull. 144. 1898.

The Diamond-Back Moth

Plutella maculipennis Curtis

In this country the (Himi()iul-l);uk moth is rarely more than a
minor enemy, of (•al)ha<ie and rehited crops. l)ut in some parts
of its extensive range its injm'ies are of considerable importance.
Apparently introduced from Europe some time before 1854,
the insect is now widely distributed throughout the United
States and Canada ; it also occurs in South America, Australia,
New Zealand, South Africa, India, Greenland and Spitzbergen.
It seems able to maintain itself wherever its food plants are
grown, whether in the tropics or in the arctic region. In Eng-
land the insect is also known as the turnip Hy and in some parts
of tlie United States it is called the shot-hole worm. Besides
cabbage, cauliflower, brussels s]:)routs, rape, horse-radish,
radish, kale, mustard, turni]) and water cress, the insect attacks
stocks, wall-flowers, sweet alyssum and candytuft. It some-
times becomes very troublesome on these plants in green-
houses.

The diamond-back moth hibernates in the adult condition
hidden away under the cal)l)age leaves left in the field. The
moths appear in the spring as soon as food plants are axailable
on which to deposit their eggs. The moth (I'ig. 14) has an
expanse of about ^ inch. In the male the front wings are ash-
colored dotted with minute dark spots and have a n'cHow stripe
outlined by a wavy dark line extending along the hind border.
A\ lien the wings are closed, the united ,\-ell()W stripes form a row
of tlu'ce diainond-sha|)cd niaikings. In tiie female the front
wings are a nearlx' nnil'orni graw The hind wings in both sexes

INJURIOUS TO CABBAGE AND RELATED CROPS 13

Fig. 14.

The diamond-buck moth, iiialo
(X3|).

are dull gray. When at rest the moth has the wings slightly
turned up at the tip and the antennie are held extended forward.
The female moth deposits her minute whitish or yellowish eggs,
7^ inch in diameter, singly or in groups of two or three, usually
on the leaves. Each
moth is capable of lay-
ing on an a\'erage
nearly 300 eggs during
a period of one to two
weeks. They hatch in
three to six days and
the young caterpillars
first eat holes in the
leaf from beneath but
do not cut through to
the upper surface. Later the upper epidermis dies, turns brown
and drops out leaving the leaf riddlefl with holes. Sometimes
in cool weather the young larva? live as miners in the leaf for
two to four days. The caterpillars are very active when dis-
turbed, wriggle from the leaf and suspend themselves by a thread
till the danger has passed. The larva reaches maturity in nine

to twenty-eight days.
It is then only about
I inch in length, })ale
green in color and
sparsely clothed with
small, erect black hairs ;
the head is brownish
yellow mottled with
black. The larvaj be-
come mature in about a month and spin their beautiful open-
work cocoons (Fig. 15), so loosely woven that the pupa can
be plainly seen within, on the underside of the leaves. In
the summer from four to thirteen days are spent in the pupal

Fig. 15. — Cocoon of the diamond-back moth
showing the larva within ( X 4).

14 MANUAL OF VEGETABLE-CARDEX IXSECTS

stage. In the northern states there are two or three broods
annually, which overlap to a considerable extent, but in the
tropics breeding is almost continuous. In Colorado there are
seven generations annually. On Long Island, larvie and moths
are often abundant on cauliflower until early December. The
insect is usually more destructive in dry seasons than when
rains are abundant. On cabbage the greatest injury is usually
inflicted early in the season while the plants are small, but in
the case of cauliflower the late broods are the most troublesome.
A closely related species, Plntello armomcia Husck, has been
reported as injurious to horse-radish in Colorad;). Its habits
are similar to those of the diamontl-back moth.

Control.

Experiments in Colorado lia\c shown that the diamond-
back moth can be controlled by spraying with 2 pounds of
paris green and G pounds of soap in 100 gallons t)f water, or
arsenate of lead (paste), 8 pounds in 100 gallons.

Referfncks

Fitfh, 1st Rf'pt. Statp V.n\. X. Y.. pp. 170-17;"). 1856.
Carpontor. Ropt. for HM)1. pp. 144-147. 1902.
Quanjcr. Tijds. Ent. 49, pp. 11-17. 1901).
Marsh, Jour. Agr. Research, 10. pp. 1-10. 1917.

The Ckoss-Striim:i) CAiujAdH Wokm

Evcrgeslis rimnsnlis Ouonep

While widely distributed throughout the I'nited States ex-
cept in the extreme north, the cross-striped cabbage worm is
most abundant and destructive in the southern states. Locally
in some years it often caiises more injury than the imported
cabbage worm and its nati\e relatives. The cater])illars
destroy the leaves in much the same way as the common cab-

INJURIOUS TO CABBAGE AND RELATED CROPS 15

bage worm and have an especial fondness for the tender central
leaves and fonnhig head, often burrowing into the latter. In
addition to cabbage and related crops, this insect has been
reported as feeding on nasturtium in California.

The insect hibernates in the pupal stage in a snug cocoon
just below the surface of the ground. The moths emerge in
early spring — in April in the District of Columbia. The
moth (Fig. 16) has an expanse of about an inch. The front
wings are pale ocher-yellow in color, marked with an indistinct
zigzag brownish line and suffused with various shades of brown,
darker towards the middle of the outer margin. The hind wings
are nearly transparent towards the
base, fuscous at the front angle and
marked across the disk with a row
of five or six small indistinct dusky
spots. The female moth deposits
her light yellow, rounded oval eggs
about T^ inch in diameter, in cir-
cular masses on the underside of Fig. i6. — The moth of the

ill 1? u cross-striped cabbage worm

the leaves, il-ach egg-mass con- (x i^)
tains twenty to thirty eggs which

are flattened and overlap. They are semi-transparent and
the green of the leaf shows through the mass. The eggs
hatch in about six days and the young caterpillars begin
feeding on the leaves, eating out long oval holes. The
newly hatched larva is of a nearly uniform gray color.
When full-grown it is about ^ inch in length, bluish gray
above with distinct transverse black stripes, three or more to
each segment. On the side a wide stigmatal line of bright
yellow extends from the second to the last segment. Beneath,
the caterpillar is green mottled with yellowish. In the summer
the caterpillars reach maturity in about a month, but in the
cooler months a somewhat longer period is required. When full-
grown the caterpillar descends to the ground and just below

16 MANUAL OF V EC, ET ABLE-GARDEN INSECTS

tlie surface constnicts a U'^ht cocoon into tli(> outer surface
of which l)its of dirt antl sand are incorjxirated. The et)Coon
is I incii in lenij;th hy '^ inch in width. 'I'he j)ni)a is f to ^ inch
in len>;th and has the head and \\ in,u-cases chirk brown and the
ab(K)men light yellowish brown. The sunnner broods of the
insect spend about ten days in the cocoon but the time in the
pupal stage has not been determined. It is probai)l\' al)out
six days. There are supposed to be three generations anmially.
The cross-striped cabbage worm may be controlled by the
measures suggested for the imported cabbage worm.

Reference
U. S. Div. Ent. Bull. 3:?, pp. rA-'>9. 1902.

The Cabbage Webworm

Ilellula undalis Fabricius

Originally a native of the tropical and subtropical regions
of the Old World, the cabbage webworm was introduced into
the southern United States shortly before ISt)") and now ranges
as far north as North Carolina and west to Oklahoma, Texas
and southern California. It also occurs in Australia and (luam.
This webworm attacks cabbage, cauliflower, collard, turnip,
radish, mustard, horse-radish and beet and will feed on shej)-
herd's purse and purslane. It is sometimes destructive to
plants in seed-beds.

In the southern United States, the insect hibernates as a pupa
in a compact cocoon of white silk attached to the injured plant
near the base or situated just below the surface of the ground.
The early seasonal history is very im])erfectl,\' known and the
number of generations annually has not bi'cn definitely deter-
mined. The moth has an expanse of about | inch ; the front
wings are brownish ^■cllow mottled with darker brown; the

INJURIOUS TO CABBAGE AND RELATED CROPS 17

hind wings are pale fuscous. The female deposits her eggs
singly or in small masses on the leaves of the plant. The egg
is about gV iii<^"li ii^ length, flattened and often })ro\ided with a
distinct nipple-like projection at one end. When first laid it is
light yellow or grayish but just before hatching takes on a
pinkish brown color. Each female is capable of laying from
300 to 350 eggs. In warm weather the eggs hatch in three or
four days.

The young caterpillars begin feeding on the underside of the
leaves, eating off the epidermis in small irregular patches. The
caterpillars often burrow into the leaf itself, into the leaf-stems
and into the developing head. After the first molt, the cater-
pillar usually covers its feeding grounds with a web of silk on
which the excrement and other dirt collect. The caterpillars
often attack the bud or heart of the plant, stop its growth and
in many cases kill it outright. They sometimes eat out holes
in the upper part of turnip roots.

When full-grown, the caterpillar is about f inch in length,
dull grayish yellow in color, and marked dorsally with five
conspicuous browaiish purple longitudinal stripes. On the
sides and below there are similar but less distinct stripes. The
caterpillars become full-grown in about eighteen days and after
constructing their cocoons transform in a day or two to pupae.
The pupa is about yo "ich in length and light yellowish brown in
color. In the summer the insect spends about six days in the
pupal state. There are probably three or four generations a
year but the exact number has not been determined under
field conditions.

Control.

In regions in which the cabbage webworm is likely to appear
in injurious numbers, the plants should be protected by fre-
quent applications of arsenicals beginning soon after trans-
planting. In this way the young cateri)illars will hv killed
c

18 MANUAL OF VEGETABLE-GARDEN INSECTS

before they arc able to si)in their proteetive webs. After tlie
\vel).s are spun, it is praetieally impossible to reaeh them with a
poison spray. Paris green, 1 pound in 50 gallons of water, or
arsenate of lead (paste), 4 pounds in 50 gallons of water, will be
found elective. In eases of severe infestation it would pay to
collect and destroy the stumps and other refuse in the field
after the crop is harvested and thus greatly reduce the number
of hibernating pupie.

References

U. S. Div. Ent. Bull. 19. pp. 'A-ryT. 1890.
Ga. State Bd. Ent. Bull. 1, pp. 17-2."). 1899.
U. S. Div. F:nt. Bull. 2:i. pp. rv^-CA. 1900.
U. S. Bur. Eut. Bull. 109, pp. 2:3-4."). 1912.

The G.\rdex Webworm

Loxoslege similalis Guenee

Many kinds of vegetables are injured by a small dark yellow
caterpillar feeding under the protection of a silken web. The
insect is widely distributed throughout North and South
America and the West Indies but is most injurious in the south-
ern states and in the Mississippi Valley. The favorite food
j)lants of the cateri)illar are pigweed and careless weed
{Amaranfus hyhridus) ; it also attacks a wide range of cultivated
plants, including cabbage, cucumber, melon, squash, j)umpkin,
sweet potato, potato, tomato, eggplant, beet, bean, pea,
lettuce, onion, corn, tobacco, flax, sugar-cane, clover, alfalfa
and many grasses.

IIow the insect passes the winter is not known, though
judging from the habits of a closely allied species, Loxostvije
sticticalif, it probably hibernates as larva' in silken tubes in the
ground. In Texas the first brood of moths is on the wing in
earlv Mav ; in Illinois in late May and June. The moth has an

INJURIOUS TO CABBAGE AND RELATED CROPS 19

expanse of about f inch. The front wings are reddish buff
marked with several transverse, interrupted hghter hues. The
hind wings are Hghter in color with darker marginal and discal
bands. The eggs are laid on the surface of leaves in bunches
of eight to twenty. Hatching takes place in three or four days
and the young larvae at first feed on the under surface of the
leaves, skeletonizing them, and spin a silken web inclosing their
food. The larger caterpillars devour the entire leaves. They
become mature in three or four weeks. The full-grown cater-
pillar is nearly an inch in length, dull green above and greenish
yellow below, marked on the dorsal surface w^ith numerous
shining black jjiliferous spots. The body is marked with a
double pale median line and a whitish lateral line. Pupation
takes place in a delicate silken cocoon spun among the debris
at the base of its food plants. The pupa is brown in color.
In the South there are probably as many as five generations
while in Illinois Forbes records four broods annually.

References

Riley, Rept. U. S. Ent. for 1885, pp. 2G.5-270.
U. S. Bur. Ent. Bull. 57, pp. 11-14. 1906.

The Purpl?:-Backed Cabbage Worm

Evergestis straminalis Hiibner

Although this insect is common throughout the northeastern
United States and Canada, it has been re{)orted as injurious
only in the maritime provinces. The in.sect also occurs in
Europe. Its food plants include cabbage, turnip and horse-
radish. When infesting the last, it is known as the horse-
radish webworm. The caterpillars feed on the leaves, often
webbing them together, and sometimes attack the crown boring
into the stems and roots. The full-grown caterpillar is about

20 MAXCAL OF VEGETABLE-GARDES INSECTS

f inch in length, bristly, with the body tapering at both ends.
The back is purplish brown to dark greenish black. There is a
yellow stripe running through the spiracles and the underside
of the body is dull greenish. The head is black, the cervical
shield is black on the sides and the body is marked with numer-
ous })lack tubercles.'

The larvse become full-grown in a little over a month and
construct thin silken cocoons covered with dirt at or just below
the surface of the ground. The larvre of the summer brood soon
transform to pupte but those of the fall brood remain in the
larval condition until the following spring. The pupa is about
\ inch in length and brownish in color. The moth has an ex-
panse of nearly an inch. The front wings are bright straw-
^•ellow crossed with two fine brown lines and the veins are
more or less lined with brown. On the outer margin of the
wing there is a broad, brown shade inclosing a triangular straw-
colored spot. The hind wings are straw-colored, translucent
white at the base with brown marginal and submarginal lines,
the latter usually incomplete and sometimes lacking. The
moth deposits her eggs in small flat masses of three to more than
a dozen, the eggs overlapping in the cluster. The egg is ovate
and very flat when first laid but gradually swells with the
development of the embryo. It is brownish yellow in color.
The egg hatches in eight days. There are two and possibly
three generations annually, the fall brood of caterpillars being
the most injurious.

Fortunately the purple-backed cabbage worm rarely becomes
sufficiently abundant to reciuire remedial treatment. Spray-
ing with arsenate of lead (paste), 2 pounds in 50 gallons of
water, should give satisfactory results.

Refkfiexces

Buckler, Ent. Mo. Mag. 10, pp. 126-130. 1882.
Fletcher, Kept. Ent. Canada for 1904, pp. 231-232.

INJURIOUS TO CABBAGE AND RELATED CROPS 21

The Zebra Catekpillau

Mamestra picta Harris

In the northern United States and Canada east of the 100th
meridian, a black, yellow-striped caterpiUar is often seen in
June and July and again in the fall feeding on the leaves of
many garden plants. Its __ .

H^itiM'iffc'ir''aiiMwaitniiatr ""^W .

a^lfitijpa

Fig. 17.

Full-grown zebra caterpillar
(X i).

striking colors often attract
attention but the insect
rarely becomes injurious
except occasionally on cab-
bage and celery. The full-
grown caterpillar is about two inches in length, black, with
bright yellow stripes on each side of the body (Fig. 17).
The back between the yellow stripes is dotted with fine
yellow spots and the space between the yellow bands on the
side is crossed by fine slightly reticulated yellow lines. The

head, legs and underside of
the body are dark red.

The caterpillars become
mature in about a month
and then enter the ground
where in slight silken co-
coons they transform to
shining brown pupse about
f inch in length. In the
summer the pupal j)eriod
is two or three weeks. The
moth has an expanse of \\ to If inches. The front wings are
purplish brown with a shade of light brown across the hind
part of the wing. The round and reniform spots are gray.
The hind wings are white edged with brown on the front and
outer margins (Fig. 18). The moth deposits her globular,

Fig. 18.

Moth of the zebra caterpillar
(X \\).

22 MANUAL OF VEGETABLE-GARDEX IX SECTS

sliglitlx' flattened e^^'s in c()nii)act flusters of 12.") to 150 or
more on the underside of the leaves. The eg^s hatch in a
week or two and the young caterpillars feed for a time in
colonies, skeletonizing the leaves, but later scatter and feed
singly. They are at first nearly l>lack hut soon become pale
or greenish and then develop the characteristic markings of
the mature larva. There are two generations a year, the
first brood of caterpillars being found in June and July and the
second in the fall. The insect may hibernate either as partly
grown caterpillars or in the pupal stage.

The zebra caterpillar rarely becomes sufficiently abundant t)
require remedial measures on crops grown under commercial
conditions. The young caterpillars may be killed by spraying
with paris green or arsenate of lead. In the home garden
hand-picking is the most satisfactory remedy.

A closely related species, Mamrsfra Jrgitima Grote, sometimes
known as the striped garden caterpillar, has been reported as
a general feeder on vegetable crops in the District of Columbia
and in Georgia. The larva of this species differs from the zebra
caterpillar in having the stiginatal yellow stripe broadly
bordered with black above. In habits and life history, the
two species are similar.

The C'AHHAfiE A I'll IS

Aphis hrnssicfF Linnaeus

The cabbage aphis is supposed to be of European origin,
but now occurs over practically the whole world wherever its
food plants are cultivated. It attacks cal)l)age, cauliflower,
brussels sprouts, kohlrabi, coUard, kale, brocolli, rape, turnip
and radish. It also breeds to a considerable extent on a number
of wild |)lants belonging to the nuistard family. In the I'nited
States, especially in the northern and eastern states, it often
takes first rank as an enemy of cabbage, cauliflower and related

INJURIOUS TO CABBAGE AND RELATED CROPS 23

plants. In some seasons the losses are severe, the crops over
large areas being so badly infested that the growers plow them
under early in the season.

In that part of its range in which the winters are severe,
the cabbage aphis hibernates exclusively in the egg stage;
farther south many of the lice doubtless
survive the winter. The elongate, oval,
smooth, black, shiny eggs (Fig. 19), about
■^ inch in length, are found abundantly on
the petioles and under surface of the leaves
of cabbage plants left in the field over
winter. Early in the spring the eggs hatch
and the young lice find abundant food in ^^°: I'J— Egg of

, , , the cabbage aphis

the tender sprouts thrown out by the old (x 19).

cabbage stumps (Fig. 20). These lice of the

first generation hatching from the eggs are all wingless females

and are known as stem-mothers. As they increase in size, the

lice molt four times, reaching
maturity in about two weeks.
A few days after the last molt
they begin to give birth to living
young. These stem-mothers
may live for six weeks or more
and give birth to forty or fifty
young. The next generation of
lice consists of wingless agamic
females which resemble the
stem-mothers very closely in
form and color, being about
Y^ inch in length, grayish green
in color and covered with a
whitish waxy bloom (I'ig. 21).
l)iii-iiig the rcniiiiiidci- of tlie
season rei)roduction continues

Fig. 20. — Stciu-niothcrs
cahljage apliis fci'dintj
[Sprout thrown out b>-

.f 111

>l<l

cabbage
hirgc(i).

.slump (greatly en-

MAMAL OF VEdKT ABLE-GARDEN IX SECTS

Fi(j. 21. — Wingless vivip-
arous female of the
cabbage aphis (X 84).

partlieii()<;(MU'ti('ally, 110 ejjgs are ])r()(lucr(l and the yoiiiif; are
born alive. From April first to October first, sixteen genera-
tions have been known to develop. From
time to time when the food supply be-
comes limited, either from overcrowding
or from some injury to the ])lant, winged
forms (Fig. 22) are developed which fly
to other plants and start new colonies.

Cabbage plants often become infested
in the seed-beds or very soon after
transplanting. The lice soon become
closely packed together in dcn.se masses,
often hiding the leaf from view. Their
presence causes the leaves to curl, some-
times forming deep pocket-like depressions, the inner surface
of which is completely covered with lice. The aphids also
cluster in the forming head. Badly infested plants cease to
grow, the larger leaves die, the heads do not develop and in
some cases the plant is killed outright. F'igure 23 shows a
badly infested radish seed-stalk.

Late in the fall, true males and females arc produced. The
female is wingless and the male is winged. After pairing the
female soon begins to deposit her eggs on the petioles and under
surface of the cabbage
leaves. When first laid,
the eggs are pale greenish
yellow in color but usually
turn black in a few davs.

ConiroJ.

Although cabbage

Fi(i. 22. — \\ iiiui'd \iviparous female
of till' cabbage aphis (X S-J).

lice
are easily killed when hit
by ordinary contact insecticides, it is difficult to control tliciii
economically' under conuncrcial conditions. The lice are ])ro-

INJURIOUS TO CABBAGE AND RELATED CROPS 25

tected in the curled leaves where it is difficult to hit them with
a spray ; their bodies are covered with a white waxy bloom so
that the spray does not readily wet them ; and they occur in
dense masses or colonies,
and considerable force is
required in order to reach
those beneath the others.
Under commercial condi-
tions, it is not possible to
destroy all the lice by
spraying. The best that
can be expected is so to
reduce their numbers that
the plant will be able to
continue its growth and
develop the head. Efficient
work can be done by spray-
ing with the so-called
whale-oil or fish-oil soap,
10 pounds in 100 gallons
of water, or with "Black
Leaf 40" tobacco extract,
f pint in 100 gallons of
water with 4 or 5 pounds
of soap added. The first
application should be made
as soon as the lice begin to
cluster on the young plants.
At least 100 gallons should
be applied to each acre

when the plants are young. The most cHVctive and economical
method of ai)plication is to use uii ordinary potato spniNcr
(Fig. 24) e(iuip|)('<l with a Y to which are attached two leads
of hose 10 or 12 feet in length. At the end of each hose is an

Fig. 2.3. — A radish sccd-stalk infested
by the cabbage aphis (enlarged).

MANUAL OF VECEr Mil.E-GARDEX IXSECTS

extension rod about 20 inches long, furnished with a Bordeaux
or Vermorel nozzle, preferably the former. The pump should
be able to maintain a pressure of at least 12") pounds. With
this arrangement three men are needed, one to drive the horse
and two to carry the nozzles. Attempts to use a potiito
sprayer with fixed nozzles have been unsuccessful. A stiH'

Fuj. 21.

."^prayiiij^ for thu fitljhaj^c uphis with u irueiiuu iJulalu-.-,prui'L-r
and two leads of ho.se.

Spray should be used, directed downward into the center of the
plant. With sufficient force it will be drixcn into many of the
curled leaves and will reach the lice.

' If the i^lants become infested with lice in the seed-beds,
they should be dipped in a solution of whale-oil soap, 1 pound
in (S gallons of water, before transplanting. The roots should
not be wet with the solution and the plants should not be left
in the sun after di|)ping ff)r fear of burning.

Hi:KKnKNrB
Cornell Ayr. Exj). Sta. Hull. :}()(). I'.Hl.

INJURIOUS TO CABBAGE AND RELATED CROPS 27
The Turnip Aphis

Aphis pseudohrassiccE Davis

Although the turnip aphis has undoubtedly been causing
serious injury to cruciferous crops for many years, particularly
in the South, it has been confused with other forms and its
injuries attributed to other species. This aphid was not recog-
nized as a distinct species until 1914 when it was described
from specimens collected in New York and Indiana. It has
received careful study in Texas where it is a serious pest of
turnip, radish, cabbage and mustard, but is also found on kale,
collard, rutabaga, rape and lettuce. It has been reported as
feeding on bean but this attack was probabl\' exceptional. The
turnip aphis is most destructive in the fall, winter and early
spring. Reproduction is rapid and the plants soon become
covered with the lice, especially on the underside of the leaves
and on the tender leaves at the center of the plant. Badly
infested plants are stunted and many of them killed outright.
The insect is distributed from Massachusetts to California
southward to Louisiana and Texas and has been found in
South Africa.

So far males and egg-laying females (the so-called true sexes)
of the turnip aphis have not been observed. In Texas the
aphids pass the winter mostly on turnips. In that climate
reproduction is considerably .slower in the winter months but
does not actually cease except for a few days at a time. Both
wingless and winged forms occur at all seasons of the year but
the relative abundance varies with the crowding of the plants
and with their vitality. The wingless form when mature is a
little over ^^ i'^'^i hi length, pale greenish, with the anteniue
pale, blackish towards the tip ; the legs are pale with the tips
blackish. The body is slightly pulverulent, but much less so
than in the cabbage aphis. The winged form is a little less

28 MANUAL OF VECET ABLE-GARDEN INSECTS

than ^ inch in length, the head and thorax arc black and the
abdomen apple-grccn. The legs and antenna^ are much chirlcer
than in the wingless form. Both forms give birth to ii\ing
young. In the course of its development the aphis passes
through four nymphal stages and becomes mature after the
fourth molt. This requires from five to twenty-five days for
the wingless forms and for the winged forms twelve to sixteen
days, depending on the temperature. Rearing from the first
born of each generation, thirty-five generations have been
secured in one year in Texas. The number of young produced
by each female varies considerably, from twenty-five to over
one hundred, born over a period of eleven to twenty-seven
days. During the summer in Texas, the turnip aphis is not
found on cultivated plants, but its wild host plants have not
yet been determined. In Indiana it is found abundantly on
wild mustard and in Colorado on shepherd's purse.

Control.

The turnip aphis can be controlled by thorough spraying
with "Black Leaf 40" tobacco extract, f pint in 1(X) gallons of
water to which 4 or 5 pounds of soap have been added. This
material will kill all the lice wet by the spray, the great difficulty
being in hitting them. Spraying should begin early, when the
first colonies of lice are found. Good pressure should be used
and the spray applied with upturned angle nozzles, so directed
as to wet the underside of the leaves. Eft'ective work can
also be done by spraying with whale-oil soap or laundry soap, 1
])()Uii(l in 7 gallons of water.

References

Tex. Agr. Exp. Sta. Bull. 180. 101.').
Ind. Agr. Exp. Sta. Bull. IS.'). l'.)l«).

INJURIOUS TO CABBAGE AND RELATED CROPS 29

The Cabbage Root-Maggot

Phorbia brassica: Bouche

Thrf)Ughout the greater part of the United States and Canada
and in Europe, cabbage, cauhflower, turnip, radish and related
crops are subject to serious injury by a small whitish maggot
that burrows in the roots. It is also destructive in Alaska.
In the northern states and Canada it is especially injurious to
early cabbage and is
very troublesome in the
seed-beds of late cab-
bage. Radishes also
rarely escape attack.
In some regions the
growing of these crops
has been abandoned
temporarily because of
the ravages of this pest.

The parent flies, as a
rule, emerge in early
spring and have been
recorded as feeding on
the pollen of flowers.
In the latitude of New

York they emerge from the middle of May till the middle of
June and may be seen around the plants searching for a
favorable place in which to deposit their eggs. In British
Columbia eggs have been found as early as April 10. The fly
is about ^ inch in length and resembles the house-fly in general
appearance. The male (Fig. 25) is dark ash-gray in color with
three blackish stripes on the thorax; there is also a wide black
stripe on the abdomen, which is contiiuied laterally along the
edge of the segments. The female is lighter in color and the

Fig. 25.

Male fly of the cabbage root-
maggot (X Sj).

MANUAL OF VEGETAHLE-GARDEX INSECTS

stripes are less distinct than in the male. This si)ecies is dis-
tinffuished from its near rehitives by the i)resence, in the mak'
fly, of a small tuft of bristles on the underside of the base of
the hind femur (Fig. 20 A). As yet no one has discovered any

characters by which the
females can be distin-
guished from those of the
seed-corn maggot. The
female (le])osits her snudl
white eggs at the base of
tile i)lant, carefully tucking
them down between the
s;)il and the stem. Some-
times the eggs are attached
to tlu> stem abo\t' ground.
Till' egg is slightly o\er ^^
inch in length, elongate,
bluntly rounded behind
and pointed and flattened
anteriorly, whitish in color,
l()iigitudinall\" striate and
deeply grooved on one side.
The eggs hatch in four to
ten days depending on the
weather. On hatching, the
yoimg maggot works its
■n, or Ti r i.i- f.i 1- 1 ^^'iv along the main root,

Fl(i. 20. — 1 lio foimir and lil)ia()f tho hiiul ' . . ,

Ic'U of the iiialo fly of: A, cahhauo root- on wllicll it fccds by rasp-
n.aggot : B, onion maggot ; f. .s«.,l-,orn j, , „^,^ ., chaimcrin the
maggot. '^ _

surface. The maggots fir.st

attack the tender rootlets and then burrow into the main root

where they may be fcanid in slimy bnrrows just under the bark.

They are sometimes seen in the stem aboxc ground and even

in the midrib of the leaves. Usuallv the first indication that

INJURIOUS TO CABBAGE AND RELATED CROPS'^ 31

a cabbage plant is seriously infested is a tendency to wilt badly
in the heat of the day ; the leaves take on a bluish cast and then
in a few days the plant
droops and dies or it may
survive in a sickly condi-
tion for some time. When
the maggots are present
in great numbers, the root
is riddled with their bur-
rows, decay sets in and
the death of the plant
quickly ensues. In such
cases great numbers of the
maggots may be found in
the soil surrounding the
root, moistened by the
juices of the injured plant (Fig
full-grown in about three weeks.

Fig. 27. — Cabbage root-maggots at
the base of an injured plant.

27). The maggots become
They are then nearly ^ inch
in length and shin-
ing white in color.
The body tapers
toward the head,
being largest be-
hind, where it is
obliquely truncate.
The mouth-parts
consist of a pair of
strong black hooks
curved downward,
by which the insect
is able to rasp ofi"
portions of the
plant tissue. The truncate surface at the posterior end of the
body is surroimded by a row of twelve fleshy tubercles, of

Fig. 28. — The cabbage root-maggot, side view
( X 8) ; a, dorsal view of eaudal segment, showing
size, nunil)er and arrangement of fleshy tubercles,
much enlarged ; b, outline of a cephalic spiracle,
greatly enlarged.

32 MANUAL OF VEGETABLE-GARDES IXSECTS

which the middle lower pair are two-toothed. At the side of
the l)ody just back of the head is located a pair of spiracles
which appear as brownish fan-like projections each having
twelve divisions. These characters are used in separating the
cabbage maggot from its near relatives (Fig. 28).

When full-grown, the maggots work their way into the soil
an inch or so, and there the skin contracts, hardens and turns
brownish, thus forming the puparium (Fig. 29). Sometimes the
maggots make this change in cavities in the roots. Within the
puparium there takes place a remarkable series of changes
whereby the tissues of the larva are broken down and rebuilt
into the organs of the fly. The fly escapes from the puparium
through a circular seam at one entl ;
the length of the period passed in the
puparium \aries greatly ; most of the
flies emerge in twelve to eighteen days ;
Fig. 29. — Puparium of a few may appear sooner, and a con-
got ('x7r^ ^*'°*^°'''^" siderable \uunber emerge irregularly
throughout the remainder of the season.
A few puparia of this first brood may hold over till the
following spring. A second brood of flies appears the last
of June and throughout July. A third brood emerges from
August till October. In some seasons a partial fourth brood
may occur. As a rule it is the first brood of maggots that
is most destructive to cabbage, cauliflower, radish and
turnip, although occasionally the second brood causes seri-
ous damage. The wild plants in which breeding takes place
are hedge mustard, white mustard and winter cress or yellow
rocket, and probably other members of the mustard family,
although shepherd's purse seems to be immune. In Canada the
flies have been reared from maggots infesting the roots of l)ean
and beet. In the North, as a rule, the insect hibernates in the
puparium stage, but occasionally a few of the flies emerging late
in the season may j)ass the winter under the i)r()tection of the

INJURIOUS TO CABBAGE AND RELATED CROPS 33

cabliage plants in tlie field. It is quite probable that farther
south a greater number of the flies hibernate.

Control.

The means employed for the control of the cabbage maggot
vary greatly with the character of the crop infested.

For early cabboge and cauliflower. — When infesting these
crops, the injury may be in great measure prevented by the
use of carbolic acid emulsion. For this purpose the stock
emulsion is diluted with thirty parts of water. About half a
teacupful of the emulsion should be poured around each plant
a day or two after transplanting. The application should be
repeated every week for a month. Apparently the carbolic
acid emulsion does not to any great extent deter the flies from
laying their eggs, but is efi^ective in killing the eggs and recently
hatched maggots with which it comes in contact. This method
has been used to a considerable extent by commercial growers,
but has not on the whole been found so satisfactory as the use
of tarred paper cards.

The value of the use of tarred paper cards to prevent maggot
attack on early cabbage and cauliflower was demonstrated many
years ago, but has not come into general use by commercial
growers. This method of protection is more effective and at the
same time less expensive than carbolic acid emulsion, and there
is also no danger of injuring the plants. The cards are made of
one-ply tarred felt roofing paper, and are cut in the form of a
hexagon 4^ inches in diameter. From one angle a slit extends
to the center of the card and radiating from the center there are
four to eight short slits whereby the card can be made to fit
snugly around the stem of the plant (Fig. 30). The cards
should be applied as soon as the plants are set out. To be most
effective, the plants should be set on a ridge rather than in a
depression because in the latter case the cards are likely to be-
come covered with dirt. The\- cannot be used on short-stemmed

MANUAL OF VEaETABLE-GARDEX IXSECTS

])l;iiits set St) fleeply in tlir ground tliat the leaves are partly
buried. After having been placed in position, the cards should
be pressed dow n so as to rest smoothly
on the soil and thus pre\ent the Hies
from working; under them.

The tarred pads can be obtained from
seedsmen and dealers in garden sup-
plies or the grower can make them
himself by using the tool shown in
Fig. 31. The method is described by
(loii" as follows :

"The i)lade of the tool, whicji should
:i().-()utiino of tarred ]^^^ ^^y^^^l^, j,^. .„j expert blacksmith, is

l):ipcr card (X J). , ,. ' i , , ,. . .

lormed from a blade oi steel, bent m
the form of a half hexagon, and then taking an acute angle,
reaches nearly to the center. The ])art making the star-shaped
cut is formed from
a separate piece
of steel, so at-
tached to the
handle as to make
a close joint with
the blade. The

latter is beveled from tlie outside all around, s) that by remox'-
ing the i)art making the star-shaped cut. the edge max* be
groimd on a grindstone. It is imj)ortaiit that tiie angles in

the blade be made perfect, and that

its outline rei)resents an exact half

hexagon.

"To use the tool, place the tarred
,, ..., ,,. , paper on the end of a section of a log

ric. .i2. — Diagram show- ' ' . . . ,

ing how the tool is used, or piece of timber and first cut the

The df)ttod line indicates i ,,.,., , ],„ ;, .^ ,, +, 1,,. , ., , ;,,,i;-..,+,wl I,,

,, ... , ,, , lower edge nito notclies. as nidicated m

the i)f)sition of the edge ,. .

of the tool. Fig. IV2, using onlv one angle of the

Fic. ;n.

Tool for cultiii}; the cards (X J).

INJURIOUS TO CABBAGE AND RELATED CROPS 35

tool. Then commence at the left end, and place the blade as
indicated by the dotted lines, and strike at the end of the
handle with a light mallet, and a complete card is made. Con-
tinue in this manner across the paper. The first cut of every
alternate course will make an imperfect card, and the last cut
in any course may be imperfect, but the other cuts will make
perfect cards if the tool is correctly made, and properly used.

"The cards should be placed about the plants at the time
of transplanting. To place the card bend it slightly to open the
slit, then slip it on to the center, the stem entering the slit,
after which spread the card out flat, and press the points
formed by the star-shaped cut snugly around the stem."

For late cahhagc srcd-beds. — The depredations of the maggot
in late cabbage seed-beds are often severe and necessitate the
growers making much larger plantings of seed than would
otherwise be required. Screening the beds with cheesecloth
has been found an efficient and practicable method of protection
and is now regularly practiced by cabbage growers in certain
localities in New York. When this method is used, the seed
should be drilled rather thickly in rows 6 to <S inches apart.
The corners of the bed should be staked out so that the cover
can be applied before the plants come up. Boards, (> to 10
inches wide, are placed on edge around the bed making a tight
enclosure and a cheesecloth cover is stretched over the top.
The cloth is supported on galvanized wires stretched across the
bed every 4 or 5 feet. The wires are sometimes supported at the
middle by short stakes. The cloth is fastened to the boards by
strips of lath. Care should be taken to have the boards fit
tightly at the corners and at the ends, and the earth should be
banked up around the bottom so that the flies cannot work their
way under. Even the ('hea])er, loosely woven grades of cheese-
cloth will exclude the Hies, but as clotli having less than twenty
threads to the inch is likely to stretcli and i)ull apart so as to
let in the flea-beetles, it is better to use cloth having twenty

36 MANUAL OF VEGETABLE-dARDKS I \ SECTS

to thirt\' threads to the inch. Cloth that is too tightly woven
will exclude too much sunlight and make the plants spindling.
The screen should be remo\'ed a week or ten days before trans-
j)lanting in order to harden the plants. Plants grown under
cheeseck)th cover are not only protected from the attacks of
root-maggots and flea-beetles but, owing to the retention of
warmth and moisture, make a much better growth than in the
open. Screened beds do not have to be as large as open beds
because under these conditions practically all the plants make
the proper growth.

For radishes. — Carb(jlic acid emulsion has bci-ii used with
some success on this crop, but better results can be ()l)tained by
growing the i)lants in beds screened with cheesecloth as de-
scribed above.

References

(\)rncll A^. Exp. Sta. Bull. 78. 1S04.
N. J. Affr. Exp. Sta. Bull. 200. 1907.

N. Y. (Geneva) \^. Exp. Sta. Bull. :i01. I'JOS.

N. Y. (Geneva) Agr. Exp. Sla. Bull. :«4. I'.tl I.

N. Y. (Geneva) Xffc. Exp. Sta. Bull. :}S2. I'.U 1.

N. Y. (Geneva) \^. E.xp. Sta. Bull. 41<). I'.IKi.
Dept. Apr. Canada Ent. Bull. 12. pp. 9-29. 191().

N. Y. (Geneva) Kffr. Exp. Sta. Bull. 442. 1917.

TiiK Sekd-Cohx Maccot

Phnrhia f)isricrpx Zrtter.stedt

The injury caused l)y the cabbage nuit-inaggot is (it'ten
augmented by the presence of a closely related species which
has received the rather inappropriate common name given above.
The seed-corn maggot is generally distributed throughout the
T'nited States and Canada and also occurs in Europe. In addi-
tion to cabbage and related i)lants. it attacks s])routing seed corn,
beans and i)eas, and has l)cen icconjcd as feeding (tn seed pota-
t(jes and onions. The food of this species is not confinecl to vege-

INJURIOUS TO CABBAGE AND RELATED CROPS 37

table matter, for at the time of the great outbreak of migratory
locusts in the West, the maggots attacked the eggs of these
grasshoppers which then (K'curred in great abundance. Gen-
erally, however, the maggots feed on planted seeds which have
softened in germination or from decay. They are sometimes
very destructive to seed beans especially in cold, wet, backward
seasons. In some cases more than half of the crop is destroyed
over large areas in this way. The maggots burrow into the
seed-leaves, destroying them, and then mine into the stem.
Some of the injured beans fail to germinate ; more often,
however, the seed-leaves push up through the soil, but as the bud
is injured the plants fail to leaf out.

The flies of the seed-corn maggot closely resemble those
of the cabbage root-maggot, but the males may be distinguished
by lacking the tuft of hairs on the under side of the base of the
hind femur, and by having on the under side of the hind tibia
a row of short spines (Fig. 20 C). The females of the two
species are indistinguishable. As far as known, the life histories
of the two species are very similar.

Control.

The seed-corn maggot, when attacking cibbage and related
crops, may be controlled by the means suggested for the cabbage
root-maggot. The injury to germinating beans may be pre-
vented in large measure by planting the seed shallow in cold
wet seasons. Beans planted in this way come up more quickly
and, being in a vigorous condition, are able to outgrow any slight
injury to the seed-leaves.

The Western Radish IMaogot

Phnrbia planipnlpis Stein

On the Pacific Coast the cabbage root-maggot is replaced by a
closely related species with similar habits. The maggots of this

38 MAXUAL OF VEGETABLE-GARDEX INSECTS

fly have hccii found infcstiiiij: radish, (•al)ha,<;o, cauliflower, ruta-
baga and turnip and ha\c also Ix-en observed abundantly in the
pods of lupine and field peas, destroying the seeds. The fly
closely reseinl)les the adult of the cabbage root-maggot. The
male is \ inch in length and the female about \ inch.

The insect hibernates both as adults and as i)uparia. The
female deposits her white, elongate, slightly curved eggs, about
1^ inch in length, singly or in loose masses on the roots (.r
on the leaves near the crown. On hatching, the maggots bur-
row into the radish roots rendering them unfit for food. Many
maggots often infest the same root and sometimes kill the
plant. The full-grown maggot is -f to f inch in length and is
whitish or yellowish in color. The body tapers toward the head
and is truncate behind. When mature the maggots transform
to puparia either within the root or in the surrounding soil.
The puparium is about \ inch in length and brownisli in color.
There are .said to be several generations annually.

A satisfactory method of control does not seem to ha\e been
worked out.

Reference
Essig, Insects of California (Ed. 2), pp. 33G-3.30. 1915.

Till. ITaRLEQUIX r.\BBAOE BlT,

M iiryantia hislrioiiicn Halin

In tile last half century the harlequin cabbage bug has spread
from its. home in Central America and Mexico northward to
Nevada. Colorado, the southern j)art of Illinois, Indiana, Ohio,
Pennsylvania and New Jersey and to Long Island. New York.
It also occurs in California. Except in the extreme northern
part of its range, it is a most destructi\e enemy of cabbage and
relatcfl plants. It is also known as the terrapin-bug, fire-bug
and calico-back. AVhcn food is abundant, it usually confines
its attacks to i)lants belonging to the nnistard family, l)eing es-

INJURIOUS TO CABBAGE AND RELATED CROPS 39

>^'

pecially fond of horse-radish, but when its favorite food plants
have been destroyed the bngs will migrate to adjoining fields
and feed on almost any plant available. Eggplant, asparagus,
potato, tomato, okra, bean, beet and even nursery stock are
sometimes severely injured under such circumstances. The in-
sect also breeds on a large number of wild ])lants belonging to
the mustard and caper families.

The harleciuin bug hibernates as an adult under rubbish ; in
southern Florida the insect remains on the food plants during the
winter, but its ac-
tivities are more A
or less retarded.
As soon as spring
opens, the adults
emerge from win-
ter quarters and
congregate on any
cole plants avail-
able. The female
deposits her eggs
on the underside
of the leaf in
masses each con-
taining normally
twelve eggs ar-
ranged in two
rows of six each.
The females that have wintered over are more prolific than those
of later generations; they are each capable of laying about one
hundred eggs. Females of the next generation lay on an a\er-
age only about seventy-five eggs. Th(> egg is o^„ inch in length
by To 'iifb J'^ width, cylindrical, truncate at each end ; the
upper end is pro\idc(l with a circular lid which is pushed oil' at
the time of hatchiug. The egg is pearl-gray or pale yellow,

Fig. 33. — Egg-clusters of the harlequin cahl^agc bug
on the underside of a leaf ( X 2).

MAX UAL OF VECETAIiLE-dARDEX IX SECTS

with two hlack bands, one broader and more distinct near the
top and the other near the bottom. There is a bhick spot just
above the lower band and sometimes the eggs are irregularly
blotched with black. The cap of the egg has a semicircular
black mark inside the marginal ridge. The
ego; has a striking resemblance to a small
white keg with black hoops, the spot on the
side suggesting thcbungholelFigs. 33and 34).

Fig. 34. — Eggs of The eggs hatch in four to eleven days, de-

the harlequin cab- pe„,li,ur on the temperature. The newl\-

bage bug, side ^^ew , , , i • i • i

(X5). hatched nymph is pale green ni color witii

black markings. The insect passes through
five nymphal stages and accpiires wings at the fifth molt. In
its later stages, the nymph is brightly colored — black, orange
or yellow, and red. About two months after hatching, the
nymphs reach maturity and transform to adults. The adult
(Fig. 35) is about f inch in length, mottled red. black and
yellow or orange. In all stages the
bugs have a disagreeable odor and
are distasteful to birds.

In feeding, both adults and
nymphs puncture the plants and
suck out the juices. A half dozen
bugs are enough to kill a- cabbage
or turnip plant. The severity of the
injury inflicted seems to be out of
proportion to the amount of food
withdrawn from the plant and is
supposed to be produced by a poison
which the insect injects while feeding.
Injured cabbage plants wither and turn brown as if scalded.
The crop in whole fields is often coniplctclx' (h'stro\'ed. Many
gardeners have been deterred from planting cabbage and collards
because of the ravages of this pest.

Fk;. ;i.'). — Tlic harlc(|uin rab-
l)age Img, adult (X 3|).

INJURIOUS TO CABBAGE AND RELATED CROPS 41

Control.

Both the nymphs and adults of the harlequin cabbage bug
are very resistant to contact insecticides. In fact it is prac-
tically impossible to kill them in this way without injuring the
plants. Loss may be prevented in large measure by practicing
clean cultural methods of farming. x\fter the crop has been
harvested, all cabbage stumps and other refuse should be plowed
under or destroyed in some other way. Hibernating shelter in
the form of overgrown fence rows or patches of rank weeds
should be reduced to a minimum. It is sometimes advised to
leave a few piles of rubbish in the field in the fall as traps for the
hibernating bugs. After they have collected in such shelter,
the rubbish should be burned.

Very effective work can be carried on against the l)ugs in the
spring by the use of trap crops. Kale, mustard and rape are
often utilized for this purpose. If a few of these plants are sown
so as to be available for food before the crop it is desired to protect
is up, the insects will congregate on these plants where they may
be killed by spraying with pure kerosene or in some other way.
In the fall it is a good plan to leave a few cabbage, turnip or kale
plants after the remainder of the field has been cleaned. The
bugs will collect on these plants where they may be easily de-
stroyed before going into hibernation. The destruction of the
adults early in the spring is the most important measure for the
control of the insect ; if this work is done with thoroughness the
crop will remain relatively free from attack for the remainder of
the season. If the bugs are not destroyed in early spring, the
only recourse is to hand-pick them into pans of kerosene — a
tedious and laborious operation.

References

N. C. Dopt. A^. Ent. Circ. S. 19(H.

U. S. Bur. Ent. Circ UY.i. IIIOS.

Smith, .Jour. Ec. Ent. 2, p]). 108 114. 1909.

MAMAL OF ve(;etable-c;arde.\ ixsects

The GRf:EX Soldi kh-Blg

Acrostcrnutn hilnris Say

In the northern states the fruit of peach, apple and pear
is occasionally seriously injured by the punctures of a large
green stink-bug. The insect is widely distributed throughout
the United States and Canada and southward to the West Indies
and Brazil. It has also been recorded as attacking cabbage,
bean, pea, corn, okra, tomato, eggplant, turnip and mustard,
and it also feeds on a large number of
shrubs and trees. The insect has been
carefully studied as a fruit pest in Ohio.
The green soldier-bug (Fig. 30) is from
I to f inch in length, oblong, oval,
bright green in color with the edges of
tile head, thorax and abdomen narrowly
bordered with yellowish or reddish.
The winter is })assed by the adults
hidden away in dry sheltered places,
often under fallen leaves. The bugs
emerge about the middle of May and
egg-laying begins about the first of
June continuing until the middle of July. The eggs are
about j-V inch in length, oval, largest toward the top which is
j)rovide(l with a small circular cap, surrounded by a single row
of about sixty-five club-.shaped spine-like processes. The eggs
are usually light yellow in color but are sometimes light green.
Just before hatching, they become j)inkish or reddish. They are
attached to the leaf by one end and arranged in clusters of
twenty to fifty. Each female usually la.\ s two batches of eggs
and a few may lay a third. The first batch is usually the
largest and the last vcr\- small. The eggs hatch in about a week
and the > onng nymphs remain in a eoni|)a(t elii->ter near the egg-

FiG. 3(j. — The green
soldier-bug (X I5).

INJURIOUS TO CABBAGE AND RELATED CROPS 43

shells till after the first molt. They are about yV inch in length,
with the head and thorax brownish black and the abdomen marked
with transverse black and light blue bands. In the course of its
development the insect passes through five nymphal stages and
acquires wings at the fifth molt. In the fifth stage the nymph
is nearly ^ inch in length, with the head and thorax blackish
marked with orange-yellow ; the abdomen is yellowish green.
The nymphs require from seven to ten w^eks to reach maturity
and adults of the new brood begin to appear the last of July,
but some of the nymphs do not reach maturity until the first of
October. There is only one generation annually.

A closely related species, Nezara viridula Linnjeus, is some-
times injurious to cabbage in the southern states. The plants
are injured in much the same way as by the harlequin cab-
bage bug. The adults so closely resemble those of A. hUaris
that they are distinguished with difficulty. The most striking
difference is that in the former there is a distinct, small black
spot on the hind outer corner of the exposed part of each ab-
dominal segment. In the latter these spots are very small and
inconspicuous. The insect ranges from Virginia to Texas and
northward to Indiana. It has also been reported as injuring
tomato, sweet potato, okra, pepper, cotton and orange.

No satisfactory method for the control of the green soldier-
bugs, other than hand-j)icking, has been suggested.

Reference
Ohio Agr. Exp. Sta. Bull. :ilO. 1917.

The Cabbace Leaf-Miners

There are three species of flies, the maggots of which develop
within the leaves of cruciferous plants, producing large whitish
blotched mines.

MANUAL OF VECETABLE-CARDEX IXSECT.^

The iiiiporfcd iurnip IfdJ'-iiiiiiir, Scdptoiii/rji Jldrcola Mcigcn

Originally a native of Europe where it is known as the turnip
leaf-miner, this insect was introduced into the United States
some time before 1801, and is now widely distributed, ranj^ing

from Alaska to New Hampshire
and south to kiwitucky and
^'ir<;inia.

\ ery little is known coneerninjj;
its early seas!)nal history and
the numl)er of broods oeeurrinir
aimually has not been deter-
mined. The parent fly ap-
parently de|)()sits her egj^s on
the u])per surface of the leaves.
On hatching, the young maggot
burrows into the leaf and feeds
just below the upper epidermis,
producing at first an irregular
tortuous burrow which is sud-
denly widened to form a large
blotch. The e])iderniis o\er the
mine turns whitish and by a
coalescence of several mines the
Fic. 37. — A younK cal)l)aKo leaf whole leaf may take on this

c;)lor (Fig. 37). The full-grown
maggot is about ^ inch in length,
whitish in color and cylindrical in form, tai)ering towards the
head and bluntly truncate behind. When mature the larval
skin hardens and turns reddish brown to form the puparium
within which the true pupa is to be found. This tran.s-
formation may take j)lacc in the mines but usually the puparia
are found under rubbish on the surface of the ground. In
Kentuckv the flies have been observed to emerge in late

.showiiiR the work of the iniiiorted

turnip Icaf-iiiiiKT.

INJURIOUS TO CABBAGE AND RELATED CROPS 45

fall. The insect may, therefore, hibernate in the adult condi-
tion. The fly has an expanse of about ^ inch and its general
color is brown, the antennae being yellow and the legs pale.
This species has been recorded as feeding on cabbage, cauli-
flower, radish, turnip, Iceland poppy, horse nettle and mouse-
ear.

The native cabbage leaf-niiner, ScaptoDtyza adusta Loew

This species is closely related to the preceding and has been
reared in company with it. It injures the plant in a similar way.
It is widely distributed from [Maine to Florida and west to
Illinois but is more abundant in the southern part of its range.

The imported cabbage leaf-m.iner, Scaptomyza
graminuni Fallen

This European leaf-miner is now distributed in this country
from New Hampshire to Texas. Its habits are similar to those
of the two preceding si)ecies. In this country it lias bccMi n^arcd
from cabbage and in Europe it attacks several plants including
chickweed, lamb's ciuarters, cockle and catchfly.

There seems to be considerable doubt as to the determination
of the three species just treated. Sturtevant, who has carefully
studied these flies, does not believe that S. flaoeola has been in-
troduced into this country and is of the opinion that th(> studies
on which tlie above account is based were made on a mixture of
S. adusta and S. gramininn.

Control.

Little is known as to the best measures for controlling these
leaf-miners. Their injuries are rarely serious. It might be
possible to kill the maggots in the mines by spraying with a
strong mixture of nicotine sulfate and soap.

MANUAL OF VEGETABLE-GARDES INSECTS

References

Ky. Af?r. Exp. Sta. Bull. 40, pp. 46-51. 1892.
Coquillett, Insect Life, 7, pp. 381-383. 1895.
U. S. Div. Ent. Bull. 33, pp. 75-77. 1902.

The serpentine leaf-miner, Agromyza pus ilia Meigen

'j'he leave.s of cabbage, turnip, radish and rape are sometimes
disfigured })y narrow, tortuous mines caused by a small, trans-
lucent yellow maggot about i- inch ill length. This insect has

also been found mining
the leaves of potato,
spinach, beet, water-
melon, and pepper, as
well as many wild and
f )rage plants. When
mature, the maggots
transform within the leaf
into brownish puparia
about Y^ inch in length.
In the summer about
ten days are spent in
this stage. The fly
(Fig. 38) is from i^ to
Yi inch in length, shining black and marked with yellow in a
most variable way. The flies deposit their small, white, oval
eggs, about ywu ''K'^i i" diameter, in the tissue of the leaf
on the underside. The eggs hatch in three to eight days.
The time required for each generation varies from twenty-
three to forty flays dcjx'nding on the temperature. Bn-cding
is continuous throughout the growing period and the number
of generations depends on the length of the season.

Fiu. ;j.s.

The fly of the .serpentine leaf-
miner (X 20).

RErERENCE

Webster and Parks. .Jour. .\gT. Research. 1, pp. .39-87.

1913.

INJURIOUS TO CABBAGE AND RELATED CROPS 47

The False Chincii-Bug

Nysius ericoE Schilling

Cabbage, cauliflower, radish and turnip are occasionally sub-
ject to injury by a small grayish brown bug known as the
false chinch-bug. This insect is widely distributed through-
out the United States from California to New Hampshire and
southward. It has been reported as most troublesome in the
upper Mississippi Valley and in the western
states. These bugs are very general
feeders and sometimes injure beets, let-
tuce, mustard, potatoes, corn, strawberry,
cotton and even apple nursery stock and
young grape vines. Seed-beets during the
second year's growth are sometimes
severely injured.

The false chinch-l)ug hibernates as an
adult in rubbish and under the leaves
around the base of its food plants. The
adult (Fig. 39) is about | inch in length,
grayish brown in color, sprinkled with
blackish ; the head is marked with two
longitudinal black lines and there is a transverse black band
across the front of the prothorax ; the legs are yellowish lirown.
The bugs are most destructive in early spring when the adults
come out of hibernation in great numbers and swarm on the
young plants. In feeding, they puncture the leaves and suck
out the sap, causing the plants to wilt, turn brown and die.
The early spring and late fall broods deposit their eggs in
cracks of the soil. The other broods place their eggs in the
heads of various wild plants. The egg is described as being
slender, cylindrical, irregularly wrinklrd and tapering at both
ends; it is yellow in color, orange-red at the anterior cikI.

Fig. ,39. — The false
chinch-hujr, adult
(X 11).

48 MANUAL OF V ECET ABLE-GARDEN INSECTS

TIic youn^ iiyinplis are ycllowisli marked with iiulistinet
lon^Mtudiiial <lark lines. They I'eed ahiiost exclusively on
weeds sueh as pepper-<^rass, sliepherd's purse, Russian thistle
and sage brush. The older nymphs are more distinctly
marked with brown and reddish lines. When mature, the
bugs scatter to all kinds of vegetation but in cases of drought
are forced to congregate on cultivated plants. In Illinois the
first brood nymphs mature in the latter part of May and the
second in July. The broods overla|) so that in midsummer
all stages may be found together. In Kansas there are said
to be at least five generations annually.

In Colorado there is a smaller race of the species which l)ears
the name Nysius vunidus I'hler. It has been recorded as \ery
injurious to beets grown for seed.

ControJ.

Much can be done to prevent injury by the false chinch-bug
by clearing the fields of all rubbish in the fall, thus depriving
the bugs of hibernating shelter. This may be accomplished
by burning over the fields. If the vegetation is not sufficient
to carry the fire, straw may be scattered over the field. A
gasoline torch may be used to kill the insects where they have
congregated on weeds or clumps of grass. The insects may
also be killed by thorough spraying with "Black Leaf 40"
tobacco extract, 1 pint in 100 gallons of water to which 10
pounds of soap have been added. Burlap shields made sticky
with a coat of crude petroleum are sometimes used to capture
till' bugs on i)lants that cannot be s|)ra\'cd.

Rkkkrknces

Riley, ,5th Kept. Ins. Mo., pp. 111-114. 1S73.
Oshorn, Kept. U. S. Ent. for 1SS7. p. 1()2.
Forbes. 2:5rd Ropt. Til. State I<:nt., pp. 117-1 IS. 190',.
U. S. Farm. Bull. 7C.2. ll»l(i.

INJURIOUS TO CABBAGE AND RELATED CROPS 49

The Cabbage Curculio

Ceutnrliynchus rnpcF Gyllenhal

One of the minor pests of cabbage, cauliflower, kale, radish
and horse-radish is a small ash-gray wee\il about ^ inch in
length. This beetle is a native of Europe where it has never
attracted attention as an enemy of cultivated crops. It was
apparently introduced into America in New England about
the middle of the last century but is now generally distributed
throughout the northern states from New York to Virginia
westward to Nebraska and Colorado. It also occurs in Cali-
fornia.

The insect hibernates in the adult condition and the weevils
appear in the field in early spring. They feed slightly on the
leaves and also puncture the stems of their food plants, eating
out a cavity as deep as they can reach with the beak. The
female deposits her eggs singly in similar punctures in the
stems. The tissue surrounding the egg-puncture becomes en-
larged, forming a noticeable scar. The eg^ is about -jt hich
in length, oval and shining white. The eggs hatch in about a
week and the grubs, several of which may infest a single stem,
hollow out the contents, often causing the plants to turn
sickly and die. The full-grown grub is -g- to \ inch in length,
milky white with a brownish head. The larvae become mature
in about three weeks, gnaw their way out of the stem and
enter the ground where at a depth of less than an inch they
transform to milky white pupse in oval earthen cells. The
beetles appear in about a week, or during the early part of
June in the District of Columbia, and feed for a time on the
stems and leaves of their food plants. Although the new brood
of beetles appears at this early date, there is apparently' only
one generation annuallx'.

Larvae of the cabbage curculio have been found in the stem
and crown of cabbage and cauliflower, the petioles of horse-

50 MAXCAL OF VECET ABLE-GARDEN IXSECTS

radish and |)r()l)a))l\ also infest the radish. Sri'ioiis injury to
(•al)l)a<,^(' and cauhHowcr |)lants in the hot-bed has heen re-
ported from Missouri. The In-etles, ho\ve\er, ])refer to deposit
their etjgs in the stems of wild pei)per-ifrass, hedfje uuistard and
shepherd's pur.se. When these i)hints are avaihd)le for ejjg-
hiyiiij;, cultivated crops are not usuallx' infested. In case wild
])lants are allowed to <;row as a traj) croj), they should he de-
stroyed before the larva* reach maturity else they will merely
ser^■e to increase the abundance of the jx'st.

Reference
U. S. Div. Ent. Bull. 23, pp. 39-50. 1900.

The Cabb.vge Seed-St.vlk Weevil

Ceutorhynchus quadridens Panzer

Another luiropean weevil closely related to the one last
treated has been introduced into Ma.ssachusett.s and Lonj^
Island, New York. On Lon^' Island this weevil has proved a
serious pest to cabbage grown for .seed, hundreds of lar\ie
being found in a single stalk, their presence causing the i)lants
ti) wilt and break over just before the seed begins to mature.
Whole fields are often ruined in this way. The adult is slightly
smaller than the cabbage curculio and the scales with which
tlie body is covered are white intermixi-d with gray hairs. This
weevil also infests kale and turnij) and in Eurojje it is recorded
as breeding in mustard, water cress, horse-radish and rape.

No satisfactory method of controlling this in.sect is known.

The Red Tihxip Beetle

Eiit<>7noscclii> ado7iidis Pallas

Tn western Canada cabbages, radishes, turnips and l)eans
occasioiialh' ha\(> the leaves eaten b\- the larwe and adults of

INJURIOUS TO CABBAGE AND RELATED CROPS 51

a scarlet beetle about \ inch in length, marked with three black
stripes down its back and with a black patch on the prothorax.
The insect is native to the region, where it fed originally on
wild cruciferous plants, particularly the prairie wall-flower,
but it is also found in Europe and Asia. The beetles deposit
their red to dark brown, elongate-elliptical eggs, ^ to i^ inch
in length, in large loose masses under clods of earth. The
mature larva is black above and yellowish beneath, slug-
shaped and about § inch in length. The larvse are said to feed
mostly at night. When full-grown they burrow into the soil
for an inch or so and there transform to bright orange pupa;
about \ inch in length. The winter is passed in the G^g stage
in the ground. The beetles become noticeable in the fields in
July and August and may be found as late as November.

In Austria the winter eggs hatch in the early spring and the
larvffi become full-grown in the latter part of April. The
beetles appear in May and after feeding a few days go into
{estivation in the ground where they remain till September or
October. It is quite probable that when the habits of this
beetle are thoroughly studied in America, its life history will
be found to be much the same as in Europe.

Spraying with arsenate of lead (paste), 2 or 8 pounds in 50
gallons of water, will kill many of the beetles and their larvie.

Reference
Fletcher, Rept. Ent. Canada for 1S92, pp. 10-13.

Otuek Insects Tnjukious to Caubage and Related Crops

Corn ear-worm : 211
South(>rn eorn root-worm : 222
Western corn root-worm : 225
Carrot, ])e(>tle : 1S.5
Tarnished ])lan1-l)u^- : 1«)2
Sugar-beet wel)W()rm : 97
Southern beet webworm : 101

52 MANUAL OF VEGET ABLK-dARDES IS SECTS

Spinach aphis : lOo

Western twelve-spotted cucumber beetle: 114

Belted cucumber beetle : 115

Garden springtail : 13i)

Potato aphis : loO

Common stalk-borer : 157

Bean thrips : 09

Garden flea-hopper : 77

Bean leaf-roller : 81

Onion thrips : 24")

Argus tortoise beetle : 238

Spotted cutworm : 262

Well-marked cutworm : 2()3

Greasy cutworm : 265

Red-backed cutworm : 2(57

Dark-sided cutworm : 268

Striped cutworm : 270

Dingy cutworm : 271

Shagreened cutworm : 272

Granulated cutworm : 273

Clay-l)acked cutworm : 274

Variegated cutworm : 276

White cutworm : 278

Glassy cutworm : 279

Yellow-headed cutworm : 281

Spotted-legged cutworm : 282

Speckled cutworm : 283

Clover cutworm : 284

Bristly cutworm : 285

Army cutworm : 287

Fall army-worm : 292

Yellow-striped army-worm : 295

Striped blister-beetle: 302

Margined blister-beetle : 305

Ash-gT'ay blister-beetle : 30(5

Black blister-beetle: 307

Spotted blister-beetle: 309

Immaculate blister-beetle: 310

Segmented black })lister-beetle : 310

Potato flea-beetle: 314

Pale-striped flea-beetle: 321

Smartweed flea-l)ee(le: 323

Striped cabbage flea-beetle: 324

Phyllolrelo rnmn-'^n : 32(5

Four-spotted cabbage flea-beetle : 326

INJURIOUS TO CABBAGE AND RELATED CROPS 53

Hemiglyptiis bnsalis : 326
Sinuate-striped flea-beetle : 326
Western cabbage flea-beetle : 327
Horse-radish flea-beetle : 328
Hop flea-beetle : 335
Root-knot nematode : 338
Millipedes: 342
Wheat wireworm : 348
Slugs: 354
Salt-marsh caterpillar : 359

CHAPTER ITT

PEA AND BEAN INSECTS

The more important insect enemies of tlie ])ea are of Euro-
pean origin, while those of the bean are native. The seed
weevils are, on the whole, the most troublesome pests of these
crops, especially in the South. Peas are subject to widespread
and destructive outbreaks of the pea a])his, especially where
they are fjrown in lartic areas for the cannery. The seed-corn
majfjjot occasionally causes serious damatje to seed i)eans in
seasons when the weather is cold and wi-t at j^lantinf; time, and
under similar weather conditions snails occasionally |)ro\e
very destructi\e to the foliage.

TiiK Pea Weeml

Bruchus pisorum Linnaeus

The pea weevil is a native of the OM World but was intro-
duced into America more than one hundred and se\t'nty years
ago. Peter Kalm records having found it in Pennsylvania,
Xew Jersey and southern New York in 174S and states that
because of its ravages the settlers had in large measure been
forced to discontinue the growing of peas. The insect is now
widcl_\- distributed in most jjarts of the woi'ld where peas are
grown. The economic importance of this pest is indicated by
the statement of .lames Eletcher in \W.\ that in Ontario alone
the amuial loss amounts to more than a million dollars. In
this proxince man\- of the farmers had gi\"en up the growing

r>4

PEA AND BEAN INSECTS 55

of peas because of the depredations of this pest. A similar
condition obtains in many parts of Germany. The pea weevil
is less abundant in the northern part of its range and a large
proportion of the seed peas planted in the South are obtained
from the northern states, Canada and northern Europe.

The pea weevil (Fig. 40) is considerably larger than the
other species infesting the pea and the bean. It is about 3"
inch in length, brownish in color mottled with gray, white and
dark brown. There is a white spot on the
middle of the hind margin of the prothorax
and the wing-covers are crossed by a more
or less indistinct whitish band towards the
tip. The w^ing-covers do not extend to the
tip of the abdomen and the exposed part
is white with two large })lack spots at
the tip. When viewed from above, the
prothorax has the appearance of being Fig. 40. — Tho pea
slightly notched on the sides. The base of weevil (x 6).
the antennae and the front and middle tibiiie and tarsi are
reddish brown. There is a sharp tooth on the underside of
the hind femur toward the tijx

The weevils appear in the field a])out the time the peas are
in blossom and after feeding slightly on the foliage, the female
deposits her elongate, fusiform, yellow eggs singly on the sur-
face of the newly formed pods. The egg is attached by a
viscid substance that on drying becomes white and glistening.
As many as fifteen to twenty eggs may be laid on a single pod.
The eggs hatch in about twelve days and the young lar\a
bores into the pod. In case it does not ha])pen to enter the
pod directl\' over a young j)ea, it may burrow through the
tissue of the ]iod as a miner until it reaches one of the seeds.
The hole thi'ough which the young larva enters soon heals over
and is indicated merely by a sinnll brownish dot. The newly
hatched lar\a is yrllow with a black head. The i)rothorax is

56 MAX UAL OF VEGETABLE GARDES IX SECTS

armed with a seriej> of six strong spines and a pair of prominent
toothed plates which point backward. These structures are
apparently of use to the larva in making its way through the
pod and in entering the pea. It also possesses three pairs of
small slender legs. Soon after entering the pea, the grub
molts and the spiny structures on the jirothorax are lost. The
larva becomes proportionately shorter and thicker and lies
normally in a curved position. It soon works its way to the
center of the pea and there eats out a large cavity. When
full-grown, it is about j inch in length, white in color, with
brownish mouth-j)arts. The short stumpy legs are easily
overlooked. In Italy the larva reaches maturity about forty
days after hatching. It then cuts out a smooth round hole to
the surface of the pea, leaving only the outer hull as a cover-
ing. It lines the cavity with a paste-like substance, thus ex-
cluding all excrement from its pupal chamber. The pupa is
dirty white in color. The insect remains in this stage from
nine to seventeen days. Only one weevil is found in a pea.
In the warmer parts of its range, many of the beetles emerge
from the seeds soon after transformation but in the North a
large proportion remain in the seeds until the following spring
and are often ])lanted with the seed peas. Weevils that emerge
in the field hibernate in dry sheltered places and fly back to the
pea fields the following spring. There is only one generation
annually.

In the case of small peas, the weevil destroys about one half
of the contents, in larger i)eas about one third. Infested peas
are not suitable for j)lanting. Experiments in Kansas have
shown that in a germination test only about 2') per cent of the
infested peas will sprout. In a field exj)eriment in which thir-
teen varieties of peas were used, only 4.4 ]H'r cent came up
and only iJ.S ])er cent ])rodu(ed fair sized ])lants. At the same
time, (11 per cent of uninfcstcd |)cas of the same \Mrieties ga\'e
a good stand of strong plants. Kxperiments in Canada have

PEA AND BEAN INSECTS 57

shown that in the case of small peas, infested seed produced
only 13 to 20 per cent of plants which bore pods and in the
case of large peas 10 to 28 per cent.

ReFERENCEvS

Costa, Insetti, etc., pp. 133-140. 1S.57.

Rilev, 3rd Kept. Ins. Mo., pp. 44-50. 1871.

Kan. Agr. Exp. Sta. Bull. 19, pp. 193-196. 1890.

Chittenden, U. S. Dept. Agr. Yearbook for 1898, pp. 234-239.

Fabre, Souvenirs Entomologiques, 8, pp. 2.3-47.

Frank, Arb. Biol. Abt. Land. Forst. Wirths. Kais. Gesundheitsamte,

1, pp. 86-114. 1900.
Fletcher, U. S. Div. Ent. Bull. 40, pp. 69-74. 1903.

The Bean Weevil
Bruchus obtectus Say

Probably the bean weevil is a native of the New World. It
was first described in 1831 from specimens collected in Loui-
siana. It first attracted attention by its injuries in 1860 in
Rhode Island. The insect is now widely distributed throughout
southern Canada, the United States, Mexico, Central America,
the West Indies and South America. It also occurs in the
Mediterranean region, Persia, Indo-China, Madeira, the Azores
and the Canaries. Its favorite food plant is the common
kidney bean, Phaseolus vuk/nri.s, but limas and cowpeas are
sometimes attacked in the field, and in storage it will also
attack the faba bean, peas, chick peas, lentils and the seeds of
Lathyrus mtivus. The bean weevil is a very serious j)est in the
South. It is not so destructive in the northern states and
Canada and it is from this region that a large })roportion of the
seed beans are ()l)tained.

The bean weevil fP'ig. 41) varies (■()nsi(K'ral)ly in size but
averages about | inch in length. The general color is light
brownish. The wing-covers are mottled with light brown,

MAMAL OF VECErABLE-UAlibES IXSECTS

Fui. 41. — The bean
weevil (X 9) .

dark brown, gray and black, arraiifjed in narrow lon<ritiidinal
stripes. On the niiddk' of each wing-cover near the inner
margin is a fairly distinct light gray longitudinal bar. The
exposed tip of the abdomen, the base and last segment of the
antcnniF and the legs, except the hind femora below, are dull
reddish brown. The hind femur is armed
on the underside near the tij) with one large
and two small teeth. The beetles appear
in the field about the time the beans are in
blossom and feed slightly on the surface of
the leaves. In cool weather the beetles are
sluggish, l)Ut in l)right warm days they can
take wing quickly and fly to a considerable
distance. As soon as the pods become
nearly full-grown but while they are still
green, the females begin egg-laying. The female first gnaws a
slit through the pod close to the ventral suture and by means
of her extensile ovipositor then deposits a cluster of eggs on the
inside of the pod. The hole made by the beetle in the pod does
not heal over but persists as a discolored spot even in the
dried i)od. The egg (Fig. 42) is translucent
white, elongate-ovate, and about -^j^ inch in
length ; the surface is slightly roughened. The
eggs are sometimes inserted through an opening
in the pod where it has been injured or where it
has split in drying. The time recpiired for the
hatching of the eggs varies considerably with the
temperature but apparently has not been ac-
curately determined for eggs laid in fresh pods.
On hatching, the young lar\a bears little resemblance to the
mature grub. It is white, the head yellow, the mouth-i)arts
brown and the eyes black. Three i)airs of distinct, slender
functional legs are j)resent and the body is clothed with long
hairs which serve to keep the lar\a u]Miglit when crawling.

Fi(i. 42. — EnK
of the lx?an
weevil (X 40).

PEA AND BEAN INSECTS 59

The youiis larva crawls actively about until it finds a bean which
it enters through a small round hole about y¥s i'lt'h in diameter.
In about three days after hatching, the larva molts and assumes
the general appearance of the mature grub. The legs, eyes
and the long hairs on the abdomen are lost, the body becomes
proportionately shorter and thicker and the grub assumes a
curved position. The larva burrows diagonally into the bean
a short distance and there eats out a large cell covered in part
only by the thin semi-transparent outer coat of the bean. It
then lines the cell with a yellowish white paste, thus excluding
all excrement from the pupal chamber. The length of the
larval stage varies greatly with the
temperature, or from eleven to forty-
two days. The full-grown larva is ^
to 4- i^t-h in length. The insect trans-
forms to a white pupa within the cell
and remains in this stage from fi\'e to
eighteen days. Soon after transforma-
tion, the beetle neatly cuts out a Fig. 43. — Beans showing
1 !• 1 ,1 I ^1 "^ 1 J. e exit holes made by the

Circular lid through the seed-coat or weevils.
the bean and makes its escape (Fig.

43). The entire life cycle requires from twenty-one to eighty
days. The beetles emerging in the field soon l)egin laying eggs
for another generation. The numl)er of generations that occur
in the field depends on the temperature and the length of the
season. Breeding is continuous in stored beans provided the
temperature is sufficiently high. In the vicinity of \Vashing-
ton, I). C, there are probably six generations annually. The
luimber of weevils reared from a single bean depends on the
size of the seed. In cases in which the beetles are allowed to
breed in stored seed undisturbed, they often reduce the contents
to a powdery mass held together by the hull. As many as
twenty-eight weevils have been reared from a single bean.
Weevily beans are unfit for planting. In a large proijortion of

60 MAMAL OF VEGET ABLE-GARDES' IXSECTS

such beans, the germ is destroyed and many of the others are
so injured that they cannot produce healthy pUmts.

References

Riley, 3rd Rept. Ins. Mo., pp. .52-56. 1871.

Lintner, 7th Rept. X. Y. State Ent.. pp. 25.5-279. 1891.

Fabre, Souvenirs Entomologiques, 8, pp. 48-05.

Kan. Agr. Exp. Sta. Rept. 1889, pp. 20(^-210.

Slingerland, Psyche, G. pp. 445-447. 1893.

Chittenden, U. S. Dept. Agr. Yearbook for 1898, pp. 239-242.

The Broad Bean Weevil
Bruchus rufimanus Boheman

The broad bean weevil is similar to the pea weevil both in
the form and general appearance of the beetle and in its life
history. It is a troublesome pest in Europe, northern Africa,
Syria and Persia and has been recently' introduced into
California. By preference it attacks the European broad
bean or horse bean but will also breed in
peas and certain species of vetch. In Cali-
fornia the weevils appear in the field by
the last of March. The beetle closel.x re-
sembles the pea weevil, both in form and
markings. The latter are, however, more
diffuse and the black spots at the tip of
the abdomen are indistinct or lacking alto-
gether (Fig. 44). The tooth on the under-
FiG. 44. — The broad • i i> . i i • i r • i . . i

bean weevil (X9). ^'^'*^ ^^ ^"^' ""^^^ lemur IS more ootuse than
in the pea weevil. The female deposits
her eggs on the outside of the bean pods, as many as
thirty-four having been found on a single P(m1. The eggs
are attached by a mass of sticky material. The egg is
elongate-ovate, white to greenish yellow, smooth, a little over
3^ inch in length and about one half as wide. The eggs hatch
in twelve to fifteen da\s. The iar\a' leaxc the egg-shell through

PEA AND BEAN INSECTS 61

the side attached to the pod and soon find their way into the
young beans. The point of entrance is indicated in the dried
beans by a small black dot. The larva very closely resembles
that of the pea weevil. It eats out a cell in the bean, its posi-
tion being indicated by a transparent spot where the larva has
eaten out the contents under the outer hull. In California the
larvae begin to pupate about the first of August and transform
to adults the same season. Hibernation usually takes place in
the beans but if they are kept in a warm room, many of the
weevils will emerge in storage. From one to five larvse may be
found in a single bean. There is only one generation annually
and the weevils do not breed in dried beans. Infested beans
are lighter in weight and their value as food for stock is con-
siderably lessened. Furthermore, the percentage of germina-
tion even of beans containing only one larva is considerably
less than that of uninfested seed, and of beans that have been
injured by four or five larvse, only about one third will germinate.

References

Costa, Insetti, otf. (Ed. 2), pp. 269-273. 1877.
Lintner, 7th Rept. N. Y. State Ent., pp. 279-28-5. 1891.
U. S. Bur. Ent. Bull. 96, pp. 59-82. 1912.

The Four-Spotted Bean Weevil

Bruchus quadrimaculatus Fabricius

This weevil breeds by preference in the seeds of the cowpea
but in storage will also attack peas and beans. The species is
distributed throughout southern Europe, Africa, the East
Indies, South America, the West Indies, Central America,
Mexico and the southern states. The four-spotted bean weevil
(Fig. 45) is about | inch in length ; the head and thorax are
black ; on the middle of the hind margin of the prothorax are
two small spots of whitish pubescence. The markings of the
wing-covers vary greatly but in typical specimens are brownish,

MAXCAL OF VEGETABLE-GARDES IXSECTS

black at the base and on each there is a hirjie (hirk spot at the
middle of the outer margin and another at the tip. The ex-
posed tip of the abdomen is brownish, usually marked with
two black spots. The antennie are lilack, reddish brown at
the base. The legs are brownish except the basal two thirds
of the hind femora which is black.

Under cage conditions, the beetles have been observed to
deposit their eggs singly on bean jxxls. The egg is oval,
lemon-yellow and about -^ inch long by
-^ inch wide. It is attached to the pod
by a thin sheet of gelatinous substance
which extends beyond the egg. Under cage
(•(tiiditions in New York, it refjuired fifty
(lays for the eggs to hatch. When breed-
ing in dry beans, the eggs are glued to the
surface of the seed and hatch in thirteen
to twenty days. On hatching, the young
lar\a bores directly through the jxxl
and attacks the seeds within, or when
the eggs are attached to the seed, it enters directly under
the egg-shell. The young larva closely resembles that
of the pea weevil but differs in the armature of the ])ro-
thorax. The full-grown larva is very similar to that of the
bean weevil from which it may be distinguished by the larger
area of black on the head just above the dypcus. The larva
also injures beans in much the same way as the bean weevil.
Pupation occurs within the seed. The rate of development
varies considerably with the temperature and moisture. Several
larva' may infest the same seed and successive generations may
be produced until the food supj^ly is e.xhausted.

Fig. 45. — The four-
spotted beau weevil
(X9).

IIeferkncfs

Rlingerland, Psyehe. »>, pp. 447-449. 1893.

Chittenden, U. S. Dept. Agr. Yearbook for 1S9S. pp. 245-248.

PEA AND BEAN INSECTS

The Cowpea Weevil

Bruchus chinensis Linnaeus

Beans and peas in the southern states often become infested
by the cowpea weevil. This insect is widely distributed through-
out the tropics. In the United States its range extends north-
ward to Maryland and Iowa. The
beetle (Fig. 46) is from ro" to 4 i»<^'h
in length, brownish in color and may
1)6 distinguished from the other
species in this country by the two
ivory-white spots on the middle of
the hind margin of the prothorax.
The wing-covers are brownish, dark
at the base and usually crossed

darker band at the middle.

male the antennte are pec-

FiG. 46. — Tho rowpca
weevil (X S) .

with a
In the
tinate.

The female glues her eggs on the outside of the pods. The
egg is ovate, flattened on the side of attachment, translucent,
about -^ inch in length by ^ in width. The eggs hatch in
four to ten days and the young larva bores through the pod
and enters the seed. In the field, the larvae become full-grown
in two or three weeks in midsummer. They closely resemble
those of the bean weevil and se\'eral larva* may infest a single
seed. Pupation takes place witiiin the seed and transforma-
tion to the beetle occurs in four or five days in warm weather.
Breeding ctmtinues in stored seeds and six or seven broods
may develop annually in the District of Columbia.

References

U. S. Div. Ent. Bull. S. pj). 24-27. 1897.
U. S. Bur. Enl. Bull. <)(), pj). SI? <)l. l'.)12.

64 MANUAL OF VEGETABLE-GARDEN INSECTS

The Control of Pka and Bean Weevils

Seed infested l)y li\iii^^ \v('c\ils sliould iicxer l)e used fi)r
planting, for it is in this way that many of tlie weevils gain
access to the field. Neither is it good economy to use infested
seed for planting in which the weevils have been killed, because
the percentage of germination of such seed is low and the
plants produced are weak and unproductive. In the case of
the pea weevil and the broad bean weevil, species that do not
breed in dried seed, the insects may be killed by holding over
the seed until the second year before planting. The weevils
will emerge in storage and, being unable to escape, will die
without laying eggs. In the case of the bean weevil, the four-
spotted weevil and the cowpea weevil, in which breeding con-
tinues in the dried seeds, holding over the seed would be use-
less. Fumigation with carbon bisulfid is the most efficient and
practicable method of killing the weevils in stored seed. To be
most effective, the treatment should be made in the fall soon
after harvesting. The seed is placed in a tight barrel or box
to which a cover has been fitted as nearly air-tight as possible.
Carbon bisulfid is used at the rate of ^ to 1 ounce to a bushel.
In larger quantities in specially constructed fumigating cham-
bers, the weevils can be killed by using carbon bisulfid at the
rate of 3 pounds to 100 cubic feet. The liquid should be placed
in some shallow dish like a i)ie tin on top of the seed. The
fumigating box should then be covered tightly and fumigation
should be allowed to contiime for twenty-four to thirty-six hours.
More satisfactory results will be obtained if the temix'rature
is kept at 70 degrees F. or above. In fumigating, care should
be taken not to smoke or to bring fire of any kind in contact
with the gas, as the carbon bisulfid vapor is very inflannnable.

When there is only a small (juantity of seed to be treated
and when it is impracticable to fumigate, the weevils may be
killed by suspending the seed in a l)ag in a kettle of cold water

PEA AND BEAN INSECTS 65

and then heating the water to a temperature of 140 degrees F.
The seed should then be spread out where it will dry quiekly.

The Bean Leaf-Beetle

Cerotoma trifurcata Forster

The bean leaf-beetle is a native American insect distributed
from New York, southern Canada, ^linnesota, ^Missouri and
Kansas southward to Florida, Texas and New Mexico. It
also occurs in Porto Rico. Its native food plants are the hog
peanut, bush clover and tick trefoil. It has been reported as
injurious to the bean, cowpea, pea, soybean, cultivated beggar-
weed and corn.

The insect hibernates in the adult stage and in the South
the beetles appear in the field in April, in the District of Colum-
bia the middle of i\Iay, and in the more northern part of their
range not until the last of June or the first of July. The
beetle (Fig. 47) is about ^ inch in length, yellowish to reddish
in color; the head is black and each wing-cover has a black
band running around its base and extending backward close
to, but separated from, the margin nearly to the tip. Near
the inner margin is a row of three black spots, larger in front
and smaller behind. The antennse are yellowish toward the
base and darker toward the tip. The legs are marked with
black and yellow, the hind pair being the darkest. The beetles
usually rest on the underside of the leaves where they are
easily overlooked. In feeding, they eat out holes in the leaves
and when abundant leave only the larger veins. The plants
are often defoliated and the crop is ruined. The beetles do
not take wing readily but when disturbed fall to the ground.
The female deposits her eggs in clusters in the soil at the base
of the plants. Clusters of over forty have been observed but
the average is about twelve. The egg is about ^ inch in
length, elliptical in outline, orange in color and the surface is

MAX UAL OF VECETABLE-GARDEX IXSECTS

Fu;

sculptured with rows of hexajjonal i)its. One feiiialo lias been
known to deposit 795 ejigs, hut this is undoubtedly far above
the average. The female continues to lay eggs for nearly a

month. The eggs hatch in about
eighteen days in the spring and in
the summer in five to eight days.
The larvcP feed on the roots, the stem
underground, and are particularly
fond of the bacterial nodules found
on the roots of leguminous plants.
The full-grown larva is ^ inch in
length, white in color, with the head,
cervical and anal shields dark. The
larva becomes mature in three weeks
in summer to six or more in the fall,
transforms to a white delicate pupa
in a small earthen cell in the ground
and in about a week the transforma-
tion to the adult takes ])lace. In the North there is only one
generation a year. In \'irginia there are two, and farther
south probably three.

Control.

The beetles may be killed by spraying the vines with arse-
nate of lead (paste), 4 pounds in 100 gallons of water, taking
care to apply the spray to the underside of the leaves. The
application should be made at the first a|ipearance of the
beetles before they have had time seriously to injure the plants
and in order to destroy the females before they have laid their
eggs. In the home garden, the beetles may be collected by hand
but spraying is the more convenient and i)ractical treatment.

References

Chittenden, U. S. Div. Ent. Bull. 9. pp. 04-71. 1S97.
McConnell, Jour. Ec. Ent., 8, pp. 2()l-2m. 1915.

47. — The bean leaf-
beetle ( X :3g).

PEA AND BEAN INSECTS 67

The Grape Colaspis

Colaspis hrunnea Fabrieius

This insect occasionally riddles the foliage of beans with
holes, its work being similar to that of the bean leaf-beetle. The
foliage of beet, cantaloupe and potato is sometimes eaten.
The beetle is about ^ inch in length, uniform yellowish brown
with the wing-covers distinctly striate. The larvse are found
on the roots of strawberry, corn, timothy and other grasses.
They are white with the head and cervical shield yellowish
and ^ to ^ inch in length. They reach maturity in May or
June and pupate in earthen cells. The beetles are common
throughout the summer but are most abundant in June and
July. The insect is generally distril)uted throughout the
northern states and Canada east of the Rocky ^Mountains.

In case the beetles become sufficiently abundant to threaten
serious injury, they may be poisoned by spraying the plants
with arsenate of lead (paste), 2 or 3 pounds in 50 gallons of
water.

References

Forbes, 13th Kept. Stale Ent. 111., pp. 155-159. 1884.
Forbes, 22nd Kept. State Ent. 111., pp. 145-149. 1903.

The Bean Ladybird

Epilachna corrupta Mulsant

In the foot-hills from Wyoming through (\)lorado to Arizona,
New Mexico, Texas and jNIexico, bean plants are sometimes
seriously injured by one of the ladybird beetles. The insect
also occurs in western Kansas.

The bean ladybird passes the winter in the adult condition.
In New INIexico the beetles appear in the field from early June
to the middle of July. The beetle (Fig. 48) is about ^ inch in

MANUAL OF VEGETABLE-GARDEN INSECTS

length, oN'al in outline, strongly convex and pale yellowish to
brownish orange in color. The eyes are hlack and each wing-
cover is marked with eight small l)lack spots arranged in three
transverse rows. The beetles feed on the foliage, eating out
holes in the leaves, and deposit their elongate, yellowish eggs
in clusters of forty or more on the underside of the leaves.
P]ach female lays on the average nearly 300 eggs and one beetle
was observed to lay o\er 7")(). The egg is about ^ inch in
length, oval and yellow in color. The eggs hatch in four to
nine days and the young larv;e begin feeding on the underside
of the leaves, skeletonizing them. The
Iar\a passes through four stages in the
course of its develojiment and becomes
full-grown in two or three weeks. It is
then about f inch in length, light yellow
'\ in color and clothed with stout branched
sj)ines. When mature it attaches the tip
of its body to the leaf and transforms
into a yellow pupa ai)()ut ^ inch in
length. The i)upal period occupies from
three to five days. The entire life cycle
is com])leted in three to four weeks in New Mexico. In
Colorado there is said to be but one generation aniniall.\- ; in
New Mexico there are two.

The seasonal history of the bean ladybird has been studied
most carefully in New Mexico. In that region the over-
wintered beetles lay eggs from tiic middle of .June to the first
of August. The Iarva> of the first brood are found until the
latter part of August, jiroducing a brood of beetles some of
which may hibernate. The earliest beetles to mature of the
second brood begin laying eggs about the middle of July and
continue till the end of the season. The two generations thus
overlap during Jul\ and August and it is at this time that the
larvae and beetles are most abundant and destructive. In

Fk;. 4S. — Tlic bean
ladybird (X 3).

PEA AND BEAN INSECTS 69

many cases the plants are completely defoliated and tlie entire
crop is ruined. The beetles also have the habit of eating into
and destroying the green pods.

Control.

The bean ladybird may be controlled by spraying the plants
with arsenate of lead (paste), 2 to 4 pounds in 50 gallons of
water. In localities in which the beetle is annually destruc-
tive, much injury may be avoided by planting early so that
the crop will mature early enough to escape serious injury.
Clean farming to eliminate hibernating shelter for the beetles
and a proper rotation of crops will accomplish much to prevent
loss. In the home garden, hand-picking the beetles and eggs
may be practiced to advantage and the larvse may be brushed
off on the hot ground during the heat of the day where they
will perish without regaining the plant.

References

Col. Agr. Exp. Sta. Bull. 19, pp. 25-27. 1892.
N. M. Agr. E.xp. Sta. Bull. lOG. 1917.

The Be ax Tiirips

Helinthrips fascintus Pergande

In California beans are subject to serious injury by a species
of thrips, the mature female of which is about -^ inch in length,
with the head and body l)lack. The narrow front wings are
black, white at the base and with a white band towards the
tip. The antennje are black and white and the wings are
fringed with long white hairs. I'he male is somewhat smaller.
Both young and adult thrips are found working on the leaves,
stem and pods of the bean, which they injure by piercing the
tissues with their sharp m()uth-])arts and then suck out the
juices at the point of injur>'. The injured leaves turn yellowish

70 MANUAL OF VEGET ABLE-GARDEN INSECTS

or white, dry up and die. In some eases tlie plants may be
entirely killed. The bean thrijjs has been most injurious in
California but also occurs in Idaho, I'tah, Nevada, Arizona and
Tennessee. It is not confined to the bean but attacks many
other plants, indudinj; beet, cabba<,'e, lettuce, radish, potato,
tomato, pea, pear, alfalfa and cotton. Amonj; weeds, its
favorite food plants are spiny lettuce, sow thistle and wild
heliotrope.

The bean thrips hibernates in the adult condition on the
underside of the leaves of nasturtium, beet, wild heliotrope
and many other plants. It is also found in drie<l leaves
and under rubbish. In the warmer parts of its ran<ie, the insect
is active throughout the fireater part of the year, feeding being
interrupted only for a short time during cool spells. On emerg-
ing from hibernation, the adults immediately seek their food
plants and after feeding for a short time the female deposits
her minute translucent white, bean-shaped eggs, about tstt
inch in length in the tissue of the leaves, in the veins and even
in the stems of beans. The eggs hatch in thirteen to eighteen
days. The newly hatched nymph is about ^ inch in length
and uniform translucent white in color with the eyes reddish.
In the second stage, the nymj)!! is about -^ inch in length
with the head and prothorax light yellow and with the re-
mainder of the body translucent white and stained on the side
with crimson. During the first two stages, the nymphs feed
on the leaves in the same way as the adults. When full-grown,
they desert the plants and hide in rubbish and in cracks in the
ground and there molt. In the third stage, the nymph or so-
called prepupa is slightly smaller than in the preceding stage
and the wing-pads are well developed. The insect does not
feed in this stage but in from one to six days, depending on the
season, it molts again. In the fourth stage or so-called pupa,
the nymph is t^ inch in length, yellow or orange in color,
marked with crimson on the sides and across the abdomen and

PEA AND BEAN INSECTS 71

the antennse are carried back over the head. In this stage the
insect is shiggish and takes no food. In four to fourteen days,
depending on the season, the nymph transforms to the adult.
In California there are seven generations a year, the first and
last being small. In the early part of the season the thrips
are most abundant on their wild food plants. They do not
become abundant on beans until later in the season, although
a few may be found on this crop from the time it first comes up.

Control.

The injury caused by the bean thrips may be lessened by
clean cultivation to destroy the weeds on which the insect
breeds. Early planting and thorough cultivation will tend to
produce a rapid and healthy growth and render the plants
more able to withstand injury. In the garden the thrips may
be controlled by spraying with "Black Leaf 40" tobacco ex-
tract, 1 part in 800 parts of water in which enough soap has
been dissolved to produce a good suds.

Reference
U. S. Bur. Ent. Bull. 118. 1912.

The Pea Aphis

Macrosiphum pisi Kaltenbach

Without doubt the most serious insect enemy of the pea is
this large green plant-louse. The insect was undoubtedly intro-
duced into this country from Europe. Although there is evi-
dence that it was present here as early as 1878, it did not attract
attention as a pest until ISOO when there was an extensive and
highly destructive outbreak in the Atlantic states, most .serious
in Virginia, Maryland, Delaware and New Jersey. The losses
occasioned by this insect in the .Vtlantic states <lnriiig the years
1899 and 1900 have been estimated at .'^T.OOO.OOO. While the
pea aphis has not maintained this rate of destructiveness in

72 MANUAL OF VEGET ABLE-G ARDEX IX SECTS

recent years, it is still the most serious insect pest with which
pea-jjrowers have to contend. In En<ihin(l the pea aphis has
been known as a pest since the early part of the nineteenth cen-
tury. It received the scientific name under which it is now
known in Germany in 1843, althou.<j:h it is quite probable that
it had been more or less imperfectly tlescribed previously.

The pea aphis occurs generally throughout Europe and has
been introduced into British India and South Africa. In
North America it is widely distributed throughout the United
States and Canada, being most abundant in the East, but has
been reported from Colorado, Texas, Xew Mexico, Arizona
and the states on the Pacific Coast. In addition to the pea
the insect attacks red clover, crimson clover, white clover,
alsike, vetch, sweet pea, sweet clover, bush clover, alfalfa and
lentil. It als3 occasionally infests shepherd's ])urse. In
Europe the aphis has been recorded as feeding on several
other leguminous plants.

The pea aphis usually passes tiie winter on clover and breed-
ing is resumed on this plant in the spring. At this time the
aphis shows a decided preference for crimson clover on which it
multiplies rapidly. In Virginia ab!)ut the last of April or the
first of May, winged aphids are produced that migrate to peas.
These migrating forms are all females that reproduce by gi\'ing
birth to living young without being fcrtili/.ecl. These winged
viviparous females (Fig. 49) are ^ to ^ iiu li in length, pea-green
in color, with the tip of the cornicles, tip of the tibijip, and the
tarsi black. The eyes are red. The antennir are slightly
longer than the body. The winged forms settle on the pea
plants, usually on the stem, and begin to give birth to living
young. In the course of its development, the young aphis
passes through four inunature stages, molting four times, and
at the last molt bccoiniug adult. On tlie average it rccpiires
about ten days for the young ai)his to reach maturity, and when
about twehc days old it begins to i)roduee lixing young. Re-

PEA AND BEAN INSECTS

Fig. 49. — Winged viviparous female
of the pea aphis ( X 5).

production continues for an average period of eighteen days
at the rate of one to eleven a day. The number of young
produced by a single female averages eighty. Both winged
and wingless forms are pro-
duced, the relative proportion
of the two varying with the
season and with the crowded
condition of the plant. The
wingless form (Fig. 50) re-
sembles the winged viviparous
female in color. The stems
become covered with the lice,
and the leaves, blossoms and
pods are soon attacked. In-
fested leaves become slightly
thickened and curled, infested blossoms are blasted and injured
pods are stunted, deformed and rendered worthless. Badly in-
fested plants take on a sickly yellowish appearance and may be
killed outright. Sometimes whole fields are destroyed in this
way. In such cases, the ground has a whitish
appearance from the cast skins of the plant
lice. Whenever the plants become crowded,
winged forms are ])ro(luced that migrate to
other parts of the field or to other food plants.
In \'irginia it has been found that while
breeding is more or less continuous throughout
the year on clover, the insect migrates more or
less regularly between its other food plants.
Fig. 50. — Winsles.s Peas are infested from April to the first of July

t^!^(xt' ^^'1^^'" "i'^">' *'*' *'^^' l>l'i"t-lice migrate to bush

clover, sweet clover, alfalfa and the clovers.

Peas again become infested in August and the plant-lice remain

here until the advent of cold weather when they return to clover.

Counting from the first-born of each brood, twenty or twenty-

74 MANUAL OF VEGETABLE-GARDEN INSECTS

two ^fenerations of the pea a])liis may (U'V(>lop ainuially in Wv-
ginia. In Indiana breeding experiments have shown that
counting from the last-born, thirteen generations are produced
annually. The insect hibernates on clover either as mature
viviparous females, winged or wingless, or in the cooler part of
its range in the egg stage. Males and egg-laying females are
produced late in the fall only. The male is usually winged, is
considerably smaller than the viviparous female and has darker
markings on the head, thorax and abdomen. Only a few
wingless males have been observed. The egg-laying female is
wingless, and much smaller than the wingless viviparous form
which it resembles closely in color. The hind tibijv arc con-
siderably thickened basally and bear numerous sensoria. The
winter eggs are usually found on red or crimson clover. Tiie
egg is about ws inch in length, elliptical oval in outline and
pale when first laid, changing to jet black.

The pea aj)his is subject to the attacks of several parasitic and
predaceous insects and particularly to a fungous disease that often
destroys a large proportion of the lice. These natural enemies
are most efVectivc during the warmer part of tiie season and
often nearly exterminate the lice locally on certain food plants.

Meaihs of control.

•As the pea aphis lives over winter and begins breeding in
the spring on clover, especially on crimson clover, the presence
of these crops in the near vicinity of fields of early peas is a
menace to the latter. In such cases, when crimson clover is
being grown for green-manure and is seen to be infested, it
should be plowed under before the migration of the lice to peas
takes i)lace, without waiting for it to reach its full growth.
The ground should then be harrowed and mllcd. In cases in
which the clover is grown for hay, it might be well to sacrifice
this cro]) in order to saxc the peas. Kxpcriciicc has shown that
peas grown in rows ab )ut thirty inches apart are, as a rule,

PEA AND BEAN INSECTS 75

less seriously infested than when they are sown broadcast or
in narrow drills. When the peas are grown in rows, the lice
can be controlled by spraying with "Black Leaf 40" tobacco
extract, 10 ounces in 50 gallons of water to which 4 pounds of
whale-oil soap have been added. A traction sprayer is used,
fitted with nine nozzles and arranged to spray three rows at
a time. One nozzle is directed downward and the other two
nozzles throw the spray slightly upward into the row. The
pump should be able to give a pressure of 120 to 150 pounds
when all nine nozzles are in operation. With this outfit it is
possible to work effectively on twelve acres of peas a day. In
spraying for the pea aphis, it is important to begin early, soon
after the winged forms from the clover appear in the field. If
the work is started on time, it is usually possible to control
the pest with two or three applications at intervals of about a
week. In Maryland, Delaware and New Jersey, it was found that
much loss could be avoided by raising the main crop of peas for
the cannery early in the season before the aphis became abundant.
At the time of the first serious outbreak of the pea aphis in
this country, spraying machinery and insecticides were not as
effective as those now on the market and spraying experiments
at that time gave very unsatisfactory results. IVIethods were,
therefore, devised for destroying the lice by mechanical means.
The aphids were brushed from the plants to the ground during
the heat of the day with pine boughs and a cultivator was
immediately run between the rows. In this way many of the
lice were either killed by the heat or buried in the soil. This
method is now little practiced under commercial conditions
but might be followed to advantage in the home garden.

References

Del. Afrr. Exp. Sta. 12th Ropt., pp. 169-180. 1900.

Va. Truck Exp. Sta. Bull. 13. 1914.

U. S. D("i)t. Asr. Bull. 270. 191.^».

Smith, 10th Kept. State Ent. Va., pp. 32-G3. 191 1-191.5.

MAXCAL OF VEGETABLE-CARDEX IX SECTS

Fig. 51. — A\ inged viviparous fpinalo
bean aphis (enlarKed).

The Be.\x Aphis

Aphis rumicis Linnaeus

This black plant-louse is widely distributed throu<i;hout the

(fi-catcr part of the subtropical and temperate regions of the

world. Its summer food
plants include a great
variety of vegetable
crops: beans, especially
the broad bean, lima bean,
beet, pea, celery, aspar-
agus, orach, onion, leek,
rlnibarb and horse-radish.
In England it has been
reported as attacking
turnip and parsnij). It

is almost certain to be found in great abundance on nasturtium

late in the season. Its common wild food plants are dock,

l)urdock, lamb's quarters, she{>-

herd's purse and pigweed.
The winter is passed in the

egg stage on Evonymus,.syringa,

snowball and Deutzia. The

egg is about -^V inch in length

and shining black in color. Tiie

eggs hatch in early spring and

the first generation develops on

the tender foliage of these shrubs.

When mature, the stem-mothers,

as the aphids of the first gen-
eration are called, give birth

to living young, a few of which

acquire wings. In the third

generation a larger j)rop.)rtion

l<i

i;. Tt'l. — Wiiiyl 'ss vivij) nous
fciuale Ix-aii apliis (X -0).

PEA AND BEAN INSECTS

become winged. The winged forms (Fig. 51) migrate to
their summer food plants but the insect is capable of breeding
the entire season on the plants on which it passed the winter.
Throughout the summer the aphids
reproduce parthenogenetically, all the
individuals being females. Whenever
the host plants become crowded, winged
forms are produced that migrate to fresh
feeding grounds. The full-grown wing-
less viviparous female is about -^t inch
in length and blackish in color (P'ig. 52).
In the last nymphal stage of the winged
form the abdomen is ornamented with
five to seven pairs of white pulverulent
spots (Fig. 53). In the fall the winged
forms fly back to their winter host
plants and there produce young that develop into wingless,
egg-laying females. These are joined by winged males and after
mating they deposit eggs in the crevices around the buds.

The bean aphis can be killed by spraying with " Black Leaf
40" tobacco extract, 1 part in 100 parts of water in which
enough soap is dissolved to give a good suds.

Fig. 53. — La^^t nymphal
stage of the winged
viviparous female bean
aphis (enlarged).

The Garden Flea-Hopper

Haltic7is citri Ashmead

This small black plant-bug resembles the cucumber flea-
beetle in size, form and in its habit of jumping when disturbed.
The female is dimor])hi('. In one form the wings are fully
developed and in the other they are short and lack the mem-
branous portion iit the end. The long-winged form (Fig. 54)
is -pj inch in length, black in color, with the thorax and wings
covered with small tufts of yellowish scale-like hairs; the tip
of the cuneus has a white spot. The legs and antennae are

MANUAL OF VEGET ABLE-GARDE X IXSECTS

Fig. 54. — The sardcn flca-hoppcr,
long-winged female (X 16).

pale, marked with black. The short-winged form (Fig. 55) is
somewhat smaller and more ovate in outline. The front wings

lack the membranous part,
do not extend to the tip of
the abdomen and are rounded
behind, thus resembling the
wing-covers of a beetle. The
male (Fig. 50) is similar to
the long-winged female but is
much narrower.

The garden flea-hopper is
generally distributed through-
out the eastern 1 iiited States
and Canada, and westward to
Kansas and I'tah. It feeds
on a great variety of j)lants
including bean, pea, potato,
tomato, eggplant, pepper, beet, cabbage, pumi)kin, cucumber,
squash, celery, lettuce, sweet potato, corn, clover, alfalfa,
sweet clover and cowpea. Among
its wild food plants may be mentioned
beggarweed, ragweed, pigweed, i)laii-
tain, smartweed, thistle, mare's tail.
burdock, wild lettuce, vervain, stick-
tight, self-heal, mallow, aster, oxalis
and convolvulus. The garden flea-
hopper has also been recorded as a
pest of chrysanthemums and smilax
in greenhou.ses.

The life history of the garden flea-
hopper is very imi)erf('ctly knnwii. It
.seems probable that hibernation takis
place in the egg stage on some of its pereiuiial host plants, but
in the South it may pass the winter in other stages. In

^^W^

Fni. oo. — The garden fie;-.-
hopper, short-winged fe-
male ( X 14).

PEA AND BEAN INSECTS

Illinois the insects appear the middle of May, become abutidant
in July and are found on the plants until October. The eggs
have not been described. The nymphs are pale green in
color with darker wing-pads. The insects are found in all
stages on the upper side of
the leaves. The\' feed by
puncturing the leaves and suck-
ing out the sap, thus causing
small round yellowish or whitish
spots. The number of gen-
erations a year has not been
definitely determined but there
are probably more than one.

Control.

When present in sufficient
numbers to warrant the trouble
the garden flea-hopper may be
destroyed by spraying with
"Black Leaf 40" tobacco extract, 1 pint in 100 gallons (jf
water to which 5 or G pounds of whale-oil soap have been added.

Fig. 5G. — The garden fleti-hoppor,
nuile (X 16).

Reference
U. S. Div. Ent. Bull. 19, pp. 57-C)2. 1899.

TiiK Pea :\roTii

Craphnlita nigricnnn Stephens

The pea moth is a European insect introduced into Canada
some time before 1S!):5. It is now distributed throughout
eastern Canada, being especially injurious in the maritime
provinces, and was reported as destructive in Michigan in
1908. The moth has an expanse of about f inch. The front

80 MAX UAL OF VECETABLE-GARDEX IXSECTS

wings arc Ijrowiiisli gray with a inctallic rcdoctioii. Along the
front l)()rder is a series of short, ohH(iiie white and (hirk hnes.
The hind wings are bhick with a bronzy reflection ; the fringe
is white. The moths appear in late June and early July and
lay their eggs during the evening on the recently set pods,
depositing from one to three eggs on each pod. The eggs
hatch in about two weeks and the young caterpillars imme-
diately burrow into the pods. They feed on the developing
peas, gnawing out irregular cavities and often webbing them
together. The full-grown caterpillar is slightly hairy, about :j-
inch in length and yellowish in color, with a black head and
brownish cervical and anal shields. Afi'ected pods usually
ripen prematurely. When the pods open, the caterpillar
descends to the ground and spins a silken cocoon a short dis-
tance below the surface of the soil. Here the winter is passed
either in the larval or pupal state, observers difi'ering as to this
point. There is but one generation annually.

Control.

In Canada it has been found tliat both very early and late
peas are less liable to injury than mid-season \arieties. Pre-
liminary experiments indicate that the pest may be held in
check by spraying with an arsenical at the time the pods are
forming and by two later sprayings at intervals of ten days. It
has also been suggested that deep fall plowing of the infested
land would destroy many of the hibernating insects in their
cocoons. Under ordinary farm conditions in America, the
most practical measure is to adoj)t a crop rotation in wliich
peas do not follow peas.

References

Curtis, Farm Insects, pp. 348-350. 18C»0.

Ritzema Bos. Ticrisr-hc SchadliiiKP und Xiitzlingo. pp. 474-47."). 1890.
Fletfhcr. Repts. Ent. raiuula for 1894, p. 187; 189.'», p. 138; 1897,
p. 194; HKM). p. 214.

PEA AND BEAN INSECTS

Tup: Bean Leaf-Roller

Eudamus proleus Linnaeus

The bean leaf-roller is a tropical insect ranging from Para-
guay through ^Mexico and the West Indies to Florida and
northward sometimes to New York and Connecticut. In the
United States it has proved injurious only in Florida. Its
injuries are usually confined
to beans, though it is
recorded as feeding on
cowpea, turnip, cabbage
and several species of
Desmodium. Sometimes
entire fields have been
ruined by the attacks of
this leaf-roller.

In the extreme southern
part of Florida and in the
tropics, the insect breeds
continuously throughout the
year. In northern Florida
it undoubtedly hibernates
in the pupal stage. The first brood of butterflies appears in
March. The butterfly has an expanse of about If inches.
The wings are dark chocolate brown ; the front wings arc
marked with several angular silvery white spots. The hind
wings are furnished with long tails, somewhat similar to those
of the swallowtail butterflies (Fig. 57).

The butterfly lays its eggs singly or in groups of four to six
on the underside of the leaves. Occasionally three to four eggs
are piled one above the other in a vertical column. The egg
is nearly globular, slightly flattened at both ends and marked
with a series of delicate longitudinal ridges. It is nearly -i^
inch in length. When first laid, the eggs are glistening white,

Fig

The bean leaf-roller butterfly
(X U).

82 .\fAXUAL OF VECETABLE-GARDEX IXSECTS

graduallx' chaiij;iiijj to a clear .wllow. In siiinincr the c<;gs
hatch in four days and the xoiintr cateri)inars iinincdiatcly
begin to cat out small i)atchcs in the surface of the leaves.
Within a day after hatching, the larva constructs a retreat by
folding over a flap of the knif made by cutting along two lines
converging from the margin. Within this retreat the larva
lives, coming out only to feed. When about to molt, the edges
of the retreat are sealed. In the third or fourth stage, the
caterpillar constructs a new retreat by folding over a leaflet
towards the middle on the upper side. During the course of its
development, the larva passes through five stages. The
mature caterpillar is over 1^ inches in length. The head is
brownish black and the })ody yellowish sprinkled with black,
lighter below. The head is separated from the botly by a
distinct neck. The length of the larval period varies from
two to three weeks. In Florida the life cycle requires about
a month and there is, therefore, a possibility of eight or nine
broods developing annually in that region.

Under cage conditions, pupation occurs within the retreats
and it is probable that this is the case in the open. The pupa
is nearly an inch in length, greenish yellow at first, changing to
shining brown. In two or three days it is covered with a white
flocculent secretion. The pupal period occupies from si.x to
ten days.

Control.

Kx|)criments in Florida liave shown that the caterpillars can
be killed on beans by spra\ing with paris green. As this
poison is likely to injure the plants, it would be better to use
arsenate of lead (paste), 4 jjounds in 100 gallons of water.

References

Scudder, Buttorflios of Eastern U. S.. 2. pp. 1.3H0-l.m3. 1889.
Fki. Af,T- Kxp. Sta. Bull. 4."). i)p. .").")-(iO. 189S.

PEA AND BEAN INSECTS

Fig. oS. — The moth of the
striped green bean caterpillar
(X U).

The Striped Greex Beax Caterpillar

Ogdoconta cinercola Giienee

Bean vines are frequently stripped of their foliage and pods
by a slender green caterpillar. This injury has been reported
from Florida, ^Mississippi and Maine.
The insect is generally distributed
throughout Canada and the United
States east of the Rocky ^Mountains.

The light brown moth has an
expanse of about an inch. The
front wings are marked with a
few wavy grayish white cross
lines. Across the outer margin
is a broad, light brownish gray
band. The hind wdngs are brownish gray (Fig. 58). The
moths are on the wing from June to September but it is not
known where the eggs are deposited. The full-grown cater-
pillar is over one inch in length, pale green, striped with whitish
and yellowish longitudinal lines. This insect is related to the
cabbage looper and like it, the caterpillar has the habit of loop-
ing like a measuring-worm. When disturbed the larvse give a
series of violent jerks and fall to the ground. Pupation takes
place in the soil. The pale yellowish brown pupa is slightly
less than ^ inch long. Knowledge of the life history of this
insect is very imperfect and additional observations should
be made whenever opportunity offers.

When abundant, the caterpillars may be destroyed by spray-
ing with arsenate of lead (paste), 5 pounds in 100 gallons of
water. On snap beans tobacco dust may be used to drive
them from the plants.

Reference

U. S. Div. Ent. Bull. 14 (old scr.), p. 21. 1SS7.

MANUAL OF VEGETABLE-GARDES IS SECTS

The (jHay IIair-Streak
Uranotes melinus Hiibner

One of the minor pests of the bean and pea is the shig-like
caterpillar of a small, dainty butterfly, the gray hair-streak.
It occurs throughout the United States, Central America,
northern South America and the West Indies and is found
rarely in southern Canada. It has been reported as injurious
to beans or peas in Xew Jersey, Virginia, Maryland. Ohio and
Colorado. In the South the caterpillars sometimes bore into

cotton squares and okra pods
and in the North they have
been reported as feeding on
the heads of the hop. Among
wild plants, they feed on the
following : Crattegus, St. John's-
wort, hound's tongue, bush clover,
loco-weed, tick trefoil, and Japan
j)lum.

Fig. 39. — The gray hair-streak The butterfly has an expanse
butterfly (XU). ^f ^ i^^.^gg ^he Upper .surface

of the wings is blackish tinted with blue-gray. The hind
wings have near the hind angle a row of bluish spots, in the
center of which is a large orange spot surrounding a small
black one. On the outer margin there are in the male one, and
in the female two, small tail-like processes. The under surface
is gray with two blackish brown lines crossing each wing
(Fig. 59). The butterflies are on the wing from May to
September in the North and ^Nlarch to November in the
South. The eggs are small and pea-green in color. Where
they are deposited and the time of incubation have not been
determined. The caterpillars bore into the pods of peas and
beans and destroy the developing seeds. The full-grown
caterpillar is green, about ^ inch in length, and slug-like in

PEA AND BEAN INSECTS 85

appearance. The chrysalis is naked, and hano;s freely, at-
tached at the caudal end to a button of silk. The pupal
period lasts from ten days to two weeks. In the North
there are two, and in the South, three broods annually.

If necessary, the caterpillars may readily be controlled by
spraying with an arsenical.

References

Seudder, Butterflies of Eastern U. S., 2, pp. 850-855. 1889.
U. S. Div. Ent. Bull. 33, pp. 101-102. 1902.

The Green Clover Worm

Plathypena scabra Fabrieius

This insect is common throughout the eastern United States
and Canada. Its favorite food plant is clover but occasionally
the caterpillars defoliate peas, beans and lima beans. They
are also found on tickweed, soybeans, vetch and strawberry.

The moths have an expanse of 1 to 1-j inches, the larger
specimens usually being males. The palpi form a rather
prominent snout. When at rest, the wings are closely ap-
pressed to the body. The front wings are blackish brown,
the outer part of the wing in the female shaded with light gray
and often with brown. The wing is crossed near the middle
by a fine black line which is wavy and often very faint on the
front half but straight and composed of raised black scales on
the posterior half. At one quarter and at three quarters the
distance from the base of the wing is a fainter wavy dark line
and at one third the distance a raised black dot. Some females
are marked with one or two longitudinal black dashes. The
hind wings are blackish brown (Fig. GO).

The moths emerge from hibernation in early spring. In
Washington, D. C, they are on the wing in warm sunny days
even in the winter. In that latitude there are three genera-

MAXVAL OF V EGET ABLE-GARDEN INSECTS

tions annually ; the first brood of caterpillars heooniing mature
about tile middle of June, the second early in Aui^nst and the
third in late September or early October. The caterpillar is
slender and loops with the front half of the body when walk-
ing. In the next to the last stage, it is nearly an inch in length,
pale green in color and striped lengthwise with fine white or
cream-colored lines. In the last stage it is nearly uniform pale
green, the stripes having become much less distinct. The
caterpillars mature in about twenty-five days and then con-
struct cocoons in leaves webbed
together with silk within which
they transform to dark brown
pupic about ^ inch in length. The
moths emerge in eight days to two
weeks and lay eggs for another
brood. The e^^^ is about ^V inch in
diameter, globular, flattened al)ove
and with coarse ridges radiating
from the apex. The eggs hatch in four to six days and the
young caterpillars feed on the underside of the bean leaves,
eating out . irregular holes and when abundant stripping the
plants of their foliage. Sometimes the caterpillars also eat
IkjIcs in the pods.

When attacking shell beans, the caterpillars may be poisoned
by spraying the vines with arsenate of lead (paste), 2 pounds
in 50 gallons of water, taking care to apply the spray to the
underside of the leaves. On string or snap beans, tobacco
dust or extract may be used. It has also been suggested that
many of the caterpillars could l)e killed by sj)raying the un-
derside of the leaves with a strong soap solution.

Fig. 60. — The moth of the
green clover worm (X 1 1).

References

U. S. Div. Ent. Riill. .30. pp. 4.">-.')0. 1901.
Conn. Agr. Kxp. Sta. Rt pt. for 1<»0S, i)p. .S'2S-,S.32.

PEA AND BEAN INSECTS 87

The Lima Bean Vine-Borer

Monoptilota nubilella Hulst

From Maryland to Florida and Alabama, pole varieties of
lima beans are occasionally infested by a caterpillar that bur-
rows in the stalk, causing a gall-like enlargement which is about
1|- inches in length by |- inch in diameter. These galls may
occur at any point from the surface of the ground to near the
tip of the vine. The injury inflicted varies with the position
of the gall and with the thriftiness of the vine. When the
caterpillar enters a well-formed stalk, the plant is not seriously
affected, but when the gall is formed in small stalks near the
tip, the terminal portion often wilts and dies or at least is not
able to produce full-sized pods. The full-grown caterpillar is
about f inch in length and of an unusual color for a borer,
being a beautiful blue-green, tinged with pinkish above. When
mature, it leaves the gall and pupates on or in the ground in
an oval silken cocoon covered with particles of dirt. The pupa
is dull olive-brown and a little less than ^ inch in length. Some
of the moths may emerge the same summer and lay eggs for a
second brood. The moth has an expanse of about ^ inch.
The front wings are brownish gray shaded with whitish especially
toward the base near the front margin and are marked with
several small blackish streaks about one third the distance
from the base of the wing. The hind wing is translucent white
in the male and dark in female.

Xo better treatment is known than to kill the caterpillars
with a knife while still in tlicir burrows.

Reference
U. S. Div. Eiit. Bull. 2:?. pp. 9 17. 1900.

Oi'iiKii I'ka and Bi:an Insects

Corn car-worm : 2 1 1
Southern corn root-worm : 222

88 MAXUAL OF VEGETABLE-aAlWEX IXSECTS

Cabbage looper : 8

Garden webworm : 18

Seed-corn maggot : 3()

Western radish maggot : 37

Harlequin cabbage bug : 3S

Green soldier-bug : 42

Red turnip beetle : 50

Yellow bear caterpillar : ■ii'tl

Salt marsh caterpillar : 359

Sugar-beet webworm : 97

Western twelve-spotted cucumber beetle: 114

Belted cucumber beetle: 115

Dinhrotica connexa: 116

DiabroHca piclicornis : ll(j

Melon leaf-bug : 121

Southern leaf-footed plant-l)Ug : 121

Melon aphis : 135

Garden springtail : 139

Potato aphis : 150

Common stalk-borer : 157

Spotted cutworm : 262

Well-marked cutworm : 2(13

Greasy cutworm : 265

Dark-sided cutworm : 2(58

Striped cutworm : 270

Dingy cutworm : 271

Granulated cutworm : 273

Clay-backed cutworm : 274

Black army-worm : 275

Variegated cutworm : 276

Glassy cutworm : 279

Clover cutworm : 284

Army cutworm : 287

Army-worm : 288

Beet army-worm : 294

Strip(>d liiister-beetle : 302

Margined blister-beetle : 305

Gray l)list«>r-beetle : 306

Ash-gray blister-beetle: 306

Nuttall's blister-beetle: 308

Spotli-d l)lis(er-beetle: 309

Two-spotted blister-beetle: 309

Western potato flea-beetle: 318

Pale-striped (lea-beetle: 321

R<'d-headed flea-beetle : 323

PEA AND BEAN INSECTS 89

Smartweed flea-beetle : 323
Western cabbage flea-beetle : 327
Desert corn flea-beetle : 334
Root-knot nematode : 338
Millipedes: 342
Slugs: 354
Red-spider : 351
Wheat wireworm : 348
Sugar-beet wireworm : 349

(IIAITKR IV
BEET AND SPINACH INSECTS

The insects attacking beet and spinach, as a rule, also feed
on relatcfl wild plants, chiefly various species of ChjTenopodiiim
and Ainaranthus. Many of these plants are common weeds
and serve as centers from which infestation spreads to culti-
vated cr()[)s. 0\er one hundred and fifty insects liaxc been
recorded as feeding; on su_ti;ar-beets, about forty of which are
considered as important pests. The sugar-beet is classed as a
field croj) and in this chapter only those insects are treated,
which have been found causing important injury to garden
beets and s{)inacli. The two ])rincipal insect ])ests of sj)inach
are the leaf-miner and the aphis, their combined attacks often
making the growing of this croj) unprofitalile in certain localities.

The Spinach Leaf-Mi \kk

Pegnmyin hynscyami Panzer

This troublesome i)est of beets and allied (•ro|)s is ]>resent in
both Euroi)e and Amt^rica. In Eun)pe the insect has been
known for over a century and in this country it first attracted
attention by its injuries about ISSO. It is now generally dis-
tributed throughout the I'uitcd States and Canada. The
maggots infest the leaves of spinach, orach, beets, sugar-beets,
mangels jind chard. Its other food plants are lamb's (piarters,
and in the British Isles and Kurojx" deadly nightshade, henbane,

BEET AND SPINACH INSECTS

Fig. 61. — The spinach leaf -miner, adult
(X4).

nettle-leaved goosefoot, common chickweed and lady's thumb
(Polygonu m. persicaria) .

The flies appear in the fields in April or May. They are
about \ inch in length, grayish in color and clothed with numer-
ous black setffi ; the legs
are yellowish with the
tarsi blackish (Fig. Gl).
The female deposits her
eggs singly or in rows of
two to five placed side
by side on the underside
of the leaves (Fig. 62).
The egg is about ^ inch
in length, white, cylin-
drical, and the surface
is distinctly reticulated.
The eggs are attached
to the leaf by one side; they hatch in four to six days and
the young maggot works its way into the tissue of the leaf
where it eats out a mine between the upper and lower epi-
dermis. The mine is at first thread-like but is soon enlarged
to form a blotch. Several maggots usually
occupy the same leaf and their mines usually
coalesce. In the course of its growth the
maggot molts twice, thus passing through
three stages. If the food material in a single
leaf becomes exhausted, the maggots may
riG. 62. — Eggs migrate to another leaf in order to complete

of the spinach \\^i.\Y growth. In casc the leaf dies, the mag-
leaf-miner (X ^ . . . ,-,,

3^). gots are able to complete their development

on manure or humus, according to observations

made in Hungary. The larva becomes full-grown in a week

to sixteen days. It is then ^ inch in length, white or

yellowish with the hook-like mouth-parts black. The body

92 MANUAL OF V EdKT ABLE-CARDES IS SECTS

tajxTs towards the head and is obliquely truiieate posteriorly.
When mature, the larva usually deserts the leaf and enters
the earth, where, at a depth of two or three inches, it changes
to a brownish ])uj)arium, about ^ inch in length. Sometimes
the puparia are found in the dead and rotting leaves on the
ground. The flies emerge in two weeks to twenty-five days
and soon lay eggs for another brood. In central New York
there are three generations and a partial fourth annually.

The spinach maggot is most injurious to spinach and chard,
and beets when used for greens. The injury to the leaves of
beets, mangels and sugar-beets also decreases the size of the
root-crop. When these crops are grown for seed, the quantity
l)roduced is often seriously lessened by the partial defoliation
of tile plants by the maggots.

Control.

No satisfactory method of preventing the damage by the
spinach leaf-miner has as yet been devised. Clean culture and
the destruction of the insect's wild food ])lants, lamb's cjuarters
and other weeds will be of some value in decreasing the degree
of infestation. In some localities growers avoid a bad infes-
tation in spinach by growing the croj) late in the fall and early
in the spring.

References

N. Y. (Geneva) Afrr. Exp. Rta. Bull. 99. 1890.

Jabloiiowski, Ticrcschcn Foiiule dcr Zuekcrriibc, pp. 303-315. 1909.

Cameron, Ann. Appl. Biol., 1, pp. 43-76. 1914.

Tin: Hi:r.T LKAiiiorpKR

Euletlix tenellus Baker

In the western states from Idaho, Nebraska and Texas,
westward to the Pacific and southward into Mexico, sugar-
beets, table beets and nianii:els ;ire subject to a disease known
as curl\-leaf, the exact cause of which is not fullv understood.

BEET AND SPINACH INSECTS 93

Diseased plants have the veins of the leaves enlarged, and the
surface becomes warty, uneven, and the edges curl inward,
bringing the under surface into view. The petioles are shorter
and bowed outward. The leaves are more brittle than normal,
although they have a leathery appearance. Young plants
may be killed outright, others are badly stunted ; the sugar-
content of the roots is lessened and there is an abnormal de-
velopment of rootlets. Cross-sections of the root often show
dark concentric circles from the darkening of the fibrovascular
bundles. Frequently large fields of beets so affected are not
worth. harvesting and in many localities the growing of sugar-
beets has been abandoned for this reason. When beets are
grown the second year for seed, the presence of this disease
greatly reduces the crop.

The disease is transmitted by a small, creamy or greenish
white leaf hopper, sometimes tinged with red, about ^ inch in
length, both nymphs and adults being capable of infecting
the plant on which they feed. This insect is a native of the
same region where it feeds on several species of Atriplex and
Russian thistle, sea blite and greasewood. Certain species of
Atriplex seem to be its favorite wild food plants. The insect
hibernates as an adult, appearing in the beet fields in late
spring.

Beet fields do not, as a rule, become infested by leafhoppers
that have hibernated in their immediate vicinity. Apparently
the infestation comes from leafhoppers that have developed on
their wild food plants in desert regions and that have hiber-
nated near their breeding grounds. In late spring these insects
migrate in great swarms, passing over high mountain ranges
and traveling to distances of several hundred miles. In the
course of the migration, the leafhoppers settle in any beet
fields in which the plants are in condition to serve as food. If
the crop in a field is not up at the time of the flight, it is not
likely to become infested from adjoining fields but may be

94 MANUAL OF V EdET AB1JC-(!A RDKS IS SECTS

attacked by a later flight if a second iniyratioii occurs. Injury
by the leafhopper is likely to take place in regions not infested
the previous year and a season of severe injury may be fol-
lowed by one in which practically no IcafliopixTs can be found.
In most localities the disease is of a periodic nature, but in
certain regions within the permanent l)ree(ling area infestation
is almost sure to occur every year.

In feeding, the insect punctures the leaf with the slender
needle-like bristles of its beak and sucks out the juices of the
plant, at the same time inoculating it with the virus of the
disease. AVhen disturbed, the leafho{)pcrs sj)ring (piickly into
the air and take wing, but soon alight seeking shelter on another
plant. When on the wing tlicy appear white. The female
inserts her eggs their fidl length singly in the stems, midrib
and petiole of the leaves and sometimes in the larger side veins.
The eggs are pale, elongate, slightly curxed and narrower
anteriorly. Before hatching the growth of the leaf usuall\'
forces the eggs i)art way out of the tissue. The eggs hatch in
about two weeks and the minute, nearly colorless nymphs begin
feeding on the leaves down in the center of the plant. The
older nymphs vary from creamy white in color to nearly black,
variously spotted and mottlerl with brown, bufi" and red.
In about three weeks the nymphs become mature, having
passed through five immature stages in the course of their
growth. The eggs are laid during a considerable period, from
late in June to the first of September in the northern part of
the insect's range, but the greater number are deposited during
the first half of Jul>-. Each female is capable of laying about
SO eggs. There is only one generation annually.

The control of this Icafhojjper and the consecjuent elimina-
tion of the curly-leaf disease is commercially inisoK-ecl. '{'he
adult hoppers are hard to hit and difficult to kill with contact
insecticides and it is doubtful whether sj)raying would Ik- com-
mercially profitable. Something can be gained, howexer, by

BEET AND SPINACH INSECTS

early planting and by gocKl care of the crop early in the season
so as to get the })lants well established before the hoppers make
their appearance in the field.

References

U. S. Bur. Ent. Bull. GG, pp. 33-ry2. 1909.
U. S. Bur. Plant Ind. Bull. 181. 1910.
Utah Agr. E.xp. Sta. Bull. 155. 1917.

The Larger Si'gar-Beet Leaf-Beetle

Monoxia puncticollis Say

\n Xew ]\Iexico, Colorado and Montana, sugar-})eets are
sometimes attacked by the larvje and adults of this leaf-beetle,
but it has not yet been reported as an enemy of table beets.
Its wild food plants are sea blite,
Russian thistle and salt-bush. Both
larvjB and adults feed on the leaves
but the greater part of the injury is
caused by the former. When dis-
turbed they fall readily to the
ground. The beetle occurs along
the Atlantic and Gulf coast and
westward to California, and north-
ward through Colorado, Itah and
Montana. It is \ to ^ inch in
length, and varies considerably in
c;)lor, from uniform dull yellowish

])rown to nearly black ; in some forms each wing-cover is
marked with one or two more or less distinct dark stripes
(Fig. 63). The insect hibernates in the beetle stage, ai)pear-
ing on its food plants early in the spring. The female de-
l)()sits her eggs, a little less than ^V •"<''• i" length, in irregular
clusters of two or three to fort\' or hft\' on tiic lea\cs. These

Fig. {'hi. — The liirgor su}.';:ir-
beet leaf-beetle (X 4J).

MAMWL OF VEGETABLE-CARDES IX SECTS

hatch in about a week and tlie larva^ beirin feedin*: on the
leaves. The youn<:; hir\a is about iV incii in len^^th, (hill ff:ny,
with tile thoracic shield and tlir areas at the base of the tubercles
dark brown. The larva becomes full-^rown in nine or ten
days. It is then about f inch in lenjjth, dark olive brown with
the tubercles j)ale yellow. The larva* enter the ground for
pn])ation and the beetles emerge a few days later. There are
two generations annually.

It has been obserxed in Colorado that the insect is most
troublesome on beets grown on or near alkali ground.

References

U. S. Div. Ent. Bull. 40, pp. 111-113. 1903.
Gillt'tte, Rept. State Ent. Col., pp. 8-11. 1903.

The Western Beet Leaf-Bketle

Monoxia conspula Leconte

This leaf-beetle ranges from California and Oregon east to
the Dakotas and Kan.sas. It has been
reported as injurious to beets and sugar-
beets in CalifojMiia and Oregon. lioth
larvre and adults feed on the leaves,
leaving only the larger veins. The
beetle (Fig. 04) is nearly ^ inch in
length, yellowish brown ; the wing-
co\ers are sometimes marked with
small scattered black spots often
arranged in rows.

The beet leaf-beetles can be con-
trolled by thoroughl\' spraying the jjlants with arsenate of
lead (paste), 5 or 0 ])i)unds in 100 gallons of water.

Fi(i. 04. — The wi'stern
hect It'iif-ljceUe (X oj).

BEET AND SPINACH INSECTS 97

The Su(;aii-Beet Webworm

Loxostegc siicticalis Linnaeus

Although the sugar-beet webworm has attracted more atten-
tion as an enemy of the sugar-beet, it also attacks a large num-
ber of garden and field crops. It is widely distributed through-
out Europe, Asia and North America and is particularly
injurious in southeastern Europe. It did not attract notice in
the United States until the beginning of the development of
the sugar-beet industry. It has been destructive only in the
Mississippi Valley and westward to the Rocky IVIountains.
In addition to the sugar-beet, it has been reported feeding on
the following : pea, bean, potato, cabbage, onion, squash,
pumpkin, cucumber, alfalfa and vari-
ous grains and grasses. Its favorite
wild food plants are pigweed (Ama-
ranthus) and lamb's ciuarters.

The winter is passed by the full-
grown caterpillars in silken tubes in
the soil. In late spring tl,e>- trans- ^;';,tt™ ™' hTS'ir
form within the tubes to yellow-brown

pupa? about ^ inch in length. In about eleven days the moths
emerge. The moth has an expanse of about an inch. The
front wings are smoky brown with faint darker markings, a
straw-colored spot below the middle of the front margin and
a similarly colored band along the outer margin. The hind
wings are paler with two blurred bands (Fig. Go). The
females deposit their pale, pearly green or yellow, oval eggs
about 2V "^ch in diameter, singly or in overlapping rows of
two to ten, usually on the underside of the leaves. The egg
is flattened below and very convex above. P^ach female lays
from 200 to 250 eggs. The eggs hatch in three to five
days. The young wliitish larvne with black heads feed at

98 MAXIAL OF VF.CF/rABI.KCARDES IXSECTS

first oil tlu" soft ti.ssiR's on the uii<l(>rsi(lc of the leaves. As
tliey increase in size, tliev heconie yellowish <,M-een in c:ilor
with (hirk niarkinj^s and eonsunic ahnost the entire leaf. 'I'he
caterpillars feed by preference on the older, outer lea\-es and do
not attack the newer leaves at the center of the plant until
the others have been consumed. Their feedinti,- ji:rounds are
covered by a slij^ht silken web. The full-.urown caterpillar is
about an inch in length, yellowish white with a broad black
median stripe and a broader sub-dorsal stripe and marked with
numerous piliferous spots surrounded by black rings. The
larva becomes mature in about three weeks and constructs a
silken tube in the ground within which it forms a cocoon and
pupates. The winter cocoon is about three times the length
of the larva and the summer cocoon only twic(> as long. There
are usually three generations a year and in some ca.ses a .small
fourth })rood may occur. A few of the first, a consideral)le
l)art of the second, and nearly all of the third generation cater-
pillars do not transform till the htilowing spring. The first
brood are destructi\e while the sugar-beet plants are small and
easily killed. At this time the crown of the plant is often
attacked. When the later broods ai)pear, the plant\are larger
and rarely killed outright but the size and sugar-content of the
roots are greatly decreased by the defoliation of the j)lants.
The third brood is the least injurious because the plants are
more nearly mature and the brood is smaller.

In some regions in which the sugar-beet is grown extensively,
the cateri)illars often occur in countless nund)ers and the moths
attract attention by flying in clouds o\'er the fields.

Means of control .

The sugar-beet webworm may be controlled on sugar-beets
})y thorough spraying with .'> pounds of paris green in KM) gallons
of water to which (i jxnuids of whale-oil soap or '.'> pounds of
lime are added as an adhesix'c. Alxmt lOO gallons of the mix-

BEET AND SPINACH INSECTS 99

tiire should be applied to the acre and the application should
be made as soon as possible after the caterpillars have hatched.
The spray should be applied with at least cSO pounds' pressure.
Recent experiments in Colorado and Kansas have shown that
paris green applied in this way will satisfactorily control the
webworm on beets and is much more effective than arsenate of
lead. In some cases in which the ground is too wet for the use
of a sprayer, paris green may be applied in the form of a dust
at the rate of 2 to 4 pounds in 100 pounds of air-slaked lime.

References

Koppon, Die Shadlichon Insekten Riisslands, pp. 394-405. 1880.
Riley, Rept. U. S. P]nt. for 1892, pp. 172-175.
Col. Agr. Exp. Sta. Bui. 98, pp. 2-12. 1905.
U. S. Bur. Ent. Bui. 109, pp. 57-70. 1912.

The Hawaiian Beet Webworm

Hymenia fascialis Cramer

In the soutliern United States beet leaves are sometimes
skeletonized on the underside by a small, slender, pale green
caterpillar which has received the rather inappropriate com-
mon name given above. The insect ranges throughout the
southern states westward to California. It is also generally
distributed throughout the warmer parts cf tiie Old World.
Its habits and life history have been studied carefully in
Hawaii. In that climate, breeding is continuous throughout
the year. Its food ])lants include table beets, sugar-beets,
Swiss chard, mangels and Amaranius (inuijeiivus, a Chinese pot-
herb sometimes known as spinach. Among weeds, it feeds on
purslane and numerous sjx'cies belonging to Amaraiithus aiul
CliaMi()])odium. The caterpillars reach maturity in nine days
to two weeks and then enter the ground a short distance, where
they form firm, oblong earthen cocoons composed of silk and

100 MAXl'AL OF VEdETAHLE-CAUDEX IX SECTS

particles of earth. The pupa is f incli in leno;th and pale brown
in color. The moths cmerfie in a week or two. Tlie moth has
an expanse of about | inch. The win<;s are uniform bhickish
l)n)wn. The front \\\\\g has a l)r()a(l translucent white band
across the middle, not quite reaching; the front margin. Two
thirds the distance to the outer marjiin a white l)ar extends
halfway across the wing. The hind wing is crossed by a nearly
even white band. The moths are shy and are usually to be
found hiding under the leaves. In Florida they are often found
in great numbers feeding on the nectar of catnip blossoms.
The female deposits her minute elliptical flattened eggs, about
4V i'lt'h in length, singly or in short rows on the underside of
the leaves. The eggs hatch in ai);)Ut four days. The cater-
l)illars sometimes spin a slight web over their feeding grounds
but more often feed openly. It is believed that in Hawaii
from six to ten generations ma\ be profhu-cd annually.

This webworm can be controlled by spraying with arsenate
of lead (paste), 2 pounds in .">() gallons of water, taking care to
coat the underside of the leaves.

Reference
U. S. Bur. Ent. Bull. 109, pp. 1-15. 1911.

The Spotted Beet Wkp.worm

Hymen a pcrspcctalis Hiibner

The spotted beet webworm is widely distributed throughout
the warmer parts of the world and in the Tnited States is
sometimes found out of doors as far iiortli as ^ irginia. In
greenhouses it often proves a troublesome pest on Alternanthera.
In the open it sometimes becomes destructive to l)eets, sugar-
beets and Swiss chard. Tlu- moth has an expanse of about ^
inch. The wings are blackish brown shaded with clay-color,

BEET AND SPINACH INSECTS 101

especially on the hiiul win<2;s. The inarkinjjjs are translucent
white ; on the front win<i; there is a narrow cur\e(l line near the
base ; a nearly square patch at the middle near the front edge ;
a line running from close to this to the hind margin, and two
thirds the distance to the outer margin a white bar extends
halfway across the wing. Across the middle of the hind wing
is an irregular white band, narrower behind.

The moth deposits her flat, oval, semi-transparent, greenish
eggs, about -g-^ inch in length, singly on the stems of the plant,
usually near the base. The young larvi3e at first skeletonize
the leaves but later devour the whole leaf. The full-grown
larva is a little more than ^ inch in length, shining green and
marked with rows of small black spots. Pupation takes place
in a thin loose silken cocoon on the ground at the base of the
plants. The pupal period occupies from one to three weeks,
depending on the season. Under greenhouse conditions the
life cycle is completed in two or three months.

The spotted beet webworm may be controlled by the meas-
ures suggested for the preceding species.

References

Davis, 27th Kept. State Ent. 111., pp. 10.3-lOG. 1912.
U. S. Bur. Ent. Bull. 127, pp. 1-11. 1913.

The Soi'thern Beet Webworm

Pachyznncla bipunctnlis Fabrieius

In Georgia, Florida and Texas, this webworm has been re-
ported as occasionally injurious to beets, cauliflower and cab-
l)age. Its wild food ])lants include ragweed, spiny amaranth
and Anidraiifiis rrfroflr.vus. The insect ranges southward
through the West Indies into South America and also occurs
in South Africa. The caterpillars feed on tiu' leaves of their
food plants, folding and webbing them together with silken

102 MANUAL OF VECiETABLE-GARDEX INSECTS

tlirt-ads. The full-trrown larva is al)out f inch in U'li^th, (hirk,
dirty fjrecn with the licad and the sides of the cervical shield
dark brown. The surface of the hody is senii-transi)arent and
<,dossy in ajjpearance. The cateri)illars heconie mature in two
or three weeks and transform to maho<;any brown pupa' §
inch in length. The ])osteri()r end of the body is prolonged into
a bill-like })rocess bearing four i)airs of recurved hooks. The
pupal period occupies about eight days in warm weather. The
moth has an expanse of about an inch. The front wings vary
from buff to pale yellowish gra>', often tinged with ])urplish
and crossed by two irregular brownish lines and marked with
two black dots near the front margin. The moth deposits her
eggs singly on the luiderside of the leaves. The eggs are
flattened, irregularly oval, yellowish or greenish in color and
about ^ inch in Icngtii. They hatch in al)out a week. There
are thought to be four generations a year.

'J'his beet webworm may be controlled by tiie measures sug-
gested for the Hawaiian beet webworm.

Rkfrrknte
U. S. Bur. Ent. Bull. 109, pp. 17-22. 1911.

Tin: St'gar-Beet Iioot-Louse

Pemphigus bctrr Doane

Tn the western Tnited States from western Kansas and
Nebraska to California, sugar-beets, beets and mangels often
have the roots infested with a small, pale yellow plant-louse.
In the case of sugar-beets, not only does the presence of the
plant-lice greatly decrease the weight l)ut also the sugar-
content of the roots, in many localities making it uni)rofitable
to grow the crop. This root-louse is a native of the western
United States, where it is found most a})un(iant on the roots of

BEET AND SPINACH INSECTS 103

lamb's quarters but has also been reported as infesting the
roots of the following plants : yarrow, knotweed, dock, aster,
goldenrod, horse-weed, winged pigweed, foxtail, salt-grass,
blue-joint grass, wheat, flax and alfalfa.

The insect passes the winter in two forms, either as wingless
viviparous females on the roots of its food plants or as eggs on
the bark of two species of cottonwood {Populus angustifolia
and P. balsamifera) . The plant-lice that have survived the
winter on the roots begin to give birth to living young in April
or May, producing another generation of wingless viviparous
females. Reproduction continues in this w'ay until mid-
summer, when winged forms begin to appear. Only about half
of the lice acquire wings, the others continue breeding on the
roots throughout the season. The form found on the roots is
about ^ inch in length, pale yellow^ in color and has the pos-
terior part of the abdomen clothed with a white flocculent mass
of waxy filaments. The remainder of the body is dusted with
a white powder. Infested roots appear to be covered with a
white or grayish mold. The winged forms produced on the
roots are slightly larger than the wingless forms. The abdo-
men is greenish, the thorax, head and antennae bluish black,
lightly dusted with the whitish powder and there is only a
little of the white flocculent material on the tip of the body.
These winged forms begin to appear in midsummer and con-
tinue until the end of the season but are most abundant in
September and October. They migrate to the cottonwood,
where, on the bark of the trunk, each female gives birth to four
to seven young, part males and part females, the latter prv-
dominating. These forms lack functional mouth-parts and do
not take food, "^lliey molt four times in as many days and
after mating the female dcjxjsits a single pale yellow egg in a
crevice of the bark, which usuall\' rests on a mass of bluisii
white waxy threads. The eggs hatch al)()iit the first of the
following May and the young ])lant-l(>iise crawls out on the

104 MAXUAL OF VEGETABLE-GARDES IXSECTS

upper side of an opening; leaf, where it establishes itself and
bejiins feeding. A depression soon appears on the leaf at this
point which gradually develops into a pocket-like outgrowth
on the underside opening by a narrow slit in the upper side.
Within this pocket-like gall, the plant-louse becomes mature
and gives birth to seventy-five to one hundred and seventy-
five young, all of which acquire wings and on escaping fly to
beets or other food plants, where they produce young which
descend to the roots. This migration from the cottonwood
takes place mostly in July. Beets become infested both from
lice living over in the ground on last year's crop or on weeds,
and by the migrants from the cottonwood.

The only practicable measure so far suggested for the con-
trol of the sugar-beet root-louse can be employed only where
irrigation is practiced. It consists in giving the plants the
maximum (luantity of water that they can stand, thus forcing
the growth and at the same time producing conditions unfavor-
able to the multiplication of the insects.

Beets are also sometimes infested by another sj)ecies of root-
louse, Tychea brevicornis Ilart. This peculiar plant-lou.se is
wingless, with the abdomen very large and without cornicles.
Corn, sorghum, salt-grass, pigweed, purslane, mustard, lettuce
and dock have been recorded as hosts of T. brevicorriift.

A closely related species, determined as the Euroi)ean T.
phnscoli Passerini, has been reported as feeding on the roots of
bean and clover. There is some doubt as to the determina-
tion of the species of j)lant-lice found on the roots of many of
our common weeds and vegetables. They arc in great need of
further study.

Wash. .\p:r. Exp. Sta. Bull. 42. 1900.
Parker, Jour. Kfoii. Ent.. 7. pp. i;it>-141. H)14.
I*arkt>r, Jour. Art. Rci^carcli, 4, i)p. 241-2">n. IKl.').
Ma.xs()n, Jour. E«-oti. Kut., '.), i)p. .")(M)-."»()."). 1!»1(».

BEET AND SPINACH INSECTS 105

The Spinach Aphis
Myzus persicoe Sulzer

The spinach aphis is also known as the green peach aphis,
and as the common green-fly of greenhouses. It is found in
both Europe and America. In some localities it is the most
serious insect enemy of spinach and is sometimes injurious to
potato, tomato, eggplant, cabbage, turnip, radish, cauliflower,
cucumber, kale, mustard, beet, rutabaga, water cress, pepper,
horse-radish, celery, rhubarb, okra and lettuce. Eggplant often
becomes infested in the hot-bed before transplanting. Radishes
and rutabagas are sometimes attacked as soon as they come
up, the first pair of leaves being entirely covered on the under-
side by the lice. Such plants are badly stunted and sometimes
killed. The spinach aphis also attacks a number of weeds,
including pigweed, lamb's quarters, dock, shepherd's purse,
dandelion, sow thistle, lupine and wild mustard. It is often
found in greenhouses, where it infests the calla lily, carnation,
rose, violet, oleander and many others. It has also been re-
corded from tulip, pansy, hollyhock, tobacco, peppermint, rape
and several ornamental plants. It is also sometimes found in
the summer on apple, pear and lilac.

The spinach aphis may pass the winter either in green-
houses or on its food plants out of doors, where the winters are
not too cold, or in the egg stage on the peach, plum, cherry,
apricot, sand cherry and choke cherry. In the last case, the
eggs hatch shortly before the buds burst in the spring and the
stem-mothers are ready to begin rei)roduction when the blossoms
appear. They are wingless and of a pinkish color. In the
second generation the i)lant-lice are for the most i)art wingless,
but instead of being ])ink, are pale \ellowish green and usuall\'
marked with three indistinct darker strii)es on the abdomen.
In the third generation, most of the lice acquire wings. They

106 MAMAL OF VEdETAliLE-CAHDEX IS SECTS

are then greenish with the head, thorax and a hirge spot on the
abdomen black. These winged forms leave the tree and fiy
to their various herbaceous food plants where they found colonies
of young. When the lice have survived the winter on weeds

or vegetables, reprtxluction is resumed
as soon as new growth starts in the
spring. They nuiltiply rapidly and
the plants soon become covered with
the lice. The wingless forms found
on the summer food ])lants have the
l)ody a uniform greenish yellow,
without the darker lines found on
the forms on the peach or i)lum
(Fig. 66). AMien the plant becomes
Fi<:. 66.— Wingless viviparous cTowflcd, winged forms (Fig. 67) are

fcnuile spinach aphis (X 11). i i i • i • f i

produced whicli migrate to new feed-
ing grounds. The in.sects are mo.st destructive to spinach
late in the season when the cooler weather prevents the rapid
multij)lication of their predaceous and i)arasitic enemies,
although they may become troublesome at any time. In th?
fall some of the winged females return to the peach, pliun ( r
cherry, establish themselves
along the veins on the un-
derside of the leaves and
give birth to true or ovipa-
rous females. The latter are
usually of a pinkish color,
similar to the stem-mothers
of the preceding spring.
After pairing with the

winged males, they deposit tlieir eggs in the axils of the buds
and in crc\ ices of the bark. The eggs are small, oval and
shining black, and closely resemble tho.se of the common green
aj)i)le aphis.

Fig. 67. — Winged viviparfni- fonialc
spinach aphis (X 7 J).

BEET AND SPINACH INSECTS

107

Control.

The spinach aphis is readily killed when hit by spraying; with
"Black Leaf 4U" tobacco extract, 1 pint in 100 gallons of
water to which 5 or 6 pounds of soap have been added. On
spinach, however, and other plants the leaves of which lie close
to the ground, it is not easy to obtain satisfactory control
owing to the difficulty of wetting the underside of the leaves
with the spray.

References

Taylor, Jour. Eeon. Ent., 1, pp. 83-91. 1908.
Col. Agr. Exp. Sta. Bull. 133, pp. 32-37. 1908.
Va. Truck Exp. Sta. Bull. 2, pp. 30-32. 1909.

Other Beet and Spinach Insects

Southern corn root-worm : 222

Cabbage looper : 8

C^abbage webworm : 10

Garden webworm : 18

Harlequin cabbage bug : 38

Serpentine leaf-miner : 40

False chinch-bug : 47

Yellow bear caterpillar : '.'>'>7

Carrot beetle : 18.5

Celery leaf-tyer : 189

Celery looper : 191

Ailelphocoris rapidus: 19.5

Western twelve-spotted cucumlx-r beetle: 114

Belted cucumber beetle : 115

Melon aphis : 13.5

Garden si)riugtail : 13'.)

Potato aphis : 1.50

Common stalk-borer : 157

Grape colaspis : 07

Bean thrips : (59

Bean aphis : 7()

Garden flea-hopper : 77

Spotted cutworm : 202

Greasy cutworm : 2()5

Red-backed cutworm : 207

Dark-sided cutworm : 208

108 MAX UAL OF VECET ABLE-GARDES INSECTS

Striped cutworm : 270
Variegated cutworm : '2H\
Yellow-headed cutworm : 1281
Spotted-legged cutworm : 282
Clover cutworm : 284
Army cutw'orm : 287
Army-worm : 288
Fall army- worm : 292
Beet army-worm : 204
Yellow-striped army-worm : 20;')
Striped blister-beetle : 302
Margined blister-beetle : 305
Ash-gi'ay blister-beetle : 300
Black blister-beetle : 307
Nuttall's blister-beetle : 308
Spotted blister-beetle : 300
Two-spotted blister-])eetle : 309
Segmented black blister-beetle: 310
Large black blister-beetle: 311
Potato flea-beetle : 314
Eggplant flea-beetle : 320
Pale-striped flea-beetle : 321
Red-headed flea-beetle : 323
Smart weed flea-beetle : 323
Western cabbage flea-beetle : 327
Spinach flea-beetle : 320
Yellow-necked flea-beetle : 331
Three-spotted flea-beetle: 331
Larger striped flea-beetle : •V.i'Z
Sweet potato flea-beetle : :i32
Hop flea-beetle : 33o
Hoot-knot nematode : 338
Sugar-beet nematode : 342
Millipedes: 342

CHAPTER V

INSECTS INJURIOUS TO CUCUMBER, SQUASH AND

MELON

Cucurbits are subject to attack by a large number of insects,
the most important of which are : the cucumber beetles, the
squash bugs, the squash-vine borer, the pickle worm, the
melon worm and the melon aphis. Cutworms and flea-beetles
also occasionally cause serious loss. The watermelon is singu-
larly free from insect enemies but is sometimes seriously in-
fected by the melon aphis.

The Striped Cucumber Beetle

Diabrotica vittata Fabricius

This small, yellow, black-striped beetle is one of the most
serious enemies of the cucumber, squash, melon and related
plants. It is a native of America and is to be found in this
country wherever its food plants are grown except in the far
West. The greatest injury is to the young plants soon after
they come uj), by the beetles that have just emerged from
hibernation; the larva^ also burrow in the stem ])()t]i above
and below the ground and often feed on the underside of the
fruit when it lies on the soil ; the beetles sometimes destroy
the flowers by eating off the i)istils and the new brood of beetles
in hite sunnner causes considerable injury to ripening fruit by
gnawing holes in the rind.

109

MAXCAL OF VEGETABLE-CARDKX IXSECTS

The beetles hilx-rnate under trash or, when sueh protection
is not avaihihle, in the ground lielow the frost line. They
emerge from hibernation in the spring from April to June, the
exact date depending on the locality and the season. They
usually appear before cucurbit plants are up and feed for some
time on the pollen of flowers and on the lea\es of certain plants,
apple, horse-chestnut, wild thorn, elm. syringa, juneberry and
many others. The beetles, hungry after their long winter's
fast, congregate on squash and cucumber plants just as they
are coming up and feed on the tender leaves and gnaw holes

in the stems often just at the sur-
face of the ground. Many i)lants
arc killed outright while others are
SI) injured that they make only a
sickly growth. Okra is sometimes
attacked.

The beetle (Fig. 68) is from ^ to
^ inch in length; the head is black;
the thorax yellow and the wing-
covers yellow with three longitudinal
black stripes, the lateral pair not ex-
tending to the tij). After feeding
for some time, the beetles mate and
the female begins egg-laying. Oviposition has been found to
begin in Kentucky about the middle of June, on Long Island,
Xew York, towards the last of June and in New IIam])shire,
about the first of July. Oviposition continues for about a
month. Each female is capable of la\ing from seventy-five to
one hundred eggs. The egg is about -^ iiu-h long. -^V i'i<^"li wide,
oval or elliptical in outline and light yellow in color. Some of
the eggs arc depositcil in crcxiccs in the ground l»ut many are
dropped by the female wherever she happens to l)e feeding.
Eggs are sometimes found caught in the hairs of the leaves at
the tip of the vines. The eggs hatch in a week or more and the

Fi(j. G8. — The .striped cucum-
ber beetle ( X 5J).

INJURIOUS TO CUCUMBER, SQUASH AXD MELOX 111

larvse work their way down along the stem or under the vines
or fruit where they He on the p-ound. They burrow into the
tissue, eausing more injury in this stage than is usually thought.
Squash vines have been observed practically killed in July and
early August from the attacks of the grubs. The stem just
below the ground is completely riddled by their burrows. The
larva becomes mature in about a month. It is then about yu
inch in length and very slender ; the color is white with the
head, thoracic and anal plates brown (Fig. 69). When mature,
the larva constructs an earthen cell a few inches below the sur-
face within which it soon transforms to a nearly white pupa.
The pupal stage lasts a
week or more. The
beetles begin to emerge
the last of August or in ^ „„ r. • , , , , ,

_ . riG. G9. — Striped cucumber beetle, larva

September m the more (X7§).

northern part of the

insect's range and after feeding for some time on Lowers,
such as goldenrod and asters, go into hibernation with the
occurrence of heavy frost. Late in the season the beetles
sometimes injure melons by eating holes in the rind and have
been known to eat holes in bean pods. In the North there is
only one generation annually; in the South it is thought that
the insect is double-brooded.

The beetles also serve as carriers for a serious disease of
cucurbits known as bacterial wilt. They not only transmit
the disease from plant to plant in the summer, but the hiber-
nating beetles carry over the wilt bacteria and infect the plants
in the spring.

Control.

As a rule, attempts to poison the beetles have not been suc-
cessful because the insects refuse to eat leaves covered with
the poison. In many cases it is ])racticable to jirotect the

112 MAXUAL OF VEGETABLE-GARDEX IXSECTS

young plants by covering tliem with some kind of screen.
C'lieeseclotii, niosciuito-nctting and wire screen are often used
for this purpose. Various methods are followed to hold the
covering in place over the plants ; sometimes a shallow wooden
box is used, open at top and bottom and the screen is tacked
over the top ; sometimes a barrel hoop is cut into halves, the
two parts crossed at right angles and the ends stuck in the
ground ; the screen is placed over the hoops and earth thrown
on the edges to hold it down ; sometimes the cover is made
entirely of wire screen in the form of a cone and one grower
successfully used wire pie-covers. The difficulty in using covers
is that they have to be removed before the plants become very
large and if the beetles are very abundant injury may follow.

Much may be accomplished to prevent injury by keeping
the plants thoroughly covered with bordeaux mixture or arse-
nate of lead (paste), 3 pounds in oO gallons of water. This
renders the plants distasteful to the beetles and is especially
valuable on cucumbers if used in connection with trap crops.
Squashes are often more attractive to the beetles than cucum-
bers and have been used successfully for trap crops. When it
is desired to protect a field of cucumbers, a few rows of squashes
should be placed around the field about a week before ])lanting
the cucumbers ; another planting of squashes should be made
at the time the main field is set and if the beetles are abundant,
more squashes should be ]:)lanted about a week later. The
beetles will collect on the squash plants, where it is sometimes
possible to poison some when they first arri\e and before they
have had a chance to feed on unpoisoned foliage. Only a part
of the trap crop should be sprayed or dusted with the poison
for fear of driving the beetles to the cucumbers. Whenever a
trap crop is used, it is im])ortant to keep the main crop well
sprayed with bordeaux mixture or arsenate of lead. Experi-
ments in New Hampshire have shown that arsenate of lead is
just as effective as a deterrent for the beetles as bordeaux

INJURIOUS TO CUCUMBER, SQUASH AND MELON 113

mixture and that it does not check the growth of the i)hints if
appHed while they are small as does the latter. Tobacco dust,
air-slaked lime and land plaster are of value as deterrents and
will be found useful in the home garden.

Much loss from beetle attack may be prevented by thorough
cultivation and the use of the proper fertilizers to stimulate
rapid growth. At the end of the season, all rubbish, including
the old vines, should be collected and burned in order to reduce
to a minimum the shelter for the hibernating beetles.

References

N. Y. (Geneva) Agr. Exp. Sta. Bull. 158. 1899.

Ky. Agr. Exp. Sta. Bull. 91, pp. 1-1.5. 1901.

U. S. Bur. Ent. Circ. .31. 1898 and 1909.

N. H. Agr. Exp. Sta. 19th and 20th Kept., pp. 499-513. 1908.

Western Cucumber Beetle

Diabrotica trivillata Mannerheim

On the Pacific Coast the striped cucumber beetle is replaced
by a closely related form. This species may be distinguished
from its eastern relative by its darker color and by having the
antenna? and the greater part of the legs black. The habits
and life history of the western form are very similar to those
of the eastern species but it has not on the whole proved as
injurious. There are said to be two generations annually.
When attacking cucurbits, it may be controlled l)y the same
means as suggested for that species.

The Twelve-Spotted Cucumber Beetle

Diabrotica duodecempunctata Olivier

This beetle is also known as the southern corn root-worm
and is discussed on page 222 as a corn pest. When attacking

114 MANUAL OF VEGETABLE-GARDEN INSECTS

cucurbits, it may l)e controlled 1)\ tiie measures sufjgested for
the striped cucumher beetle.

The Western Twelve-Spotted Cucumber Beetle

DiabroHca soror Lcconte

On the Pacific Coast the southern corn root-worm (page 222)
is replaced by a closely related species which may be distin-
guished by having the entire underside of the body and the legs

black; the antennre are only
slightly paler at the base. The
two posterior spots on the wing-
covers have a tendency to
coalesce (Fig. 70).

The beetles attack cantaloupe,
watermelon, squash and cucum-
l)er plants just as they are com-
ing up and also eat holes in the
fruit. They are also destructive
to beet, spinach, bean, pea, cab-
bage, turnip, j)otato, lettuce,
mustard, peanut, corn, alfalfa
and clover. They are especially troublesome on farms on
which flowers are grown for seed. They sometimes defoliate
young deciduous and citrus trees and cause considerable injury
by eating holes in the fruit of the peach, prune and apricot.
The beetles hibernate in sheltered places, emerging in early
spring. After fee<ling for about eighteen to twenty-four days,
the small, dirty white, oval eggs are deposited singly or in
clusters of four or five to fifty in the ground near the base of
the food i)lant, about one quarter to one half inch from the
surface. The eggs are deposited over a j)eriod of about three
weeks. They hatch in nine to twenty-six days with an aver-
age of about two weeks. The lar\;e have been found feeding

Fio. 70. — The western twelve-
spotted c'ueumljer beetle (X ■'))•

INJURIOUS TO CUCUMBER, SQUASH AND MELON 115

on the roots of pea, alfalfa, peanut and beet and are said to
mine into the stems and rinds of melons, cucumber and squash
where they touch the ground. The larvse become mature in
five weeks to two months, those hatching first requiring the
longer period. The full-grown grub is a little less than ^ inch
in length, elongate, cylindrical, white or yellowish in color,
with the head, thoracic shield and anal plate brown. The
larva? pupate in earthen cells in the ground and in about two
weeks the beetles emerge. In Oregon the beetles of the new
brood become abundant in early July ; in California somewhat
earlier.

The western twelve-spotted cucumber beetle can be con-
trolled by the same measures as recommended for the striped
cucumber beetle.

The Belted Cucumber Beetle

Dinhroticn halteata Leconte

In the lower Rio Grande Valley in Texas truck crops are
often subject to attack by the belted cucumber beetle. This
beetle is about \ inch in length,
the head red and the prothorax
and wing-covers bluish green, each
of the latter marked with two spots
in front, two transverse bands and
a spot near the apex which are yel-
lowish. The femora are greenish,
the remainder of the legs blackish
(Fig. 71). The beetles feed on
pea, bean, potato, pepper, turnip,
])eanut, squash, cantaloupe, cucum-
ber, watermelon, pumpkin, okra,
spinacii, beet, lettuce, onion, asparagus, corn, cotton, alfalfa,
cowpea and other leguminous crops. They seriously injure

Fig. 71. — The belted fuciimber
licet Ic (X oV).

116 MANUAL OF VEGETABLE-GARDEN INSECTS

eggplant, tomato and cucurbits by destroying tlie foliage and
by feeding on the blossoms and blossom buds.

The adults are active during the winter but do not lay eggs
until March. The egg is oval, pale yellow in color and about
-^^ inch in length. The eggs are laid in the ground near the
base of the food j^lant singly or in clusters of four or five.
They hatch in nine to eleven days. The larvie have been
found feeding on the roots of corn, sorghum and beans. The
larva becomes mature in about twenty-tive days. It is nearly
■J inch in length, light yellow in color with the head and anal
plate brownish. The light \ellnw pup;v, about ^ inch in
length, are found in small earthen cells two or three inches
below the surface. About eleven days are si)ent in the pupal
stage. In the second generation the time recpiired for the
insect to pass through its ditl'erent stages is somewhat shorter;
viz., egg stage five days, larval stage fourteen days and pupal
stage five days.

Experiments in Texas have shown that truck crops may be
protected from the attacks of this beetle by spraying with
arsenate of lead (i)aste), (5 to 10 pounds in 100 gallons of water
or bordeaux mixture.

Two other closely related cucumber beetles, l)i(il)r<>flc(i cou-
ncxa Leconte and /). piciirornis Horn, occur in Texas and
sometimes attack cucurbits and beans. The latter species
deposits its eggs on the under surface of cucumber leaves.

Referkn'cb
U. S. Bur. Ent. Bull. 82, pp. 7()-S'_>. 1!)1().

The Squash Brc.

Aiinsn Irislis T)vCu'vr

Thri»ngli()\it the wli')lc rnit<'(l States, cncm-bits are subject
to the attacks of a large brownish hug that has a highl\- od'en-

INJURIOUS TO CUCUMBER, SQUASH AND MELON 117

sive odor, hence the name stink-l)iig by which it is known in
many localities. The insect ranges from Canada to Central
America. Its favorite food plants are squash and pumpkin,
but melons and cucumbers are sometimes severely injured.
As a rule the squash bug is more destructive in the small garden
than in the fields of the commercial grower. The reason is
that in the case of large tilled fields the quantity of hibernating
shelter is relatively smaller, and as the insects are distributed
over a larger area the injury is not so great to any particular
plant. In the home garden the
squash bug is a most troublesome
and vexatious pest.

The adult bugs hibernate in
rubbish, in board-piles or under
any convenient shelter. They
emerge from winter quarters
rather late in the spring and are
often found about gardens resting
under pieces of boards or other
shelter, apparently waiting for the
squashes to come up. The adult
bug (Fig. 72) is about f inch in
length and of a dirty brownish
black color above and brown

mottled w4th black below. The old bugs attack the plants
as soon as they are well out of the ground and often kill them
outright. In feeding, the insect punctures the plant with
the bristles of its beak and sucks out the sap. At the same
time it apparently injects into the wound some injurious
poison. When the plants are small, a few punctures are
enough to cause serious injury. After mating, the female
deposits her eggs in clusters of three or four to fifty or more
usually on the under surface of the leaves. The arrangement
of the eggs varies greatly ; usually they are placed in more or

Fig. 72. — The sciuash hug,
adult (X 2i).

118 MAXiAL OF VECETABLE-GARDEX JXSECTS

less n\<,nilar rows, SDinctiines crowded cltsely to<j;('tlior hut more

often rather widely se|)arateth The e<;g (Fij;. 73) is al)out

Yf iiicii in lenj^th and fiatteneil on three sides; the side next

to the leaf is somewhat concave. When first laid it is whitish,

but soon turns to a yellowish brown and gradually becomes

darker as the time for hatching approaches.

The eggs hatch in six to fifteen days. The young bug leaves

the egg through an opening at one end made by pushing out a

small circular disk-like piece of the shell. The newly hatched

nymph is gayly colored ; the body is green, the legs, antenntc

and beak rose color and the head and the front part of the

thorax another shade of rose. After a

few hours the rose color changes to

black. In the course of its development,

the insect passes through five nymphal

„ „„ „ , ^. stages, molting its skin five times and
Fig. 7.3. — Eggs of tho . . .

squash bug (X 1^. acquiring wings at the fifth molt. After
the first molt, the color of the nymj>hs
is a pruinosc gray, almost white. Four or five weeks are
passed in the nymphal stage. The young nymphs hatching
from a cluster of eggs remain together for some time
feeding on the underside of the leaf. After the first molt,
they move about more freely. AVhen not feeding, the older
nymphs and the adults often congregate around the base of
the jilant or hide under lumps of earth. The feeding of the
nymphs causes the injured leaves to wilt, curl up, turn brown
and die. Sometimes the bugs kill the ])lant outright but more
often they merely injure it so that growth is checked and the
vine is unable to mature a full crop of fruit. The nymjjhs
begin to reach niaturit\" in August but it often hai)i)ens that
frost kills the vines while many of the bugs are still immature.
In such cases tliey often congregate on the unripe fruits, from
which they are able to extract enough food to comijlete their
growth. There is only one generation annually.

INJURIOUS TO CUCUMBER, SQUASH AND MELON 119

Control.

The adult squash bug is very resistant to contact sprays
and recourse must be had to other methods of control. The
number of bugs appearing on the plants in the spring can be
greatly decreased by practicing clean farming and thus reduc-
ing the available shelter for the hibernating insects. After the
crop is harvested, the vines should be raked up and either
burned or converted into compost. This will prevent many
of the later hatched nymphs from reaching maturity. The
use of proper fertilizers and thorough cultivation will often
enable the vines to withstand attack and outgrow the injury.
After the ground has been fitted but before the plants are up,
many of the bugs can be trapped under pieces of boards placed
on the ground. They collect under such shelter during the
night. The boards should be examined every morning and the
insects killed by hand. It will also pay to keep watch of
the plants for some time after they come up and hand-pick all
the bugs found on them. All egg-masses should be destroyed
by scraping them off with a knife or by crushing. When the
nymphs are found, they too may be hand-picked or killed by
spraying with "Black Leaf 40" tobacco extract, 1 part in 400
parts of water in which enough soap has been dissolved to
make a good suds. An upturned nozzle will be found con-
venient for reaching the young bugs on the underside of the

leaves.

References

U. S. Div. Eiit. Bull. 10, PI). 20-28. 1899.
U. S. Div. Ent. ("ire. I'A). 1S99 and 1908.
N. H. Agr. E.xp. Sta. Bull. 89. 1902.

The Horned Squash Bug

Anasa armigera Say

The honied s(niasli bug is frequently associated with the
preceding species, from Missouri to Marxland and situthward.

120 MANUAL OF VEGET ABLE-GAR I)H.\ IX SECTS

The two species are very similar in .general api)earance but the
horned squash bug may be distinguished from the common
form by the prominent angles of the thorax, by the row of four
white spots on each side of the upper surface of the abdomen
and by the spine near the tip of each femur. There is also an
acute horn just in front of each eye (Fig. 74). The nymphs
are easily distinguished. In the earlier stages ^1. anuigcra has
the legs banded with red or brown and the next to the last seg-
ment of the antennfB is widened ; in J . fri.siis the legs are nearly
uniform black and the antennal segments
are of nearly the same width ; in the
later stages the sides of the thorax are
strongly dentate in A. annif/rra, smooth in
.1. frisfi.s. The life history and habits of
the two species are nearly alike. Tlu-
liorned squash bug may be controlled by
the .same measures as are suggested for
tlie common squash bug.

In the South from Florida to Louisiana
and New Mexico, another species, AnaMt
andmcsl Guerin-Meneville, closely related
to the common .squash bug, has recently
been reported as injurious to cucurbits. The adult of this
species is more slender and of a lighter color than the common
form but the insect does not difVer greatly in life history,
hal)its or the nature of the injurx' inflicted. The egg and
early stages have not been described in detail.

This subtroi)ical squash bug may be controlled by the
measures recommended for its northern relatives.

Fi<i. 74. — The horned
s(iuash bug ( X 2).

Rrferknce
U. S. Div. Knt. Bull. I'.t. i)]). 'JS :n. 1S99.

INJURIOUS TO CUCUMBER, SQUASH AND MELON 121

The Melon Leaf-Bug

Pycnode es quadrimaculatus Guerin-Meneville

This leaf-bug has been reported as seriously injuring melons,
squashes and beans in Arizona. The adult bug is about ^
inch in length, black, mottled with gray and whitish. The
legs are pale yellow with the outer two fifths of the hind femora
black. The life history has not been recorded. The injury is
caused by the feeding punctures of the insects. The adults
are very active and difficult to hit with a spray. No satis-
factory method of control has been devised.

The Southern Leaf-Footed Plant-Bug

Leptoglossus phyllopus Linnaeus

In the southern states, tomato, eggplant, melon, potato and
artichoke are often injured by the feeding punctures of a
chocolate-brown bug closely related to the
squash bug. This insect is also well
known to fruit-growers from its habit of
puncturing oranges, peaches, plums and
pears, causing them to decay. The adult
(Fig. 75) is between ^ and f inch in
length. The hind tibiae are flattened and
greatly expanded. The edge of the ex-
panded portion is notched and toothed
and flecked with yellowish white so as to
resemble a bit of dried leaf. The wings
are crossed near the middle !)>• a yellowish
white band. The adults hibernate and
in the sj)ring may be found in abundance on tlic yellow
thistle, where they deposit their eggs end to end in a row-
along a stem or the midrib of a leaf. The egg is golden

Fi<i. 75. — The .southern
loaf-footed plant-bug

(X li).

122 MAMAL OF VEdlCTAIil.E-dARDEX IXSKCTS

brown, cylindrical and flattened at each end and on the side
of attachment. The eggs hatch in a few days and the young
nymphs may be found sucking the juices from the i)lant.
The nymphs are more reddish than the adults and do not
acquire the leaf-like expansion on the hind legs until nearly
mature. They become full-grown in about three weeks, pass-
ing through five stages in the course of their development.

Most of the injury to cultivated plants is inflicted by the
adults, the nymphs being usually found only on yellow thistle.
They puncture the stems of cucum})er, melon and asparagus,
causing them to wilt and die. The tender growing tii)s of
tomato, potato, pea and bean are injured in a similar way and
the bugs sometimes attack the fruit of tomato. In Louisiana
the insect has been rej)orted as a serious pest of the globe arti-
choke. The bugs also puncture the bolls of cotton and are
injurious to pepper.

ConiroJ.

In the small garden, hand-picking the bugs in the morning
while they are sluggish is ])rol)ably the most })ractical method
of controlling the pest. Since the insect l)reeds largely on the
yellow thistle, this weed should not be allowed to grow in
abundance in the vicinity of susceptible cro])s. In some cases
it might be advisable to leave a few thistles as a trap crop on
which the adults will congregate and where they may be
destroyed.

The NoKTiiKRX Lkak-Footed Plant-Bug

LeptngloftauK nppnsilus Say

From New Jersey to Indiana, Missouri, Oklahoma and
southward, squash, cucund)er, niclDU and tomato are occa-
sionall>' attacked by a leaf-footed ])lant-l)\ig closelx- related to
the species last treated. The northern form is slightly larger

INJURIOUS TO CUCUMBER, SQUASH AND MELON 123

and stouter and the }>and across the front wings is represented
by two small whitish spots. The wild food plants of the insect
have not been accurately determined. The bugs often punc-
ture the fruit of peach, plum, cherry, pear, tomato and cucum-
ber and sometimes attack cotton bolls. They also feed on
the stems of cucumber, squash, cantaloupe, watermelon and
tomato, causing the vines to wilt and die.

The insect hibernates in the adult stage but the bugs do not
appear in the held until late in the season, about the first of
July at Washington. The egg is bronze-brown, about ys i'^ch
in length, cylindrical and flattened at each end. The eggs are
laid end to end in rod-like rows of six to twenty-six, attached
to the stems or along the veins of the leaves. The eggs hatch
in about a week and the yoiuig nymph leaves the egg-shell by
forcing out a circular lid on the side near the end of the egg.
The newly hatched nymi)h is coral-red in color with the legs
nearly black. The basal half of the antennsie is black and the
outer half red. The insect passes through Hve nymphal
stages and becomes adult in twenty-five days to about a month
after hatching. There is only one generation annually so far
as known.

Control.

The nymphs can be killed with "Black Leaf 40" tobacco
extract, 1 part in 500 parts of water to which enough soap has
been added to make a suds. Kerosene emulsion and strong
soap solutions have? also })een suggested for the control of this
pest. In the garden the adults may be han(l-i)i(ked in
the cool of the luorning while the>- are sluggish.

References

TT. 8. Div. Ent. Bull. .33, pp. IS -2.'). 1002.

Forbes, 2.3rd Rcpt. State Enl. 111., pj). 11)7-108. 100.'').

124 MAX UAL OF VEGETABLE-GARDES IK SECTS

The Squasii-Vixk Bohi:u

Melitlia satyriniformis Hiibner

In many localities the squash-vine borer is the most injurious
insect enemy of the squash and pumj)kin. It also attacks
cucumber and melon. It is most destructive to late squashes,
such as Hubbard and Marrowfat. The insect ranges from
Canada, through the states east of the Rocky Mountains south-
ward into South America.

The moths appear in the lields as early as April or May in
Georgia and North Carolina, in early June in New Jersey and
a little later in Connecticut, or at about the time that early
cucurbits have come up. The moth has an expanse of 1 to l:j
inches ; the front wings are opaque, nearly black in color with
metallic greenish reflections in certain lights ; the hind wings
are transparent and scales are present only along the margin
and on the veins. The abdomen is marked with red or orange ;
the hind legs are long and ornamented with tufts of long orange,
black and white hairs. The moths fly in the heat of the day
and when on the wing are often mistaken for wasps. In the
evening they may be seen resting on the leaves of the vines
and are then easily caught. The female moth deposits her
eggs on the stem of the vine near the base, while the plants are
smafl and later at almost any point. The egg is about ^ inch
in length, dull red in color, oval in outline, flattened on the side
of attachment and has an impressed area on the upper side.
Tiie shell is \ery brittle. Each moth is capable of laying over
two hundred eggs, but the average number is probably some-
what less. The eggs hatch in six to fifteen days. The young
caterpillar soon enters the vine and then burrows through the
stem, preferably towards the root but often in the opposite
direction. Later in the season the larvje may be found in all
parts of the istem and even in the leaf petioles and in the fruit.

INJURIOUS TO CUCUMBER, SQUASH AND MELON 125

The young caterpillar differs from the later stages in ha\ing
the head larger in proportion to the body, in being more hairy
and in having the body more tapering behind. When full-
grown, the caterpillar (Fig. 76) is about an inch in length; the
body is white and the head dark brown with an in\'erted \-
shaped white mark. The burrows occupied by the larger larva?
are usually wet, slimy and partly filled with excrement ; decay
often ensues and hastens the death of the vine. The greater
part of the excrement, however, is thrown out of the burrow

Fig. 70. — The squash-vine borer (X l\).

through holes in the stem. These coarse, yellowish grains of
frass collect on the ground under the vine and are usually the
first indication that the plant is infested. The caterpillars
reach maturity in about four weeks in the latitude of Xew
Jersey. When mature the caterpillar leaves the stem, enters
the ground one or two inches and there constructs a tough
silken brownish or blackish cocoon into the outer layers of
which particles of dirt are incorporated. The cocoon is about
f inch in length. After making the cocoons, some of the cater-
pillars soon transform to pupa', while the others remain in the
larval condition until the following s])ring. Those that pupate
soon after spinning the cocoon usually transform to moths

126 MAX UAL OF VFAiET ABLE-GARDEN I \ SECTS

the same season. The dark brown pupa is about f inch in
length ; its head is armed with a sharp horn-Hke process by
means of which it cuts its way out of tlie cocoon. After leav-
ing the cocoon, the pui)a works itseU' up to the surface of the
ground in order to permit tlie escape of the moth. In the
Gulf states the insect has normally two broods ; in the latitude
of Washington the second brood is only j^artial while farther
north, in Xew Jersey and on Long Island, the second brood is
much smaller, and still farther north there is only one genera-
tion annually.

Control.

The squash-vine borer cannot be controlled by applications
of insecticides, but it may be held in check by j^racticing such
of the following methods as are warranted by the severity of
the outbreak or by other local conditions. As the insect j)asses
the winter in the ground, it is not good policy to grow scpiashes
in the same field year after year. If for any reason it is neces-
sary to raise successive crops of squashes on the same ground,
the land should be harrowed in the fall to expose tlie cocoons
and then plowed (leei)ly the following spring. In all cases the
vines should be collected and destroyed as soon as the croj) is
harvested in order to prevent the late caterpillars from reaching
maturity. If all the growers in a locality would co-operate in
the early destruction of the \ines. the nunilxT of moths apjjcar-
ing the following si)ring would i)e greatl\- reduced. In s;)me
cases mucii injury may be avoided by late planting in connection
with heavy fertilization to promote rapid and hea\y growth.
In some localities the use of early sciuashes as a trap crop has
been attended with success. A few early sc|uashes. such as
crooknecks, are plantecl vi\v\y around the field and between the
rows of the late varieties. The moths will dejxjsit their eggs
on the early squashes and the main croj), coming uj) later, will
escape the greater part of the infestation. As soon as the

INJURIOUS TO CUCUMBER, SQUASH AND MELON 127

early s([iiaslu's arc harvested, or sooner if they crowd the main
crop, the vines shonld be pulled up and burned or composted
in order to kill the borers they contain. After the borer has
once entered the vine, there is nothing to he done but to cut it
out with a knife. If care is taken to make the cut lengthwise
of the stem and if the vine is immediately covered with earth
at the injured point, the wound soon heals and the vine con-
tinues its growth. Some growers make a practice of covering
the stem with earth two or three feet from the base in order
t) make the vine throw out a new root system, which will
sustain the plant in case the main stem is injured at the base.
In s;)me cases it would pay to keep a sharp lookout for the
•moths in the evening when they are resting on the vines. They
are easily seen and are not difficult to capture. For every
female killed before she has deposited her eggs, there will be
from one to two hundred less eggs laid on the vines.

References

N. J. Affr. Exp. Sta. Bull. 94, pp. 27-40. 189.3.
U. S. Div. Ent. Bull. 19, pp. 34-40. 1899.
U. S. Farm. Bull. ()()8. lOl.'j.

The Pickle ^Y()R^r

Didphania tiiiidnliti Stoll

The pickle worm and its near relative the melon worm are a
serious drawback to th(> ])rofitable growing of cantaloupes,
squashes and cucumbers throughout tlu> southern states. In
some years the former ap])ears in destructive numbers as far
north as New York and Michigan and the moths have been
taken in Canada. The insect ranges southward through the
West Indies into South America. As far as known, its food
j)lants are all members of the gourd family : cantalouiH', cucum-

128 MAXCAL OF VEGETABLE-GARDEX IX SECTS

1 \:2

hvv and s([ums1i. It lias hvvw tv\m)vXv{\ as attackiii;; the water-
melon in (ieorj^Ma; tin- ])urnpkin is said to hv ininunu'.

The i)ickle worm hibernates in the \)\\\)\\\ sta^e in a flimsy
cocoon in a curled leaf of the food i)]ant usually lyin<j; on the
ground. The moths do not emerj^e until rather late; the early
part of June in Georgia and North Carolina. The moth (Fig.
77) has an expanse of 1 to 1^ inches; the general color of the
wings is yellowish brown with a j)ur])lish metallic reflection in
certain lights; a large irregular sj)()t on the front wing and
the basal two thirds of the hind wings are semi-transj)arent

yellow. In both sexes
the tip of the abdomen
is ornamented with a,
brush of long .scales,
larger in the male. The
moths do not fly during
the day or in the early
part of the night ; they
are acti\e and deposit
their eggs after mid-
night and go into hid-
ing at daylight. The
egg is about -^V i'K'h in length, nuich flattened and ellijjtical
in outline. It is nearly white when first laid but soon
becomes yellowish. The eggs are deposited singly or in
masses of three to eight on the flowers, flower-buds or on
the tender opening leaves at the end of the \ines. They are
loosely attached to the ])lant-hairs and can be easily brushed
off. They hatch in three or four days and the young cater-
l)illars soon burrow into the tender tissue of the blossom or
bud. The greater number do not reach the fruit until after
the first or second molt. On scjuash many complete their
growth within the blossoms, but on cantahmpes and cucum-
bers the caterpillars that arc feeding in the blossom buds usually

Fir,. 77. — TIk' pickk- worm moth ( X 2).

INJURIOUS TO CUCUMBER, SQUASH AND MELON 129

migrate to the fruit when about half grown. Many of those
that start feeding on the chister of terminal buds burrow down
into the stem and complete their growth there ; some are found
in the leaf petioles. The vines are often riddled in this way
but the greatest injury is caused by the burrows made in the
fruit. On reaching the fruit, some of the caterpillars feed for
a time in the rind while others burrow directly to the center.
While the caterpillar is near the surface, the excrement is thrown
out of the opening ; later it is left in the burrow. The cater-
pillars often leave one fruit and enter a second or third and
may even migrate to another vine. In the case of cantaloupes
and squashes, decay is almost certain to result whenever a
caterpillar has gnawed through the rind, thus greatly increasing
the loss.

The newly hatched larva is about ^t inch in length and
yellowish white in color. After a short time a transverse row
of brownish or blackish spots becomes apparent on each seg-
ment. These spots become more distinct with successive molts
and persist until the fourth, when they are lost. In the fifth
and last stage the caterpillar is about f inch in length, the head
and thoracic shield are yellowish brown and the body is whitish,
yellowish or greenish, depending on the nature of the food.
Most of the caterpillars take on a dull coppery color above soon
after the fourth molt. The caterpillar becomes mature in
twelve to sixteen days after hatching. It then spins a loose
silken cocoon, usually in a curled leaf, and after resting for
about a day transforms into a pale green pupa, ^ to nearly f
inch in length, which after a short time changes to brownish.
The head of the pupa is bluntly pointed and the caudal end is
acute and armed with a group of short hooked spines. In the
summer the duration of the pupal stage is a week to ten days.
The time required for the complete life cycle of the insect as
<letermined in North Carolina varies from twenty-three to
thirty-Dne days. In North Carolina there are four generations

130 MANUAL OF VEGETABLE-GARDEX IXSECTS

annually with sometimes a partial fifth when the fall is warm.
The first generation is always small in numbers and is usually
entirely oNerlooked. In the second and third generations the
caterpillars become very numerous and the loss is correspond-
ingly great. Cantaloupes harvested before the appearance of
the second brood of caterpillars usually escape injury, while
those that mature later are often entirely destroyed.

Control.

Attempts to control the pickle worm by spraying with arseni-
cals have been unsuccessful. The caterpillars feed very little
in the open and, therefore, do not eat enough of the poison to
be killed. The number of moths appearing the following season
can be considerably lessened by collecting and destroying the
vines as soon as the crop is harvested. The waste fruits and
fallen leaves should be raked up and destroyed with the vines
either by burning or by turning them into compost. Early
fall plowing of infested fields will also destroy a large j)ropor-
tion of the larvae and pupfe. Rotation of crops and planting
cucurbits at a distance from fields infested the previous season
does not give as much relief as would be expected, because the
moths are able to fly a considerable distance in search of plants
on which to deposit their eggs. By planting the crop early,
much injury may be avoided and this method should hv ad()i)ted
whenever practicable.

In the case of cantaloupes, excellent results in protecting
the crop have been obtained by planting s(juashes as traps
throughout the field. Squash vines with their large and odor-
ous flowers are more attractive to the moths than other cucur-
bits. If enough squash vines are present in a field, the moths
will deposit nearly all of their eggs on them and the canta-
loupes will escape. For this purpose the squashes should be
planted at intervals of about two weeks so as to furnish an
abundance of buds and blossoms during July and .\ugust.

INJURIOUS TO CUCUMBER, SQUASH AND MELON 131

The earlier squash vines should be remo\ed and destroyed
before many worms have reached maturity on them. The
use of squashes as trap crops seems to be the most practicable
way of preventing injury to cantaloupes in many parts of the
South.

References

Ga. Agr. Exp. Sta. Bull. .54. 1901.

N. C. Agr. E.xp. Sta. Bull. 214, pp. lOG-126.

1911.

The INIelon Worm

Diaphania hijalinafa Linnaeus

The melon worm is occasionally found as far north as Xew
York, southern Canada and Michigan but causes little or no
injury north of North
Carolina. In the south-
ern states, it is a serious
pest of cantaloupe,
squash, cucumber and
pumpkin and has been
known to injure water-
melon.

The insect passes the
winter as pupa' in loose
silken cocoons in the
(lead leaves or under the
shelter of any convenient rubbish. The moths do not emerge
until rather late in the season, in June or July in North
Carolina. The moth (Fig. 7(S) has an expanse of less than
an inch to 1| inches. The wings are pearly white with a
broad shining, iridescent brown band along the front and
outer margins. The head and front part of the thorax
are brown. The body is silvery white and the tip of

Fi<;. 78. — The molori worm moth ( X 2).

132 MAXCAL OF VEGETABLE-GARDES LX SECTS

the al)fl(»men bears a conspicuous brush of elonrjate scales,
yellowish at the base and white, brown or black at the tip.
The eggs are laid on the buds, young leaves, stems and some-
times on the main stalk of the vine, singly or in groups of two
to six, sometimes overlapping. The egg is oval, about ^V i"t'h
in length, flattened and pearly white when first deposited but
soon acquiring a yellowish tinge. The eggs hatch in three or
four days in warm weather and the larvje begin feeding on the
underside of the leaves or among the buds and sometimes bore
into the latter. The newly hatched larva is about tt^ inch in
length, light straw-color with the head light brown. The two
light stripes do not become apparent until after the first molt.
In the second stage the color becomes yellowish or greenish
from the ingested food. In the third stage the two white sub-
dorsal stripes become more prominent and serve to distinguish
the caterpillar from the pickle worm, in which they are not
present. In the fifth and last stage the larva is f to \\ inches in
length and mottled greenish yellow in color. Shortly before
puliation, the larva contracts to about f inch in length and
changes to a light yellow or straw-color, the white stripes hav-
ing disappeared some days earlier. The caterpillars become
mature in about two weeks and spin loose silken cocoons usually
in a folded or rolled leaf in which they transform to browni.sh
pupve about f inch in length. The moths emerge in a week or
ten days. The life cycle requires a little less than a month in
the summer in North Carolina. The first brood of caterpillars
feeds to a considerable extent on the foliage and usually does
not cause much injury to the fruit. The larvjF of the later
generations at first feed on the buds or foliage and do not attack
the fruit until the third stage. On reaching the fruit, they may
feed for some time on the surface but soon burrow through the
rind causing decay. In Xorth Carolina there are three genera-
tions annually, the second, beginning the latter part of July,
being the most destructive.

INJURIOUS TO CUCUMBER, SQUASH AND MELON 133

Control.

Cantaloupes and cucumbers may be protected from the melon
worm by using summer squashes for a trap crop as recom-
mended for the pickle worm. As the young caterpillars feed
to a considerable extent on the foliage and on the surface of
the fruit, many of them may be killed by spraying with arsenate
of lead (paste), 3 pounds in 50 gallons of water. Usually the
arsenate of lead can be applied to the greatest advantage in
combination with bordeaux mixture as used for the control of
fungous diseases. As soon as -the crop is harvested, the vines
and waste fruits should be gathered up and destroyed. Deep
plowing and a rotation of crops will also tend to hold the in-
sect in check.

Reference
N. C. Agr. Exp. Sta. Bull. 214, pp. 12G-143. 1911.

The Squash Ladybird

Epilnchna horealis Fabrieius

Nearly all the ladybird beetles are beneficial to man, feed-
ing, both as larva" and adults, on plant-lice, scale-insects and
other small insects or on the eggs of larger ones. The squash
ladybird, however, is an exception to the rule ; both beetles
and larvje feed on the leaves of squash, pumpkin, cantaloupe,
watermelon and cucumber. The insect is a native of America
and ranges through the United States east of the Rockies and
southward to Argentina. Besides the plants just mentioned,
it feeds on the prickly cucumber or wild balsam apple and on
the one-seeded bur-cucumber. While capable of causing seri-
ous injury to cucurbits, the insect is rarely abundant enough
to become of economic importance.

The squash ladybird hibernates in the adult condition in
sheltered places, often in large colonies. The beetles emerge

134

MAXl'AL OF VECETABLE-CARDEX IX SECTS

al)()ut the middle of June in New Jersey. They are 3 inch in
lenjith, hemispliericid in form and dull yellowish in color.
The thorax has four small black spots and the wing-covers
have twelve large spots arranged in three transverse rows
(Fig. 79). The yellow, elongate, subcylindrical eggs, yV inch in
length, are deposited in clusters of six to more than fifty. They
hatch in about a week. The larva is yellow in color and armed
with six rows of long branched spines; when mature it meas-
ures about J inch in length. The larvtie feed generally on the
underside of the leaves, eating off the surface in circular clearly
defined areas. They become mature in
about three weeks and then crawl to
the upper surface of the leaf where
they transform to pupir. The pupa is
about I- inch in length, yellow in color
and covered with short simple black
spines most abundant on the head,
thorax and appendages. It is attached
to the leaf by the posterior end of the
])ody. The pupal stage lasts from six
to nine days. The beetles appear from
the latter i)art of July throughout the remainder of the
season. Tliere is only one generation annually.

Control.

The squash ladybird is usually ])resent only in small num-
bers ; in such cases haii(l-])icking will be the easiest and cheapest
method of control. When more abundant, it would be better
to spray the vines with arsenate of lead (paste), 2 to 2.V pounds
in !"•){) gallons of water.

Fk;. 7'.). — The siiua.sh
ladybird (X 3).

Reference
U. S. Div. Ent. Bull. l'.», pp. 11-20. 1899.

INJURIOUS TO CUCUMBER, SQUASH AND MELON 135
The Melon Aphis

Aphis gossypii Glover

This insect is also known as the cucumber aphis, cantaloupe
aphis, cotton aphis and orange aphis. When occurring in green-
houses, it is known to gardeners as black aphis or black fly.
It is widely distributed throughout the United States but has
been reported as a serious enemy of cucurbits from Minnesota
to Xew Jersey and southward. Its range extends to Brazil.
It has attracted most attention in those localities where melons
or cucumbers are grow^n on a large scale and in such cases the
losses are often very great. It sometimes becomes of con-
siderable importance as a cotton pest. The melon aphis has a
wide range of wild food plants, including many common weeds
and is occasionally found on a number of culti\'ated plants,
such as spinach, okra, tomato, asparagus, eggplant, hop,
morning-glory, bean and beet.

The life history of the melon aphis has not been fully worked
out and there is considerable difference of opinion as to how
the insect passes the winter. It has been commonly supposed
that winter eggs are produced in the fall and deposited on
some food plant that will survive the winter. In fact eggs
found on portulaca and strawberry have been described as
belonging to this species. Great doubt has been cast on this
view by the studies of Sanborn, who has shown that in Okla-
homa the insect is unable to sur\'i\e the winter in the open,
and that each year it migrates northward from southern Texas,
where it breeds continuously the year round. If it is true that
the melon aphis does not winter over in the northern ])art
of its range and that the infestation is annually renewed by
migrants from the South, its habits in this respect are \ery
similar to those of the famous green-bug of wheat, Toxoptera
graiiihunn.

13G MANUAL OF VEGETABLE-GARDEN INSECTS

The date at which the melon apliis makes its first appear-
ance on cucurbits \aries considerably from year to year, but
in the northern part of its range it is usually rather late in the
season. Winged females fly or are })lo\vn into the field and,
alighting on a vine, crawl to the underside of a leaf and begin
feeding on the juices of the plant, which are extracted by means
of the insect's beak. The female begins to give birth to li\ing
youngat the rate of four or fi\e each day and is soon surrounded
by a numerous colony of young lice. When about six days old,
these in turn reach maturity and begin to produce young.
After remaining on one leaf two or three days, the female may
move to another and found a new colony. The feeding of the
lice causes the leaves to curl downward, turn brown, shrivel
and die. When food becomes scarce, many of the wingless lice
crawl to the tender leaves towards the end of the vine ; these
in time succumb to the attack and the \inc is finally killed or
stunted so that the crop is small and of inferior quality. A
large proportion of the lice of each generation acquire wings
while the others remain wingless. The former fly to other

vines and start new colonies
of aphids. In this way the
whole field soon becomes
infested and unless the
aphids arc checked by the
attacks of their numerous
insect enemies or killed by
artificial means, the crop is
sure to be destroyed.

The wingless female is
about ^ inch in length, varying in color from yellow to green
or black, the eyes are brown and the cornicles black. In the
winged female (Fig. 80) the head and the greater ])art of the
thorax are black with the abdomen \ar\ing from yellow to
dark green. Breeding continues until frost. Males and egg-

FiG. 80. — Winged viviparous female
melon aphis (X 10).

INJURIOUS TO CUCUMBER, SQUASH AND MELON 137

producing females — the so-called true sexes — have not been
observed.

The melon aphis is held in check by the attacks of a large
series of predaceous and parasitic insect enemies, most im-
pt)rtant of which are several species of ladybird beetles, syrphus
fly larvffi, aphis lions and several species of parasites belonging
to the family Braconidfe. Under favorable weather conditions,
these foes of the melon aphis are able to keep it so well under
control that little or no damage is done. In cool, moist weather,
however, following a backward spring, the activities of these
beneficial insects are retarded and as the aphis is able to breed
rapidly under such conditions, the infestation becomes severe
and it is not till late in the season that the enemies of the aphis
regain their supremacy. Many of these enemies feed on other
kinds of aphids having different food plants and it has been
suggested by Sanborn that it might be a useful practice to
plant cabbage early around fields intended for cucurbits.
The cabbage plants soon become infested with the cabbage
aphis which furnish food for great numbers of predaceous and
parasitic insects. At the first appearance of the melon aphis
in the field, they will be on hand in sufficient abundance to
hold the pest in check.

Control.

The melon aphis usually makes its appearance in a field on
isolated vines scattered throughout the patch. It is important
that a close watch should be kept in order to locate and destroy
these first colonics. Growers sometimes pull up and bury the
vines first attacked. While the vines are small, it is possible
to kill the aphids by fumigation with tobacco or carbon bisulfid.
For this purpose portable covers are used made of oiled cloth
stretched over a light wooden frame. The cover is placed
over the vine and the t()l)acco fumes generated by burning
strips of paper inii)rcgiiated with nicotine. In case carbon

138 MAXCAL OF VEGETABLE-GARDES INSECTS

bisulfid is used, the liquid is placed in a shallow dish under the
cover and allowed to evaporate. About a teaspoonful is suffi-
cient for one cubic foot of space. The cover should be made to
fit tifjhtly to the ground to prevent the escape of the gas. The
fumigation method is of most value when only a small number
of vines are to be treated and when the aphids make their
appearance before the vines have begun to run so as to cover
much space. In large fields, spraying is more practicable and
more likely to give satisfactory results. For successful spray-
ing it is necessary that the vines be trained to run in the rows;
this also makes the cultivation easier. When the vines arc
trained in this way, it is not difficult to kill nearly all the
aphids b_\- using "Black Leaf 40" tobacco extract, f {)int in
100 gallons of water in which 5 or G pounds of soap have been
dissolved. The spraying should be done as soon as the lice
appear. A fine nozzle should be used, which, with good pres-
sure, will produce a fine mist. It is important that the s])ray
hit the underside of the leaves. This can be accomplished by
-using an upturned angle nozzle on a short extension rod. By
doing careful and thorough work, it is possible to hit the under-
side of practically every leaf. In case the infestation has be-
come severe, it may sometimes be advisable to use a stronger
solution of the tobacco extract, 1 pint of "Black Leaf 40" to
100 gallons of water. Much stronger mixtures will not injure
the foliage but are unnecessary and rather expensive. This
method of fighting the melon aphis has proved practicable
under conunercial conditions.

References

Perpande. Tnsoft Lifo. VII. ])p. :i00-31.'). 1S9.").
Tox. Aprr. Exp. Sta. Bull. SU. ]^]). y.i~H\. VMM.
U. S. Bur. Ent. Circ. SO. I'.KMi.
Okla. Akt. E.xp. Sta. Bull. !»S. 1«H2.
111. A^T. Exp. Sta. Bull. 171. HU 4.

INJURIOUS TO CUCUMBER, SQUASH AND MELON 139
The Squash Aphis

Macrosiyhum cucurhitw Middleton

Squash and pumpkin are sometimes found infested by a
green plant-louse about yV inch in length. The body of the
winged form is green with the thorax tinged with brownish and
the abdomen has a median line of darker green. In the wing-
less form the body is green with few markings. This species
has been reported as injurious in Connecticut, Ohio and Illi-
nois and as infesting eggplant in Florida. Fortunately, it does
not, as a rule, become abundant on the vines until late in the
season when the crop is nearly matured. Its wdld food plants
include shepherd's purse, wild mustard and ground ivy. The
aphids multiply parthenogenetically throughout the summer,
both winged and wingless females being present. INIales and
egg-laying females are produced only in the fall. The ovip-
arous female is wingless with the body green. The antennae,
except the first tW'O joints, and the tip of the cornicles are
black. The males are smaller than the females with the body
black and the margin of the abdomen greenish. The antennae
are black, dark l)rown at the base. The winter is passed in the
egg stage.

The squash aphis can be controlled by the measures sug-
gested for the melon aphis.

The Gakden Sprixgtail

Sminthurus horlensi^ Fiteh

Many garden plants are subject to injury soon after they
come up by a minute wingless insect that eats out very small
holes in the epidermis of the leaves and enlarges the wounds
made by other insects. The insect is about 7>V inch in length,
dark purple in color spotted with pale yellow. The head is

140 MAXI'AL OF VECETABLE-GARDEX IXSECTS

large, separated by a narrow neck from the nearly ijlohular
united thorax and al)donien. At the tip of the hitter there is
a forked, tail-Hke appendage whieh when at rest is held elose
to the underside of the body and by means of whieh the insect
is al)le to throw itself into the air. This habit has suggested
the name of garden flea for these insects.

The garden springtail has a wide range, ha\ing been reported
from the northern United States, Europe, Jajjan and subant-
arctic America. It has been reported as injurious in Maine,
Massachusetts, New York, Indiana and ^'irginia. It attacks
cucumber, squash, watermelon, cantaloupe, lettuce, bean,
pea, cabbage, radish, turnip, kale, onion, beet, spinach, carrot,
potato, tomato and tobacco and has alsp been found infesting
wheat, rye and clover. The insects appear in great numbers
just as the {)lants are coming up and so injure the leaves as
either to stunt or kill the seedlings, "^riic insects disappear in
two or three weeks, practically all of the injury being done by
the time the second or third true lea\es aj)pear. The life history
of this springtail does not appear to have been worked out.

Injury to seedlings by springtails may be prevented by dust-
ing them with tobacco dust or air-slaked lime when they first
come up and again in about a week if the insects are still present.
The plants may be assisted to outgrow the injury by the appli-
cation of a quick-acting fertilizer and by thorough early culti-
vation.

Reference

Fitch, 8th Rept. State Ent. X. Y. for 180.3, pp. l.Sr)-101 in 7th to 0th
Rept.s. I8(w.

Other Cucumber, Squash and Melon Insects

Corn ear-womi : 211
Southfrn forn root-worm : 222
Western corn root-worm : 22.'>
Stink-lniKs: 2:^2
Garden webworm : IS

INJURIOUS TO CUCUMBER, SQUASH AND MELON 141

Serpentine leaf-miner : 46
Yellow bear caterpillar : 357
Tarnished plant-bug : 192
Sugar-beet webworm : 97
Spinach aphis : 105
Grape colaspis : 67
Garden flea-hopper : 77
Well-marked cutworm : 263
Greasy cutworm : 265
Striped cutworm : 270
Dingy cutworm : 271
Variegated cutworm : 276
Spotted-legged cutworm : 282
Army-worm : 288
Fall army-worm : 292
Yellow-striped army-worm : 295
Striped blister-beetle : 302
Margined blister-beetle : 305
Potato flea-beetle : 314
Tobacco flea-beetle : 319
Pale-striped flea-beetle : 321
Larger striped flea-beetle : 332
Hop flea-beetle : 335
Root-knot nematode : 338
Millipedes: 342
Wheat wireworm : 348
Red-spider : 351
Corn and cotton wireworm : 349

CIIAPTEPi VI
POTATO INSECTS

The potato plant is a native of America and the insects
affecting it are, with few exceptions, indigenous to the New
World. In the East the most important potato insects are
the Colorado potato beetle and the potato flea-beetle. The
latter is treated on page 314. In California the potato tuber
moth has in some localities threatened the i)otato-gr(>wing
industry. Potatoes are especially subject to attack by blister-
beetles. These pests are discussed in Chapter XVI.

The Colorado Potato Beetle

Leptinntarsa decemlineata Say

The genus to wiiich the Colorado ])otato beetle belongs
occurs in greatest abundance in southern Mexico and Central
America and it is supposed that this species originated in that
region wiiere it is now represented by closely related forms.
It had, however, migrated northward so that by the early
part of the last century it occupied a strip on the eastern .slope
of the Rocky Mountains from Texas and New Mexico north-
ward to the Canadian boundary. The potato beetle was first
described by Thomas Say in 1.S24 from specimens collected
in tile ui)i)er Missouri Uiver Valley. The original food plant
of the insect was the buffalo bur, Solanwn rostratiim. When
the early settlers first began to plant pf)tatoes in western

142

POTATO INSECTS 143

Nebraska, the beetles cliscovered in this new plant a food
greatly to their liking. In 1S59 the beetles were feeding on
potato about one hundred miles west of Omaha in Nebraska.
This marks the beginning of the rapid and destructive eastern
spread of the species. The INIissouri River was crossed about
1861 and the Mississippi by 1864. The main line of advance
continued around the south shore of Lake Michigan, across
Illinois, Indiana and Ohio, down through the natural highway
of the lower Great Lakes through Ontario to the Province of
Quebec and through Pennsylvania and New York and into
New England. The Atlantic Coast was reached in 1874.
In the early part of this great migration, the beetles averaged
less than fifty miles a year, but after crossing the IVIississippi
River the yearly advance was considerably greater and the
whole distance was covered at an average rate of about eighty-
eight miles a year.

It is now difficult to realize the apprehension with which
the farmers viewed the coming of the potato beetle. Spray-
ing was then unknown and arsenical poisons had not yet been
used for the control of injurious insects. Although the value
of paris green for the destruction of this pest was demonstrated
in 1869, suitable apparatus for its application was not to be
obtained. The first dusting and spraying machines were
crude, clumsy and generally inefficient. If one considers the
enormous hordes in which the beetles appeared and the com-
pleteness with which they defoliated the plants in the newly
infested areas, some idea can be gained of the serious situation
that confronted the potato-growers of this period.

In the newly occupied territory the beetles found few of
their natural enemies and, therefore, for a time multiplied
unchecked. In their eastward advance they moved through
a region which was thickly settled, where their food was grown
in great abundance and in a climate to which they easily
adapted themselves. They were aided in their rapid advance

144 MAXUAL OF VEGETABLE-GARDEX IXSECTS

In- the prevailing west and southwest winds during the season
when the beetles were on the wing. The rapid spread of the
Colorado j)()tato beetle across the eastern I'nited States has
luul no equal in historic times, except possibly in the case of

I'lC. si. — Knupluiit killed by the Colorado potato IktI!

the recent advance of the cotton boU-wecvil through the cotton
belt of the southern states.

After reaching the Atlantic Coast in 1874, the potato beetle
gradually extended its range southward east of the Appa-
lachian Mountains, but northern Florida was not invaded
until ai)out 11)00. The advance down the Mississippi Valley

POTATO INSECTS

145

had also been slow and the beetles did not appear in central
Louisiana until about the same date. The potato beetle is
now generally distributed east of the Rocky Mountains from
Montana to New Brunswick and Nova Scotia and southward
to northern Florida. It also occurs in New Mexico and Ari-
zona and in Idaho, Washington and Alberta. Where the
potato is not available for food, the beetles will sometimes
attack eggplant (Fig. 81), tomato, pepper and even tobacco.
Ground cherry, thorn apple, henbane, Jamestown weed, horse
nettle, belladonna and petunia also serve to carry the beetles
through periods of scarcity.

The potato beetle hibernates as an adult sometimes under
rubbish but more frequently in the soil at a depth of several
inches. The beetles emerge
from their winter quarters in
the spring just before early
planted potatoes come up.
At this time they will feed on
pieces of seed potatoes left on
the surface and will some-
times dig into the soil in
search of the tender sprouts.
They feed for a time on the
tender foliage and then, after

pairing, deposit their eggs on end in masses on the under-
side of the leaves (Fig. 82). Each mass contains from four
or five to nearly seventy eggs with an average of about twenty-
five. The egg is about yt i'^^'li in length, elongate oval and
orange in color, with the surface smooth and shining. The
egg is glued to the leaf with a small mass of orange-colored
material. The female is capable of laying from 200 to over
1800 eggs with a probable average of 400 or 500. The eggs
do not ripen continuously but in successive batches ; all the
eggs which ripen at a given time may be deposited in one or

Fig. 82. — The Colorado potato beetle,
CKgs and newly hatched larvae
(enlarged).

146 MANUAL OF VECET ABLE-GARDEX IXSECTS

more clusters. The average length of the egg-laying period
in the field is j)r()hal)ly In'twecn four and six weeks, but under

cage conditions
the beetles have
continued to lay
eggs for ten weeks
or more. The
eggs hatch in four
to nine days. On
hatching, the
young larva be-
gins at once to
feed on the leaves.
In the first stage
it is about ^ inch
in length, dark
red in color with
the head, thoracic
shield and legs black and witli a double row of black spots
along each side of the body. In the course of its development
the larva passes througii three or
four stages according to different
observers. In the last stage it is
about % inch in length ; the head,
legs and posterior part of the cervi-
cal .shield are black ; the body is
red, lighter than in the first stage
and there are two rows of distinct
black spots on each side ; the ab-
domen is strongly convex and is
nuich larger than the head and
thorax (Fig. 83). The larvie be-
come full-grown in ten days to three wc(>ks and then enter
the ground to a depth of several inches where they transform

Fig. 83. — Larvae of the Colorado potato beetle ( X

I I .. ^ 1. Pupa of the Colo-
rado |)otato beetle (X 4).

POTATO INSECTS

147

in earthen cells to pupae. The pupa is a little over ^ inch in
length and orange-yellow in color (Fig. 84). After a pupal
period of five to ten days the adults emerge. The beetle is
about f inch in length, strongly convex above and yellow in
color. The head has a triangular black spot between the
eyes ; the prothorax is marked with two divergent elongate
black spots near the middle and four to six smaller spots on
each side. Each wing-cover has the sutural margin and five
narrow stripes black, the second and third united at the tip ;
the knees and tarsi are blackish (Fig. 85). The beetles are
often called hard-shells to distinguish them from the larvse,
which are known as slugs or soft-shells.
After feeding a few days, the beetles may
either go into the ground for a more or
less extended period of aestivation or they
may immediately lay eggs for a second
generation. Owing to the long period
over which egg-laying takes place, all
stages of the insect may be found at any
time during the latter part of the summer.
There are normally two generations pro-
duced annually but in some cases a small

third brood of larva? may develop and in IMontana it is
claimed that there is only one generation.

Control.

For many years paris green has been the standard insecti-
cide for the control of the Colorado potato beetle. It is some-
times applied in the form of a dust, 1 pound in 50 pounds of
land plaster or hydrated lime. It is more effective, however,
when applied in water, 1 pound in 50 gallons. To avoid burn-
ing the foliage, 2 pounds of lime should be added. Paris green
is most effective and least liable to injure the vines when ap-
plied with bordeaux mixture as used for the control of fungous

Fig. 85. — The Colorado
potato beetle (X 2|).

148 MAXUAL OF VEGETABLE-GARDEN INSECTS

diseases. From 8 ounces to 1 jxjuikI should l)c added to each
50 gallons, depending on the thoroughness of the application.
Arsenate of lead, 3 or 4 pounds of the paste to 50 gallons, has
also been found satisfactory. It adheres to the foliage better
than paris green but does not kill the insects so quickly. It
may be used either in water or in bordeaux mixture. Arsenate
of lead may also be applied in the dry or powdered form diluted
with sulfur, gypsum or hydrated lime. Experiments in New
Jersey, however, have shown that, on the whole, this treatment
does not give as good results in yield as are obtained by spray-
ing with bordeaux and arsenate of lead. AVhen expense is an
important item, sodium arsenite may be used instead of paris
green or arsenate of lead with satisfactory results, at the rate •
of 1 (piart of the stock solution to 50 gallons of bordeaux mix-
ture. P'or the preparation of sodium arsenite see page 309.

The first application for the potato beetle should be made
about the time the eggs are hatching. The larva? are much
harder to kill when nearly full-grown and they have then
caused the greater part of the damage. It sometimes happens
that the eggs are deposited in ])atches in the field so that the
infestation is not general. In such cases it is a good plan to
treat these areas early and not wait till the whole field can be
spra>ed. In Virginia, where potatoes are seriously injured
by the over-wintered beetles, just as the j^lants are peeping
through the ground, it is recommended that they be dusted
with a mixture consisting of 1 pound of paris green and 20 to
30 pounds of hydrated lime. This application is intended to
protect the plants until they are large enough to be sprayed.

In the home garden where only a few ])otatoes are grown,
it is practical)le to han(l-])ick tlu- beetles into pans containing
a little kerosene oil or the ])lants may be dusted with paris
green or powdered arsenate of lead diluted with land plaster,
hydrated lime or some similar substance.

For the protection of tomato plants, arsenate of lead should

POTATO INSECTS

149

be used instead of paris green because of the danger of foliage
injury by the latter.

References

Riley, Potato pests, N. Y. 1876.

Tower, An investigation of evolution in Chrysomelid beetles of the

genus Leptinotarsa. Washington. 190G.
U. S. Bur. Ent. Circ. 87. 1907.

Girault and Rosenfeld, Psyche, 14, pp. 4.'>-.57. 1907.
Girault, Ann. Ent. Soe. Am., 1, pp. 15.5-178. 1908.
U. S. Bur. Ent. Bull. 82, pp. 1-8. 1909.
Girault and Zetek, Ann. Ent. Soc. Am., 4, pp. 71-83. 1911.
Va. Truck Exp. Sta. Bull. 14. 1915.
Johnson and Ballinger, Jour. Agr. Research, 5, pp. 917-925. 1916.

The Three-Lined Potato Beetle

Lema trilineata Olivier

Throughout the United States and Canada east of the Rocky
Mountains, potatoes and tomatoes are sometimes attacked
by the larvae of a yellowish leaf-
beetle (Fig. 86) about \ inch in
length. The head and thorax are
reddish yellow, the latter constricted
at the middle and usually marked
with two black spots. The wing-
covers are reddish yellow and marked
with three black stripes. The an-
teiuuB are black, except the base,
and the legs are reddish yellow
with the outer half of the tibiai
and tarsi black. A closely related
species, Lema n'ujrociitdta (luerin-
Meneville, occurs in California; by
some it is considered identical with the eastern s{)ecies.

The thr(>e-lined potato beetle i)r()babjy hibernates in the
adult condition, the beetles appearing in early spring. They

Fic!. 86. — The three-lined
potato beetle (X 3-^).

150 MANUAL OF VEGETABLE-GARDEN INSECTS

feed at first on various wild i)laiits, preferriiifj solanaceous
weeds. As soon as potato and tomato plants are available,
the beetles migrate to them and deposit their eggs usually on
the underside of the lea\es in clusters of six to ten. Each
egg is about ^ inch in length, smooth, oval and yellowish
in color. The eggs hatch in about two weeks and the young
larvai at first feed in a row side by side, beginning at the edge
of the leaf and moving backward as they devour the tissue.
When mature the larva is about ^ inch in length with the head,
thoracic shield and legs black and the body yellowish. The
body of the larva is kept moist and sticky by a secretion and
is usually covered with a coating of excrement. The grubs
become full-grown in about two weeks and then enter the ground
where they construct earthen cells lined with a gelatinous
secretion from the mouth. The ])ui)al period occupies about
two weeks. There are said to be two generations aimually.
The three-lined potato beetle has never been reported as
a very important pest but it may occasionally become trouble-
some when conditions are favorable for its dcvelo])ment. It
ma\" be controlled by s])ra\ing with arsenical poisons as recom-
mended for the Colorado ])otato beetle.

Referexce.s

Harris, Insects injurious to vegetation, pp. O.'')-^!). 1S41.
Fiteh, 10th Rept. N. Y. State Ent., X. Y. State Afjr. Soe., 24. pp. 441-
447. 1864.

The Potato Aphis

Macrosii>hum snlnnifolii Ashmoad

Although the ])otato ai)his is generally distributed through-
out the I'nited .States and southern Canada, injurious out-
breaks have been reported onl\- from Maine, Connecticut,
Xew York, New Jersey, Pennsylvania. Ohio, Illinois, Iowa,
Kentucky, Maryland and \'irginia and the j)rovinces of Ontario,

POTATO INSECTS

151

Quebec and Prince Edward Island. While the insect is doubt-
less present in small numbers each year in these states, it has
appeared in destructive abundance only at intervals of several
years. This plant-louse is not confined to potatoes but also
injures tomato, eggplant, pea, turnip, beet, spinach, pepper,
asparagus, sunflower and sweet potato and has been found
infesting various weeds such as ground cherry, Jamestown
weed, ragweed, lamb's quarters and wild lettuce. It is also
found on canna, hollyhock, gladiolus, iris and matrimony vine.
It was originally described from specimens collected on the
pepper-vine, Solanum jasminoidcs, in Florida.

The potato aphis passes the winter in the form of shining
brownish black eggs on the rose and possibly on other peren-
nials. The eggs hatch about the time the leaf-buds are opening
and the young aphids reach maturity on this plant. Probably
in the second or third generation, most of the aphids migrate
to the potato and other herbaceous food plants. Throughout
the entire growing season, only female aphids are produced
and these give birth to li^•ing young. Both winged and wing-
less females occur through-
out the season. In warm
weather a female reaches
maturity in ten days to
two weeks and may give
birth to more than fifty
young over a period of
about fourteen da^'s. The
adult winged viviparous
female is about |- inch,
and the wingless form
about ^ inch in length (Figs. 87 and 8<S)
usually green
closelv

Fifi. 87. — The winged viviparous female
potato aphis ( X 5) .

Both forms are
)ut pink individuals are common. The ])otato
aphis closely resembles the pea aphis but may be dis-
tinguished under the microscope by having the tip of the

152 MANUAL OF VEGET AHLE-CARDES IS SECTS

cornicles reticulate for a short distance instead of being im-
bricated throujjhout. At the approach of cold weather,
the winged forms migrate to the rose and there prochice a
generation of winged males and wingless egg-laying females.
In Maine the winter eggs are laid in late September.

Fig. 88. — The winRless vivijjarous female potato aphis ( X 7}).

The time at which the pest becomes destructive to potatoes
varies from year to year. In Maine it has been found most
abundant in August, but in 1917, when the outbreak was the
most extensive and destructive st) far recorded, the attack be-
came serious in New York in early July and in Ohio in late
June. On potatoes the aphids cluster on the underside of the
leaves, causing them to curl downward. They also infest
the tender tips and the blossom stems. When badly infested,
the vines soon become covered with the sticky honey dew
secreted by the aphids. The tips are first killed, and in 1917
many large fields were obserxctl in which all the j)lants were
killed to the ground. Vavu when tlic \in('s arc only partly
killed, the size and cpialitN- of the crop is seriously affected.
On tomatoes the lice also infest the leaves but cause their
greatest injury by attacking the blossom stems and young

POTATO INSECTS 153

fruits. The blossoms are killed, the fruit is dwarfed and the
ripening period is delayed so that in many cases the crop is a
total loss.

Control.

The potato aphis can be killed by spraying with "Black
Leaf 40" tobacco extract, ^ pint in 50 gallons of bordeaux
mixture. If for any reason bordeaux mixture is not used, the
"Black Leaf 40" may be diluted with water at the same rate
but in this case 3 or 4 pounds of soap should be added to each
50 gallons. Since many of the aphids are on the underside
of the lea\'es, it is necessary to have the spray directed upward.
Some potato-sprayers have the nozzles arranged to do this.
Other potato-sprayers may be adapted for this work by remov-
ing the nozzles and inserting a l-foot extension directed down-
ward. On the end of this extension a T-coupling is attached.
To each side of the T-coupling is joined a piece of pipe 6 inches
in length directed at right angles to the rows and equipped
with a 45° angle nozzle, so attached as to throw the spray
obliquely upward and backward. This outfit can be used to
advantage as long as the plants are upright. After the vines
are down, effective work can be done by using two leads of hose
10 or 12 feet in length equipped with 4-foot extension rods
and angle nozzles. With this outfit a traction pump will not
deliver the liquid in sufficient quantity and it is, therefore,
necessary either to operate the pump by hand or with a gaso-
line engine. It requires at least 100 gallons of the s])ray mate-
rial to the acre to be effective. It is usually better to use the
tobacco extract in combination with the bordeaux mix'ture
than with water and soap because of the value of the bordeaux
in preventing potato blight. I'urthermore, it has been ob-
served that potatoes regularly sprayed with bordeaux mixture
are less likely to be seriously infested with the aphid than un-
treated vines. Where there is anv reason to fear an outbreak

154 MANUAL OF VECETABl.E-a ARDES IXSECTS

of the potato aphis, careful watch should he kept of the plants
and when the lice bejiin to appear in any ahundance, steps should
be taken to destroy them before the vines become stunted.

The potato aphis is often aided in its destructi\e work on
potato and other garden j)lants by the spinach aphis, for a
discussion of which see page 10.").

References

Main(> Agr. Exp. Sta. Bull. 147. 1007.
Maine Afrr. Exp. Sta. Bull. 100. 1911.
Maine Agr. Exp. Sta. Bull. 242. 191.5.
Ohio Agr. Exp. Sta. Bull. 317. 1917.

The Apple Le.vfiiopper

Empoasca imili I^ Baron

The well-known apple leafhopper, a troublesome pest on
apple nursery stock, often breeds during the summer on potato
vines. The in.sect passes the winter in the e\f^ stage on the
apple and the first brood of nymphs de\c'l()ps on this plant,
reaching maturity about a month after hatching. Some of
the adults of the second and later broods migrate to potato
and there in.sert their small, whitish, elongate, slightly curved
eggs about -^ inch in length, in the tender parts of the potato
vines. The eggs hatch in a few days and the young nymj)hs,
in company with the adults already present on the vines, feed
on the underside of the leaves, causing them to curl and stunt-
ing the tender growing tips. The injury is most noticeal)le
in periods of drought. The young hoj)j)ers pass through five
n\-mpiial stages, acfpiiring wings at the fifth molt. The
nymi)iis are \)i\\v greenish and in the last stage are about yg
inch in length. The adult leafho])p('rs are ai)ont >, inch long and
of a pale yellowish green color, with six or eight distinguishing
white spots on the front margin of the pronotum (Fig. 89).

POTATO INSECTS

155

When disturbed the nymphs run in all directions but the adults

can jumj) quickly and fly away, often rising in swarms as one

walks through an infested field. About a month is required

for the completion of the life cycle. There

are three generations of the insect a season

on the potato. In the fall the adults find

their way back to the apple and there

deposit the winter eggs in the bark of the

smaller branches, just below the epidermis,

two-year-old wood being most often selected.

The position of the egg is indicated by a

low blister-like elevation of the bark about

^ inch in length and about half as wide.

The apple leafhopper has also been
reported as causing spots on the white
stalks of celery and as feeding on sugar-
beets and beans. It is rarely of sufficient importance on potato
to warrant special applications of insecticides. The nymphs
may be killed by spraying with "Black Leaf 40" tobacco
extract as recommended for the control of the potato aphis.

Fig. 89. — Thu
leafhopper,
(X llj.

References

Minn. Agr. Exp. Sta. Bull. 112, pp. 145-164. 1908.

Iowa Agr. Exp. Sta. Bull. 111. 1910.

Iowa Agr. Exp. Sta. Bull. 1.^).^). p]). 394-400. 1915.

The Potato Stalk-Weevil

Trichoharia trinotatn Say

Throughout the northern states from New York to Xorth
Carolina westward to Kansas, Nebraska, Texas and southern
California, potatoes are subject to the attacks of a small weevil,
the larva of which bores in the stalk. This insect has been
found most injurious in Kansas, Nebraska and Iowa, but more

156 MANUAL OF VEGET ABLE-GARDES INSECTS

or less serious outbreaks have occurred in southeastern Penn-
sylvania and in Xew Jersey. In New York the insect has been
tr()ul)les()nie in the upper Hudson River \alley and in Ontario
on Pelee Island in Lake Erie. Its wild food plants include a
number of solanaceous weeds, such as jjround cherry, James-
town weed, buffalo bur and horse nettle and it has also been
recorded as infesting cocklebur. P^ggplant is sometimes at-
tacked and there is at least one record of injury to tomato.
Early potatoes are more subject to injury than late varieties.
The adult (Fig. 9()) is a snout-beetle, about | inch in length,
bluish gray in color with the head and scutellum black and
with a black spot on each side near the
margin at the junction of the prothorax
and the base of the wing-covers. The
ground color of the beetle is black, its
blue-gray color being derived from a
f . , thick c'overing of narrow scales. The

f^ ^ »,, beetles a])pear in the field in spring

and feed for a time on the stems of
the potato which they puncture with
their beaks. The female inserts her
eggs singly in the stalk or brandies
and sometimes even in the leaf petioles.
In o\ii)ositing, she first hollows out a ca\ity with her beak
and then turning around places the egg in the puncture.
The egg is oval, yellowish white and about xV i"<^"h in length.
The eggs hatch in a week to eleven days and the young
grub burrows down through. the pith several inches and then
turning about retraces its course. When nearly full-grown,
it eats out the entire pith for some distance. When mature
the larva is ^ to \ inch in length, yellowish white, with the
head brownish. Legs are lacking. The presence of the
grubs is indicated by :i wilting and dying of the leaves,
while the stem ma\' remain i,'reen for some time. Several

1m«;. !)(). — The potato
.stalk-weevil (X 6^.

POTATO INSECTS 157

larvse may infest the same stalk and often kill the entire plant.
When full-grown, the grub eats out an exit hole for the future
beetle nearly to the surface but does not penetrate the outer
bark. It then constructs a cell or cocoon of fibers stripped
from the wall of the burrow and then transforms into a creamy
white pupa about ^ inch in length. In Kansas the larvae
begin to pupate about the middle of July and in New Jersey
the last of the month but some do not reach maturity till early
fall and in a few cases have been known to enter the winter
in this stage. The insect spends from eight to fifteen days or
longer in the pupal stage. Although some of the beetles are
to be found in the stalks in early August, they do not usually
emerge until the following spring, but when the stalks are broken
open they may be forced to seek winter quarters elsewhere.
There is only one generation annually.

Control.

The potato stalk-weevil is best held in check by collecting
and burning the vines soon after the crop is dug. If this is
practiced regularly and if all solanaceous weeds in which the
weevils breed are reduced to a minimum by clean farming,
the pest can be prevented from doing any serious damage.

References

N. J. Agr. Exp. Sta. Bull. 100, pp. 2.5-32. 1895.

Kans. Agr. Exp. Sta. Bull. 82. 1899.

U. S. Div. Ent. Bull. 33, pp. 9-18. 1902.

The Common Stalk-Borer

Papaipemn niteln Guenee

The common stalk-borer is generally distributed throughout
the United States and Canada east of the Rocky Mountains.
Although the insect is usually present in small numbers, oc-
casionally serious outbreaks occur locally. The borers attack

158 MANUAL OF VEGET ABLE-GARDEN INSECTS

potato, tomato, eggplant, pepper, corn, bean, rhubarb, spinach,
cauliflower, dahlia, aster, chrysanthemum, lily, hollyhock,
golden glow, peony, sunflower, castor bean and several other
ornamental plants. I'lieir wild food plants include ragweed,
great ragweed, cocklebur, burdock and pigweed. Wheat,
rye, barley, blue-grass and timothy are sometimes attacked
as well as the tender shoots of rasj)berry, blackberry, currant
and gooseberry.

The insect passes the winter in the egg stage on the stalks
of such plants as ragweed, dock, j)igw(>ed and burdock. The
egg is 5^ inch in diameter, brownish gray, globular, slightly
flattenetl and with numerous ridges radiating from the tip.
The eggs hatch in late May or early June and the young cater-
pillar begins feeding on the first suitable ])lant that it finds.
It may first feed as a miner in the lea\es for a few flays and then
burrow into the stem. RagAveed, pig^veed, blue-grass and
timothy, as well as wheat and other grains, are often attacked
by the young larva'. Many of these plants arc soon killed and
the caterpillars then migrate to other plants. It usually haj)-
pens that the young larva' get their start in the rank weeds
surrounding the field or garden and when forced to migrate
in search of fresh food attack the culti\ated crops. It has
often been noticed that corn is most subject to infestation along
the edge of the field and that other crops, such as j^otatoes and
tomatoes, are more liable to injury when grown in small gardens
than when planted in large open fields. In Xew York the cat-
erj)illars usually attract most attention by their injuries to
garden plants from the middle of June to the last of July. The
caterpillar until the next to the last molt is dull brown, the head,
cervical and anal shields honey-yellow, smooth and shining,
with a black stripe on each side of the head and on each side
of the cervical and anal shields. Each end of the body is
grayish brown with a white dorsal stripe and two white .stripes
on each side. The integument is apparently thinner from the

POTATO INSECTS

159

Fig. 91. — The common stalk-bore r,
larva (X U).

middle of the third thoracic segment to the middle of the
fourth abdominal segment, dirty greenish gray with the white
dorsal stripe only present, the lateral stripes being broadly
interrupted. This caterpillar is distinguished from its near
relatives by having but one tubercle behind the spiracle on
the eighth abdominal segment ;
by lacking the large plates on
the second and third thoracic
segments and by the presence
of a pair of small plates on
the next to the last abdominal
segment. The full-grown caterpillar is slightly less than 1^
inches in length and similar to the preceding stages except
that the stripes on the body gradually fade out into a dirty
greenish gray and finally disappear shortly before pupation
occurs (Fig. 91). The caterpillars reach maturity in August
and transform, usually in the burrow, into a brownish pupa f

inch in length. The moths
emerge in September and
October and deposit their
eggs on the stalks of their
food plants. The pupal
period lasts about three
weeks.

There are two varieties
of the moth. In the
typical form (/'. nifcla),
the front wings are grayish
brown with a slight olive
tinge, lightly dusted with white. The usual outer line is
pale and bent inward about one fourth of the distance from
the front margin of the wing and then runs nearly straight
across the inner margin. The hind wings are slightly j)aler
in color except towards the margin and on the veins. In the

Fig. 92. — Moth of the common stalk-
borer, variety P. nehris (X li).

ICO MAXTAL OF VECETABLE-CARDEX IXSECTS

other variety (P. nebris), there are three distinct white spots
nearly one thinl the distance from the base of the winf;, the
middle one being the smallest (Fig. 92). Just inside the outer
line near the front margin of the wing is a fine yellow crescent
with a yellow spot lying within its concavity and with three
to five white dots on its lower and inner side. There is only
one generation annually.

Control.

No satisfactory method of reaching the borers in their bur-
rows is known. Mucli loss may be avoided, however, by de-
stroying all rank weeds in which tlic caterpillars live growing
in the vicinity of the garden and along the edges of fields planted
to tomatoes, potatoes, corn and other plants especially subject
to injury.

References

N. J. Agrr. Exp. Sta. Rept. for 190.'). pp. .'")S4-.')87.

111. Afrr. Kxp. Sta. Bull. 95, pp. 374-:i77. UHn.

Franklin. 12th Rept. State Ent. Minn., pj). 197-198. 1908.

And in other papers puhli.shed by Washburn.

Tin: BruDocK Borer

Papaipemo cataphrncla Grote

Potato, tomato, rhubarb and corn liavc been reported in
Canada as injured by a stalk-borer closely related to the species
last treated. The insect ranges throughout the northern states
and Canada westward to Minnesota. The favorite food
plants of this caterpillar are burdock and thistle, but sunflower,
ragweed, golden glow, hollyhock and many other ornamental
plants are also subject to attack. The work of the borers
becomes noticeable in July, specimens one third to full-grown
being found till the first of Augu.st. The caterpillar is very
similar to the common stalk-borer but the stripes run from end

POTATO INSECTS 161

to end with no interruption in the middle. The caterpillars
reach maturity in August and transform to brownish puppe
within the burrows. The moths are on the wing in September
and October. They have an expanse of about 1-j inches. The
ground color of the front wings is light yellow, dusted with
brown, the outer margin grayish, leaving a yellow spot at the
apex. The outer line runs as in P. nitela and is double and
the wing is spotted in much the same way as in the variety
nebris of that species. The hind wings are light brown. The
eggs are deposited singly in cracks and crevices on the stems
of the food plants in the fall but do not hatch until the follow-
ing spring. There is only one generation annually.

The injury inflicted by the burdock borer may be avoided
by adopting the measures recommended for the common
stalk-borer.

The Potato Scab Gnat

Pnyxia scabiei Hopkins

Potatoes are sometimes injured by a small, white, black-
headed maggot, about ^ inch in length, that causes an injury
similar to that produced by the scab fungus. Outbreaks of
this insect have been recorded in West Virginia and in Ohio
and infested potatoes have been shipped from Philadelphia.
The adult insects have been found in New York and have been
collected under dead leaves in the woods in Missouri. It is
probable that the normal food of the scab gnat maggot is de-
caying vegetable matter. Under certain conditions, however,
it will attack potatoes in the field and in storage. The
maggots have also been found injuring peony bulbs in Pennsyl-
vania. Potatoes are more subject to injury when grown in
low ground where there is an abundance of humus or when
stored in warm, damp cellars.

The female fly is -j^ to -^ inch in length, pale in color and
without wings. The male is somewhat dusky, smaUer than

162 MANUAL OF VEGETABLE-GARDEN INSECTS

the female and occurs in two forms, one with normal functional
win^s and the other with abbreviated wings. The fly deposits
her small, white, oblong eggs, about y^^ inch in length, on the
surface of the potato. The eggs hatch in five or six days and
the young maggot works its way into the tuber, usually taking
advantage of a scab spot or other injury. The maggots attack
the healthy tissue and under favorable conditions of tempera-
ture and moisture will continue their work generation after
generation until the tuber is completely destroyed. The mag-
gots become mature in about a week and then transform to
delicate white pupne in flimsy silken cocoons either in the soil
or on the surface of the tuber. The adults emerge in three or
four days. From twenty to twenty-fi\e da\ s are required for
the insect to complete its life cycle.

Control.

Serious injury by the potato scab gnat is of rare occurrence.
Only uninfested seed putatoes should be ])lanted and laiitl on
which the crop has been infected should not be used for potatoes
the following year. Potatoes grown in dry, light soil are not
likely to be attacked.

References

W. Va. Agr. Exp. Sta. Sp. Bull. 2, pp. 07-111. 1895.
Hopkins, Proc Ent. Soc. Wasli., :i, pj). ItO-lf)*). 1895.

The Pot.vto Ti"hi:i{ Moth

Phthorimcra cperculella Zeller

Potatoes in California and Texas are subject to attack by
a small whitish (•ateri)illar about ^ inch in length that riddles
the tubers with burrows, causing them to decay. The potato
tuber moth is also a troublesome tobacco pest and when feeding
on tills plant is known as the split-worm or tobacco leaf-miner.

POTATO INSECTS 163

The insect ranges from Virginia to Colorado and southward
and on the Pacific Coast is present in CaHfornia and Washing-
ton. It is also known as a serious enemy of the potato in
Australia, New Zealand, the Mediterranean region and South
Africa. Besides potato and tobacco, the insect sometimes
attacks eggplant and tomato, mining the leaves and stalks
and burrowing in the fruit. Its wild food plants include com-
mon nightshade, horse-nettle, Jamestown weed and several
other solanaceous plants.

The potato tuber moth has been studied most carefully in
California and in France. The caterpillars not only infest
the tubers both in the field and in storage but also mine the
leaves and petioles and bore into the stalks. The parent moth
has an expanse of a little more than ^ inch. The front wings
are yellowish brown, more or less spotted and mottled with
dark brown. The hind wings are light yellowish brown and
provided with a long fringe. The moths appear in the field
early in the spring and deposit their eggs singly, usually on the
underside of the potato leaves. The egg is oval, about ^-^ inch
in length, pearly white with a faint iridescence, becoming
leaden gray just before hatching. The eggs hatch in three to
five days. On hatching, the young larva bores into the leaf
where it produces a blotch mine. As it increases in size, it
may migrate to another leaf or bore down through the petiole
and into the stalk, causing the branch to wilt and die. When
full-grown the caterpillar is about ^ inch in lengtli, white,
tinged with pink or greenish above, with the head and cervical
shield dark brown and with the small anal plate light brown.
It reaches maturity in two weeks to seventeen days in warm
weather. When ready to pupate, the larva constructs a small
grayish silken cocoon about ^ inch in length, which is covered
with dirt and pieces of excrement. The cocoons are sometimes
found in the opening of the burrow, in trash at the base of the
plant or more commonly in the dried leaves still clinging to the

164 MANUAL OF VEGETABLE-GARDEN INSECTS

vine. The pupa is brown, becoming darker with age and is
about f inch in length. The insect remains in the pupal stage
from a week to ten days in warm weather. In two or three
days after emergence, the moths lay eggs for another brood.
Reproduction is continuous throughout the season.

After the tubers have formed, they may become infested
in several ways. Some of the caterpillars may leave the stalks
and migrate to the potatoes. When the soil is loose and the
potatoes are near the surface, the moths may work their way
down through the cracks and lay their eggs on the tubers.
When the potatoes are planted shallow some of the tubers
may become exposed and the moths will lay their eggs on them.
Potatoes are most likely to become infested at digging time.
If left exposed in the field during late afternoon or overnight,
eggs are laid on them in abundance. When the piles of pota-
toes are covered with infested ^•ines, the caterpillars may leave
the stalks and enter the tubers. When infested tubers are
placed in storage, the insect will continue breeding throughout
the winter provided the temperature does not fall below 40°
or 50° F. When deposited on the tubers, the eggs are usually
placed around the eyes or on the edge of holes made by the
larvie. On hatching the young caterpillar soon works its way
into the potato, throwing out a small mass of frass through
the opening. The young caterpillars at first burrow just
underneath the skin but when half grown or more work their
way into the flesh, sometimes fpiite to the center of the tuber.
The burrow is lined with a silken tube through which the larva
can move back and forth readil\'. When about to pupate,
the larva leaves the tuber and in some crack or corner or be-
tween two potatoes spins its cocoon. In storage the insect
will continue to breed as long as any ])otatoes remain in con-
dition to serve as food for the larva\ Five or six generations
may develop in the course of a year.

Under storage conditions, a longer period is required for the

POTATO INSECTS 165

completion of the life cycle because of the lower temperature.
Under such conditions the egg stage requires a week or ten
days, the larva about six weeks and the pupa two weeks or over.

Control.

The injuries caused to the vines by the potato tuber moth
are not in themselves serious. The great loss comes from the
infested tubers. This may be prevented in large measure by
planting the potatoes rather deep and by keeping them care-
fully hilled so as not to allow any of the tubers to be exposed
on which the moths can deposit their eggs. Care should be
taken at digging time not to leave potatoes exposed overnight
while the moths are laying. Piles of potatoes should not be
covered with infested vines since the larvee will leave the stalks
when they begin to wilt and enter the tubers. After the pota-
toes have been placed in storage, they should be examined at
frequent intervals and if any are found to be infested, they
should be fumigated with carbon bisulfid at the rate of 2
pounds to 1000 cubic feet of space, allowing the fumigation
to continue for about forty-eight hours. This should be re-
peated at intervals of about a week in summer or two weeks
in winter. Directions for fumigation will be found on page 380.

Where the potato tuber moth is abundant, it is not advisable
to plant potatoes on the same land for two years in succession.
By practicing rotation of crops and by destroying all solana-
ceous weeds on which the insect may breed, much loss may be
avoided.

References

Cal. Agr. Exp. Rta. Bull. 13a. 1901.

Pieard, Ann. Service Epiplivtios, 1, pp. 100-170. 1913.

U. S. Farm. Bull. r>r^7. 1913.

U. S. Dept. Agr. Bull. 59. 1914.

U. S. Dept. Agr. Bull. 427. 1917.

lOG MANUAL OF VECET ABLE-CARDEX INSECTS

Other Potato Insects

Corn ear-worm : 211

Southern corn root-worm : 222

Cabbage looper : 8

Garden webworm : 18

Seed-corn maggot : 'M)

Harlequin cabbage l)ug : 38

Serpentine leaf-miner : 4()

False chinch-bug : 47

Yellow bear caterpillar : '.^'tl

Carrot beetle : 185

Adeiphocoris rapidus: 195

Sugar-beet webworm : 97

Spinach aphis : 105

Tomato worms : 168

Western twelve-spotted cucum])er Ix'cth': 114

Belted cucumber beetle : 115

Southern leaf-footed plant-bug: 121

Garden springtail : 139

Grape colaspis : 07

Bean thrips : 69

Garden flea-hopper : 77

Eggplant tortoise beetli' : 177

Eggplant lace-bug : 178

Spotted cutworm : 262

Greasy cutworm : 265

Dark-sided cutworm : 268

Striped cutworm : 270

Shagreened cutworm : 272

Clay-backed cutworm : 274

Variegated cutworm : 276

Army cutworm : 287

VaW army-worm : 292

Beet army-worm : 294

Yellow-striped army-worm : 295

Semi-tropical army-worm : 297

Striped blister-beetle: 302

Margined blister-beetle: 305

Gray blister-beetle : 306

Ash-gray blister-beetle : 306

Black blister-beetle : 307

Spotted l)lister-bectle: 309

Two-spotted blister-beetle : 309

Macrobasis longicolHs: 310

POTATO INSECTS 167

Immaculate blister-beetle : 310
Segmented black blister-beetle : 310
Panther blister-beetle : 311
Crow blister-beetle : 311
Potato flea-beetle : 314
Western potato flea-beetle : 318
Tobacco flea-beetle : 319
Eggplant flea-beetle : 320
Pale-striped flea-beetle : 321
Red-headed flea-beetle : 323
Smartweed flea-beetle : 323
Hop flea-beetle : 335
Root-knot nematode : 338
Millipedes: 342
Wheat wireworm : 348
Sugar-beet wireworm : 349
Slugs: 354

niAITKIl \\\
TOMATO INSECTS

]\Ia\y potato insects also attack tlic tomato. Tlic most
important of these are the potato flea-beetle and tiie Colorado
potato beetle. In the South, the corn ear-worm is usually
the most destructive pest to be contended with and the tomato
worms often cause serious loss.

The Tomato Worms

Throufrhout the I nited States and southern Canada, tomatoes
are sul)ject to attack l)y lartje greenish or i)rownish caterpillars
.3 or 4 inches in lenjjth which are provided with a shar]) horn
on the back near the hind end of the body. They are also
known as horn-worms and tobacco worms. These tomato
worms belong to two distinct species. The areas occui)ied by
the two forms overlaj) to a considerable extent. Throughout
the greater part of the I'nited States, cater])ilhirs of both species
are found feeding together, the relatixe abundance varying
from place to place and from year to year. The northern form
ranges from Canada to Florida westward t(» the Pacific. The
southern species breeds from Massachusetts, New Jersey,
Ohio and Illinois southward through the West Indies to
Patagonia. Both species occur in California. In addition
to tomato, eggplant, i);)tato and i)ei)per are sometimes
attacked.

X68

TOMATO INSECTS

169

The northern tomato icorm, Phlegethontius quinquemaculata
Haworth

The adult of the northern tomato worm is a moth having an
expanse of 4 to 5 inches (Fig. 93). The front wings are ashy

Fig. 93. — The northern tomato worm moth (XI).

gray marked with irregular brown and black lines. The hind

wings are whitish with a broad gray band on the outer margin

and crossed with four black bands, the middle pair being

sharply zigzag. The abdomen is

gray marked with a narrow

median black line and with a row

of large yellow spots on each

side which are surrounded with

black. On the posterior margin

of each segment are two white

spots on each side, one above

and one below the yellow spot

of the succeeding segment. The

moths appear on the wing in May or June. They fly in the

evening or on dark days and may be seen hovering over flowers

Fi<i. 94. — Em;?; of the northern
tomato worm ( X 7).

170 MAXCAL OF VEGETABLE-GARDEX I X SECTS

from which they suck the nectar. The mouth is provided with
a long sucking tube from 2:^ to 5 inches in length which when
not in use is coiled under the head. The eggs are deposited
singly, usually on the underside of the leaves. The egg (Fig.
94) is globular, nearly j^ inch in diameter and greenish yellow

Fig. 95. — Full-grown northern tomato worm (X |).

in color. The eggs hatch in three to eight days and the young
caterpillars begin feeding on the leaves. They grow rapidly,
reaching maturity in three weeks to a montli. The larger
caterpillars feed ravenously and will strip a tomato vine in a
few days. The full-grown caterpillar (Fig. 95) is 3 or 4 inches

in length and varies
in color from green
to dark brown. Fach
segment of the abdo-
men is marked on the
side ju.st above the
spiracle with a greenish white oblicpie .stripe which, with a
similar horizontal stripe below the spiracle, forms a V with
the apex pointed forward. The horn at the posterior end of
the body is green with the sides black. When disturbed the
caterpillar has the curious habit of elevating the front part

Fig. 96. — Pupa of northern tomato worm in
it.s cell (X J).

TOMATO INSECTS 171

of the body and drawing In the head, In which position it will
remain motionless for a long time. When mature the cater-
pillar goes into the ground a few inches and there in an earthen
cell transforms to a
dark brown pupa (Figs.
96 and 97) about 2
inches in length. The
sucking tube of the

future moth is inclosed ^^^- 97. — Pupa of the northern tomato worm
J. (Xl|).

in a separate case trom

one third to nearly half as long as the pupa, resembling the
handle of a pitcher. The number of generations varies with
the length of the season ; in the North there is apparently
only one, in IVIaryland and Kentucky there are two and in
Florida there are said to be three or four.

The southern tomato worm, Phlegethontius sexta Johannsen

The moth of the southern tomato worm is similar to that of
the northern species but the ground color of the wings is
brownish gray instead of ash-gray. There Is usually a small
white spot near the middle of the front wing and the Interme-
diate lines on the hind wings are not zigzag and often coalesce.
The life history of this species is similar to that of its northern
relative. In Kentucky and Tennessee, the moths begin to
emerge from over-wintered pupse about the first of June and
continue to emerge over a long period, until the latter part of
August in some years. The oblicjue bands on the side of the cat-
erpillar extend higher up on the back and are not V-shaped. The
horn Is usually strongly curved and reddish in color. The tongue-
case of the pupa Is somewhat shorter than in the northern species.

Control.

The presence of tomato worms is readily detected by the
defoliation of the vine and by the droppings of the caterpillars

172 MANUAL OF VEaETABLE-CAIiDEX IX.^ECT.'^

on tho fijroiuul, although it is not easy to see the caterpiUar
itself as it rests motionless on a stem, its colors hlendinj^ with
the green of the foliage and the light stripes on its side suggesting
the veins on the underside of the lea\es. In the small garden
or in larger fields where the caterpillars are not numerous,
hand-picking is the cheapest and most practical means of
control. When the worms ai)i)car in considerable abundance,
spraying with paris green or arsenate of lead will give good
results. Arsenate of lead is to be preferred on tomatoes because
it is not so likely to burn the foliage. It is usually used at the
rate of 2 or 3 pounds of the paste to 50 gallons of water. The
first application should i)e made while the cateri)illars are still
small because they are then killed more (|uickl\ and by a smaller
quantity of the poison than later. There is no danger in
spraying tomatoes until the fruit is half grown, and some
growers apply paris green till witiiin ten days of picking. The
arsenate of lead may be applied in the form of a dust diluted
with some inert material.

References

Ky. Agr. Exp. Sta. Bull. G6, pp. 6-32. 1897.
U. S. Farm. Bull. 120, pp. 10-14. 1900.

The Tomato Stii.t-Bug

Jalijsus spinosus Say

The tomato stilt-bug is generally distributed throughout
the United States and Canada east of the 100th meridian and
has been reported as injurious to tomato in Missouri. The
adult (Fig. 98) is a slender, elongate, brownish bug with long,
delicate, thread-like legs and antemue. The last joint of the
antenna is enlarged and i)la(k. The insects arc found on low
vegetation in woods and fields.

The female attaches her eggs singly to the stems of tomato
plants. The egg is -^ inch in length, cylindrical, roimded

TOMATO INSECTS

173

at each end, whitish to pale brownish in coh)r and faintly ridged
lengthwise. The eggs hatch in about five days. The nymphs
are brownish green with the legs dark. In feeding, the bugs
puncture the stems, the
blossom stems, the ova-
ries and the young fruits,
causing the blossoms and
fruit to fall. There are
supposed to be at least
three generations an-
nually in southern Mis-
souri.

The bugs may be
killed by spraying with
"Black 'Leaf 40" to-
bacco extract, 1 part in 800 parts of water to which enough
soap has been added to make a suds. The insects are more
easily hit in the early morning or late in the afternoon.

Reference
Mo. Fruit. Exp. Sta. Bull. 24, pp. lG-17. 1914.

Fig. 98. — The tomato stilt-bug ( X 4).

Fig. 99. — The
tomato wire-
worm (X 3).

Fig. 100. — Adult of the
tomato wireworm ( X 4) .

The Eastern Field
Wireworm

Limonius agonus Say

In Xew York, young
tomato plants are
sometimes seriously
injured b\' a wireworm
that bores up through
the stem, causing them
to wilt and die. This
wireworm (Fig. 99) is

174 MANUAL OF VEGETABLE-GARDEN INSECTS

over ^ inch in length and reddish brown in color. The parent
beetle (Fig. 100) is f inch in length, with the head and prothorax
black, the legs brownish and the wing-covers reddish brown.
The life history of the species has not been fully worked out.

Injury may be avoided by not planting tomatoes on land that
was in sod or corn the previous year.

The Erinose of the Tomato

Eriophyes cladophthirus Nalepa*

In Florida, Georgia and South Carolina, tomatoes are some-
times infested by a minute mite which attacks the growing tips
and the blossom buds. The feeding of the mites causes an
irritation of the tissue, inducing the i)lant to send out a dense
growth of white hairs, giving it the appearance of being covered
with a white mold. It is under the protection of this dense
growth of plant-hairs that the mites live, lay their eggs and
feed, (irowth is stoi)pcd and the bufls do not set fruit. The
life history and habits of this mite have not been carefully
studied. The adult is elongate, vermiform and nearly color-
less. It is provided with two j)airs of legs and the abdomen is
transversely striate and apparently divided into about seventy
narrow rings. The female mite is about -g^js inch in length and
the male about ^^.

The erinose of the tomato may be controlled by spraying
the plants with the soda sulfur spray conmionly used against
mites on citrus. The formula for this niixtiu'c is:

1 The identity of this mite is somewhat unoertain. Rolfs (Fla.
Apr- Exp. Sta. Bull. 47, p. 143. 1898) referred the speeies to Phyinplus
CdlcUidnphnrn Nalepa, slating that the mite oer-urs in southern Europe.
We have been unaV)le to find any such speeies deserihed by Nalepa.
Apparently the P. ctilrliidopliora used by Rolfs is a misprint for Phytop-
(us (Eriophyes) cladnphlhinis Nalepa. The latter was described from
bittersweet (Solanum Dulcamara) in Franee, on whieh it produced
erinea. Kirchner states that it produces a similar condition on tomato
in Europe.

TOMATO INSECTS 175

! Caustic soda (98 per cent) 10 pounds

[ Flowers of sulfur 20 pounds

[ Water 20 gallons

Mix the sulfur in cold water to a thick paste, add the soda and
as it boils add water gradually to make 20 gallons. The water
should be added fast enough to prevent burning, but not fast
enough to stop boiling. The result will be a dark coffee-
colored liquid. Strain through a fine-meshed cloth or spray-
strainer. Keep in tightly-corked jugs. For use, mix one half
gallon of this stock solution in 40 gallons of water.

Dusting the plants with finely ground sulfur has also been
found of benefit.

Other Tomato Insects

Corn ear-worm : 211

Southern corn root-worm : 222

Stink-bugs : 232

Cabbage looper : 8

Garden webworm : 18

Harlequin cabbage bug : 38

Green soldier-bug : 42

Nezara viridula: 43

Spinach aphis : 150

Belted cucumber beetle : ll.'j

Southern leaf-footed plant-bug: 121

Northern leaf-footed plant-bug : 122

Garden springtail : 139

Colorado potato beetle : 142

Three-lined potato beetle : 149

Potato aphis : 150

Potato stalk-weevil : 155

Common stalk-borer : 157

Burdock borer : 160

Potato tuber moth : 1()2

Bean thri])s : (iO

Garden flea-hoi)per : 77

Spotted cutworm : 2()2

Greasy cutworm : 2()5

Dark-sided cutworm : 268

Striped cutworm : 270

Dingy cutworm : 271

176 MANUAL OF VEGETABLE-GARDEN INSECTS

Granulated cutworm : 273
Clay-baoked cutworm : 274
Variegated cutworm : 27r>
Army cutworm : 2S7
Fall army-worm : 2*.)2
Yellow striped army-worm : 295
Semi-tropical army-worm : 294
Striped l)lister-beetle : 302
^largined blister-beetle : 30")
Ash-gray blister-beetle : iiOCi
Black blister-beetle : 307
Two-spotted blister-beet U": 309
Immaculate blister-beetle: 310
Potato flea-beetle: 314
Western potato flea-beetle: 318
Tobacco flea-beetle : 319
Pale-striped flea-beetle: 321
Striped cabbage flea-beetle : 324
Hop flea-beetle : 335
Root-knot nematode : 338
Millipedes: 342
Slugs: 354
Red-spider : 351

CHAPTER VIII
EGGPLANT INSECTS

The eggplant is subject to attack by most of the insects
affecting the potato and tomato. Several species of fiea-
beetles attack eggplant and of ten cause serious injury, especially
to the young plants. They are treated in Chapter XVII.

The Eggplant Tortoise Beetle

Cassida pallidula Boheman

In the southern states, the eggplant is occasionally subject
to injury by the larvae and adults of a beautiful green or greenish
yellow tortoise beetle about ^ inch in length. This beetle is
distributed throughout the southern United States from Mary-
land to Indiana and Kansas southward to Louisiana and west-
ward to southern California. It feeds on eggplant, potato and
horse-nettle and in California on nightshade. The beetles
deposit their eggs singly or in groups of two to four, usually
on the underside of the leaves. The egg is about 3^ inch in
length, elongate oval and brownish in color. It is covered
and fastened to the leaf with a transparent brownish substance
which is usually composed of two layers. Each female is
capable of laying 250 eggs or more. The eggs hatch in four
days to two weeks and the young larva is greenish white with
the head dirty brown. The body is armed on each side with
sixteen branched spines and on the back near the hind end of
the body two long spines arise and extend forward. On this
fork the insect carries its cast skins and excrement, using this
N 177

178 MAX UAL OF VEGETABLE-GARDEX IX SECTS

load as a kind of sunshade. The larva i)asses throufih five
stages and reaches maturity in twelve to twenty days. Pupa-
tion takes place on the leaf, to which the pupa is attached by
the hind end of the body and in two to ten days transformation
to the beetle occurs. In Louisiana there are four or five
generations annually. Both the larvae and adults eat out round
holes in the leaves and often seriously injure young eggplants.
The eggplant tortoise beetle rarely becomes sufficiently
abundant to require remedial treatment but may be readily
controlled by spraying with arsenate of lead (paste), 2 or '■)
pounds in 50 gallons of water.

Reference
U. S. Dopt. Agr. Bull. 422. 191G.

The Egc;pl.\.nt LACE-Brr,

Gargaphia solani Ileidomann

Throughout the southern states from Virginia, Missouri
and Oklahoma southward, the eggplant is sometimes injured
by a grayish or light brownish lace-bug. This insect is a
native of America and fed originally on hor.se-ncttlc. It s:)me-
timcs occurs in great abundance on ])otatoes.

The adult lace-bug is about ^ inch in length. Hat. and under
a lens presents a striking ai)pcarancc. The |)rothorax is de-
veloped into a hood that extends backward between the wings
at the base, and its sides are expanded angularly. The front
wings are broad, rounded at tiie tij), blackish at the base and
ai)cx, with a pale band across the middle and with the veins
arranged so as to form a beautiful reticulated network, resem-
bling lace. The expanded margin of the prothorax is similarly
reticulated.

The female deposits her eggs on the underside of the leaves
in circular clusters of 100 to iiearl.v 'JOO. The eggs are placed

EGGPLANT INSECTS 179

on end and lean in different directions. The mass is then
covered with a protective secretion. The egg is bottle-shaped,
greenish at the base and brownish towards the tip and about Cl-
inch in length ; the top is crater-like with a white lace-like
border. The eggs hatch in five to nine days. In feeding, the
nymphs insert the bristles of the beak into the leaf and suck
out the juices. The mother lace-bug watches over her egg-mass
until the young are hatched and then cares for the nymphs
until they have reached a considerable size. A small area
surrounding an egg-mass is killed and the feeding of the nymphs
enlarges the injured part. The colony of nymphs then migrates
to a new position and there repeats the process. When abun-
dant, the whole plant may be killed or so injured that a crop of
fruit is not produced. In the course of its development, the
n}'mph sheds its skin five times, acquiring wings at the last
molt. About ten days are required for the nymphs to reach
maturity. The fifth stage nymph is yellow^ish in color with
a dark spot at the tip of the abdomen and is armed with numer-
ous spiny processes. In Tidewater, Virginia, there are six gen-
erations produced on eggplant and after this crop is harvested
two or more generations develop on horse-nettle.

Both nymphs and adults can be killed by spraying with 7
or 8 pounds of whale-oil soap in 50 gallons of water.

Reference
U. S. Dept. Agr. Bull. 239. 1915.

Other Eggplant Insects

Corn oar-worm : 211
Southern corn root-worm : 222
Garden webworm : LS
Harlequin cabbas*" bufi: : 38
Gre(>n sol(li(T-bug : 42
Yellow bear eaterpillar : 357
Spinach aphis : 150
Tomato worms : 168

ISO .\fA\rAL OF VEGET ABLE-CARDEX ISSECTS

Belted fuoumbor beotlr : 115
Southern leaf-footed plant-bug: 121
Melon aphis : 135
Colorado potato beetle : 142
Potato aphis : 150
Potato stalk-weevil : 142
Common stalk-borer : 157
Potato tuber moth : 102
Garden flea-hopper : 77
Greasy cutworm : 265
Semi-tropical army-worm : 297
Striped blister-beetle : 302
Potato flea-beetle : 314
Western potato flea-beetle : 318
Tobacco flea-beetle: 319
Egerplant flea-beetle: 320
Pale-striped flea-beetle : 321
Root-knot nematode : 338
Red-spider : 351

CHAPTER IX

INSECTS INJURIOUS TO CARROT, CELERY, PARSNIP
AND RELATED CROPS

As a rule, these plants are relatively free from insect attack,
but the carrot rust-fly, recently introduced from Europe and
now gradually spreading over Canada and the northern states,
promises to become a serious pest.

The Carrot Rust-Fly

Psila rosce Fabrieius

The carrot rust-fly is a native of Europe, where it has been
known since 1794. It was introduced into Canada probably
in the early eighties, but
first attracted attention
at Ottawa in 1885. It
soon became abundant
in Quebec, New Bruns-
wick and Nova Scotia.
In New York it was
first observed in Fulton
County in 1901. It now
occurs in the northern
states from Maine to

M- I • T, • • Fic. 101. — Tho carrot rust-fly ( X 7i).

icnigan. Itis a serious ^ ^ "

enemy of carrots and celery and also attacks parsnips, parsley,

celeriac and wild carrot.

181

182 MANUAL OF VEGET ABLE-GARDES IXSECTS

The parent insect (Fig. 101) is a small two-winged fly about
^ inch in length. The body is shining dark green ; the head
yellowish with the eyes red. The legs are pale yellowish. In
New York the flies usually make their appear-
ance some time in May, depending on weather
conditions. Observation of the flies confined
in cages has shown that they feed for about
five days before they are ready to begin egg-
laying. In the field they doubtless subsist on
such drops of liquid as they may find. The
Fig. 102. — Egg of moutli-parts are somewhat similar to tho.se

the carrot rust- ,,f ^^^ ^^^^^^ g^ ^j^.^^ j ^j^^^. ^^^ developed

into a fleshy, tongue-like organ with which
the insect is able to lick or lap up liquids.

The female fly has the tip of the abdomen i)ro\ided with a
sharp, extensile ovipositor by means of which she is able to
tuck her eggs into crevices of
the soil around the plant. Some
of the eggs are laid between the
base of the plant and the soil
but many are found scattered
about on the surface of the ground
near the plant; others are attached
to the plant it.self. Females have
also been observed depositing eggs
in cracks at some little distance
from the plant. The egg (Fig.
102) is about ^ inch in length
and about 3 as wide as long.
It is elongate oval, white in color
and under the microscope shows
a most beautiful sculptured pattern of delicate ridges and
pits. Eggs have been found in abundance the last of May.
The eggs hatch in about a week aii<l the young maggot

Fic. 10.3. — Young carrots in-
jured l>y ru.st-fly maggots.

INJURIOUS TO CARROT AND RELATED CROPS 183

works its way down along the root and at first feeds on the
tender tip.

In the case of carrots and parsnips, the maggots at first feed
on the tip of the tap-root and later the whole root is riddled
with burrows which run in every direction. These burrows
are of a rusty color, hence the common name of the insect.
When badly infested, the carrot roots decay and when one

^^^^r^:^^- """.^

^xBsms^

mw^i-'r '\ .t-*

Fig. 104. — Two celery plants injured by the carrot rust-fly and an unin-
jured plant of the same age.

attempts to pull them the lower part will break off and remain
in the ground (Fig. 103). The outer leaves of infested plants
soon turn yellowish and the whole top may wilt down and die.
The injury to celery is of a somewhat different nature.
Here the fibrous roots are eaten off and destroyed. Infested
j)lants take on a sickly whitish color and remain stunted. The
plants are often able to throw out a new set of fibrous roots
near the surface of the ground and can thus outgrow the injury

184 MANUAL OF VEGETABLE-GARDES IXSECTS

Fig. lUG. — Pup.iriunj of the carrot
rust-fly (X'Jl).

in a measure, but the
size and quality of the

Fig. 105. — Larva of the carrot rust-fly (X 7J). ^'""P ^^^ SCriOUslv im-
paired. In Y'l^. 104 are
shown two injured plants in comparison with a healthy one.
The maggots become mature in about a month. When full-
grown the larva is about ^o
inch in length, pale straw-
colored, pointed in front with
the posterior end of the
body obliquely truncate. The
mouth is provided with a j^air
of black, curved hooks with which the maggot is able to rasp
off portions of the tissue of the root (Fig. 105).

When mature, the greater number of the larvie desert the
roots and in the surrounding soil trans-
form to puparia. The jniparium (Fig.
106) is about ^ inch in length, light
brownish in color and in shape re-
sembles somewhat a grain of wheat.
F>om these puparia there emerges in
late August a second brood of flies.
The insects hibernate as puparia
in the soil or as maggots in the
roots.

It is (|uite pr()l)al)le that not all
the pu|)aria of the first brood trans-
form the same season, but the .second
brood of flies is often large enough to
produce a serious infestation of late
carrots and to cause appreciable
injury to celery in the fall. While
P.O. 107 - .\ celery root in- ^j,^. "maggots of the sccoud brood

jured l)y rust-fly niaKcr)ts ~^

of the . 'second brood. burrow ill the tap-root of the celery

INJURIOUS TO CARROT AND RELATED CROPS 185

plant, they very rarely ascend so as to enter the base of
the leaves (Fig. 107).

Unfortunately no method of controlling this pest has been
devised applicable to the conditions under which its food plants
are grown in this country.

References

U. S. Div. Ent. Bull. .33, pp. 26-32. 1902.

Felt, 18th Kept. N. Y. State Ent., pp. 99-103. 1903.

The Carrot Beetle

Ligyrus gibbosus DeGeer

Throughout the United States, except in the extreme North,
the roots of carrot, parsnip and celery are sometimes seriously
injured by a medium-sized reddish brown
insect which has much the appearance
of a small June beetle. It is from ^ to
f inch in length. On the front part of
the thorax is a depressed area, in front
of which is a small distinct tubercle
(Fig. 108). The beetles feed mostly
underground, gnawing out holes in the
roots and underground stems. In
addition to the plants mentioned above,
the beetles have been known to attack
beet, celery, sweet potato, potato, corn,
dahlia, cabbage, sunflower and cotton, and among weeds
ragweed and red-root.

The beetles hibernate in the soil at a depth of six inches to
four feet and are found in the field in greater or less abundance
throughout the growing season. The eggs are laid in the soil.
They are similar to those of the .Innc beetles, white, smooth
and shining, nearly globular, grayisii, and al)()ut I'f inch in

Fig. lOS. — The c-urrot
hectic (X 2^).

180 MAM'AL OF VEGET ABLE-GARDES IS.^ECTS

length when newl>' laid. They increase considerably in size
before hatching, which takes place in one to three weeks. The
larvae feed on the roots of grasses and decaying vegetable matter
and sometimes attack the same plants as do the beetles. When
mature, the larva is 1^ inches in length, bluish white with the
head brown. From six to eleven weeks are spent in the larval
stage. The mature grubs construct earthen cells within
which to pupate and the beetles emerge two or three weeks later.
There is apparently only one generation annually.

The measures suggested for the control of the carrot beetle
are of little practical value. Clean farming and a short r;)ta-
tion of crops will under ordinary conditions prevent serious loss.

References

U. S. Div. Ent. Bull. 33. pp. 32-37. 1902.
Hayes, Jour. Ec. Ent., 10, pp. 253-261. 1917.

TiiK Black Swallow-Tail Butterfly

Papilio polyxenes Fabricius

The caterpillar of this large black and yellow butterfly feeds
on the leaves of celery, parsnij), carrot, parsley, caraway,

fennel, sweet-fennel, dill,
anise and nearly all wild
umbelliferous plants. It is
most destructive to y<'Ung
celery. The butterfly ranges
throughout N(»rth America
from S!)Uthcrn Canada
southward through Central
.America and the West
Indies to Venezuela.
The butterfly (Fig. 109)
^L u. , „ .1 'lii'' a" expanse of :]\

Fig. 109. — The blark swallow-tail . • i n^u

butterfly (X*). to nearly 4 inches. Ine

INJURIOUS TO CARROT AND RELATED CROPS 187

Fig. 110. — Eggs of the black swallow-ttiil butterfly (X 12).

male is somewhat
smaller. The wings
are black with two
rows of yellow spots
crossing both wings
with a marginal row of
yellow lunules. Be-
tween the rows of yel-
low spots on the hind
wing and on the hind
part of the front wing
is a bluish band. On
the posterior angle of
the hind wing is an
orange spot with a black
center. In the male the
yellow markings are

Fig. 111. — The black swallow-tail butterfly,
a ycjung caterpillar and one nearly full-
grown with the osmateria protruded (X |).

188 MAXUAL OF VECETABLE-GARDEX IXSECTS

more distinct and on the hind wing the inner row of
spots is replaced by a broad yeUow band. In the North the
butterflies emerge from over-wintered pupse in May and June
and (lei)osit their eggs singly on the upper side of the leaves of

the host plants. In

Fici. 112. — Caterpillar of the black swallow-
tail butterfly suspended for pupation
(X f).

Florida the butterflies
hibernate. The egg (Fig.
110) is globular, about
2^ iiK'h in diameter, pale
honey-yellow when first
laid, changing to reddish
brown in parts. The
eggs hatch in about ten
days. In the first stage
the caterpillar is about
^ inch in length, black,
banded about the midflle

and rear end witli white. \\ hen mature the caterpillar

is about 2 inches in length, green, and each segment has a

black band near the front margin inclosing six yellow spots.

When disturbed this caterpillar has the habit of extruding a

pair of orange-red horn-like

scent organs from the dorsum

of the prothorax (Fig. 111).

These organs are known as

osmateria and are probably

for defense. The caterpillars

become full-grown in three to

four weeks and suspending

themselves by a silken girdle

(Fig. 112) transform to pupa^ on some nearby support.

The pupa (Fig. 113) is \\ inches in length, light dirty

brown marked with black and dark green. It is attached

to its support by a button of silk at the hind end of the body

l'i«i. 11.1.— Ciiry.-ulis of till'
swallow-tail butterfly (X A).

lack

INJURIOUS TO CARROT AND RELATED CROPS 189

and held in place by a silken girdle around the thorax. The
pupal period lasts from nine to sixteen days. There are two
broods in the North and at least three in the South.

In California the black swallow-tail butterfly is replaced as a
celery and parsley pest by a related species, Papilio zolicaon
Boisduval.

Control.

As this insect rarely becomes abundant, it may be usually
held in check by hand-picking the caterpillars.

Reference
Scudder, Butterflies of Eastern U. S., 2, pp. 1353-1364. 1889.

The Celery Leaf-Tyer

Phlyctoenia ferrugnlis Hiibner

Celery is occasionally injured by a small greenish caterpillar
that folds or webs together the leaves and sometimes bores
down into the
stalks. This in-
sect is widely
distributed in
Europe, Asia and
North America.
In the United
States it has
been reported
injuring celery,
spinach and beet
but is best known
as a greenhouse

Fk;. 111. — Tiie celery lc:if-tycr, raterpillar (X 3]).

pest, attacking a wide variety of hot-house plants. Its
wild food plants include boneset, hedge nettle, strawberry

190 MANUAL OF VEGETABLE-GARDES IXSECTS

Fig. 115. — The celery Icaf-tyer, pupa ( X 5).

and burdock. The caterpillars have been occasionally found
feeding on celery and beet in August and September.

The full-grown
caterpillar (Fig.
114) is f inch
in length, trans-
lucent greenish
white with a pair
of black spots on
the cervical shield. The body is marked with a dark green
median stripe bordered by a much wider greenish white one.
When disturbed the caterpillar has the habit of wriggling
actively back and forth. The larva generally
feeds openly on the under surface of the
leaves, but sometimes it forms a retreat by
webbing together several leaves loosely with
silk. L'nder greenhouse conditions, the cater-
pillars mature in about three weeks. Pupa-
tion takes place within thin white, silken
cocoons spun within folded leaves. The _,

,„. ,^_, . ,. , , , , • 1 • Fi<;. no.— The eel-

pupa (ing. llo) IS a little less than ^ inch in pry loaf-tyor

length and dark brown or black. The pupal "^''^^^ ^ x iJ)-

period varies from twelve to twenty days. In one instance

the moth did not emerge until a year after the pupa was

formed. The moth (Fig. 116) has an

expanse of about | inch and is rusty

brown with somewhat obscure blackish

markings on the front wings. The

flight of the moths is short and jerky and

on alighting they quickly hide on the

niidcrsidc of the object. The small, flat,

elliptical, translucent eggs (Fig. 117),

about -^ inch in diameter, arc deposited

on the underside of the leaves in small

Fig. 117. - K(ik^ of the
celery leaf-tyer (X 22).

INJURIOUS TO CARROT AND RELATED CROPS 191

clusters of two to twelve, often overlapping. The eggs hatch
in twelve to fourteen clays. Under greenhouse conditions, there
are from seven to eight generations annually ; in the open there
are said to be only four.

The celery leaf-tyer has never been found causing serious
injury in the open and no methods of controlling it under such
conditions have been devised.

References

Buckler, Ent. Mo. Mag., 14, pp. 200-204. 1878.
Fletcher and Gibson, Can. Ent., .33, pp. 140-144. 1901.
Cornell Agr. Exp. Sta. Bull. 190, pp. 159-164. 1901.

The Celery Looper

Autographa falcigera Kirby

Throughout the United States and southern Canada east of
the Rocky Mountains, celery, lettuce and sugar-beets are some-
times subject to the attack of a looping caterpillar. These
caterpillars hibernate in a partly grown condition and com-
plete their development in early spring. The full-grown larva
is 1^ inches in length, pale translucent green in color, and
marked with a median dark line, on each side of which are
three light lines. The stigmatal stripe is white bordered
above by a dark green stripe. The spiracles are white, dis-
tinctly ringed with black, a character by which it may be dis-
tinguished from the cabbage looper. The body becomes
gradually larger towards the posterior end, which is obliquely
truncate. Although these caterpillars are closely related to
the cutworms, they crawl with a peculiar looping motion owing
to the absence of prolegs on the third and fourth abdominal
segments. In Illinois the over-wintered caterpillars become
(nature in late April and pupate in silken c-ocoons. The pupal
period occupies nine or ten days.

192 MANUAL OF VEGETABLE-GARDEN INSECTS

The moth has an expanse of about 1^^ inches. The front
winjis arc purpUsh l)ro\vn with an obhciue hand in the front
angle and the area hack of the silver sjjot velvety reddish brown.
The silver mark is distinct and the hind margin of the front
wing is scalloped so as to leave a rounded projection at the

1 hind angle. The hind wings are

^^^. ---i^^tk y^l''>^^'i^l^ brown, darker toward the

^^^^kgH^^^^H^ margin, wiiich is edged with white

^^^■Hj^^^V The egg is about ^V ^^^^^^ in

^^^ ^ ^^^ diameter, milky white, globular,

slightly flattened and marked with

delicate longitudinal ridges. The

eggs hatch in about a week.

In Illhinis tiiere are ai)i)arently three broods annually, the

moths flying in Ai)ril and early May, in late July and early

August and again in late September. The caterpillars of the

summer brood recjuire about three weeks to reach maturity.

The celery looper does not often occur in sufficient numbers
to require remedial measures. As arsenicals cannot be used
on celery or lettuce, hand-])icking the caterpillars is the only
measure availabU- and will usualK' be found sufficient.

Fig. lis. — Moth of the celery
looper (X 1|).

Reference
Coquillett, 11th Ropt. State Knt. 111., pp. 38-4.3. 1882.

The Tarmsiied Pla\t-Bl(j

Lygns pratcttsis Linnaeus

The tarnished plant-bug is one of the commonest insects
found on garden ])lants. It feeds on a great variety of trees,
shrubs and herbs, showing a special liking for opening buds,
flowers and tender new growth. It is widely distributed through-
out tile entire north temperate zone. The adult (Fig. 119) is an

INJURIOUS TO CARROT AND RELATED CROPS 193

Fig. 119. — The tarnished
plant-bug, adult (X 4§).

inconspicuous, brownish bug mottled with varicnis shades of
reddish and yellowish brown, ^ to ^ inch in length. The bugs
are shy, taking flight at the slightest alarm, and are often over-
looked by the gardener.

This insect hibernates as an adult in leaves, grass, stone
piles and under other rubbish. The
bugs emerge in early spring and are
then often destructive to the buds of
fruit-trees and nursery stock. They
are also to be found abundantly in
mullein rosettes and as soon as the
days become warmer they begin
feeding on various weeds. In New
York the eggs become mature in the
over-wintering females by the last
of April or the first cf Way and a
generation of young is produced,
giving rise to a new brood of adults the latter part of June.
The egg (Fig. 120) is nearly ^ inch in length, flask-shaped
and obliquely truncate at the anterior end. The eggs are in-
serted their full length into the tender tissue of the plant.

They have been found in the petioles
of peach leaves, the blossom buds of
dahlias, the seed-stalks, stems and
leaves of volunteer turnips and later
in the season in the heads of com-
posite plants such as daisies and
asters. They hatcli in about ten
days. The nymphs are yellowish
green to greenish, marked on the
thorax with four black spots. In the older nymphs the
thorax and wing-])a(ls are ^■ari()usly mottled with brownish
(Fig. 121). In late sunnncr and fall the nymphs are very
abundant on wild carrot, goldcnrod and wild asters. There

Fig. 120. — Eggs of the tar-
nished phmt-bug in position
in tender peaoh tip (X 11).

194 .U.4.Vr.lL OF VEGETABLE-GARDEN INSECTS

Fig. 121. — The tar-
nished plant-bug,
fifth stage nvmph
(XG).

are five nymphal stages, the insect becom-
ing mature at tlie fifth molt. The life cycle
requires from twenty-five to thirty days,
and there are probably four or five genera-
tions annually.

IMost of the injury to cultivated plants
is caused by the feeding punctures of the
adults, since most of the nymphs are to be
found on weeds. In feeding, the bug
punctures the plant with the sharp needle-
like bristles of its beak and sucks out the
juices, at the same time apparently inject-
ing some substance poisonous to the tissue.
The character of the injury varies with the
nature

of the
plant attacked. In the
case of potatoes, the in-
jury is similar to that
produced by several other
insects and is known as
tip-burn. This is most
serious in years of
drought. The bugs
sometimes puncture bean
pods, arresting growth at
the point of injury. In
the case of beets the
punctures cause a curling
or kinking of the leaves
(Fig. 122) and in severe
cases a stunting of the
plants. The bugs often
attack celery plants that

122. — Beet h-af kinked by the tarnished
plant-bug.

INJURIOUS TO CARROT AND RELATED CROPS 195

Fig. 12.3. — Add phocoris
rapidus, adult ( X S^).

are blanching, puncture the tender stalks, producing large
brown wilted spots and a blackening of the tissue at the joint.
This trouble is known among celery-growers as black joint.
The injury mars the appearance of
the plants, lessens their market value
and causes considerable loss. Cab-
bage, cauliflower, turnip, salsify and
cucumber are also subject to attack,
but serious injury to these plants is of
rare occurrence.

It is rarely possible to prevent attack
by the tarnished plant-bug because the
injury is inflicted by the adults that
have developed on wild plants,
common weeds that are everywhere
present. They are too active to be hit by a spray and so
resistant to insecticides that it is impossible to kill them with-
out using some material that would injure the plants. Clean
farming is often recommended as a means of reducing the
numbers of the bugs, but under
ordinary circumstances gives little
if any relief.

Another plant-bug,
A (leJphocoris rapid us
Say, is often associated
with the tarnished
plant-bug, feeding on
potato, sugar-beets, cel-
ery and cotton. It

also feeds on numerous Fig. 125. — Addphocoris rapi-

weeds and is sometimes '^"'' ^^*^ ^^'"^^ "^^^^ ^ ^ "^•
injurious to the fruit of the strawberry. The adult (Fig. 123)
is a little over \ inch in length. The head, legs and prothorax
are yellow ; there are two black spots near the hind margin of

Fig. 124. —Egg
of Addphocoris
rapidus (X 2.3).

196 MAXCAL OF VEGETABLE-GARDEX IXSECTS

the prothorax and the winjrs are dark brown exeept the edjje,
which is narrowly bordered with yellowish. The antennae
are black, broadly ringed with yellowish white.

The life history is similar to that of the tarnished plant-bug
and the eggs are deposited in similar places. The egg is also
similar but bears a small spine at the edge of the cap (Fig. 124).
The insect passes through five nymphal stages. The nymphs
are gayly colored with green, red and various shades of brown
(Fig. 125) and are found abundantly throughout the growing
season.

Reference

Cornell Agr. Exp. Sta. Bull. 346. 1914.

The Xegro-Bug

Thyreocoris pulicarius Germar

A .serious outbreak of this small black stink-bug occurred in
the celery fields of Michigan in 1S93, causing a loss of many
thousand dollars. A similar outbreak took place in northern

Ohio in 1906. It is surprising that
attacks of this kind have not been
more frequent, since the bugs are
often abundant on their wild food
plants over large areas every year.
The insect ranges throughout the
I'nited States nnd Canada east of
the Rocky Mountains southward to
Florida and Arizona. The adult
(Fig. 12()) is about ^ inch in length,
- The ricgro-bug. shining black, stronglv convex, short

It ( X 14).

and broad, widest on the thorax

and rounded behind. The scutellum is greatly developed

and covers the abdomen ; the exposed vdjxv of the wing

is yellowish white.

The insect hibernates in the adult condition and the bugs

Fig. 126.

idult

INJURIOUS TO CARROT AND RELATED CROPS 197

appear on their food plants in the spring. In Illinois the eggs
are laid in May and June. They are deposited singly on the
leaves. The egg is ^^ inch in length, elongate, shining, light
orange when first laid but deepening to bright red just before
hatching. The egg has been observed to hatch ui sixteen
days*. The older nymph is similar to the adult but has the
abdomen blood-red. The nymphs become mature in July and
the adults, after feeding for a few weeks, go into hibernation
rather early. The insect breeds abundantly on various weeds,
including beggar-ticks, tick-seed, red-root, ground-nut, great
lobelia and neckweed {Veronica peregrina?). It has also been
found injurious to corn, wheat and grass and the bugs often
give an unpleasant flavor to raspberries and strawberries.
There is only one brood developed annually.

The injury to celery has been caused almost entirely by the
adults. They congregate in clusters at the base of the petioles
on the highest stalks and suck out the sap, causing the leaves
to wilt and die. Later they attack the lower leaves at the
center of the plant. Celery so injured is stunted and the stalks
more or less deformed, and much of it is rendered unsuitable for
market.

When infesting celery, the negro-bug can best be controlled
by spraying with "Black Leaf 40" tobacco extract, 1 j)int in
100 gallons of water in which 5 to () pounds of soap have been
dissolved. Much may be accomplished in preventing attack
by keeping down all wild plants on which the insect may breed.

Reference
Mich. Agr. Exp. Sta. Bull. 102, pp. 13-18. 1893.

The Parsnip Webworm

Depressaria heracliana Linnaeus

In growing parsnip and celery seed, much trouble is often
experienced from the depredations of small greenish yellow

198 MANUAL OF VEGETABLE-GARDEX IXSECTS

caterpillars that web together and devour the uiifoldinjj blossom
heads. The insect is widely distributed in luirope and eastern
North America. It feeds on wild parsnip, wild carrot and
other umbelliferous plants.

The insect hibernates in the adult stage. The small grayish
moths are found under flakes of bark, in crevices, or in similar
situations. The moth has an average expanse of about an
inch. The front wings are brownish gray marked with inter-
rupted longitudinal dark lines and a small black spot near the
center. The hind wings are pearl-gray. Over-wintered speci-
mens are usually much rubbed and are much lighter in appear-
ance. The moths deposit their eggs singly in May, June and
July on the leaves, stems and particularly on the sheath sur-
rounding the flower-head. The egg is elongate, oval, pearly
white, ri})bed longitudinally, and about ^V i'^<^''i i" length.
The eggs hatch in about seven days and the young caterpillars
enter the flower-buds, where they feed, webbing them together
with silk. When the flower-cluster opens, the catcrj)illars re-
main in the protection of the web and continue to feed on the
flowers and later on the seeds. They become full-grown in
four to five weeks. The mature caterpillar is about 3 inch in
length, greenish yellow above, lighter yellow on the sides and
beneath. The head, cervical shield and thoracic legs are
shiny black. The body is sparsely clothed with hairs arising
from small black warts.

When nearly mature, the caterpillars leave the flower-heads
and burrow into the stems, usually in the axils of the leaves.
After entering the stem, the caterpillar feeds for a short time
and then constructs a slight cocoon of silk and excrement in
which })ui)ation takes place. The pupa is about ^ inch in
length, with a dark brown thorax and light brown abdomen.
The moths emerge in a})out three weeks and soon go into hiber-
nation in sheltered places.

Xo practical method of controlling this insect has l)een de-

INJURIOUS TO CARROT AND RELATED CROPS 199

vised. After the flower-heads have opened, many of the
caterpillars may be destroyed by spraying or dusting with an
arsenicah

References

Riley, Inseot Life, 1, pp. 94-98. 1888.

Micii. Agr. Exp. Sta. 3rd Rept., pp. 112-115. 1890.

Brittain and Gooderham, Can. Ent., 48, pp. 37-41. 1916.

The Parsnip Leaf-Miner

Acidia fratria Loew

Sometimes the leaves of parsnip are disfigured by the mines
of a small whitish maggot. This insect is never very abundant
but is widely distributed throughout the whole United States
and is probably identical with the European celery fly, Acidia
heraclei Linnaeus. The greenish translucent maggots are found
in the leaves from May till July, where they produce blotch
mines. Several larva occupy the same leaf and the mines
coalesce. The mines are most abundant on the lower leaves
or on plants grown in partial shade. When mature, the maggots
are a little over i inch in length. They transform to straw-
colored puparia usually within the mine, and the flies emerge
in about two Aveeks. The fly is about ^ inch in length. The
head, thorax and legs are pale yellow and the abdomen green.
The wings are beautifully marked with yellowish brown curved
bands. The number of generations annually has not been
definitely determined.

Reference

U. S. Bur. Ent. Bull. 82, pp. 9-13. 1909.

The P.\rsley St.\lk-Weevil

Listronotus laliusculuft Boheman

This insect has been recorded as injuring parsley planted on
low land in \'irginia and in coldframes in Connecticut. The

200 MAM'AL OF VECErAHI.E-GARDES INSECTS

larvae were found boring in the stems and roots, causing the
death of the plant. This weevil breeds normally in the heads
and stalks of the common arrowhead, a plant found growing in
low, wet ground. Its attack on parsley was apparently more
or less incidental.

Other C.\rrot, Celery .\.\d P.\rs.vip Lvsects

Cabbage looper : 8
Yellow bear caterpillar : 3r)7
Spinach aphis : 105
Garden springtail : 139
Bean aphis : 76
Garden flea-hopper : 77
Spotted cutworm : 2G2
Striped cutworm : 270
Variegated cutworm : 276
Spotted-legged cutworm : 282
Army cutworm : 2S7
Army-worm : 2<S8
Striped blister-beetle : 302
Black blister-beetle : 307
Potato flea-beetle: 314
Pale-striped flea-beetle : 321
Itoot-knot nematode : 338
Millipedes: 342
Wheat wreworm : 348
Slugs : 354

CHAPTER X
ASPARAGUS INSECTS

The important insects infesting asparagus are relatively few
in number, and, like their host plant, are of European origin.

The Common Asparagus Beetle

Crioceris asparagi Linnaeus

This common beetle is a native of Europe and was first found
in this country at Astoria on Long Island in 1860, although it
had probably been present in that locality for several \ears.
The insect has gradually extended its
range until it is now widely distributed
from North Carolina to Massachusetts
and Canada and westward to Illinois. It
was introduced into California about 1904
and is now widely spread throughout the
central part of the state. It has also
been reported from Colorado.

The asparagus beetle (Fig. 127) is
about ^ inch in length. The head, under
parts, legs and antennae are bluish black
frequently tinged with green. The tibia?
are reddish at base. The thorax is
reddish usually with two black spots near
the center. The markings on the wiiig-

2U1

Fig. 127. — The com-
mon asparagus beetle
(X 5).

202 MAXrAL OF VECICTAIU.F.CARDEX I. \ SECTS

covers vary greatly even in specimens from the same locality.
The inner margin of each wing-cover is bluish black ; the
outer margin and the tip are orange. The intervening space
is yellowish white broken into three spots by bluish black
bands which are usually connected with the inner marginal

stripe. Insomecases
these bands are
broken into spots.
Sometimes the two
wing-covers on the
same insect are not
marked alike. Varia-

FiG. 128. — Diagram to show variations in the tions in the pattern
pattern on the wing-covers of the common aspar- , . ,,.

agushootic. are shown m big.

128. There is a
tendency in the South for the beetles to be lighter in color.

The beetles pass the winter under any convenient shelter
such as piles of rubbish, under the bark of trees or in similar
situations. They have often been found in great numbers in
heaps of old asparagus roots where tiie field has been plowed up.
The beetles emerge from their winter quarters at the time
the young shoots are just coming up. They attack the tender
tips, eating out holes
and producing a
brownish discolora-
tion of the tissue.
When abundant the
crop may be seriously
damaged. The beetles soon l)egin to hiy their eggs on the young
shoots. The egg (Fig. 129) is elongate oval, blackish brown and
about -jV inch in length. The eggs are laid on end singly or
in rows from two to eight. Early in the season they are laid
on the tips, but later are attached to the leaves and flower-
stems. The eggs hatch in three to eight days and the young

Fig. 129. — Eggs of the common asparagus
beetle (X 6).

ASPARAGUS INSECTS

203

grubs begin feeding on the tender tips. The body of the newly
hatched larva is gray and its head and legs are black. The
grub becomes mature in ten days to two weeks. It is then
about Y^ inch in length, dark gray in color, with the head and
legs shining black. On the segment behind the head there
are two shining black spots. The abdominal segments are
provided with prolegs which are used by the grub in maintain-
ing its hold on the plant (Fig. 130). When mature the grubs
fall to the ground and there just below the surface construct a
small earthen cell within which they transform to pale yellow-
ish pupte. Transformation to the beetles takes place in about
a week, although in
cool weather the pupal
period may be much
longer. In England
the insect remains in
the pupal state from
fourteen to twenty
days. After trans-
formation the beetles
require three or four
days to harden before they are ready to make their appear-
ance above ground. The entire Hfe cycle requires from three
to seven weeks depending on the climate. In the North
there are at least two generations annually and in the South
there are said to l)e four or five.

In addition to the injury to the tender shoots in the s])ring,
the beetles and larvtie seriously damage the plants after they
have leafed out. Both beetles and grubs feed on tiie leaves
and the epidermis is chewed from tiie stem. In this way the
growth of the plants is seriously checked and the proper develop-
ment of the roots is prevented. Plants stunted in this way
are not able to send up large and N'igorous shoots, and the size
and quality of the crop are decreased. The common asparagus

Fig. 1.30.

— • Full-grown larva of the pommon
asparagus beetle (X 4^).

204 MANUAL OF VKCETA BLE-CA RDEX IXSECTS

beetle is very trouhlesoiiie in newly set })e<ls. Frequent de-
foliation weakens the plants, inakinij it (iiflicult for them to
})ee()nie established.

The eommon asparagus beetle is held in eheek by a small
C'haleid parasite, Teira.siichns (i.sjxiracji Crawford, the life his-
tory of whieli is remarkable. The adult parasite appears in
the asparagus field in the spring while the eggs of the beetle
are being laid. The female inserts her eggs in those of the
beetle. The beetle egg hatches and its larxa, containing the
larvae of the parasite, reaches maturity, enters the ground and
constructs its pupal cell but does not j)ui)ate. The parasites
then complete the destruction of the host and emerge from its
shriveled remains, pupate within the cell constructed by the
l)eetle larva and later emerge as adults. From one to ten para-
sites have been reared from a single beetle larva.

Methods of control.

In asparagus fields in which the croj) is being cut for market,,
the injury to the young shoots by the larvte may be prexented
by cutting the crop clean every three to five days. In this way
all the eggs deposited on the shoots will be removed before or
very soon after hatching. All volunteer i)lants should be de-
stroyed but it will often pay to leave a row here and there
uncut to serve as a trap on which the beetles will congregate,
feed and la,\' their eggs. Ilcri' tlu-y may be poisoned with
arsenate of lead (paste), 1 ])()und in 20 gallons of water, or the
plants may be cut and burned, thus destroying the early stages
of the beetle. After the cutting season is over, the j)lants may
be protected from beetle injury by two or three aj)plicati()ns
of arsenate of lead (paste), 1 pound in 20 gallons of water. It
is not an easy matter, however, to si)ray thoroughly a large
field of asparagus when the plants have made a heavy growth.
In newly set beds, spraying with arsenate of lead is often re-
S()rtc(| tn w ith satisfactory results. In this case the a|)plication

ASPARAGUS INSECTS 205

should be made early in order to destroy the first brood of
beetles and larvte and thus give the plants a chance to make a
strong growth early in the season.

The use of poultry for the destruction of the beetles was
advised by T. W. Harris nearly eighty years ago. This method
of control is still practiced with good results in some localities.
The asparagus field is surrounded with a chicken-wire fence,
and poultry are allowed the run of the field. Thirty or forty
hens are sufficient to keep a two-acre field practically free from
the beetles during the early part of the season. When the
plants grow up, some of the beetles will keep out of reach and
they may become abundant in the fall. It is rarely necessary,
however, to resort to spraying in fields in which poultry are
allowed to run. In the home garden the larvae may be de-
stroyed by dusting the plants with hydrated lime or land
plaster.

References

Fitch, 8th Kept. State Ent. N. Y., pp. 177-186. 1863.

Lintner, 1st Kept. State Ent. N. Y., pp. 239-246. 1882.

Board Afjriculture [England] Leaflet 47. 1902.

Chittenden, Yearbook U. S. Dept. Agr., pp. 341-.349. 1896.

Johnston, Jour. Agr. Research, 4, pp. 303-314. 1915. Parasite.

Sajo, Prometheus, 13, pp. 166-171. 1902.

U. S. Farm. Bull. 837. 1917.

The Twelve-Spotted Asparagt^s Beetle
Crioceris duodecimpunctata Linnaeus

In this country, the . twelve-spotted asparagus beetle (Fig.
131) was first noticed in 1881 in ^Maryland. It gradually
spread northward, reaching New Jersey in 1892, New York in
1898 and (\anada in 1898. Its range now extends from Maine
to the Niagara peninsula in Canada and southward to Virginia.

This beetle is most injurious early in the season when the

206 MANUAL OF VEGETABLE-GARDEX IXSECTS

adults attack the growinj; tips and sometimes eat the buds as
soon as they appear above the ground. The beetles also feed
on the foliage and eat out irregular areas in the bark of the
stems. The larv?e cause very little injury
since they feed almost entirely inside the
berries.

The insect passes the winter in the
adult condition, hidden away in dry,
sheltered places. The beetles leave their
winter quarters about a week later than
the common asparagus beetle. They feed
on the tender asparagus shoots in much
the same way but do not deposit their
eggs until about the time the plants
begin to blossom or from three weeks to
a month after appearing in the field.

The twelve-spotted asparagus beetle is
slightly larger and more robust than the
other species. Its general color is reddish orange. The
antennfe, eyes, knees, tarsi and the underside of the thorax
are black. On each wing-cover there are six distinct black
spots. The eggs are deposited singly on the leaves of
asparagus plants, usually those bearing fruit. The egg (Fig.
132) is about -i^ inch in length by ^'^ inch in width and is
pointedly rounded at each end. The surface is smooth, shin-
ing and without apparent sculp-
ture. When first laid, the egg is
nearly white, changing through
yellow or orange to light green or
brownish olive. It is attached to
the leaf by one side. The eggs hatch in a week to twelve
days. The young larva is about ^ inch in length, pale
yellow or orange in color, with the head, legs and a spot on
each side of the first segment black. The young larva feeds

P'iG. 131. — Thetwclvo-
spotted asparagus

beetle (X 5).

Fk;. 1.32. — Egg of the twelve-
spotted asparafrus beetle (X 12).

ASPARAGUS INSECTS 207

very little if at all on the foliage but wanders about till it
finds a berry, which it enters usually at the blossom end.
The larva feeds on the seeds and migrates from berry to
berry until full-grown. Sometimes three or four berries are
attacked by a single larva. In the course of its develop-
ment, the larva passes through three stages. When full-
grown it is about -g- inch in length and varies in color from
light orange to brownish yellow. The legs and two spots on
the prothorax are black. The larva becomes mature in three
to four weeks. It then descends to the ground, where just
below the surface it spins a tough silken cocoon into which
particles of dirt are incorporated. In about two days after
building its cocoon, the larva transforms to a yellowish pupa
and in twelve to sixteen days the transformation to the adult
takes place. In New York the beetles of the second brood
appear in July and lay eggs for a second generation. The
beetles of the next brood emerge in August and September and
go into hibernation with the advent of cold weather. There
are two generations annually in the North.

In Europe two other beetles attack asparagus, the fourteen-
spotted and the five-spotted asparagus beetles (Crioceris qua-
iuordecimpundata and C. qidnquepundata) . The larvae of both
species are said to feed on the foliage in much the same way
as the larva of the common asparagus beetle.

Methods of control.

Since the larvae live inside the berries, they cannot be reached
with an arsenical poison but the beetles may be killed by spray-
ing with arsenate of lead as suggested for the control of the
common asparagus beetle.

References

Lintner, 12th Rept. State Ent. N. Y., pp. 248-252. 1897.
Sajo, Prometheus, 13, pp. 16(5-171. 1902.
Cornell Agr. Exp. Sta. Bull. 331, pp. 422-435. 1913.
U. S. Farm. Bull. 837. 1917.

208 MAX UAL OF VEGETABLE-GARDES INSECTS

The Asparagus Miner

Agromyza simplex Loew
{Agromyza maura var. simplex Loew)

In the present state of knowledfje of this group of flies, it is
impossible to indicate with any accuracy the geographical dis-
tribution of this species. There are several closely related
forms in the genus Agromyza considered as distinct species by
some authors and as varieties of Agromi/za maura Meigen by
others. The asparagus miner belongs to this group. As the
habits and early stages of most of these varieties or species are
still unknown and as it is very difficult to distinguish them
from a study of the flies alone, it is at present impossible to
determine the actual range of this pest. In America Agromyza
simplex has been recorded from Massachusetts, Ontario and
Illinois and southward to Georgia. It also occurs in central

California. It has been
reared in France and the
flies have been captured
in England and (icrmany.
What is apparently the
same species but deter-
mined as Agromiiza maura
was reared from aspara-
gus in Hungary.

The adult of the aspara-
gus miner (Fig. 133) is a
small, metallic, black,
two-winged (ly, ^ to ^
inch in length and having an expanse of \ to \ inch. In
New York the flies appear from the middle to the last of
May. In about a week after emerging, the female inserts
her eggs just under the epidermis of the asparagus stalk near

Fit;, l.i.1.

The a.sparagus iniiipr, adult
(X «).

ASPARAGUS INSECTS 209

the ground. The egg is elongate oval, slightly wider at one
end and st)me\vhat pointed at the other. It is about 5^
inch in length and when first laid is glistening white in
color. The eggs hatch in twelve to eighteen days and the
young maggot begins to mine just under the epidermis. At
first the larva works upward, following a more or less sinuate
course, but when nearly mature it turns downward towards
the base of the plant. In the case of the first brood, pupation
may take place aboveground but the maggots of the second
generation usually work down from one to seven inches below
the surface before transforming. The full-grown maggot is
creamy white in color and is ^ to ^ inch in length. The maggots
attain their growth in two or three weeks and transform into
puparia within the mine. The puparium is ^ to ^ inch in length
and brownish in color, becoming darker with age. The insect
remains in this stage for two to three weeks and the flies of
the second brood begin to emerge the latter part of July. The
maggots of the second brood are most abundant in their mines
during August but both maggots and flies are present until
frost. The winter puparia are formed in late August and
September. These are found under the epidermis of tiie
stems below ground. There are two generations annually.

When, as is often the case, several maggots infest a single
stem, their mines cross each other, thus girdling the shoot.
Stems injured in this way take on a sickly yellowish appearance
and die prematurely, thus weakening the plants to a consider-
able extent.

Methods of control.

The asparagus miner rarely does enough damage to warrant
commercial growers making any serious efforts to control it,
and no remedial measures satisfactory for commercial condi-
tions have been devised. The insect causes little or no trouble
in beds that are being cut, its injuries being chiefly confinetl to
p

210 MAXUAL OF VEGETABLE-GARDEN INSECTS

now beds. It lias been recommended to pull up and burn
infested stalks in the fall after frost or in the spring and thus
destroy the over-wintering puparia. This is a laborious opera-
tion and, as many of the stems are broken ofY, enough puparia
will be left to reinfest the field. It has also been suggested
that the flies might be killed with a sweetened poison bait but
as this method has not been tried under field conditions its
value is very doubtful.

References

N. Y. (Geneva) Agr. Exp. Sta. Bull. 189. 1900.

U. S. Bur. Ent. Circ V.i'). 1911.

Cornell Agr. E.xp. Sta. Bull. 331. pp. 411-421. 1913.

Other Asparagus Insects

Corn ear-worm: 211
Southern corn root-worm : 222
Stink-lmgs: 232
Cabbage looper : 8
Harlequin cabbage bug : 38
Yellow bear caterpillar : 3.")7
Belted cucumber beetle: 11")
Southern leaf-footed plant-bug: 121
Melon aphis : 135
Potato aphis : 150
Bean aphis : 76
Greasy cutworm : 20.5
Black army-worm : 275
Variegated cutworm : 270
Yellow-striped army-worm : 295
Root-knot nematode : 338

CHAPTER XI
CORN INSECTS

The insects feeding on Indian corn are numerous, over two
liundred species having been recorded as more or less injurious
to some part of the plant. The roots are injured by wireworms,
white grubs, corn root-worms, by the larvpe of bill-bugs and are
infested by the corn root-aphis. The young plants are fre-
quently eaten off by cutworms, the leaves riddled by flea-
beetles and the crown tunneled by the stalk-borers. The
unripe ears are attacked by the ear- worm, which is the most
important insect infesting sweet corn. In this chapter no
attempt is made to give a comprehensive account of the insects
injurious to field corn ; only the more important species are
treated and only those most likely to attack sweet corn.

The Corn Ear- Worm

Heliothis ohsoleta Fabricius

The corn ear-worm ranges throughout the I nited States
and southern Canada, southward through Mexico and the
West Indies to Argentina. In the Old World it is found
throughout Africa and Eurojic eastward to China, India, the
East Indies, Australia and New Zealand. In the southern
states, this insect is a serious enemy of cotton and is there known
as the cotton bollworm. Corn is the favorite food plant of this

211

212 MANUAL OF VEGETABLE-GARDEN INSECTS

insect, serious injury to this crop being of annual occurrence
from the vicinity of Xew York City southward east of the
Apj)alachian ^Mountains ; from Ohio, llHnois, Nebraska and
Montana southward to the Gulf and in the warmer parts of
the Far \Yest. It occurs in the greatest abundance, however,
and is most destructive in the cotton belt. From New Jersey
southward, the corn ear-worm is considered the worst insect
pest of tomatoes, and peas and beans are also subject to serious
injury. Among tobacco-growers the insect is known as the
bud-worm from its habit of boring into the roll of unopened
leaves at the center of the plant. Other plants liable to more
or less serious injury are okra, pepper, eggplant, pumpkin,
scjuash, melon, cucumber, asparagus, peanut, collards and
l)i)tatoes. The insect also attacks sorghum, sugar-cane, millet,
cowpeas, vetch, alfalfa and clover. Its wild food plants are
numerous; some of the more common are Jamestown weed,
ground cherry, wild sunflower, coeklebur, bindweed, horse-
nettle, velvet-leaf and hcinj). Many ornamental plants are
also attacked, such as gladiolus, geranium, mignonette, morning-
glory and rose. When driven by hunger, the caterpillars will
feed on almost any succulent vegetation they can find. Ripen-
ing fruits, such as peaches, plums and even quinces, are some-
times attacked.

Throughout the greater i)art of the Inited States and Canada,
the corn ear-worm hibernates in the pui)al stage, but in southern
Florida some of the moths remain active during the winter.
The moths emerge in early spring over a period of at least a
month. The moth has an expanse of about 1^ inches. In
the commonest form, the front wing is straw-color, usually
marked with a spot in the middle and frequently with a darker
area near the tip. The spots ma\' be entirely lacking or the
wing may be heavily shaded with brown, and the wings are
sometimes tinged with reddish or greenish. The hind wings
are creamy white with a difl'use blackish border containing a

CORN INSECTS 213

pale spot and there is usually a dark spot near the middle of the
wing. The flight of the moths is low, swift and irregular. They
lay their eggs mostly on dark days or at dusk. The eggs are
deposited singly on the leaves and stems of tomato, tobacco
and cotton, and on the leaves, tassels and silk of corn, the last
being preferred above all others for oviposition. Each female
is capable of laying from 500 or 000 to over 2500 eggs. The egg
(Fig. 134) is a little less than ^V hich in diameter, waxy white,
faintly tinged with yellowish, nearly globular, with the base
flattened and the tip depressed. The surface is marked with a
series of ridges radiating from the tip. The first moths usually
appear in the spring and are ready to lay their
eggs before corn is available. Under such cir-
cumstances, eggs are deposited on early to-
matoes, peas and beans. The time required
for the hatching of the eggs varies with the
temperature. In April thev hatch in about a ^* ''^; V^^' ~ ^^^

, I , . ' , , of the corn ear-

week, m the summer m two or ttiree days worm (x 30).

and in the late fall in two weeks or over. The

newly hatched larva is a little over ^ inch in length, nearly

white, with the head and cervical shield black and the body

marked with numerous small black tubercles. In the course

of its development, the caterpillar usually passes through six

stages but sometimes may pupate after the fifth stage. In the

spring the caterpillars reach maturity in about a month ; in

the summer, in from eleven days to three weeks, and in late

fall, the larval period is again lengthened with the decreasing

temperature. The corn ear-worm belongs to the same family

as the cutworms and resembles them in general appearance.

The full-grown caterpillar (Fig. 135) is 1^ to 2 inches in length,

varying from light green to brown. The coloration is highly

variable but the cater])illar is usually marked with longitudinal

stripes, the most distinct one being a pale stigmata! stripe

edged above with blackish. There is a dark stripe along the

214 MANUAL OF VECETABLE-CARDEN INSECTS

(-J,

middle of the back divided by a narrow white line. The corn
ear-worm might be mistaken for an army-worm of the summer
brood, which it somewhat resembles, but may be distinguishetl
by the granulose skin which under the microscope appears as
if studded with minute hob-nails.

When mature, the caterpillar leaves its food plant, descends
to the ground and burrows into the soil in a slanting direction
to a depth of two to seven inches, leaving the passage filled
with loose earth. It then constructs a
tunnel almost to the surface of the ground
for the emergence of the moth. This
tunnel is lined with compacted soil and a
thin layer of silk. After completing the
exit tunnel, the larva retreats to the en-
larged lower part of the burrow and there
transforms to a pupa. The ])uj)a is
smooth, brownish, f to nearly 1 inch in
length and usually rests in a slanting posi-
tion with the head upward. Pup;e formed
by the summer broods are usually found
nearer the surface than those which winter
over. The period passed in the pupal stage
varies with the season. In the summer it is
about two weeks and in the fall three weeks
or more. The number of generations produced ainniall\" varies
with the length of the season. Throughout the cotton belt there
are probably four generations and sometimes a few moths of a
fifth brood may emerge. In southern Texas and Florida seven
generations may develop. In New Jersey and in other northern
localities where the insect is a serious corn pest, only two
or three generations occur. Farther north there is probably
only one brood. After the first generation, the later ones
become badly mixed, owing to the overlapping of broods caused
by the irregular emergence of the moths, and the unequal

Fig. 135. — The corn
ear- worm, dorsal
view (uatural size).

CORN INSECTS 215

development of individuals. The later generations are only
partial, owing to the fact that some of the pupae of these broods
do not transform until the following spring.

As a rule, tomatoes are most seriously injured by the corn
ear- worm early in the season. At this time corn is not large
enough to be attractive to the moths and they are forced to
lay their eggs on tomato. The young larvse feed slightly on the
leaves and may sometimes even burrow into the stem of the
plant, killing it down to the point reached by the larva. The
injury, however, is greatest to the fruit. The caterpillars bore
into tomatoes of all sizes. A caterpillar does not, as a rule,
remain long in one fruit but as soon as decay sets in leaves it,
often entering several fruits in succession. It is not unusual
in the South for half or more of the crop to be destroyed in
this way. In New Jersey the injury is confined mostly to the
early crop, but in Florida the attack may continue throughout
the season.

Peas and beans are often attacked by the corn ear-worm when
corn is not available. The caterpillars bore into the pods and
devour the seeds and may sometimes tunnel in the stems as well
as feed to some extent on the foliage. Cucumber, squash,
melons and pumpkin are sometimes injured, the larvre boring
in the stems, and even entering the fruit.

Corn may be attacked while still quite small. The eggs
are deposited on the leaves and the caterpillars eat out irregular
holes, especially in the tuft at the center of the plant. The
moths begin depositing eggs in the silk as soon as it appears.
On hatching, the young caterpillar usually devom's its egg-shell
and then works its way through the silk and in about twenty
minutes reaches the tip of the ear, having fed very little if at
all during this time. It then begins feeding on the silk and
after a time burrows down under the husk, continuing to feed
on silk and the unripe kernels (Fig. 13G). The injury may
extend halfway down the ear. The injured kernels and the

216 MAMAL OF VECETABLK-GARDES I \ SECTS

excrement left by the larva in its burrow under the husk serve
as an excellent medium for the growth of various molds and
bacteria, which greatly augment the injury inflicted by the
insect. As many as six larvie sometimes infest an ear but
usually only two or three are present, in spite of the fact that
normally a much larger number of eggs are deposited on each

mass of silk. This is to be

■■jiVK«PV

accounted for by the can-
nibalistic habits of the
'j caterpillars. They feed
voraciously not only on
each other ])ut on any other
caterpillars that come in
their way.

Both field and sw(>et corn
are subject to attack but
tlie latter seems to be pre-
ferred by the insect. The
loss to field corn is not so
great because the uninjured
kernels can be used, but in
the case of sweet corn good
L i)rices cannot be obtained

M full-grown car-worms for worinx' ears. The pest
.t an car of field corn |^ „„,j,t destructive in the

latter j)art of the season,
owing to the greater number of moths in the later broods.
In the last crop of corn in the \icinit>' of New York, some-
times nearly every ear is infested, while the earlier plantings
may be practically free. In many parts of the South, it is
imj)()ssible to raise a clean crop of sweet corn because of
the depredations of this ins<'et. When full-grown, the cater-
pillar IcaNcs the ear, usnallv' by gnawing a nnind hole through
the husk, but in some cases it may escai)e at the tij). Some-

Fic;. i;:c.. •|^

on tlio ii|)
(natural .size)

CORN INSECTS 217

times the larvte desert the ear when only partly grown and mi-
grate to other ears on the same or nearby plants. In the cotton
belt the later broods of caterpillars produced after corn has
become hard are to be found mostly on cotton. In Iowa and
Nebraska, late brood caterpillars have been found on alfalfa
and clover.

Control.

No practical method of controlling the corn ear-worm on
field corn has yet been discovered. Experiments in New
Jersey have shown that the injury to sweet corn may be greatly
decreased by dusting the silk with a mixture of 50 per cent
powdered arsenate of lead and 50 per cent finely ground sulfur.
The first application should be made soon after the silk appears,
followcfl by one or two others before the corn is ready to pick.
Dust can be applied most conveniently by means of a small
hand bellows carried under the arm and equipped with a piece
of rubber hose about two feet long attached to the outlet by
which the dust is directed downward into the tip of each ear.

When sweet corn is grown for the cannery, early planting
is advisable, but cannot be practiced when corn is grown
for the market because for this purpose a succession cover-
ing as l')ng a period as possible is required. ^luch benefit
may be derived from fall or winter plowing land on which an
infested crop has been grown in order to destroy the pupre. As
large an area as possible should be included in this treatment
as the moths are capable of flying a considerable distance.

The injury to tomatoes may be in part prevented by spraying
the vines with arsenate of lead (paste), 4 to 6 pounds in 100
gallons of water, making one or two applications before the
fruit is lialf grown. Later applications are likely to stain the
fruit. Injured tomatoes should not be left in the field but
should be picked along with the others, sorted in the packing-
house and should then either be buried or dumped into a pond.

218 MANUAL OF VEaETABLE-dARDEX INSECTS

Tomatoes can also be partially protected from the corn ear-
worm by using corn as a trap crop on which, in preference to
the tomatoes, the moths will lay their eggs. Two rows of corn
should be planted for every ten or twenty rows of tomatoes
and so timed as to come into silk when the first tomatoes are
forming. It should be cut and destroyed before the cater-
pillars reach maturity.

References

Comstoek, Rppt. Cotton Insects, pp. 287-31.'). 1S79.

Riley, 4th Rept. U. S. Ent. (^omm., pp. 3.").">-3.S4. 1885.

Mally. Rept. on BoUworm, Tex. Art. dA. 1002.

U. S. Farm. Bull. 191. 1904.

U. S. Bur. p]nt. Bull. .^>0. 190.''). BMwqraphii.

U. S. Vavm. Bull. 290. 1907.

Ky. Agr. E.xp. Sta. Bull. 1S7. 1914.

Thk Cohx iiooT-Ariiis

Aphis ninidi-rndicis Forbes

Although the corn root-aphis is generally distributed through-
out the Ignited States east of the 100th meridian, it is mo.st
injurious in the corn belt and in New Jersey, Delaware and
eastern Peimsylvania. In the South Atlantic states, it has
proved a troublesome pest of cotton and has also been known
to infest the roots of cultivated asters in Illinois. There is
some doubt as to many of the wild food plants of the corn
root-aphis because of confusion with a similar species, Aphis
viifhlh'tofii Thomas, often found on the roots of certain wild
plants such as asters and Krigeron. It is, however, definitely
recorded from smartweed, knotweed, crab-grass, i)urslane, dock,
foxtail, fleabane, mustard, sorrel, i)hintain, pigweed, great
ragweed, thorny amaranth, green amaranth, Koman wormwood,
(log fennel, shepherd's purse, laml)'s cjuarters, poverty weed,
buttonweed, purplish cudweed, sneezeweed, pineweed, dwarf

CORN INSECTS 219

dandelion, pepper-grass, toadflax, mild water pepper, cockle-
bur, vervain, common nightshade, skullcap, Teucrium laciniatum,
Leptochloa fiUformis and Mentha arveiuis.

The corn root-aphis has been studied most carefully in
Illinois. The insect passes the winter in the egg stage in the
care of a little brown ant, Lasius niger americanus Emery.
The ants tend the aphids in much the same way as man cares
for domestic animals, being very fond of the sweetish liquid,
known as honeydew, secreted by them. This aphis has become
so dependent on the ants for the care of the winter eggs and for
placing the young lice on the roots of their food plants that they
would doubtless all perish were there no ants present to attend
them. The eggs are stored in the ants' nest, where they are
protected by the workers as carefully as are the young of their
own species. Sometimes in warm days in early spring, the
ants carry the eggs to the upper galleries of the nest or even
lay them out in the sunshine and carry them back at night.
This is probably done in order to keep the eggs in good condition
and to hasten their hatching. In central Illinois the eggs begin
to hatch in early April, just as the smartweed, pigeon-grass and
ragweed plants are coming up. The young aphids are carried
by the ants and placed on the roots of these weeds. Here they
are attended by the ants, whose burrows are extended to include
the roots. The young aphids pass through four nymphal stages
in the course of their growth and reach maturity in about
nineteen days, on the average, in Illinois. As the eggs hatch
over a considerable period, usually from early April to the last
of May, the last nymphs hatched will find themselves surrounded
by representatives of three generations. All the individuals
of the first generation are wingless but in the later generations
there is a varying percentage of winged forms produced. The
latter- occur in greatest numbers when the roots are crowded
and food is scarce. The winged forms leave the roots, come
to the surface and take flight, seeking new feeding grounds.

220 MAXl'AL OF VEGETABLE-GARDES IXSECTS

During tlie summer only two forms of tlie aphids occur, winfj;-
Icss and winged vi\ii)arous females; males and egg-laying
females are not ])n)du(e(l till October or
■K \ X>^ November and constitute tlie last genera-

tion of the season. From eleven to
twenty-two generations are produced
-^^|^\ annually, each female giving birth to

''«^-^"''.v\ nearly fifty young. With the advent of
cool weather, wingless egg-laying females
and wingless, or rarely winged, males
are produced. The small black eggs are
fri '^ dci)()sitcd underground in the galleries of
Fiu. 137. — Wiiijjile.ss vi- the aiits where they are cared for till
viparoiis female corn- ^^ following spring. The full-grown

root aphis ( X 13). . . , ,^ . ,

vi\ii)aroiis female (Fig. 137) is about ^
inch in length, bluish green, dusted with a whitish waxy
j)ulverulence. The head and transverse bands on the thorax
are black. In the winged form, the head and th(»rax are
black or dark brown and the alxlomcn is pale green with
three distinct black
spots on each side
(Fig. 138).

By the time the . V7^*=9==2^ /^ti

corn is ])lant('d and

comes up, the '^ — ^^'''^!^^::<^^^r^^^lNN\
aphids have become
crowded on the
roots of the weeds
and many winged
forms have devel-
oped. At this time ^''^'- ^•'^•^- - '^^■'"«"\ y'V!:^";""-' ^'''''''^' corn-root
' aphis (X 16).

the weed roots have

become hardened and are thus less favorable for the develop-
ment of the lice. The ants transfer many of the wingless

CORN INSECTS 221

aphids from the weeds to the corn roots and also seize any of
the winged migrating forms that come their way and carry
them down to the roots. In this way the corn soon becomes
badly infested. The injury is ordinarily first noticed in irregular
patches usually on the lower ground. The loss of sap caused
by the feeding of the aphids lessens the vitality of the plant,
causing the leaves to turn yellowish or reddish. The aphis is
most destructive in years of drought because under such condi-
tions the plants are least able to bear the loss of sap. Corn
plants badly stunted by the root-aphis often fail to bear ears
or produce only nubbins.

Control.

Experiments and the experience of practical corn-growers in
Illinois have shown that the losses caused by the corn root-
aphis may be in large measure prevented by plowing land
intended for corn to a depth of six or seven inches early in the
spring followed by thorough and repeated disking to break up
the ants' nests and scatter the eggs of the aphis. This treat-
ment also destroys the weeds on which the root-lice get their
start. It also puts the soil in good tilth, making possible a
strong and rapid growth of the corn. Corn is most likel}' to
be injured by the root-aphis when the crop is grown on the same
land for two successive years. Much injury may, therefore,
be avoided by adopting a rotation in which corn does not
follow corn. As a supplementary treatment, S. A. Forbes
recommends the use of oil of tansy applied to each hill as a
deterrent for the ants. One fourth pound of oil of tansy
and 1 gallon of wood or denatured alcohol is mixed \\\t\\
100 pounds of bone-meal. This is enough for an acre and
should be ajjplicd with a fertilizer dr()p])er attached to the
planter. (Jareful preparation of the soil and thorough culti-
vation will tend to make the plants able to outgrow injury by
root-lice.

222 MANUAL OF VEGETABLE-GARDEN INSECTS

References

Forbes, 14th Kept. State Ent. 111., pp. 23-33. 1885.

Forbes, 18th Rcpt. State Ent. 111., pp. 58-85. 1894.

111. Agr. Exp. Sta. Bull. 44, pp. 237-2.56. 1896.

111. Agr. Exp. Sta. Bull. 104, pp. 102-123. 1905.

111. A^. Exp. Sta. Bull. 130. 1908.

111. AfTT. Exp. Sta. Bull. 131. 1908.

U. S. Bur. Ent. Teeh. Bull. 12. pp. 123-144. 1909. Bibliography.

U. S. Bur. Ent. Bull. 85. pp. 97-118. 1910.

111. Agr. Exp. Sta. Circ. Jan. 9, 1913.

The Southern Corx Root-Worm

Diahrntica duodecimjninctola Fabricius

The southern corn root-worm is also known as the twelve-
spotted cucumber beetle and in the South as the corn bud-worm

from the liabit of the larvsr of kill-
ing the bud or central leaves of
the young corn plant. The beetle
is generally distributed through-
out the I'nited States and .southern
Canada east of the Rocky Moun-
tains southward to Florida and
IMexico. It is injurious to corn
from .southern Illinois to Virginia
and .southward.

The beetle (Fig. 139) is about
^ inch in length, with the head
black and the thorax and wing-
covers yellowish green. Each
wing-cover is marked with six
black spots arranged in three transverse rows. The antenna
and legs are black; the first three joints of the anteiniu' and
basal half of the femora are pale. The l)ectles hibernate
under any convenient shelter, often in alfalfa fields. In the

Fig. 139. — The southern rorn
root-worm beetle ( X 5) .

CORN INSECTS 223

South they are dormant only for a few days at a time during
periods of cold weather, and in southern Florida and Texas
the beetles are active throughout the winter. The adults feed
on a great variety of plants both wild and cultivated. They
are often found in the blossoms of squash, pumpkin, melon
and cucumber, feeding on the pollen. They also attack
seedling cucurbits in much the same way as the striped
cucumber beetle and often gnaw holes in the fruit. They
sometimes seriously injure young beans, peas, cabbage, cauli-
flower, kale, turnip, mustard, rhubarb, asparagus, eggplant,
potato, tomato and beet and there is a record of their being
destructive to spinach in New Mexico. The beetles are often
found in the spring feeding on the blossoms of fruit-trees and
later in the season on the flowers of cotton and on the silk
of corn, but they are probably most abundant on the flowers
of various wild plants such as goldenrod, wild sunflower and
many others. The larva? are found most abundant on the
roots of corn but they also attack the roots of bean, rye, wheat,
millet, alfalfa, southern chess, barnyard-grass, Johnson-grass,
golden glow, Jamestown weed and pigweed (Amaranthus).

The beetle deposits her eggs in early spring in cracks and
crevices of the ground around the base of the plant. A single
female has been known to lay over 500 eggs, but the average is
probably much less. Only a few days are required for the beetle
to lay her full complement of eggs, but as all the beetles do not
mature at the same time, egg-laying will continue over a period of
a month or more. The egg is dull yellow, oval and about tV
inch in length. The eggs hatch in a week to over three weeks
and the young larva begins feeding on the roots. In the case
of young corn plants, the grubs often enter the stalk near
the upper circle of roots, killing the bud or inner leaves, or they
may eat out irregular holes in the root, often severing them
from the plant. The injury is usually most severe to corn
growing in low wet land. The larva becomes mature in fifteen

224 MANUAL OF VEGETABLE-GARDEN INSECTS

to thirty-five clays. It is then a slender ^nih, about V inch in
length, whitish or yellow ish in color w itli the head and cerxieal
shield brownish. When l'ull-<iTown, the lar\a leaves the j)lant
and constructs a small (>arthen cell within which it transf(jrms
to a small whitish pui)a, the beetles emerging in one to two
weeks. Throughout the greater ])art of the insect's range,
there are two generations annually. In the extreme South
where the beetles are acti\e during the entire year, an additional
generation may develop. The larvae of the second generation
are not so injurious to corn as those of the first but they some-
times injure the roots so that the ])lants are easily blown
over by storms and in some cases ripening is delayed and the
size and quality of the crop reduced.

In the southwest, a variety of the southern corn ro )t-W()rm
has received the name of tciuila Leconte. In this form the
sj)ots on the wing-covers are greatly reduced in size and the
posterior ones may be entirely lacking.

Confrol.

Injury to corn by tliis insect may l)e in large measure pre-
vented by ])lanting late, after the beetles ha\e deposited most
of their eggs. Corn jjlanted the first of May in Alabama will
usually escape injury. Farther north the corresponding date
would be somewliat later. In the case of sweet corn when
it is desirable to plant the cro]) early, it is often possible to get
a good stand in s])ite of the root-worms by planting an excess
of seed. A rotation of croj)s has not pro^'ed of nuich value in
preventing injury because the beetles are good fliers and readily
find their way to corn fields for egg-laying. Since the injury
to corn is usually most severe on low wet land, tile drainage is
often the most i)ractical method of solving the i)roblem.

When attacking cucumbers, stpiashes and melons, the beetles
may be controlled 1)>- the measures suggested for the striped
cucumber beetle on page 111.

CORN INSECTS 225

References

Garman, Psvche, 6, pp. 28-30 ; 44-49. 1891.

Ky. Agr. Exp. Sta. Kept, for 1890, pp. 9-22. 1894.

Quaintance, U. S. Div. Ent. Bull. 26, pp. 35-41. 1900.

U. S. Bur. Ent. Cire. 59. 1905.

Ala. Agr. Exp. Sta. Cire. 8. 1911.

S. C. Agr. E.xp. Sta. Bull. 161. 1912.

U. S. Dept. Agr. Bull. 5. 1913.

The Western Corn Root-Worm

Diahrotica longicornis Say

The western corn root-worm is also known as the northern
corn root-worm, neither name being especially appropriate ;
the former because there is no eastern corn root-worm and the
latter because the species also occprs in the South. Although
the insect ranges from Nova Scotia to Dakota and southward
to Alabama and Mexico, it has been noticeably destructive to
corn only in the specialized corn-growing region from Ohio to
Nebraska and Kansas. The winter is passed in the egg stage
in the ground, usually in fields in which corn grew the preceding
year. The egg is about 4V int'h in length, oval and dirty white
in color. The eggs are deposited by the beetles in late summer
or fall in the ground within a few inches of the corn plant. The
female burrows into the soil for oviposition and deposits her
eggs in loose groups from three or four to eight or ten. The eggs
hatch in the spring over a considerable period and the larvae
soon find their way to the roots of the young corn plants in case
the field is again planted to this crop. They feed on the
smaller roots and tunnel out the larger ones, making a slightly
sinuate burrow on the side of the root just below the surface.
Many of the roots are killed in this way and by the decay that
often accompanies the injury. After destroying one root, the
grub often attacks a second but as a rule does not burrow into
Q

226 MAXUAL OF VEGETABLE-GARDES IXSECTS

the crown. As far as known, corn is the only food plant of the
hirxjf, but it is probable that they also feed on the roots of
broom corn and sor<;huni. The injury to the roots inflicted by
the grubs, if severe, may cause the ])lants to remain dwarfed
and sickly or may merely weaken them so that few or imj)erfect
ears are produced. When many of the roots have been
destroyed, the corn is likely to be blown over by the wind. The
larvae mature from late .June to late August. They are then
elongate, slender, whitish grubs with the head, cervical shield

and anal plate yellow-
ish brown and are
about I inch in length.
When full-grown, the
larxa leaves the root
and transforms within
a snuill earthen cell to
a whitish pupa. The
beetles of the new
brood emerge o\er a
long perioil, from
about the first of July
until Sej)tember.
They are about ^ inch
in length and grass-green in color with the antennne brownish,
paler towards the base (Fig. 140). In Illinois the eggs are mostly
laid between the first of August and the early part of October.
There is only one generation anmially. The beetles feed on
the pollen and silk of corn and are often found on the blossoms
of buckwheat, goldenrod, smartweed, thistle and many other
wild plants as well as in the flowers of cucurbits. They some-
times gnaw into the unripe kernels of corn where the husk has
been broken and have been known to gnaw holes in the rind of
pumpkin and squash and to feed on the leaves of radish and
turnip.

140. — The western corn root-worm
beetle (X 8).

CORN INSECTS 227

Control.

Owing to the eggs of the western corn root-worm being
deposited only in corn fields, injury may be avoided by not
planting land to corn for more than two years in succession.

References

Forbes, 12th Kept. 111. State Ent. for 1882, pp. 10-31.
U. S. Dept. Agr. Bull. 8. 1913.

The Colorado Corn Root-Worm

Diahroticn virgifern Leconte

In Colorado, sweet corn is sometimes seriously injured by
a larva similar to that of the southern corn root-worm that
burrows into the stalk below ground. The female beetle is ^
inch in length and closely resembles the striped cucumber beetle
in general appearance, but in the male the wing-cover is black
except for a narrow yellow margin and a yellow spot near the
tip. The beetles are often troublesome in vegetable-gardens
where they feed on a variety of plants. The eggs are pale
yellow and about ^V i'l^^'l^ ^^ length. They are laid in the fall
in the ground near the corn plants and do not hatch till the
following spring. The larva is a little less than ^ inch in length,
pale yellow, with the head and anal j)late black. The insect
is apparently single brooded in Colorado.

Injury by this species may be prevented in large measure by
not growing corn for successive years on the same land.

Reference
Gillette, Jour. Econ. Ent., 5, pp. 364-366. 1912.

228 MAMAL OF VEGETABLE-GAliDE\ LW'iECTii

The Larger Corn Stalk-Borer

DiatrcEa zeacolella Dyar

In the southern states northward to Kansas and ^laryhind,
corn is sometimes attacked by a whitish caterpilhir marked with
dark brown spots. This insect is closely related to the su<jar-
cane borer and until recently the two have been considered the
same. These caterpillars bore into the stalks of young corn,
causing the plants to become dwarfed and distorted. They
often bore through the unopened leaves, producing groups
of small holes symmetrically arranged on the two halves of the
expanded leaf. The larva? of the second generation burrow into
the stalks below the second or third joint, weakening them so
that the plants are easily blown over by the wind. The insect
hibernates as a full-grown larva in a burrow in the tap-root
below the surface of the ground. Pupation takes j^lace in the
spring w'ithin the burrow and the moths emerge in ten days or
more. The straw-yellow moth, with an expanse of 1 to Ij
inches, lays her eggs in clusters of two to twenty-five, either on
the lower or more rarely on. the upper side of the leaves of the
young corn. The egg when first laid is creamy white, grarlually
changing to orange-brown, flattened, oval, slightly convex
and about -^ inch in length. In the cluster the eggs overlap
and arc usually arranged in two, three or four rows. The egg
hatches in a week to ten days and the young caterpillars at first
feed on the upper leafy part of the young plant but soon bore
down into the stalk. There is considerable migration of the
caterpillars from plant to plant and a borer may leave the
stalk at one place only to re-enter at another point. The
caterpillars mature in twenty to thirty days. The full-grown
larva is about an inch in length, dirty white, usually marked
with numerous dark brown spots. When about to pupate, the
caterpillar cuts through the stalk an exit hole for the moth

CORN INSECTS 229

which is covered with silk and the burrow is phigged below with
a mass of frass. The shining brown pupa is nearly an inch in
length. The moths of the second brood emerge in six to ten
days and lay eggs for another brood of larvaj. These borers
riddle the stalks near the base with numerous burrows and
when mature descend to near the surface of the ground, where
they usually remain in the larval condition till the following
spring. These hibernating larvte are nearly pure white, the
brown spots having disappeared. There are apparently only
two generations annually.

Control.

The most practical measure so far suggested for the control
of this insect is the adoption of a proper system of crop rotation.
In this system corn should not follow corn. When it is necessary
to plant corn after corn, the stalks and stubble should be raked
up and burned before the moths emerge in the spring.

References

Comstock, U. S. Ent. Rept. for 1880, pp. 243-245. 1881.

Howard, Insect Life, IV, pp. 9.5-103. 1891.

U. S. Farm. Bull. 6.34. 1914.

Holloway, Jour. Agr. Research, VI, pp. 021-625. 1910.

The Lesser Corx Stalk-Borer

Elasmopalpus lignosellus Zeller

In the southern states, corn, sugar-cane, cowpea, bean and
peanut are sometimes attacked by a small greenish, brown-
striped caterpillar that burrows in the stalk at or just below the
surface of the ground. It is most injurious on thin sandy or
gravelly land. The insect has also been recorded as infesting
crab-grass and Johnson-grass. It ranges from Maine along the
coast to Pennsylvania westward to Iowa, Texas and southern
California and southward to Pataijonia.

230 MANUAL OF VEGETABLE-GARDEN INSECTS

Hibernation takes place in three stages: larva, pupa and
adult. In South Carolina the insect usually enters the winter
in the larval state but may transform to a pupa before spring.
The egg is greenish white to rc>ddish, ovate, about -^ inch in
length. The time and method of depositing the eggs in the
field have not been recorded. The eggs hatch in about three
days in the summer and in five days to a week in the fall.
The caterpillars burrow into the young corn plant near the
surface of the ground and kill the central tuft of leaves, often
causing the plant to die or leaving it in a dwarfed, deformed
condition, incai)able of bearing a crop. The larva becomes
mature in two or three weeks, depending on the season. In the
late, fall it may require nearly six weeks to reach maturity. In
the course of its growth, the larva molts from four to six times.
When full-grown, it is about f inch in length, greenish in color,
whitish above and the body is marked with nine narrow longi-
tudinal brownish stripes and crossed by a broad brown band
on the posterior margin of each segment. The head and cervical
shield are shining dark brown, with a pale line running over the
top of the head and crossing the shield. The larvae do not
remain in their burrows in the plant except when feeding but are
usually found in a thin silken tube, in which bits of excrement
and grains of sand are incorporated, attached to the side of the
plant just below the surface of the ground. In feeding on the
older corn plants, they not only burrow into the stalk but also
girdle the plant, causing it to break over easily. Several larvte
may infest a single ])lant. When mature they construct oval
silken cocoons covered with particles of sand and dirt in which
they transform to brownish pupne about ^ inch in length. The
moths emerge in one to three weeks, depending on the tempera-
ture. The moth has an expanse of f to 1 inch. In the male
the front wings are light brownish yellow, usually dark gray
on the margins with two or three small dark sj)ots on the disk.
The hind wings are whitish, edged with light brown. In the

CORN INSECTS 231

female the front wings are darker, sometimes nearly black but
forms occur in which they are reddish. The moths are inactive,
feign death when disturbed, and fall to the ground with wings
and antennae drawn closely to the body. Their flight is swift
but of short duration. There are apparently four generations
annually in South Carolina.

The injury caused by the lesser corn stalk-borer may be
prevented in part by clearing the field of crop remnants in
the fall and by plowing the land in late fall or early winter
to destroy the insects in their winter quarters. In some cases
early planting will cause the crop to escape serious infestation.

References

Riley, U. S. Ent. Rept. for 1881 and 1882, pp. 142-145.
U. S. Div. Ent. Bull. 23, pp. 17-22. 1900.
U. S. Dept. Agr. Bull. 539. 1917.

The Brown FRUiT-rnAFER

Euphoria indn Linnaeus

The ears of sweet corn are sometimes injured in the fall
by a thick-set, yellowish brown beetle ^ inch or more in length.
Its wing-covers are sprinkled all over with small, irregular black
dots. The^e beetles appear in late summer or early fall and feed
on the pollen of flowers, ripe fruit and corn in the milk. They
attack the tip of the ear, working down under the husk and
devouring the unripe kernels. After feeding for some time, they
go into hibernation and very early the next spring may be seen
flying close to the ground with a loud buzzing sound.

The female deposits her white, nearly spherical eggs in the
vicinity of manure heaj)s, in piles of rotting sod and other
decaying vegetable matter. When full-grown the larva is some-
what over an inch in length, strongly curved and dirty white
in color; the posterior part of the body has a dull leaden hue

232 MANUAL OF VEGETABLE-GARDEN INSECTS

from the contents of the alimentary canal. It differs from the
white grub (Lachnosterna) in its shorter and more robust form,
in the shorter legs and smaller head, and in its habit of crawling
on its back. In July the larvje pupate within earthen cocoons
of a somewhat angular external form. The beetles emerge
during August and September. There is only one generation
a year.

Hand-picking of the beetles is apparently the most practicable
means of controlling this insect when it is found working on
sweet corn.

Stixk-Buc.s

Two species of stink-bugs, Eu.s-c}dMu,s carioldriii.s I'alisot de
Beauvais and E. cuschiMoides Snellen van Vollenhoven, some-
times injure sweet corn l)y puncturing the
kernels through the husk. They suck out
the juice, causing the kernels to become
sunken or to pop open. The injured
kernels become infected with mold.

These stink-bugs are about \ inch in
length, dull grayish
brown, sometimes tinged
with reddish or greenish
and dotted with innncr-
ous black punctures. In
/•>. I'oriolarius (Fig. 141)
the sides of the ])ri)-
thorax are acutely pointed, wliile in /-'.
euschistoides (Fig. 142) they are rounded.
In the male of the former, there is a dis-
tinct black spot on the iniderside of the last
abdominal segment.

The first mentioned of these bugs has also been recorded as
injuring tobacco, raspberries, peaches and strawberries. It has

Fu i. 141. — Ensch is-
lus variolarius, adult
(X2).

Fi(i. 142. — iiuschistus
ruschistoides, adult
(X2).

CORN INSECTS 233

been known to puncture ripening tomatoes and the stems of
melon, asparagus and the pods of okra. The adults are to
be found throughout the summer and the insect is said to hiber-
nate in this stage. The life history of each species has not been
fully recorded.

These stink-bugs are most abundant on corn and tomatoes
raised in the vicinity of waste land grown up to rank weeds.

Other Corn Insects

Cabbage web worm : 16

Seed-corn magfjot : 36

Green soldier-bug : 42

False chinch-bug : 47

Yellow bear caterpillar : 357

Carrot beetle : 185

Negro-bug : 196

Western twelve-spotted cucumber beetle: 114

Belted cucumber beetle : 115

Common stalk-borer : 157

Burdock borer : 160

Bean leaf -beetle : 65

Garden flea-hopper : 77

Spotted cutworm : 262

Well-marked cutworm : 263

Greasy cutworm : 26.5

Dark-sided cutworm : 268

Striped cutworm : 270

Dingy cutworm : 271

Granulated cutworm : 273

Clay-backed cutworm : 274

Variegated cutworm : 27()

Glassy cutworm : 279

Yellow-headed cutworm : 2S1

Spotted-legged cutworm : 282

Bristly cutworm : 28.5

Bronzed cutworm : 286

Army cutworm : 287

Fall army-worm : 292

Beet army-worm : 294

Yellow-striped army-worm : 295

Black blister-beetle : 307

234 MAXUAL OF VEGETABLE-GARDES IXSECTS

Potato flea-beetle : 314
Pale-striped flea-beetle : 3121
Smartweed flea-beetle : 323
Western cabbage flea-beetle : 327
Desert corn flea-beetle : 334
Millipedes : 342
Slugs : 354

Wheat mreworm : 348
Sugar-beet wireworm : 349
Corn and cotton w-ireworra : 349

CHAPTER XII

SWEET POTATO INSECTS

The sweet potato in the United States is not, as a rule,
subject to serious injury by insects, except in limited areas
where the weevil has become established. When the plants
are just set out, they are likely to be attacked by flea-beetles
(see page 332) and by tortoise beetles. In Florida the late
crop is often seriously injured by the sweet potato white-fly.

The Tortoise Beetles

Sweet potato vines are subject to injury soon after trans-
planting by several species of tortoise beetles that eat out
more or less circular holes in the leaves. These leaf-beetles
are flattened below and convex above and have the margins
of the prothorax and wing-covers broadly expanded and more
or less semi-transparent, giving the insect a regularly oval
outline. The head is concealed under the expanded margin
of the prothorax. The beetles have a striking resemblance
in form to miniature turtles — hence their common name. The
larvae are sometimes known as peddlers from their habit of
carrying their cast skins and excrement in a pack over the
back supported on two k)ng spines arising at the ])()steri<)r
end of the body. Along the edge of the body is a row of rather
large branched spines.

In Xew Jersey, the beetles aj)pcar on the sweet potato ])lants
as soon as they are transplanted in late May or early June
and, after feeding for a time, lay eggs from which a new brootl

235

23G MAXUAL OF VEGETABLE-GARDEN INSECTS

of lioetles is prodiKXMl in July. The new beetles feed for a
short time and then ^o into hibernation. There is only one
generation a year, at least in the northern states.

The striped tortoise beetle, Cassidci biciftata Say

This is the commonest and most injurious species attacking
sweet potatoes in New Jersey and is widely distributed thronyh-
out the regions in which this croj) is grown in the eastern I'liited
States. The beetle (Fig. 143) is about -^ inch in length ; the
prothorax is reddish with the margin yellowish ;
the wing-covers are dull yellow marked with fi\e
longitudinal black stripes; the underside of the
body and the legs are dark brown or black. The
beetles appear in the field in early si)ring and
feed for a time on A\iM morning-glory and attack
the sweet potato ])lants as soon as they are set
T? 1 ..J ^i. <>ut in the field. The eggs are glued to the under-

FiG. 14.1 — The _ , '^'^ ^

stripod tor- sidc of the leaves singly and hatch in a few days,
beetle rp|^^ lar\a is yellowish white with a grayish longi-
tudinal line along the middle of the back. This
larva differs from the other species infesting the sweet potato in
not mixingexcrement with the cast skins carried on the anal fork.
This a])pendage is not c-arried close to the back but is usually
elevated at an angle of about 45 degrees. When full-grown,
the larva attaches itself to the leaf by the tij) of its Ixuly and,
after resting for two days, the lar\al skin s])lits along the back
and is pushed back towards the hind end of the body where it
is retained surrounding the point of attachment. When fully
colored, the {)Ui)a is dull brownish and may be distinguished
from the other species by the elongate whitish mass of cast
skins on the anal fork which still adheres to the insect. The
beetles emerge in July and after feeding a short time on the
leaxcs of sweet jjotato and wild morning-glory go into hiber-
nation earl\'.

toise
(X5).

SWEET POTATO INSECTS

237

The black-legged tortoise beetle, Cassida nigripes Olivier

This beetle (Fig. 144) is a little over \ inch in length. When
at rest in the sunshine, it is of a beautiful golden tint but loses
its brilliancy when disturbed and after death fades to a yel-
lowish brown. Each wing-cover is marked with three black
spots arranged in a triangle. The legs and
the tip of the antennae are black. The eggs
are laid in rows of three to twelve on the
stems of the plant. The larvae are bright
straw-yellow with a curved black mark on
each side of the prothorax. The spines along
the side of the body are tipped with black.
The anal fork is carried close to the back and
the excrement is arranged in a characteristic -piG. 144. — Tho biaok-
manner with long shreds extending out side- legged tortoise beetle

• • ( X 5)

wise. The pupa is dark brow^n with the

lateral spines transparent white. The larvae reach maturity in

about two weeks and the pupal period is nearly as long.

The golden tortoise beetle, Coptocycla bicolor Fabricius

When basking in the sunshine, this beetle has been likened
to a drop of molten gold ; the coloration becomes duller, how-
ever, when the insect is disturbed or in
cloudy weather and after death fades to a
light reddish brown. The scientific name,
bicolor, was apparently given because of
the contrast between the golden central
part of the body and the thin semi-trans-
parent margin. The beetle (Fig. 145) is
a little over -^ inch in length. The
eggs are glued singly to the underside of
the leaf. The egg is about ^V i'l^'h in length, dirty white in
color, rounded below, ridged on the sides above and is usually
armed at one end with three sharp diverging spines. The

Fig. 145. — The
golden tortoise
beetle (X 5).

238 MANUAL OF VEGETABLE-GARDES INSECTS

larva is dark brown in color, lighter on the back and is com-
pletely covered by the large mass of excrement carried on the
anal fork. The larva becomes mature in about eighteen days
and transforms to a brown pupa with three dark stripes on the
transparent prothorax. The coxering of excrement is retained
during the pupal period, which lasts a week to eleven days.
In addition to sweet potato and wild morning-glory, this in-
sect occasionally feeds on bittersweet.

The mottled tortoise beetle, Coptocycla sign if era Ilerbst

This beetle (Fig. 146), which is about \ inch in length, is readily
distinguished from the others feeding on sweet potato by having
the disk and tlie front margin of the wing-
covers black, mottled with gold or yellow.
The disk of the prothorax is black and
contains two yellow spots. The larva is
green in color, bluish along the back. The
excrement is arranged on the anal fork
„ ,.„ „, , in broad masses, sometimes with shreds

Fig. 146. — The mot- _ '

tied tortoise beetle extending from the sides. The larva be-
^^^^* comes mature in about sixteen days and

transforms on the leaf to a green pupa marked with a con-
spicuous black ring around the first abdominal spiracle. This
species is not confined to sweet potato and wild morning-glory
but also attacks buckeye and thorn.

The orgus tortoise beetle, Chelymorpha argus Herbst
This species has been reported as occasionally attacking the
sweet potato. It is ^^ to ^s i"C"h in length and varies in color
from brick-red to day-yellow. The wing-covers are marked
with thirteen black spots and the prothorax usually with
six, arranged in two rows. It has also been reported as
feeding on milkweed, sunflower, wild morning-glory and
horse-radish.

SWEET POTATO INSECTS

239

Control.

Tortoise beetles are readily killed by spraying the vines
with arsenate of lead (paste), 2 pounds in 50 gallons of water,
taking care to spray the mixture on the underside of the leaves.
The young plants may also be protected frorn injury by dipping
them in a mixture of arsenate of lead and water as recommended
for the control of the sweet potato flea-beetle on page 333.

Reference
Walsh and Riley, Am. Ent., 1, pp. 234-238. 1869.

The Sweet Potato Weevil

Cylas formicarius Fabricius

This highly destructive pest of the sweet potato is a native
of the tropics. It was first seen in the southern United States
in 1875 and now occurs from Georgia and
Florida westward along the Gulf of IVIexico
into Texas. The insect is also found in India,
Australia, Cochin China, Java, ISIadagascar
and the West Indies. The adult is a slender
snout-beetle about j inch in length (Fig. 147).
The head is dusky black ; the prothorax and
legs are reddish and the wing-covers a metallic
bluish black. The prothorax is strongly con-
stricted near the hind margin ; the snout is
stout and is carried projecting forward. The
beetles are decidedly ant-like both in form and
coloration. While they possess functional wings, they rarely
use them, but are sometimes attracted to lights.

The beetle deposits her creamy white, elongate oval eggs,
about ^ inch in length, singly in a small hoUow eaten out
in the stem or in a tuber that has become exposed. The eggs
hatch in four to six days. The larvae hatching in the stems

Fig. 147. — The
sweet potato
weevil (X 41).

240 MAXVAL OF VEGETABLE-CARDEX IX SECTS

l)urr(»\v (lownwanl tliroufjli tlio center to the tiiher. On reach-
ing the potato, its bnrrow becomes somewhat larger and winds
aimlessly througli tiie flesh. The full-grown larva is about
-j^ inch in length, the body is white and the head yellowish
or brownish. The grubs become mature in two to three weeks.
The tissue surrounding the burrow becomes discolored and decay
sets in, giving the tuber a peculiar odor. When mature the
grub eats out an oval cavity and after resting a day or two
transforms into a white pupa about ^ to ^ inch in length. The
pupal period occupies five to eight days, and after waiting
two or three days to harden, the beetle eats its way out of the
pupal cell. The beetles may then either leave the potato or
may deposit eggs for another brood in the same tuber. Several
hundred larvje may occupy the same potato and breeding may
continue until all food material has been destroyed. Gen-
eration after generation follow each other as long as food is
available, but the beetles are able to exist for a long period
without eating and resume re])r()ductive acti\ity when food is
again available. The life cycle is completed, under favt)rable
conditions, in about a month. The beetles are rather general
feeders and are often found feeding on sjH'cies of wild morning-
glory and it is believed they can breed in these plants.

The sweet potato weevil is a most destructive pest and has
caused the abandonment of the growing of sweet potatoes in
many localities. It is especially injurious to the potatoes in
storage pits, where breeding may continue until the tubers are
entirely consumetl.

Control.

Under conditions obtaining in the southern states, the in-
juries inflicted by this weevil may be pre\cnted in large measure
by not planting sweet potatoes on or near infested fields. In
some localities it would ])ay to abandon the crop over a large
area for two or three years in order to starve out the weevils.

SWEET POTATO INSECTS 241

Infested tubers should not be left in the field. Those only
slightly injured may be fed to stock but those more badly in-
fested shoukl be burned or buried deeply. Care should be
taken not to introduce the weevil into uninfested localities by
means of infested tubers used for seed.

References

Tryon, Queensland Agr. Jour., 7, pp. 176-189. 1900.
Tex. Agr. Exp. Sta. Bull. 93.

Maxwell-Lefroy, Mem. Dept. Agr. India, Ent. Series, 2, pp. 155-159.
1910.

The Sweet Pot.vto Leaf-Roller

Pilocrocis tripunclata Fabrieius

A leaf-roller has been reported as occasionally injurious to
sweet potatoes in southern Texas. It is a native of the West
Indies and occurs sparingly in Louisiana and Florida. The
larvse are bluish green in color with the head pale yellow, and
when mature are almost an inch in length. The caterpillars
feed on the foliage and fold the lea\-es, thus making a retreat
within which the larva lives and within which it spins its cocoon.
The pupa is dark brown and about f inch in length. The moth
has an expanse of about an inch and is light yellow in color.
The front and outer edge of the front wings are grayish brown.
There is a nearly straight brown line across the base of the
front wing and a wavy line of the same color three quarters
the distance from the base on both wings. There are two
black spots near the front margin of the front wing and one
on the hind wing. There are several generations annually,
about twenty-five days being required for the completion of
the life cycle.

This sweet potato pest may be controlled by s])raying the

vines with arsenate of lead (paste), 4 pounds in 50 gallons of

water. „

Reference

U. S. Dept. Agr. Bull. OOO. 1917.

242 MAX UAL OF VEGETABLE-GARDES INSECTS

The Sv>'eet Potato Wiiitk-Fly
Bcmisia inconsirictia Quainlance

In southern Florida sweet potatoes, especially the late crop,
are often subject to very serious injury by this species of white-
fly, which in <;eneral appearance is similar to the conimon green-
house white-fly. The eg«;s are deposited on the underside of
the leaves and hatch in about a week. The nymphs are often
abundant enough nearly to cover the entire under surface of
the leaf, sucking out the sap and sometimes killing the plant.

This white-fly may be controlled by one or two appHcations
of soap solution or kerosene emulsion applied to the underside
of the leaves.

Other Sweet Potato Insects

Gardt'ii webworm : IS
Nezara viridula : 43
Yellow bear eateri)illar : 357
Carrot beetle: 1<S.")
Potato aphis : 1 ")()
Garden llea-hojjpcr : 77
Dark-sided eutworm: 2('»8
Striped cutworm : 270
Dingy eutworm : 271
Clay-hacked eutworm: 274
Variefjated eutworm : 27(i
Army-worm : 288
Fall army-worm : 292
Ash-}^ay ])lister-beetle : 300
Pale-striped tlea-beetle: 321
Sweet i)otato flea-])eetle: 332
Hoot-knot iKMnatode: 338
Corn and eotton wireworni : 349

CHAPTER XIII
ONION INSECTS

Onions are subject to attack by a relatively small number
of insects. The most important of these are the onion maggot
and the onion thrips, but occasionally cutworms and wire-
worms may cause serious loss.

The Onion Maggot

Phorbia ceparum Meigen

In Europe and America, onions are often severely injured
by the attacks of a small white maggot that feeds on the under-
ground stem or in the bulb. The maggots may attack and
destroy the plants soon after the seeds have germinated, and
the failure to obtain a stand is, therefore, often attributed to
poor seed.

The flies appear in the onion fields in the spring and the
female deposits her smooth, white, elongate oval eggs, which
are slightly grooved on one side and about ^ inch in length,
in the base of the leaf-sheath, on the side of the stem near the
ground, and in cracks and crevices of the soil. The eggs hatch
in three to ten days and the young maggot works its way
down along the stem, usually within the sheath. If the plant
is very young, the maggot may so injure the stem that the
whole top dies. When the plants are older, the maggots bur-
row into the bulb and cause decay to develop. Several maggots
are often found in a single bulb. The full-grown maggot is
nearly ^ inch in length, smooth, and dull whitish in color. The

243

244 MAMAL OF VEGETABLE-GARDEX I X SECTS

maggot is largest at the hind end of the body and tapers to a
point at the head. Posteriorly the body is obliquely truncate.
The flat surface is surrounded by a row of tv.-elve fleshy tubercles,
of which the middle lower pair are single-pointed and not two-
toothed as in the case of the cabbage root-maggot. In the
onion maggot, in addition to the two tubercles just back of the
vent, there are two smaller ones on the ventral side just in
front of the two large ventral marginal tubercles ; they aid the
larva in crawling.

The maggots become full-grown in two to three weeks in
green onions. In second-year onions, they develop more slowly
and sometimes require four or five weeks to reach maturity.
When full-grown, they transform to pupje within the hardened
larval skin or pui)arium, generally in the ground surrounding
the plant ; sometimes the transformation takes place within
the bulb. The puparium resembles a grain of wheat in form,
is of a chestnut brown color and about \ inch in length. The
flies closely resemble those of the cabbage and seed-corn mag-
gots but the males may be separated by the characters given
in Fig. 26. They emerge from the puparia in about two
weeks and lay eggs for another brood. There are at least two
or three broods annually. The insect hibernates principally
in the form of puparia, but both maggots and flics some-
times survive the winter.

Control.

The onion maggot has been found rather difficult to control.
Carbolic acid emulsion applied as described under cabbage
root-maggot, page 33, has been found of some value for killing
the eggs and young maggots. Clean cultivation and rotation
of crops are widely r('c;)nniiende(l to prevent maggot attack.
Recent experiments in Wisconsin have shown, however, that
since the flies require from ten days to two weeks after emer-
gence in which to mature their eggs for deposition, the insects

ONION INSECTS 245

can be more easily and satisfactorily controlled by killing them
with a sweetened poison spray. The most satisfactory results
have been obtained by using the following formula :

Sodium arsenite I ounce

Water 1 gallon

Molasses 1 pint

This material should be sprinkled over the plants and sur-
roimding soil when the flies first appear so that they may be
killed before laying their eggs. The application should be
repeated at intervals of a week, or oftener during rainy seasons.

References

Cornell Agr. Exp. Sta. Bull. 78, pp. 495-49G. 1894.

N. J. Agr. Exp. Sta. Bull. 200. 1907.

Conn. Agr. Exp. Sta. Kept, for 1911, pp. 286-292.

Severin and Severin, Jour. Ec. Ent., 8, pp. 342-3.50. 191.5.

The Onion Thrips

Thrips tabaci Lindeman

Onions are subject to injury by a small yellowish thrips
which punctures the epidermis of the leaves, sucks out the
juices and causes the plants to turn whitish, wilt and fall down.
This trouble is known among onion-growers as white blast.
The onion thrips is almost cosmopolitan in its distribution,
occurring in Europe, North America, South Africa and Aus-
tralia. In the United States it has been reported from nearly
all parts of the country and is present in southern Canada.
In some seasons this insect is the most serious enemy of the
onion crop on the muck lands of New York, Ohio and Indiana
and in the Bermuda onion regions of Texas. It sometimes
seriously infests cabbage and cauliflower and is found on many
wild and cultivated plants including cucumber and melon.
In Europe it is a serious enemy of tobacco.

24G .u.t.vr.iL OF vegetable-garden insects

'u\wM^^

Fig. 148. — The onion thrips, adult
female (X 30).

The onion thrips passes the winter in both the achilt and
nymphal state on onion plants left in the field. It is also

probable that the thrips
hibernates in the rubbish
/J/fM> •'ground the edgeof the field,
•'r^.J-A since the infestation usually
beijins along the weedy
borders and gradually
spreads over the remainder
of the field.

The adult female thrips
(Fig. 148) is about tjV i'lt-h
in length and varies from
light yellow to brownish
yellow in color. The wings are long and narrow and bear on
the hind margin a fringe of long hairs. The male is rari'ly
found and the females normally reproduce with-
out being fertilized. The egg is translucent
white, irregularly bean-shaped and about too
inch in length. It is inserted nearly its full
length into the tissue of the leaf; the tip of
the smaller end projects slightly above the
surface. The eggs hatch in five to ten days,
the longer period being the more common.
The newly hatched nymj)h is about -eu inch in
length and translucent white in color witii tiie
eyes bright red (Fig. 149). After feeding, the
body assumes a greenish color from the ingested
food. The first stage lasts about two days but in
some cases the period is longer. In the second
stage, the insect is about ^V inch in length and
v-aries in color from pale yell:)w to lemon-yellow
(Fig. 150). These second-stage nymphs comi)lete their growth
in ab;)ut ten days after hatching ; they then leave the plant and

Fui. 14'J. — The
onion thrip.s,
first staRP

nynii)h ( X 75).

ONION INSECTS

247

enter the ground a short distance, where, by twisting and turning
their bodies, they construct small earthen cells. In these cavities
the insects molt and thus enter the third nymphal, or so-called
prepupal, stage. These third-stage nymphs are yellowish
white in color and the wing-pads extend to the middle of the
second abdominal segment. They do not feed in this stage
but remain quietly resting in their earthen cells.
They are able to walk, however, and when
disturbed soon crawl into hiding again. In
two or three days the insect molts and enters
the fourth and last nymphal stage (sometimes
known as the popular stage) . The fourth stage
is whitish in color and the wing-pads extend
to the eighth abdominal segment ; the body
is more spiny than in the preceding stages. In
this stage, which lasts from one to six days, the
insect remains in a quiescent condition and
takes no food. At the next molt the tlirips
becomes adult, returns to the plant and re-
sumes feeding. The life cycle is completed
in about twenty-six days. There are five or
six generations annually and breeding con-
tinues until stopped by cold weather.

A careful examination of infested onion plants at any time
during the summer will disclose the })resence of four stages of
the onion thrips, viz., eggs, first- and second-stage nymphs,
and winged adult females. The first- and second-stage nymphs
may be distinguished by the difference in size and by the more
distinc-tly yellow coloration of the latter. Both the nymphs
and adults feed on all parts of the leaves but are to be found in
greatest numbers hidden under the sheath at the base of the
leaves or between the young leaves at the center of the plant.
In feeding, the thrips punctures the epidermis of the leaf with
its sharp needle-like mouth-parts and then sucks out the juices

Fig. 150. — The
onion thrips,
second stage
nymph (X45).

248 MAXl'AL OF VEGErAHLE-aARDE.W IXSECTS

of the plant, killing the cells and causing them t;) turn whitish.
When the infestation is severe and the punctures consequently
very numerous and close together, the leaves lose their dark
green color and assume a dirty white or bleached appearance.
The tender leaves at the center of the plant do not turn white
when punctured by the thrips, but instead curl inward and
downward and present a thickened deformed appearance.

Badly injured plants wilt and the leaves fall over on the
ground ; in such cases, the bulbs do not make the proper
growth and the crop is of small size and inferior in quality.
The plants are most susceptible to injury by thrips during
June and July when they should be making their most ra|)id
growth. Thrips are most destructive in years of drought
because, under unfavorable conditions, the plants are less able
to outgrow the injury. Onions grown on poor soil or when
poorly cultivated are more likely to be injured by thrips than
when planted on good ground and well cared for. When
onions are grown for seed the thrips often infest the flower-
heads in sufficient numbers greatly to reduce the crop.

Infested cabbage and cauliflower leaves turn brownish or
rusty instead of dirty white, as in the case of onions. As a
rule the injury is confined to the outer leaves, and is usually
outgrown by the plants, provided other conditions are favorable.

Confrol.

Onion tlirij)s can be killed 1)\' api)lication of such contact
insecticides as whale-oil soap, kerosene eniulsinn and tobacco
extracts. The best results have been obtained by spraying
early, before the leaves turn down, with "Black Leaf 40"
tobacco extract, I pint in 100 gallons of water in which there
have been dissolved ."> ]).)Uiids of soap. There are great difficul-
ties ill applying the spra\' to large fields; heavy traction or
])ower sprayers caiuiot be eniploxed on the soft muck soil on
which onions .are usually grown. The knapsack sprayer can

ONION INSECTS 249

be used in the small onion patch but its use is too laborious
and expensive to be practical in the large commercial onion
field. To be effective, a considerable quantity of the liquid
must be utilized thoroughly to wet the plants and a strong
spray is needed to force the material down into the sheaths of
the leaves and between the tender leaves at the center of the
plant. Some better method of applying is needed in order to
make spraying for the onion thrips a practical success under
commercial conditions.

References

N. Y. (Geneva) Agr. Exp. Sta. Bull. 83, pp. 680-683. 1894.

Fla. Agr. Exp. Sta. Bull. 46, pp. 103-114. 1898.

J. C. Faure, Unpublished thesis, Cornell University Library.

The Barred-Winc.ed Onion Fly

ChcEtopsis nenea Wiedemann

Onions are occasionally injured by a yellowish or whitish
maggot about j inch in length, that burrows in the bulbs,
causing decay to ensue. The maggots of this insect have also
been found injuring corn, wheat, oats, sorghum and sugar-
cane and have been reared from the common reed. The larv.e
have also been recorded as parasitic on the common stalk-
borer and on a lepidopterous borer in cat-tail. The insect is
native to America and ranges throughout the eastern United
States from Canada to the West Indies. The fly is about te
inch in length with the head grayish and the thorax and abdo-
men metallic green. The wings are whitish crossed by three
broad brown bands. The life history of this insect has been
studied on oats. The female deposits her minute, elongate,
l)ointe(l white eggs just under the edge of the leaf-sheath,
singly or in groups of two to five. The maggots work down
inside the leaf-sheath where, when mature, they transform
into polished brown pui)aria about ^'V inch in length. In

250 MAMAL OF VEGETABLE-GARDEN IXSECTS

Michigan the maggots were found to winter in the onions.
There are said to be three or four broods annually.

References

Tnspot Life, 7, pp. .352-.3.54. 1895.

Mich. Agr. Exp. Sta. Bull. 200, pp. 20G-208. 1902.

The Black Oxiox Fly

Tritoxa flexa Wiedemann

Occasionally associated with the insect last treated are found
the maggots of another fly. This species is native to America
and ranges through the northern states from New Jersey to
Minnesota. The fly is te inch in length and dull black in color.
The wings are dull brown marked with three oblique whitish
bands. There are thought to be two broods annually. The
maggots sometimes continue to work in stored onions, reduc-
ing them to mere shells.

No satisfactory control for this onion pest is known.

Other Onion Insects

Cabbage web worm : 16
Seed-<'orn maggot : 36
Yellow bear caterpillar : .357
Sugar-beet webworm : 97
Belted cucumber beetle : 11.5
Garden springtail : 139
Bean aphis : 76
Spotted cutworm : 202
Greasy cutworm : 2().")
Dark-sided cutworm : 208
Striped cutworm : 270
Clay-backed cutworm: 274
Black army-worm : 27.")
Variegated cutworm : 276
Army cutworm : 287
Beet army-worm : 294
Black blister-beetle: 307
Root-knot nematode : 338

CHAPTER XIV

INSECTS INJURIOUS TO MINOR VEGETABLE CROPS

The crops treated in this chapter — • rhubarb, okra, salsify,
pepper, water-cress and lettuce — are not, as a rule, seriously
injured by insects and the control of these pests is of less im-
portance in the culture of these vegetables than in the case of
those previously treated.

Rhubarb

Rhubarb is not usually seriously affected by insects. Its
most important enemies are the rhubarb curculio, the hop
flea-beetle, the spinach aphis, the bean aphis and certain species
of cutworms.

The rhuhnrh curculio, Lixus concavus Say

The leaf-stalks of rhubarb are often injured by the feeding and
egg-laying punctures of a rather large black, yellow-dusted
snout-beetle. The sap exudes from the wounds and collects
as glistening drops of gum. Fortunately the eggs do not hatch
when deposited in rhubarb but are killed by the flow of sap.
This insect ranges from New England to Idaho and southward
to Florida and Louisiana.

The beetle (Fig. 151) is about ^ inch in length and black in
color dusted with a yellowish covering which easily rubs off.
The head is provided with a curved snout on the end of which

251

252 MAXUAL OF VEGETABLE-GARDES' INSECTS

the .maii(lil)les are borne. The insect passes tlie winter usually
in the adult sta^re hidden away in dry sheltered places. The
adults appear in the spring and are often seen restinfj on the
stems and f()lia.ij:e of rhuharh and dock. They feed on the edge
of the leaves and puncture the stems with their heaks. The
female deposits her eggs singly in cavities al)out i inch deep
in the stalks of dock, sunflower, thistle and in the leaf-stems and
flower-stalks of rhuharh. The eggs are oblong oval, yellowish
white in color and about Ye hich in length. They hatch in a
week or ten days when deposited in their wild food i)lants but,
as previously stated, are not able to dexeloj) in rhubarb. On
hatching the larva burrows down through the stalk so that

when it reaches maturity it occu-
j)ics a ca^■ity just below the surface
of the ground. .Vlthough many
eggs are often laid in the same
stem, usually only one grub reaches
maturity. The full-grown lar\"a is
a footless grub about f inch in
length and is white with a brownish head. As the eggs are
laid over a considerable period from the flrst of June till the
middle of July, the grubs do not reach maturity at the same
time. The larval period occui)ies, on an a\eragc, eight or
nine weeks. In New Jersey the greater muuber are mature
b.\' the middle of Augu.st. The i)upa is white, about I inch
in length, and is found in a rather large caNity in the crown
of the plant just below the surface of the ground. The pupal
period occupies a little o\-er a week. After transformation
the beetle remains in the i)upal chamber for several dax s until
fnll_\' hiiideiied and then gnaws its way out and after feeding a
short time goes into hibernation. There is only one generation
anmially.

The beetles are easily seen resting on the plants and nia>' 1)0
readilx' captured and destroyed b>- hand. .Ml wild ])lants in

I'k;. 1.")1. — The rhubarb
curculio (X 2j).

INJURIOUS TO MINOR VEGETABLE CROPS 253

which the beetles breed should be destroyed in the vicinity of
rhubarb beds or a few dock plants may be left growing as a
trap in which the beetles will deposit their eggs, when they
should be destroyed before the grubs reach maturity.

References

U. S. Div. Ent. Bull. 23, pp. 61-69. 1900.
Weiss, Jour. Econ. Ent. .5, pp. 434-436. 1912.

Other rliuharh insects

Southern corn root-worm : 222
Yellow bear caterpillar : 357
Spinach aphis : 105
Common stalk-borer : 157
Burdock borer : 160
Bean aphis : 76
Spotted cutworm : 262
Striped cutworm : 270 '
Variegated cutworm : 276
Army cutworm : 287
Hop flea-beetle : 335

Okra

The insect enemies of okra are not numerous. TIi(> pods are
often attacked by the corn ear-worm and the buds and leaves
are injured by the caterpillar of the gray hair-streak butterfly.
The plants are also attacked by the spinach aphis and melon
aphis and are often defoliatcnl by the okra caterpillar.

The okra cater pillar , Annmis erosa Hiibner

Okra and roselle are likcl.\- to be defoliated by a green looping
cater])illar related to the cotton worm. This insect also feeds
on several species of hibiscus, abutilon, hollyhock and on
Urena lobata and is occasionally found on cotton. It ranges
throughout the southern Ignited States, the West Indies,

254 MAXliJAL OF VECETABLE-GARDEX IX SECTS

Soiitli Africa, Madai^ascar, Mauritius, the Oriental rojjion and
Australia.

The moth has an expanse of li to li inches. The front wing
has the outer marf^in an<jle(l at the middle. The l)asal half is
yellow usually shaded with li<,dit hrown and the outer half is
light pinkish brown often shaded with yellow. The hind wings
are pale yellow shading into oelier yellow towards the outer
border. The moth de])()sits her pale green, globular, slightly
flattened eggs singly on both the upper and under side of the
leaves. The egg is about ^ inch in diameter and marked with
a series of ridges radiating from the aj)ex. The eggs hatch in
about four days and the young caterpillar, after eating its
egg-shell, begins feeding on the leaf in which it eats out small
holes. The larger larvae (>at out irregular areas from the
side of the leaf and when abundant often tlefoliate the plant.
The cateri)il]ar passes through seven stages in the course of its
development and reaches maturit\- in about twenty-four days
in warm weather. It is then al)()Ut \^ inches in length, pale
])ea-green in color, inconspicuously marked with five narrow
broken yellow lines abo\(> and with a broader yellowish white
stripe on each side. While young the caterpillars suspend them-
selves by a thread when disturbed and are able to climb back
to the plant when the danger has passed. They walk with a
peculiar looping motion owing to the fact that only four pairs
of prolegs are present on the abdominal segments. When full-
grown the caterpillar transforms in a folded leaf into a blackish
brown pupa about f iiicii in length and in fixe days to two
weeks depending on tlu' sc-ason the moths emerge. In Florida
the life cycle requires nearly fi\-e weeks.

The caterpillars can be killed by spra> ing with arsenate of
lead (paste), 2 i)()unds in '){) gallons of water. Uecent experi-
ments also indicate that cirective work against the cater|)illars
can be done by spraying with " Black Leaf 40 " tobacco ex-
tract, 10 ounces in 100 gallons of water in which o or 0 pounds
of soap have been dissolved.

INJURIOUS TO MINOR VEGETABLE CROPS 255

References

Riley, Rept. U. S. Ent. for 1881 and 1882, pp. 167-170.

U. S. Bur. Ent. Bull. 126. 1913.

Dozier, Jour. Econ. Ent. 10, pp. 536-542. 1917.

Other okra insects
Spinach aphis : 105
Corn ear-worm : 211
Stink-bugs : 232
Harlequin cabbage bug : 38
Green soldier-bug : 42
Nezara viridala: 43
Striped cucumber beetle : 109
Belted cucumber beetle : 115
Melon aphis : 135
Gray hair-streak : 84
Semi-tropical army-worm : 297
Red-spider : 351

Salsify

The insects affecting salsify have not been carefully studied
and those that have been listed as injurious to this plant are,
as a rule, general feeders and have not been recorded as causing
any serious injury to this crop. The following insects treated
under other crops have been reported as attacking salsify :

Yellow bear caterpillar : 357
Tarnished plant-bug : 192
Yellow-striped army-worm : 295
Root-knot nematode : 338

Pepper

Peppers are subject to attack by a number of insects that
infest the potato, especially Hea-beetles and the spinach aphis
and potato aphis.

The pepper weevil, Anthonuinus eugenii Cano

In southern Texas and Mexico peppers are sometimes seri-
ously injured by a small shining blackish or reddish black snout-

256 MANUAL OF VEGETABLE-GARDEN INSECTS

beetle with a brassy luster, ro to s inch in len<;th. The weevils
are injurious in late sinnnier and fall. In IVediiii; they punc-
ture the buds and young fruits with their beaks iiiid the female
deposits her small white oval eggs, about 5V i"<^''i •■> length, in
the cavities so made. The eggs hatch in two to four days and
the young grubs feed on the surrounding tissue. The injured
buds are blasted and the infested fruits usually drop pre-
maturely. The grubs become mature in about two weeks.
They are then about ^ inch in length, white and strongly curved.
"When about to pupate, the larva constructs a cell of excrement
and bits of decayed tissue inside the fruit. The pupa is light
amber in color, about ^ inch in length and rather robust in
form. From six to ten days are spent in this stage. Soon after
transformation the beetle leaves the pupal cell but remains
within the fruit until thoroughly hardened, wlicn it gnaws out
an exit hole through the pod.

The pepper wcnnil may be controlled by collecting and
})urning all infested fruits once a week during the egg-laying
])eriod of the weevils. It is not advisable to grow peppers
year after year on the same land. In Mexico s|)raying with
l)aris green is said to ha\c been found of some \ahu' for the
control of this ])est.

Iii;rr.uKNCKs

U. S. Hur. Kill. Hull. r,\. pp. i:{ JS. 1<)0.").
U. S. Bur. Kill, liiill. (■>;;, i)|). .')."> .")S. I ".107.

Other pcpjur inxccla

Corn ear- worm : 21 1

Serponlino leaf-niiiRr : 1(1

Spiiiaf'h aphis : 10.")

Southern leaf-footed planl-huf^ : 121

Tomato worm : KiS

Nezara riritlula : 43

Belted eueumber beetle: 11.")

Colorado potato beetle : 142

INJURIOUS TO MINOR VEGETABLE CROPS 257

Potato aphis : 150
Common stalk-boror : 157
Garden flea-hopper : 77
Army-worm : 288
Semi-tropieal army-worm : 297
Potato fiea-beetle : 314
Western potato flea-beetle : 318
Root-knot nematode : 338
Red-spider : 351

Water-Cress

Owing to its semi-aquatic habit water-cress is comparatively
free from insect attack. In certain localities its most serious
enemy is a small crustacean, the water-cress sowbug.

The water-cress sowbug, Mancasellus brachyurus Harger

In the eastern United States water-cress is often seriously
injured by an aquatic species of sowbug that attacks the sub-
merged portions of the plant, cuts off the roots and stems and
causes large masses of the cress to float on top of the water.
This form differs from the species found in greenhouses by hav-
ing longer legs and antennae and being shrimp-like in form
when viewed from the side. It is about ^ inch in length and
gray in color. It often occurs in immense numbers so as to
destroy practically the whole crop.

Where cress is grown in natural streams or ponds, no j)rac-
tical method of controlling the sowbugs has been devised.
Some growers, however, have been able to overcome the dif-
ficulty by growing the plants in broad shallow beds sloping to-
wards the center, where a trough ten inches square lined with
boards extends the whole length of the bed. When the sow-
bugs become abundant, the water is shut off for twelve to
twenty-four hours allowing the beds to drain. Water is re-
tained in the trough, in which the sowbugs soon accumulate in
great numbers. They may be destroyed by the addition of

258 MANUAL OF VECET ABLE-GARDEN INSECTS

a liberal (juantity of copper sulfate solution. I>e.ss injury will
result to the i)laiits if the water is drained oil' soon after the
cress has been feathered.

Reference

U. S. Bur. Ent. Bull. 60, pp. 11-15. 1907.

The ivater-cress leaf-becllc, Pliadon wruginnsa Suflfrian

In the eastern United States water-cress is occasionally in-
jured by the lar\8e and a<lults of a small shininj;, bronzy black
leaf-beetle about i inch in length. The life history of this
insect is very imperfectly known. The full-tjrown larva is
about i inch in len<;th ; the head is shinint; black and the re-
mainder of the body is brownisii black. li<;hter between the
se^nuents and below. Its body is proxided with munerous
prominent tubercles from which hairs arise. Both larvie and
adults feed on the underside of the leaves.

No satisfactory method of controllinir this pest has been

devised.

Other icfitvr-crcss insects

Diamond-bafk iik)1]i : 12

Spiiuifh aphis : 10.")

Striped eabltaj;:*' tica-bcctle : .324

Lettuce

The most important insect enemies of lettuce are the cab-
ba^^e looper, the celery Iooiht and se\eral si)ecies of cutworms.
Sexeral kinds of i)lant-lice infest the j)lants and are especially
troublesome in <,'reenhouses. Slufjs and millii)edes often at-
tack the crop, sometimes causing considerable tlamage.

The lettuce root-louse, Rhizobius lactuccc Fitch

The roots of lettuce are often infested by a yellowish wing-
less plant-louse about yj inch in length which has the body

INJURIOUS TO MINOR VEGETABLE CROPS 259

dusted with a whitish powder and bears tufts of white waxen
threads. The insects often occur in dense masses on the roots
and may retard the growth of the plant. They are attended
by ants and are probably carried by them to new feeding
grounds. The hfe history of this species is very imperfectly
known and its wild food plants have not been determined.

The lettuce root-louse rarely causes enough injury to warrant
repressive measures.

Reference
Fitch, 14th Kept. State Ent. N. Y., pp. 360-363. 1870.

Other lettuce insects

Cabbage looper : 8

Garden webworm : 18

Turnip aphis : 27

False chinch-bug : 47

Celery looper : 191

Spinach aphis : 10.^

Western twelve-spotted cucumber beetle: 114

Belted cucumber beetle : 115

Garden springtail : 139

Bean thrips : 69

Garden flea-hopper : 77

Dark-sided cutworm : 268

Striped cutworm : 270

Variegated cutworm : 276

Glassy cutworm : 279

Yellow-headed cutworm : 281

Spotted-legged cutworm : 282

Clover cutworm : 284

Pale-striped flea-beetle : 321

Root-knot nematode : 338

Millipedes: 342

Slugs : 354

CHAPTER XV
CUTWORMS AND ARMY WORMS

Of all general crop j)csts, none is more ul)i(iuit()us nor per-
sistent in its attacks on trnck crops than a <;ronp of cater-
pillars of Xoctnid moths which has received the name of cnt-
worms or army-worms. I'nder favorable circumstances, almost
any cutworm may become so abundant as to migrate from field
to field in so-called armies devouring practically every green
thing in its path. The name army-worm, however, has been
restricted to two or three species in which the tendency to
adopt this habit has been highly developed.

Cutworms are smooth, nearly naked caterpillars varying in
length from 1 to 2 inches when full-grown, usually dull colored
and indistinctly marked with spots and longitudinal stripes.
The name cutworm has been well applied to these caterpillars
because of the habit of many species of cutting ofl' succulent
plants near or just below the surface of the ground. Cut-
worms feed mostly at night and spend the day cither in a
burrow in the soil or under the protection of stones and rubbish
near their food plants. Some species rarely come to the sur-
face at all but feed on the roots and underground stems.
Others, however, have the habit of climbing shrubs and trees
to feed on the buds, foliage and even the fruit. Species i)ossess-
ing this habit to a marked degree are sometimes known as climb-
ing cutworms.

When mature, cutworms transform through brownish puptu
into dull-colored, rather heavy-bodied moths. The wings are
marked with bands and spots which for convenience in

200

CUTWORMS AND ARMY-WORMS

261

description have received the names indicated in Fig. 152.
They are active only at night and many species are at-
tracted to hghts anfl to sugar baits. A large proportion
of the moths which fly into our rooms in summer evenings
belong to this family. Their glowing eyes and heavy tufts of
scales and hairs on the thorax together with their nocturnal

Transverse dnterior

Transverse posterior
SubtierTnin^l

I iMedian

iCkviform

TermiTkil

Fig. 152. — DiaKruni of the wiiig-pattcrn of a cutworm moth.

ha})its have given them the name of owlet moths. They are
rarely seen by day, being hidden away in sheltered places, as
under the loose bark of trees, in board piles and in crevices of
fences.

The si)ecies treated in this chapter are those which have
caused outbreaks of sufficient importance to attract the atten-
tion of entomologists. It is quite probable that other species
may have been concerned but so far have escaped detection.
These may at any time become so al)uii(ia:it as to cause serious

262 MANUAL OF VEGET ABLE-GAIiDEX IXSECTS

(laiiiaije. Tii this account all the more important facts known
re<farfling each species are ])resentetl hut nuich remains to be
learned of their habits and life histories. Here is a fruitful
field of investigation which warrants more attention than it
has received in the past.

The Spotted rTTwoiar
Kociua c-ni(jrum Linnajus

Tn the northern I iiited States and Canada the spotted cut-
worm is one of the most common and troublesome species.
It is generally distributed throughout the northern hemisphere.
In Asia it is found as far south as northern India ; it ranges
throughout all of Europe and in North America is most abun-
dant in the northern United States and Canada and has been
reported from ^lexico. This cutworm is a general feeder attack-
ing cabbage, tomato, turnip, potato, celery, rhubarb, onion,
pea, beet, carrot, mangel, corn, grasses, clover, violet, ferns,
lobelia, helianthus and chicory. As a climber it is reported as
injurious to the tips and buds of cranl)erry in Massachusetts;
it also feeds on currant and gooseberry. The caterpillars of
the July brood sometimes injure the fruit of the tomato. Tn

years of great abundance
they ma\' assume the army-
worm habit.

Fio. I5.'i. — The spotted cutworiii So far as known, the

^ spotted cut worms ])ass the

winter as partly grown cateri)illars. They become mature in
early spring. The lar\ a is 1 .V iix-hes in length, of a ])ale brownish
to ashy gray color. This s])e<ies may be easily recognized by
a double row of oblicpie triangular black spots on the dorsal
surface of the abdominal segments. These s])ots incTcase in
si/e and distinctness towards the posterior end of the body
(Fig. \'h\). On the side there is a more or less distinct dark

CUTWORMS AND ARMY-WORMS

263

stripe running tlircuigh the spiracles below which the color is
decidedly lighter than above. Pupation takes place in the
ground. The pupa is f inch in length and of a dark mahogany
brown. The pupal period varies from two to four weeks.

The moths are on the wing from late May to October and
apparently belong to two overlapping broods. The moth
has an expanse of 1^ to 2 inches (Fig. 154). The front wings
are rich purplish to reddish brown. The kidney-shaped spot
is usually tinged with reddish. Fr,)m this spot there extends
towards the base of the
wing a black bar deeply
incised by a triangular
light area which often
extends to the front margin
of the wing. The hind
wings are smoky, darker
along the outer margin.

The moth deposits her
eggs singly, in rows, or in
compact clusters of 200 or
more on leaves. The egg is hemispherical in shape, strongly
ribbed, almost transi)arent and is about ts inch in diameter.
There are probably two generations annually.

Fui. 154. — The spotted cutwurni iiioth
(natural size).

References

U. S. Div. Enl. Bull. 27, pp. 54-.^. 1901.
Dept. Agr. Canada Ent. Bull. 10, pp. 23-24.

191^

TiiK Wkll-^Iai{Ki:i) Citwoum
Noctna rhnidestina Harris

This cutworm is distributed from Nova Scotia to ^Flssouri
and Colorado, and nortiiward. Tt also occurs in Greenland
and Kamchatka. It has been rcjxirtcd as injuring the I'ltliow-
ing crops: corn, buckwheat, wheat, cabbage, cauliflower, bean,

264 MANUAL OF VEGETABLE-GARDEN INSECTS

"E^Epj^^^flSR^ easily recosi
.^Lh^2JtJ±^±^!^j:i!^^ row of di

pumpkin and other vegetables. As a climbing cutworm, it
attacks apple, currant and gooseberry. Among its wild food
I)lants are included soft maple, box elder and wild endive.

These insects hibernate as ])artly grown caterpillars which
become mature during 'Slay and June. The caterpillar is If

inches in length and is
niized by a double
listinct, oblicpie,

Fig. 1.55. — The well-marked cutworm black spotS OH the back

^^ ^-^' of the abdominal segments

(Fig. loS). The rows of black spots are bordered laterally
by a distinct yellow strij)c. The median yellowish stripe
is distinct. The reddish brown pupa^ are found buried
a few inches in the soil. The moths emerge during June and
July and have been collected as late as the middle of October.
During the day they have the habit of hiding under loose
bark, in crevices about buildings
and in fences. When at rest the
wings are folded closely one above
the other, giving the moth a flattened
appearance. The moth has an ex-
panse of li inches. The front
wings are of a dark, smoky brown

^^fv

color, the transverse lines j)alcr Fk;. 150. — The well-marked

I , r 4.' J- T>1 • cutworm moth (natural size).

and not very distinct. Ihe inner

spot is oval bordered with black; the rciiiforin spot is marked
with black on the inner side and the two are often united by
a black line. The hind wings are smoky, darker towards the
margin (Fig. 156). The eggs have not been described. So
far as known, there is onK' a sin<flc i^cneratidn aniniall\-.

References

Harris, Insects Injurious to Vegetation, pp. 32.5-.327. 1S41.
Cornell Aprr. E.xp. Sta. Bull. 104. pp. r)71-.574. 1895.

CUTWORMS AND ARMY-WORMS 265

The Greasy Cutworm

Agrotis ypsilon von Rottenburg

The p;reasy cutworm is cosmopolitan in distribution, occurring
in injurious numbers in Europe, Asia, Africa, North and South
America, AustraHa, New Zealand, the East Indies and Hawaii.
The caterpillar is a general feeder. Its food plants include
many wild species and the following cultivated crops : corn,
grasses, potato, tomato, cabbage, beet, eggplant, spinach, bean,
squash, cauliflower, cucumber, radish, asparagus, onion, straw-
berry, tobacco and cotton. In the United States and Canada
this cutworm is usually abiuidant, though on the whole not so
injurious as some of the other species.

Owing to the wide distribution of the insect, inchuling many
life zones, its seasonal history presents many variations. In
North America, hibernation occurs in either the larval or ])upal
stage. In Florida all stages of the larva have been found
during mild winters and in Texas and Georgia moths liaAe
been reared from pupfe plowed up in cotton fields during the
winter. It is quite probable that in the northern United States
and Canada hibernation takes place most commonly in the
larval stage, though winter pupje have been recorded from
Illinois.

The moths emerge over a considerable period, from June to
October, being most abundant in July and August. The
moth has an expanse of li to nearly 2 inches. The front
wings are dark brownish gray varying to dark brown, with
the apical third lighter in color and are crossed by a diagonal
light band in which are two black elongate spots. Near the
outer margin of the dark area is a characteristic U-shaped black
mark with a black dash extending from its outer side. The
hind wings are light brownish gra\' with a i)early luster; the
veins are brown (Fig. l.')?). I'^roni -Inly to Septenil)er the
females deposit their eggs in small (lusters on the leaves or

266 MANUAL OF VEGETA HLI'J-dARDK.W I. \ SECTS

stems of plants, usually near the ground. Eaeh female may lay
from 200 to 400 eggs. The egg is dome-shaped, about -^ inch
in diameter, and creamy white when laid, becoming darker
before hatching. At the top there is a slight depression from
which radiate many ridges extending to the base of the egg.

In Illinois, eggs laid in July were observed to hatch in twenty-
two days, while in Hawaii they hatch in only two or four days.
The young caterpillars are pale green, the black tubercles on
the segments showing prominently. Later the pale longitudinal
stripes become evident. When full-grown the caterpillar is li
to If inches in length, of a nearly uniform dark greasy gray

color with an indistinct mid-
dorsal yellow line and two
faint lateral stripes. It is
dark greenish yellow be-
neath. In the summer the
caterpillars require at least
a month to reach maturity.
They are voracious feeders
and have developed to a
high degree the habit of
cutting ofi" tender plants and
dragging them to their burrows. They feed mostly at night
and during the day remain hidden in burrows an inch or so
from the surface of the ground.

The mature caterpillars transform in earthen cells a short
distance below the surface into brownish pupa^ about t inch
in length. Observations in (\Tnada indicate that the length of
the pupal period in late summer is ai)out three weeks, while in
Illinois in early summer it is foin* weeks ; in Hawaii the i)upal
period is ten days to three weeks.

In Canada there are two broods annually, llic lar\a; of the
second brood hibernating in a partix' grown condition. This
is probably general for the ncjrthern United States and Canada,

Fig. 157. — The prcasy cutworiii moth
(luiturul size).

CUTWORMS AND ARMY-WORMS 267

though undoubtedly exceptions occur since pupae of the first
brood may not transform the same season.

References

Riley, Rept. U. S. Ent. for 1884, pp. 294^295.

Forbes, 23rd Rept. State Ent. 111., pp. 21-23. 1905.

Hawaii Sugar Planters' Exp. Sta. Div. Ent. Bull. 7, pp. 19-21. 1909.

Dept. Agr. Canada Ent. Bull. 10, pp. 16-17. 1915.

The Red-Backed Cutworm

Paragrolis ochrogaster Guenee

This destructive cutworm ranges from Nova Scotia to British
Cohimbia southward to Colorado and Missouri. It is more
abundant in the northern part of its range, being the most
injurious species throughout Canada. The larva is almost
omnivorous in its tastes, attacking any succulent plant, especially
cabbage, cauliflower, beet, radish and many annuals of the
flower-garden. It is a serious pest in the West to grain crops,
particularly oats, wheat and barley. This species may be dis-
tinguished from other common cutworms by the reddish color
of the upper surface of the body.

In eastern Ontario, the red-backed cutworm has been found
to hibernate in both the egg and larval stages. The over-
wintered eggs hatch the latter part of April and the caterpillars
become mature in about seven weeks. In its feeding ha})its it
resembles the greasy cutworm. The mature caterpillar is 1^
inches in length, reddish above with a pale median stripe ;
the reddish area being bordered on each side with a darker
band. The under surface is grayish to brownish. The head
and cervical shield are yellowish brown, and there are two
black spots on the vertex.

In Canada the caterpillars become mature during tin- latter
part of June and pupate in earthen cells from one to two inches
below the surface of the ground. The pupa is reddish brown

268 MAXFAL OF VECET ABLE-CARDEX IXSECTS

158. — The red-backed cutworm
moth (X U).

and about f inch in length. The moths emerge during tlie
hitter part of July and August and have an ex])anse of 1|-
to If inches. The front wings vary from i)ale day to dark

reddish or hlackish brown.
The wing is crossed on the
basal third by two wa\y
light lines. On the outer
half are two prominent
light spots, the inner one
nearly round, the outer
kidney-shaped. The hind
wings are brownish gray,
lighter in the center (Fig.
158).

Caterpillars hatching from eggs laid early in the season be-
come partly grown before cold weather and hibernate in this
condition ; some of the eggs laid late in the season do not
hatch till the following s])ring. There is apparently but one
generation a year.

References

Fletr-h(T, Rc])t. Canada Eiit. for 1904, pp. 22.3-22.").
Dept. Agr. Canada Eiit. Bull. 10, pp. ir>-10. iyi.'>.

TlIK DaUK-SiDED ClTWORM
Paragrolis messoria Harris

Tliis species is a native of North America, ranging from Xew
Jersey westward to Colorado and California and northward.
It is reported as very injurious in Ontario and Quebec. It is
especially destructive to garden crops and has the habit of
climbing young fruit-trees to feed on the opening buds. It is
recorded as feeding on the following plants: cabbage, si)inach,
lettuce, potato, tomato, bean, pea, radish, turnip, beet, onion, to-
bacco, sweet potato, corn, clover, buckwheat and grasses. It also
attacks the opening buds of apple, currant, soft majilc and grape.

CUTWORMS AND ARMY-WORMS

269

So far as known, the dark-sided cutworm passes the winter
in a partly grown condition. In the spring the caterpillars
resume feeding and become mature in June and July. The full-
grown caterpillar is slightly more than an inch in length. It is
dull grayish in color with the sides of the body decidedly darker.
Pupation takes place in the ground and the moths emerge in
about a month. Sometimes the emergence is retarded, the
pupal period extending over
eight weeks. The pupa is
about f inch in length, light
yellowish brown marked
with darker brown.

The moth has an expanse
of

front

to If inches. The
wings are brownish

- The dark-sided cutworm
moth (X U).

are
gray with darker, some-
times blackish markings
consisting of a double line Fig. 159.
extending halfway across
the wing at the base, a double wavy line one third the distance
from the base, a fainter single wavy line near the middle, an-
other double wavy line about two thirds the distance from the
base and just inside the outer margin there is an inconspicuous
line of the ground color lying in a blackish shade. The or-
bicular and reniform spots are both present, large and are out-
lined with black. All the markings are distinct, including the
median shade, but are not contrasted. The hind wing is dirty
white shading to brown towards the margin (Fig. 159). The
eggs of this species have not been described. There is but one
generation annually.

References

Riley, 1st Rept. State Ent. Mo., pp. 74-76. 1869.
Forbes, 23rd Kept. State Ent. 111., pp. .32-3.3. 1905.
Dept. Agr. C-.nada Ent. Bull. 10, pp. 20-21. 1915.

270 MAM'AL OF VEaETMiI.E-dARDEX IS SECTS

The Striped Cutworm

Paragrotis tessellala Harris

The striped cutworm is particularly a vegetable pest attack-
ing potato, tomato, sweet potato, radish, squash, cabbage,
lettuce, celery, spinach, bean, cucumber, melon, beet, carrot,
parsnip, onion and rhubarb. It is a serious enemy of alfalfa
in Colorado and may also feed on flax, buckwheat, clover and
corn. In Iowa it has been found injuring root-grafts of apple,
pear, plum and cherry. This cutworm is restricted to the

northern Tnited States and
Canada.

The striped cutworm
liihcrnatcsin a partly grown
condition and becomes ma-
ture in May and June.
The full-grown larva is
1^ inches in length, pale
brownish tinged with yel-
low above, grayish on the
sides and greenish below. It has a median pale stripe
bordered with brown ; a brownish subdorsal stripe, which
is bounded below by a light line ; a narrow distinct
white lateral stripe and a l)n»a(l white stigmal band. Pupa-
tion takes place in the soil, the \m\yd\ i)eri()d occui)ying from
two to three weeks. The moths arc most abundant during
July and August. The moth has an expanse of l-^ to 1^ inches.
The front wings are grayish to blackish brown sometimes with
a purplish tinge. The orbicular and reniform spots are distinct,
and between these spots, and extending to the second cross
line, is a contrasting dark brown or black area. There is a
tuft of yellow hairs at the base of the front wing. The hind
wings are brown becoming whitish towards the center and base
(Fig. IGO). There is but one generation a year.

Tig. KJG.

The striped cutwurin moth

(X U).

CUTWORMS AND ARMY-WORMS

271

References

Forbes, 23rd Rept. State Ent. 111., p. 34. 1905.
Dept. Agr. Canada Ent. Bull. 10, pp. 29-30. 1915.

The Dingy Cutworm
Feltia subgothica Haworth, F. ducens Walker, and F. jaculifera Guenee

Under the term dingy cutworm are included several forms,
the moths of which have been given separate names by special-
ists as indicated above. So far as known, the early stages
and habits of these forms are practically identical. This cut-
worm is widely distributed in the United States and Canada,
being more abundant in the northern part of its range. It is
a general feeder, its food plants including corn, wheat, grasses,
clover, strawberry, bean, pea, squash, cucumber, tomato, sweet
potato, cabbage and horse-radish. It sometimes assumes the
climbing habit and feeds
on the buds of various
fruit-trees.

The dingy cutworm hi-
bernates in a partly grown
condition, completing its
growth in the spring.
When mature it is H
inches in length, grayish
brown, with a very wide
buff-gray dorsal stripe out-
lined by a narrow dark stripe on each side. Pupation
takes place in the soil. The pupa is nearly I inch in length,
honey-yellow, with dark brown markings.

The moths are on the wing from early July to late Septem-
ber, being most abundant in August. The adult has an expanse
of It inches. The front wings are grayish brown marked with
darker brown and suffused with purplish. The kidney-shaped

Fig. 101. — Tlio diiiKV cutvvurni niotlr
(X U).

272 MANUAL OF VEGETABLE-GARDES IXSECTS

spot is distinct and rcddisli lirown ; tlio round spot is open in
front and confluent with a l)road inari^inal uray hand. The
hind wings are whitish, chirker toward the margin or in some
forms entirely ])rownish (Fii,'. 1()1). The e<;gs are hiid in
August and September. Tiie egg is about 5V inch in diameter,
dirtywhite with brown mottlings, dome-shaped and marked
with numerous ridges radiating from the apex. Tiiere is but
one generation annually.

References

Cornell Agr. Exp. Sta. Bull. 104, pp. 574-579. 1895.
Dept. Agr. Canada Ent. Bull. 10, pp. 2<>-27. 1915.

The Shaoreened Cutworm

Feltia malcfida Guenee

In the southern states cabbage, j^otato, cotton and clover
are sometimes attacked by a cateri)illar which, from its
roughened skin, has received the name of shagreened cut-
worm. This cutworm does most of its work
underground, living in a burrow into which
it drags leaves and stems which it cuts ott'
at night. The insect ranges from New
York to New Mexico and California and
southward to Argentina. 'J'he full-grown
larva is nearly li inches in length, grayish
brown in c()k)r with a very wide bufl" gray
dorsal .stripe. The head is pale brown with
a curved, dark brown stripe on each side of
iM.;^ Ui2. — The ^j^^. f.^^.^ When mature, the caterijillar

shagreened cut- .... . n • i

worm moth transforms withm its burrow mto a yellowish

^^^-■^- brown }nii)a about t inch in length. The

pupal ])eri()d in Texas \aries from fifteen to twenty-seven

days. The moth has an exi)anse of nearl\' \i inches. The

front wings arc powdery i)ale gra\- with the front margin dark

CUTWORMS AND ARMY-WORMS

273

gray. The reniform spot is conspicuous and dark gray. Just
behind the so-called round spot, which in this case is shaped
like a tennis racket, there is a distinct short bhick bar. The
hind wings are white, often lined with brown along the veins
and with a narrow brown margin (Fig. 162).

The seasonal history has not been carefully studied. The
moths of the summer brood are abundant in Texas in late
June and July. In Xew Jersey the moths are to be found in
September.

The Granulated Cutworm

Fellia annexa Treitsehke

This species is most abundant in the tropics. It ranges
through the West Indies, Mexico, Central America, southward
to Chile and Argentina and northward to Nova Scotia and
Minnesota. Among its food
plants are tomato, cabbage,
pea, bean, corn, wheat,
grasses, clover, cotton and
tobacco.

In the northern part of
its range the winter is
passed in the larval state.
The caterpillars reach ma-
turity in May and June.
The full-grown caterpillar is nearly li inches in length,
dark gray, with a pair of yellowish drab oblique marks on each
segment and a substigmatal })ale gray line borflered with yellow-
ish ; the underside of the body is i)ale greenish gray. Pupa-
tion takes place in the ground. The reddish brown pupa is
nearly | inch in length. The pupal period lasts from four to
six weeks. In the North there are two generations annually.
The first brood of moths is on the wing during June, July and
August ; the second brood in August, September and October.

Fig. 163. — The granulated cutworm
moth (X U).

274 MANUAL OF VEGETABLE-GARDES INSECTS

Tlu' inotli lias an expanse of about \\ inches. In tlie female
tlie front wind's are dark jfrayish hrown with the outer border
and a broad costal band clay-color. The orbicular and reni-
form sj)ots are small, distinct and connected by a black bar
(Fifj. 1()3). In the male the front winj^s are lighter and the
hind wings are pearl-white with the front margin brownish.
The eggs are white, about ^V inch in diameter and beautifully
ribbed, one third of the ribs reaching the apex. The eggs hatch
in about four days.

References

French, Can. Ent., 14, pp. 207-210. 1882.
lU. Agr. Exp. Sta. Bull. 95, p. 302. 1904.

The Clay-Backed Citwoum

Fellia gladiaria Morrison

The clay-backed cutworm is widely distributed in North
America east of the Rockies. Its food ])lants include ])otato,
tomato, sweet potato, bean, cal)bage, onion, corn, c1o\(t, oats
and grasses. This species, when abundant and lacking food,

may a(lo])t the army-worm
habit.

This cutworm hibernates
in the lar\al condition
and matures in early spring.
The full-grown caterpillar
is nearly \h inches in
length, dull greenish to
dark brown with a broad
median dorsal stripe \ary-
to brown. This median

I'lij. Hi4. — The clay-biickcd cutworm
moth (X \l).

ing in color from straw-yellow
.stripe has gi\en it the common name of clay-backed cut-
worm. The lar\a' enter the ground in June and remain
in the i)Upal condition for nearly six weeks. The moths

CUTWORMS AND ARMY-WORMS 275

are on the wing during September and October. The moth
has an expanse of about li inches. The front wings are
grayish brown, the orbicular spot small, the reniform spot in-
conspicuous. Through the middle of the wing there extends
a pale narrow streak in which is a fine forked black line. In-
side the subterminal line is a row of wedge-shaped black spots.
The hind wings are brownish (Fig. 164). There is but a single
generation a year.

References

Ky. Agr. Exp. Sta. Bull. .58, pp. 93-9.5. 1895.
111. Agr. Exp. Sta. Bull. 95, pp. 358-359. 1904.

The Black Army Cutworm

Noctua fennica Tauscher

Throughout the northern United States, Canada, northern
Europe and Asia and in the Alpine regions the black army
cutworm is found. It is more particularly a field crop pest,
being especially fond of clover and peas, and occasionally
assumes the army-worm habit, doing serious injury to grass-
lands and sometimes, when other food is not available, climbs
trees, feeding on the foliage and even the bark. Asparagus,
onions and other vegetables are occasionally attacked.

The lar\'{e hibernate in a half-grown condition and reach
maturity quickly in the spring. The full-grown caterpillar is
nearly If inches in length, beautifully striped with black and
white. The caterpillars transform to light lirown j)U])a> in
earthen cells in the ground and the moths emerge in about
ten days. The adults are on the wing from late June to the
last of August. The moth has an expanse of slightly more
than li inches. The front wings are chocolate-brown; the
spots are distinct, the reniform si)ot being reddish yellow and
the round one gray. The hind wings are pale, brownish on
the margin or entirely suffused with brownish. So far as
known, there is but one generation a year.

276 MAMAL OF VEGETABLE-GARDEX INSECTS

References

Lugger, 2nd Rept. State Ent. Minn., pp. 20-22. 1896.
Dept. Agr. Canada Ent. Bull. 10, pp. 27-28. 1915.

The Variegated Cutworm

Pcridroma margaritosa Haworth

Tlie varief::ate<l cutworm is nearly cosmopolitan in its dis-
tribution, occurring in North and South America, the West
Indies, Europe, northern Africa, southeastern Asia and Hawaii.
In Europe it is of little economic importance but in the northern
United States and Canada it is one of our most abundant and
destructive cutworms. It is always present in greater or
lesser numbers in this region and occasionally severe outbreaks
occur when the caterj)illars become so lumierous that the food
supply is exhausted and they assume the army-worm habit.
The most striking instance of such an outbreak was in 1900 in
the northwestern Fnitefl States and British Columbia. This
cutworm is a serious pest in greenhouses, where it gains entrance
through the use of rotted sod containing the caterpillars. It
has also the pernicious habit of climbing young trees and
vines to feed on the buds, foliage and fruit.

The variegated cutworm has the widest range of food plants
of any of its class. It has been recorded as seriously injurious
to the following vegetable crops : cabbage, turnip, radish, beet,
carrot, lettuce, celery, rhubarb, asparagus, onion, squash,
cucumber, potato, tomato, sweet potato, bean and i)ea. Among
field cro|)s it injures corn, wheat, various grasses, clover, hops,
sugar-cane and tobacco. Alfalfa is especially liable to attack
in the western Cnited States. Apple, cherry, pear, plum, prune,
peach, currant, gooseberry, raspl»crry, blackberry, strawberry
and grape are often severely injurcil. Of greenhouse and orna-
UK-ntal plants, it is knf)wn to feed on xiolct, ])ansy, carnation,
smilax, rose, sweet pea, hollyhock, sunflower, nasturtium and
chrysanthemum. It has also been recorded as attacking

CUTWORMS AND ARMY-WORMS

277

cedar, mulberry and box elder and such weeds as nettle, thistle,
dog fennel, fireweed and dock.

In the northern part of its range this species hibernates
either as pupte or as partly grown larvae. Farther south hiber-
nation occurs principally in the larval stage. The over-
wintered larvae emerge from hibernation in early spring and
may cause serious damage before reaching maturity. The
first brood of moths is on the wing in late May and early June,
the second brood in late
July, August and Septem-
ber. Occasionally in the
more southern localities
there may be a partial
third brood.

The moth has an ex-
panse of li to li inches.
The front wings are brown-
ish gray, washed toward
the front margin with
reddish in one form and with yellowish in the other.
The round and kidney-shaped spots are distinct, the latter
being the darker. The hind wings are pearly white with the
veins and margin brown (Fig. 165). The females deposit their
eggs in patches of sixty or more on the stems or leaves of low
plants or on twigs or branches of trees. A single female may
lay as many as 500 eggs. The egg is tu inch in diameter,
dome-shaped, marked with about forty ribs radiating from the
apex, cream colored when laid, changing to ])inkish and becom-
ing lilac just before hatching.

The eggs hatch in five to six days and the young cater-
pillars, after devouring the egg-shells, begin feeding on the
leaves and buds. For the first week they may feed openly,
crawling with a looping gait like a measuring-worm. Later
they feed mostly at night and during the day remain hidden

Fig. IGo. — The variegated cutworm
moth (natural size).

278 MANUAL OF VECET ABLE-CARDES INSECTS

in the earth or under hoards or ruhhish. The caterpilhir
l)eeomes mature in twenty-five or thirty days and is then
from 1 V to 2 inehes in length. The general eolor is ashen or
light dirty hrown liglitly mottled with darker brown. The
underside is light gray. This eutworm may be distinguished
from all other common species by the presence of from four to
six yellow spots along the mid-dorsal line. Pupation takes
place within an earthen cell just below the surface of the
ground. The pupa is reddish brown and about to inch in
length. In summer the insect remains in the pupal stage
from two to three w'eeks. Under greenhouse conditions the
complete life cycle requires forty-five to fifty-four days.

References

Lintner, 5th Ropt. State Ent. N. Y.. pp. 200-206. 1889.

(\;rnell \^. Exp. Sta. Bull. 104, pp. .579-584. 1895.

Fletcher, Kept. Canada Ent. for 1900, pp. 21.5-227.

Wash. Agr. E.xp. Sta. Bull. 47. 1901.

U. S. Div. Ent. Bull. 29, pp. 4(>-()4. 1901.

Davis, 27th Kept. State Ent. 111., pp. 84-88. 1912.

State Ent. Nebr. Bull. 1, pp. :i.5-41. 1913.

Canada Dept. Agr. Ent. Bull. 10, pp. 17-20. 1915.

Tin: WlIITK ClTWoR.M
Paragrotis scandeiis Riley

From its habit of cliini)ing fruit-trees and destroying the

opening buds, tlu^ white cutworm has become n;)torious.

, In a severe oiiti)rcak in

- ' western Xew York m 1S93

and lsy4, over 00 per cent

of the caterpillars foimd on

fruit-trees were of this

Fig. 1 Of). — .\ f<iii-(rr()\vn white cutworm species. It is a native in-

'"^""'■^^'•'^'^''^- sect generally distributed

over the northern United States and Canada east of the Rocky

Motmtains. In addition to injuring fruit-trees and grape vines,

CUTWORMS AND ARMY-WORMS

279

it has been recorded as attacking radish aiifl cabbage though
doubtless it feeds on other garden vegetables.

The partly grown caterpillars hibernate. They emerge in
early spring and soon complete their growth, usually in the
latter part of 'Slay and June. The mature caterpillar is If
inches in length, of a very light yellowish gray with irregular
whitish areas on the dorsal
and lateral aspects of the
body. There is a faint
white stripe just below the
spiracles (Fig. 106). Pupa-
tion takes place in the
ground and the moths
emerge during June and
July. The pupa is f Fig. ig7.
inch in length. The moth
has an expanse of If inches. The front wings are ash-
gray suffused with either brownish, yellowish or reddish. There
is a dark area at the posterior half of the reniform spot. The
hind wings are whitish with a double dusky shade on the outer
edge and have a dark discal spot (Fig. 167). The eggs of this
species have not been described. There is only a single genera-
tion a year.

References

Riley, 1st Kept. Slate Ent. Mo., pp. 76-79. 1869.
Cornell Agr. Exp. Sta. Bull. 104, pp. .')67-r)69. 1895.
Dept. Agr. Canada Ent. Bull. 10, p]). 21-22. 1915.

- The white cutworm moth
(natural size).

TiiK (Glassy Cutworm

Iladenn devaslalrix Brace

This cutworm is more distinctl\- a forage crop pest but
occasionall>- becomes injurious to vegetables. It is widely
distributed through mt the United States and ('inuida. more
abundantly in the North. It feeds on corn, gra.sses, wheat,

280 MANUAL OF VEdETABLE-dAIiDKX I \ SECTS

oats, barley and strawlxTrw In mixed fields of timothy and
clover, it is recorded that the former was destroyed while the
clover remained uninjured. Beans, lettuce and cabbage are
sometimes attacked. Unlike the more common cutworms,
this species rarely comes to the surface, but works in a burrow,
feeding on the roots and stems below ground. There is a case
on record in Ohio of peach seedlings being destroyed in this way.
Hibernation takes place as partly grown larvje. Some of
them become mature in early May but the greater number

during June and July. The
full-grown c-aterpillar is 1^
inches in length, dirty white
with a greenish tinge and
has a translucent glassy
appearance; the head is
reddish brown. Pupation
takes i)lace in earthen cells,
If inches in length by f
inch in width. These cells
are formed a few inches
below the surface of the
ground. The pupa is nearly an inch in length and of a
reddish brown color.

The moth has an expan.se of 1^ to If inches. The front
wings are ])ale ashy gray to dark brownish gray, mottled with
darker brown. The subterminal transverse line is whitish and
usually distinct. On the imicr margin of this line is a row of
five or six wedge-shaped black sjjots. The hind wings are
browni.sh. darker on the outer third (Fig. 168). There is ap-
parently but a single brood amuially, the eggs being laid in the
latter ])art of the season, the greater number after August first.

Fig. 168. — The glassy cutworm moth

(X n).

KlOKKKK.NeES

Forbes, 'iiinl Kept. State Kiit. 111., i)p. 19-20. l««)."j.
Dept. Agr. Canada Ent. Bull. K). i)p. 24-2.^. 11)1.5.

CUTWORMS AND ARMY- WO RMS

281

The Yellow-Headed Cutworm

Hadena nrctica Boisduval

Like the glassy cutworm, this species Hves from one to two
inches below the surface of the ground, feeding on the roots
and cutting off the underground stems of plants. The moths
are attracted to lights in great numbers and are often seen ;
the caterpillars, however, have not elicited as much attention
by their injuries as would be expected. It is primarily a field
crop pest injuring grasses, oats, wheat and corn. It also feeds
on cabbage, spinach, turnip, lettuce and the succulent shoots
of roses and currants. The insect is widely distributed through-
out the northern United States and Canada.

The winter is passed as partly grown caterpillars. The
larvae are most destructive in May and June. The full-grown
caterpillar is 1^ inches in
length and closely resembles
the glassy cutworm, from
which it may be distin-
guished by its yellow head.
Pupation takes place in the
ground. The pupa in size
and color is almost identical
to that of the glassy cut-
worm. The adults emerge
in about a month and are on
the wing from June to September. The moth has an exi)anse of
nearly 2 inches. The front wings are rich reddish brown,
bluish gray at the base and with a broad transverse band of
the same color near the outer margin. The whole wing is mot-
tled with varying shades of deep brown and blnc-gray, giving
it the appearance of a rich brocade. The liiiid wings are
brownish, darker on the outer third and with a dark discal
spot. The thorax is ornamented with dense tufts of chestnut-

Fk;. 169. — The yellow-headed cutworm
moth (natural size).

282 MAXi'AL OF VEGErABLE-GARDEX I.XSECTS

colored hairs (Fijj. 1()9). The eggs of this species have not
been described. There is only one brood amnially.

Keferknces ,

Forbes, 23rd Ropt. State Ent. 111., p. 21. 190.5.
Dept. Agr. Canada Ent. Bull. 10, pp. 25-2C.. 101.5.

The Spotted-Legged Citwokm
Porosagrolis vetusta Walker

Although a rather uncommon species, this cutworm has

occasionall.N ap[)carcd in destructive numbers in \'irginia and

North Carolina. It ranges
from Xova Scotia south to
(Georgia and west to Colo-
rado. Its food plants in-
clude cowpea, watermelon,
cantaloupe, kale, spinach,
lettuce, cabbage, cultivated

dandelion, parsley and c »rn. It has also been recorded as

climbing peach-trees to feed on the buds.

Ill Xew York the winter is probably passed as partl\- grown

caterpillars which complete

their growth the following

season and pupate in July.

The moths are on the

wing in late July, August

and Sei)tembcr. In the

South the caterpillars are

destructive in April and

May and again in Sep-
tember. Tiu' full-grown

caterpillar is about li inclic

above the spiracles is a (\\\

underside is lighter (Fig. 170). The body is niarkc<| with

Fig. 170. — A full-grown spotted-
legged cutworm (X IJ).

- T'lie spot t('(l-l(>f;nci| (iiluoiiri
moth (X 1 ', ).

lies ill length; the whole body
<lark gra\ish biown; the

CUTWORMS AND ARMY-WORMS

283

numercnis black piliferoiis tubercles. The base of the true
le^s behind and the prolegs in front bear each a greenish black
spot, whence the common name. The moth has an expanse
of about li inches and is easily distinguished from the other
species here treated. The front wings are pale powdery ash-
gray, sometimes tinged with pinkish. There is a small dark
median spot and inside the submarginal line is a row of small
triangular black spots. The hind wings are white (Fig. 171).
The egg has not been described. The pupa is about f inch
in length and {xile brown in color.

References

Cornell Agr. Exp. Rta. Bull. 104, pp. 570-571.
U. S. Bur. Ent. Bull. 109, pp. 47-51. 1912.

1895.

The Speckled CuxwoRii

Mamestra suhjuncta Grote and Robinson

The speckled cutworm ranges throughout Canada and the
northern United States southward to Colorado and New
^Mexico. So far it has been recorded as feeding only on cab-
bage and climbing fruit-
trees to devour the buds
and foliage.

It is not known in what
stage hibernation takes
place, though it is probably
as partly grown caterpillars.
The mature caterpillar is
slightly over 1^ inches in
length, reddish gray, mi-
nutely speckled with black and white, hence the common name.
When they have completed their growtli, the larva* burrow
into the ground and transform to dark brown pupa> from which
the moths emerge from late June to September. The moth

Fig. 172.

The speckled cutworia iiiotli
(X l\).

284 MANUAL OF VECET ABLE-GARDEN INSECTS

has an expanse of about Ij inches. The front \vin<^s are dull
gray with the usual pattern lit^htly marked but distinct. There
is a dark dash at the base of the win*;- and another below the
middle. The subterminal line has two lon^^ teeth nmning
to the margin. The hind wings are dirty white, darker towards
the margin (Fig. 172).

Reference
Riley, 1st Rept. State Ent. Mo., pp. 84-85. 18G9.

Tin; Clovek Cutworm

Mameslra Irijolii von Rottenburg

This cutworm ranges throughout the northern hemisphere
and has been reported from Chile. It has been especiall\' in-
jurious to cabbage in the \icinity of Washington, I). C, and in
Canada it has proved destructive to peas and clo\er. It also
attacks mangel, turnij), beet, lettuce and spinach. Among its

wild food plants are lamb's
(juarters and purslane.

Unlike many cutworms,
it passes the winti'r in the
])upal stage. The s|)ring
brood of moths is on the
wing in May and June and
the second brood in August
and September. The first
brood of caterpillars is rel-
ativel\ small and doeseom-
paratively less injury. The second brood in August and Sep-
tember often i)roves very destructive to peas, clover and late
cabbage. The mature catcri)illar is about 2 inches in length,
greenish yellow, mottled with i)rown and black, and has a broad
|)iid<isli baiul below the spiracles. Pupation takes place in
the 'M-ound.

I'l.

17:5.

I'Ik' (ioMT cut worm iiiolli
(X U).

CUTWORMS AND ARMY-WORMS

285

The moth has an expanse of li to 1|- inches. The front wings
are yellowish brown marked with gray and dark brown. The
posterior half of the reniform spot is fuscous (Fig. 173). Ap-
parently the eggs of this species have not been described.

Reference
Dept. Agr. Canada Ent. Bull. 10, p. 2G. 1915.

TiiE Bkistly Cutworm
Mamestra rcnigera Stephens

The range of the bristly cutworm is from Georgia and New
Mexico northward to Colorado, Ontario and Nova Scotia. It
is mainly a grass and garden pest, feeding on clover, grasses,
turnip, corn, cabbage, chic-
ory, comfrey and garden
flowers. It feeds chiefly
on the roots.

The winter is passed as
partly grown larvte, which
cause the most serious in-
jury in April and May. The
full-grown caterpillar is
about an inch in length,
yellowish gray marked with
two distinct black lateral stripes. Scattered o\Tr the entire
body are many black and yellow bristles — hence its common
name. Pupation takes place in the ground. The moth has
an expanse of about an inch. The front wings are rich brown,
the reniform spot green margined with white and the orbicular
spot inconspicuous. There are on each wing a distinct (juadrate
green patch on the hind angle and an elongate one near the
middle of the base. The hind wings are smoky, darker towards
the edge (Fig. 174). There are two generations annually. The

Fig. 174. — The bristly cutworm moth
(X li).

286 MAXrAL OF VECETABLE-GARDEN INSECTS

moths of tlie first brood are on tlic \vin<i; from late May to the
middle of July ; those of the second, from Auj;ust to October.

Reference
Forbes, 23rd Rept. State Ent. 111., pp. 35-36. 1005.

The Bronzed Cutworm

Nephelodes minians Guenee

Although rarely injurious in vejijetable-sardens, the bronzed
cutworm is often destructive to corn, j^rain and "grasses. This
species ranges throughout the northern Unitetl States and
Canada.

The winter is passed as partly grown caterpillars. They
mature in June and are then nearly 2 inches in length, of a

grayish brown or l)ronze
color with consi)icu()Us pale
stripes ext(Miding the whole
length of the body, a median
stri])e, and on each side two
strii)es above the spiracles,
the uj)])er one broader and
more distinct. The dtirsal
stripes cross the cervical and

Fig. 175. — The bronzed cutworm moth anal shields. The catcr-

^'^^*^- pillars transform to dark

brown pupaj in earthen cells. The pui)al period may last as
long as ten weeks. The moth has an exixinse of about 1^
inches. The front wings are rich reddish brown often suffused
with violet, and crossed near the middle l)\- irregular darker
brown bands. The hind wings arc i)rown sulfuscd with reddish
or violet (Fig. 175). 'I'he eggs of this species have not been
described. So far as known, there is only a single generation
annually.

CUTWORMS AND ARMY-WORMS 287

References

Lintner, 1st Kept. State Ent. N. Y., pp. 99-110. 1882.
Forbes, 23rd Kept. State Ent. 111., pp. 29-31. 1905.
Dept. Agr. Canada Ent. Bull. 10, pp. 28-29. 1915.

The Army Cutworm

Chorizagrotis auxiliaris Grote, C. introferens Grote, C. agrestis Grote

This is one of the most common and injurious species in
Colorado, Montana, California and Alberta. It is generally
distributed throughout western North America from ^Mexico
northward and as far east as Louisiana, Kansas and ^lanitoba.
It is distinctly a surface feeder, burrowing very little. When
abundant this species assumes the army-worm habit to a
marked degree ; in California it is known as the western army-
worm. Its food plants are cabbage, horse-radish, mustard,
turnip, beet, corn, pea, celery, tomato, potato, onion, rhubarb,
alfalfa, lupine, clover, timothy and other grasses, wheat, oats,
barley, rye and strawberry. The caterpillars also climb and
feed on the buds of fruit- and forest-trees.

The winter is passed as partly grown larvae on or in the
ground. In Montana they become mature in early April.
The full-grown caterpillar is 1^ to 2 inches in length, dull green
to greenish brown with the back broadly pale or with two broad,
lighter dorsal stripes. The underside is lighter, nearly white
at the level of the spiracles. The dark side is divided by a
fine pale line and the light dorsum strongly shaded with white ;
the head is light yellow mottled with brown but without brown
stripes on the sides. Occasionally the larva is almost uniform
dark green above except for two rows of i)alc patches on the
back. Pupation takes place in earthen cells in the ground
two or three inches from the surface. The dark brown i)upa
is about f inch in length. The moths emerge in about two
months or from llie last of June to tlic middle of Julv. The

288 MAXCAL OF VECETABLE-CARDEX IX SECTS

moth has an expanse of nearly If inches. The front winfjs
are gray or day-c-olored sha(le<l with brown and marked with
black. The orbicular and rcniforni spots are distinct, outlined
with dirty white and the basal two thirds of the front margin
of the wing has a broad light band. The hind wings are brown-
ish, darker towards the margin (Fig. 17(3). In the agresii.s form
the markings are nearly all obscure. Although the moths

emerge in late June and
early July, they do not
deposit their eggs until
September and October.
The yellowish white, globu-
lar, slightly flattened eggs,
about xo ii^c'Ji ill diameter,
are dej)osited on the surface
of the soil often in newly
plowed fields and hatch in
nine or ten days. The
larvae become partly grown before the advent of cold \\ tatlur.
There is onlv one generation a vear in Montana and Alberta.

17lJ. — The army cutworm moth
(X IM.

Refekences

Mont. Agr. p]xp. Sta. Bull. 17, pp. 1()-1S. 1S08.
Mont. A{?r. Exp. Sta. Circ. 4. 1910.
Col. Agr. Exp. Sta. Bull. OS. pp. 17 22. UK).",.
Cooley, Jour. A^. Rcscarfh. (i, pp. S71-SS1. 1916.
Dept.'Agr. Canada Ent. Bull. 13. 191(i.

The Ak.mv-Wor.m

TIcHophila (Lcucnuin) nnipuncta Ilaworth
The army-worm is one of tlic most cosmopolitan of insects.
It occurs in i)ractically every region of the world except .\frica
but is most injurious in the northern Fnitetl States and Canada.
In this species the habit of migrating from field to field in large
numbers, or so-called armies, is developed to a high degree and

CUTWORMS AND ARMY-WORMS 289

has attracted widespread popular interest. In North America
periodic outbreaks have been recorded at intervals since 1743.
One of the most widespread and injurious broke out in 1861
when the caterpillars appeared in greater or less abundance
in twenty states. Other notable outbreaks occurred in 1890
and in 1914. The insect is always present in low pastures and
meadows and nearly every year there are local outbreaks in
some parts of the country. ]\Iany theories have been offered
to account for these widespread and periodic manifestations
but no satisfactory explanation has been advanced. \Vhate^•er
factors are concerned in determining the abundance of this
insect in any one year, they must be effective over a wide area.
The abundance of the species in different years is undoubtedly
dependent on a combination of circumstances, such as temper-
ature, drought and moisture, and the prevalence of fungous
diseases and parasitic insect enemies.

The army-worm feeds normally on grasses. When abun-
dant it completely destroys its food supply in a given area and
then migrates in armies, devouring almost every green thing
in its path, although it eats clover only sparingly. Besides
grains and grasses, it feeds on bean, sugar-beet, sweet potato,
parsley, cucumber, watermelon, celery, pepper, strawberry,
cranberry, sugar-cane and many weeds. The caterpillars
feed at night or during cloudy weather; in the heat of the day
they hide under any convenient shade.

In the Xorth hibernation takes place as partly grown cater-
pillars, in the South in the larval and adult stages and excep-
tionally in the egg stage. The over-wintering caterpillars are
rarely sufficiently abundant to attract much notice. In New
York these mature in May ; in New Jersey in April. The
caterpillar (Fig. 177) is described by Slingerland as follows :

When full-grown, army-worms measure nearly 1| inches
in length. They are of a general greenish black color, nuich
lighter on the venter, which is more or less mottled with blackish.

290 .U.l.Vr-4L OF VEGETABLE-GARDEX INSECTS

and each side bears several distinct stripes. Alony each side
of the body extend three stripes of al)out the same width ; the
one just below the sjMracles is of a light greenish yellow with
whitish edges ; the one bordering on the dorsum is a little darker
with a mottled greenish black center and narrow white lines

along its edges ; the
central stripe, or the
one with the spir-
acles in its lower
e<lge, is black, some-
times lighter along
its center. The
dorsum is finely
mottled with green-
ish black and closely
resembles the dark
stigmatal strijx' in
color ; along the
middle line of the
dorsum there ex-
tends a narrow white stripe, usually quite indi.stinct except
on the thoracic and anal segments. The six true legs
are light brown in color, and each proleg is marke<l with
a large, shiny, ])la(kisli spot. The head is of a greenish
brown color, rather coarsely mottled with black whi<h merges
into distinct blackish strijx's along the sutures. There is con-
siderable \ariati()n in general color among the caterpillars,
some being much lighter than others, due to diflFerences in the
intensity of the strijjcs and the mottlings on the body.

The moths deposit their eggs in the sheath or unfolded base
of the leaves of grains and grasses. The eggs are laid in rows
of ten to sixty and covered with a white, gelatinous substance
which fastens them together and folds tin- edge of the leaf
closelv around them. Kach fi-male moth la\s from 5(K) to

Fu;. 17:

Army-worms, showing variation in color
(slightly enlarged).

CUTWORMS AND ARMY-WORMS

291

750 eggs. The egg is about tV inch in diameter, spherical,
nearly smooth and very light yellow in color. The eggs hatch
in six to ten days. The young caterpillar is translucent whitish,
with a dark brown head and is about Tt inch in length. In
the course of its development the larva passes through six
immature stages, molting five times. In the first two stages
the first two pairs of prolegs are not fully developed and the
young larvse consequently loop along like measuring-worms.
When disturbed they drop by means of a silken thread. In the
third stage they begin to acquire the characteristic stripes
of the mature caterpillar. From twenty to thirty days are
usually spent in the larval stage. When full-grown the cater-
pillars enter the ground, where at a short distance below the
surface they transform to mahogany brown pupse about f
inch in length. In about three weeks the moths emerge (Fig.
178). They have an ex-
panse of about If inches.
The front wings are brown
and are marked with two
more or less distinct
lighter spots near the
middle. In the reniform
spot there is a small,
distinct white dot. The
hind wings are dull gray,
paler at the base.

In New York there are usually three broods of caterpillars
annually ; the first brood or o\'er-wintcrcd hxrvvo in April and
May, the second in July and the third in September, the last
not maturing until the following spring. There are thus only
two generations a year in this state. In the South there are as
many as five or six generations anmially. In the North the
second brood is the most injurious but in the South either the
first, second or third may prove the most destructive.

Fig. 178.

— The army-worm moth
(natural size).

292 MAX UAL OF VEGET ABLE-r, ARDES I. \ SECTS

References

Third Kept. U. S. Ent. Comm., pp. 89-1.56. 1883. Bibliography.

X. H. A^. Exp. Rta. Bull. 39. 1896.

Cornell Univ. Agr. Exp. Sta. Bull. 133. 1897.

Kv. A^. Exp. Sta. Bull. 137. 1<X)8.

Neb. State Ent. Bull. 1, pp. 41-48. 1913.

Cornell Univ. Agr. Exp. Sta. Bull. 376. 1916.

Davis and Satterthwait, Jour. Agr. Research, 6, pp. 799-812. 1916.

The Fall Army- Worm

Laphygma frugiperda Smith and Abbot

The range of the fall army-worm extends from Canarla
southward through Central America and the West Indies to
Argentina, it being most injurious in the warmer parts of its
range. It is called the fall army-worm because in the United
States it usually appears in armies later in the .sea.son than the
true army-worm. Destructive outbreaks have been recorded
from Nebraska to Indiana and southward in the Mississippi
\'alley and in the Gulf states to Georgia. Along the Atlantic
Coast outbreaks of lesser importance have been reported as
far north as Connecticut. Its favorite food plants are certain
grasses and in the South it is known as the grass-worm. When
abundant and migrating it becomes a general feeder. Serious
injury to the following crops has been reported : rice, teosinte,
kafhr corn, millet, cowpea, chick-})ea, velvet bean, clover,
corn, alfalfa, oats, rye, barley, cotton, tobacco, strawberry,
sweet potato, spinach, cabbage, tomato, potato, cucuml)er
and turnip. It also occasionally climbs trees and has been
recorded as injuring orange, peach and apple.

Normally hibernation takes place in the pupal stage, at least
in the northern j)art of its range. It is quite jjrobablc, however,
that in the South the larva' and moths may also hibernate. In
southern Nebraska the moths emerge in late May and June.
They have an expanse of It inches. The front wings are dull

CUTWORMS AND ARMY-WORMS

293

grayish brown with the orbicular spot obHque; in one form
all markings are indistinct ; in the other there is near the tip
of the wing a bluish white spot and the orbicular spot is crossed
by a diagonal white bar ; the cross lines are also more distinct.
The hind wings are pearly white margined with brownish
(Fig. 179). The moth deposits its eggs in clusters of fifty to
one hundred or more on the leaves of its food plants. They
are arranged in two layers, one above the other, and covered
with fine gray down from the moth's body. The egg is nearly
spherical, white to pinkish, about -jV inch in diameter and
marked with about sixty
vertical ribs, crossed with
smaller ones. The eggs
hatch in ten days or less
and the caterpillars reach
maturity in about a month.
The full-grown caterpillar
is li inches in length,
varying in color from
pale yellowish brown to
blackish and is marked with three narrow pale yellow stripes
on the back and a broader yellowish line on each side. The
larvae transform to dark brown pupae, about i inch in length,
in earthen cells slightly below the surface of the ground. The
pupal cells are placed vertically and the pupse lie with their
heads directed upward. The cells in which hibernation takes
place are heavily lined with silk.

Recent observations have shown that in southern Nebraska
there are three generations a year. The spring brood of moths
appears in May and June. The caterpillars of this brood
occur in July and give rise to a second brood of moths in late
July and early August. The cater])illars of the second brood
mature in August and early September. The third brood of
moths appears in September and eggs are deposited within a

Fiu. 179.

The fall arniy-wonn iiioth
(X U).

294 MANUAL OF V EGETABLE-CARDEX INSECTS

short time. The hist or fall hrood of (•ater])illiirs does the
jireatest damage (lurin<j Sej)tember and October. In the South
another generation probably occurs but definite information
in regard to this jjoint is not available.

References

U. S. Div. Ent. Bull. 20, pp. i:}-4.^). JOOl. Bibliography.
Neb. State Ent. Bull. 1, i)p. 4S-.j7. 1913.

Till-: Bkkt .\i{My-Woini

Carndrina exigua Hiibner, C. jldHmaculata Harvey

This cosmopolitan army-worm is represented in North
America by a variety {('. Jlavimaculata) which, by some author-
ities, is considered as a distinct .species. In North America
it is found only in the western United States and Mexic-o. Its
favorite food plant is the sugar-beet but it al.so feeds on corn,
alfalfa, potato, pea, onion, cotton and many weeds. In P^gypt
and the Sudan it is very destructive to cotton and lucerne,
while in India it does serious injury to the indigo i)lant.

The hibernation habits are not known with certainty. In
Colorado it would a])pcar from the late emergence of the moths
in the fall that the winter is passed in the adult state. In
California the first brood moths appear in April; in Colorado
in May. The moth has an exjjanse of about an inch. The
front wings are grayish brown ; the small, round, orbicular
and reniform spots are pale. The hind wings are opalescent
white with the veins and margin brown (Fig. ISO). The eggs
are dept)sited in mas.ses of twelve to fifty on the underside of
the leaves and covered with grayish down. The egg is pyram-
idal in sliape, the u])i)cr third in the form of a caj) and sep-
arated from the remainder by a white band. The eggs hatch
in about four days. The young lar\a' lixc in small colonies
and skeletonize the leaves under the j)rotcction of a web si)ini

CUTWORMS AND ARMY-WORMS

295

over their feeding ground. When lialf grown they abandon
their webs and feed openly, devouring the whole leaf except
the larger veins. They feed only at night, during the day
remaining hidden in the soil. In about two weeks the cater-
pillars become full-grown and are then slightly over an inch
in length. They vary considerably in color but arc usually
green with a broad, gray
or black lateral band bor-
dered on the upper side by
a narrow white line. The
mature caterpillars burrow
a short distance into the
soil and there in earthen
cells transform to yellowish
brown pupte a little less
than i inch in length.
The insect remains in this condition for about two
weeks. In California there are two or three broods a season,
the second being the most injurious.

I'iG. 180.

The beet army-worm moth

(X 11).

References

U. S. Div. Ent. Bull. 33, pp. 37-46. 1902.
Col. Agr. Exp. Sta. Bull. 98, pp. 13-15. 1905.

King, 3rd Rept. Welleome Res. Lab. Gordon Mem. College, Khartoum,
pp. 234-235. 1908.

The Yellow-vStriped Army- Worm

Prndenia orHithiignlli (luonee

This species ranges throughout the United States from
Massachusetts to California and southward to Costa Rica and
the West Indies. It is more injurious in the southern i)art
of its range, where it attacks cotton and tobacco. It also feeds
on })eet, cabbage, potato, tomato, salsify, asj)aragus, water-

296 MAMAL OF VEdETABLE-GARDEX IXSECTS

Fig. 181. — The ycllow-striped arnij'-
worm (natural size).

melon, ruciimber, corn, wheat, alfalfa and clover. As a
climber it attacks peach, raspberry and grape. It is reported
as also feeding on cotton bolls and the heart of young corn
plants in the same way as the cotton boll-worm.

Hibernation takes place cither as larvte, pupie or adults. In
Californiat the spring brood of caterpillars is most abundant in

May and June. The full-
grown larva is from 1^ to
2 inches in length (Fig. 181).
There are two varieties; one
is velvety black above and
reddish brown beneath with
two prominent and many fine bright yellow lines on the
side ; the f)ther is reddish gray and has the back marked
with a pair of triangular black spots on each segment, the
lateral markings not being so distinct. In late May and
June the caterpillars transform in earthen cells to rich reddish
brown pupae and the moths emerge two or three weeks later.
The moth has an average
expanse of li inches. The
front wings are brownish
gray with a beautiful and
complicated pattern. The
reniform spot is .small and
pyriform ; the orbicular is
elongate oval, and is placed
in a light-colored bar ex-
tending towards the hind
angle of the wing. In the iniddle of the wing there is a
small sharply defined white \'. The hind wing is opalescent
white, narrowly margined with l)rown (l''ig. 182). Nothing is
known as to the egg-laying habits of this species. In Cali-
fornia it is said to be double brooded, the spring bnxxl being
the more destructive.

Fi(

182. — The ycllow-striped army-
worm moth (X 1 ').

CUTWORMS AND ARMY-WORMS 297

References

111. Agr. Exp. Sta. Bull. 60, pp. 496-497. 1900.

Essig, Insects of California (Ed. 2), pp. 401-402. 1915.

The Semi-Tropical Army-Worm

Prodenia cridania Cramer

The semi-tropical army-worm ranges from Georgia, Florida
and Texas southward through Central America and the West
Indies to Argentina. In Florida it has been reported as in-
jurious to tomato, potato, sweet potato, eggplant, pepper,
okra, collard and cowpea. The caterpillars commonly climb
the plants on which they feed and when abundant may assume
the army- worm habit.

In this species breeding is almost continuous throughout
the year, there being four or more generations annually. The
moth has an expanse of about li inches. The front wings are
dull gray, sprinkled and dotted with brownish and black. The
hind wings are pearly white. The eggs are laid in irregular
masses, sometimes in two layers, and are covered with whitish
down from the female's body. The egg is about to- inch in
diameter, hemispherical, finely ribbed and pale green in color.
The eggs hatch in about six days and the c-aterpillars mature
within three weeks. The full-grown larva is 1 to li inches
in length and varies in color from dark grayish to nearly black.
It is marked with a median, subdorsal and lateral yellow
stripes. The mahogany brown pupa, about f inch in length,
is to be found in th(> ground a few inches from the surface.
The insect passes about ten days in this stage.

Refehknce
U. S. Bur. Ent. Bull. 66, pp. 53-70. 1909.

298 MAX UAL OF VEGETABLE-GARDEN INSECTS

Other Cutworms

Pnragrotis atomaris Smith

This cutworm is abundant in California wliere it is reported
as feedinj; on weeds and (garden erops. It also climbs <irape
vines and j)runc trees to feed on the buds and foliage. The
full-grown caterpillar is 1^ inches in length and light gray in
color. This species is said to hil)crnate in both the larval and
pupal stages. The almost uniform gray moths emerge in April,

The following species ha\'c been recorded as occasionally
injurious :

Dargida prorinctii.s Grote. In Hritish Columbia.
Feltia venerahili^s Walker. In ISIanitoba.
Leiirnnia alhiliiicd IIiibn(>r. In the eastern United States.
Paragrotis dcicrm Walker. In Manitoba.
Paragrotis insnlsa W'alker. In IManitoba.
Pnragrotis perexceJIem Grote. In British Columbia.
Porusagrutis orthogonia Morrison. In Alberta. Injurious
to grain.

Plu/nrhagrofis- (ilicnuifa Grote. In Missouri.
Rhynchagrotin plucida Grote. In Michigan.

The Control of Cutworms and Ahmv-Worms

The means employed for the control of cutworms will vary
according to the croj), the conditions under which it is grown
and the habits of the species causing the injury.

In small vegetable-gardens and greenhouses, hand-j)icking
may be used to advantage, (\ireful watch of the plants should
be kept and whenever injury is notictnl, the soil around the base
of the plants should be searched and the cutworms destroyed.
Shingles or small boards laid about the beds will form attrac-
tive hiding places for the worms during the da> ; hen- they may
be easily found and destroyed. Wln-n such plants as tomatoes

CUTWORMS AND ARMY-WORMS 299

are transplanted, they may be protected hy iisino; cardboard
or tin cylinders sunk a short distance in the soil. Tin cans
with the top and bottom removed are convenient for this
purpose. Greenhouses often become infested by cutworms
in the rotted sod used in the beds. This may be prevented
by sterilizing the soil by steam before using.

Probably the most practical, cheap and convenient method
of cutworm control is the use of poisoned baits. These may
be employed equally as well in the home garden, greenhouse
or in the field. For general field work, a bait made according
to the following formula has been found effective against the
variegated cutworm and others of similar habits :

Bran 20 pounds

Paris green 1 pound

Molasses 2 quarts

Oranges or lemons 3 fruits

Water 3i gallons (about)

The dry bran and paris green are thoroughly mixed in a tub
or similar receptacle. The juice of the oranges or lemons is
squeezed into the water ; the remaining pulp and peel are
chopped into fine bits and added to the water. The molasses is
dissolved in the water and the bran and poison wet with it,
the mixture being constantly stirred so as to dampen the mash
thoroughly. Only enough water should be used to just moisten
the mash })ut not enough to make it sloppy.

This quantity of bait will treat about three acres. The
material should be scattered broadcast evenly over the in-
fested area at nightfall. If applied during the day, it dries
out and is not then attractive to the cutworms. In the garden
or greenhouse a small quantity of the bait may be placed near
each plant.

Another fornnda which has given excellent results in western
Canada is as follows :

300 MANUAL OF VECET ABLE-CARDEX IXSECTS

Sliorts 50 pounds

Paris green 1 pound

Molasses 2 quarts

Water 2i gallons

The ingredients should l)e mixed as in the j)re('eding formula
and applied in the same way. This is said to give better

results under dry
conditions.

These baits are
also effective in the
control of army-
worms. In such
case, the baits
should be sown
liberally in the i)ath
of their march.

A bait may be
made of bundles of
fresh clover, grass or
other tender vegeta-
tion (lipjx'd ill or
sprinkledwith a mix-
ture of paris green
and water. Small
piles of this material
arethen distributed
in the evening at
short distances in
the infested fields.
Much may be done to prevent injury from cutworms by
fall i)lowing of land intended for vegetable crops. In this way
hibernating shelter is reduced to a minimum and many of the
caterpillars are either killed or exposed to the attacks of their

Fk;. \s:i. — A furniw witli post-linlo in iIm- Iimii,.!,,,
iiluiiK IIk; C'dKe of ;i corn fk-ld to .stop an anrr> -woiiii
invasion.

CUTWORMS AND ARMY-WORMS 301

enemies. Clean farming through the destruction of weeds
along fences and ditch banks will also do much to prevent the
prevalence of cutworms.

Whenever cutworms assume the army-worm habit, their
advance may be stopped by plowing a furrow across their
line of march (Fig. 183). The vertical side of the furrow should
be next to the field to be protected and should be smoothed
by means of a spade. Every ten or fifteen feet along the bot-
tom of the furrow post holes a foot or so in depth should be dug.
When the migrating caterpillars reach the furrow and find
themselves unable to climb up the smooth side, they crawl
along the furrow and drop into the post holes, where they may
be easily and readily killed by crushing or with kerosene oil.
Any caterpillars that succeed in crossing the barrier may be
killed by the free use of the poison baits described above.

C'lIAITKrv XVT
BLISTER-BEETLES

The blister-beetles are elongate, long-legjjed insects which
ill the adult sta<!;e fre(iuently attack cultivated crops in swarms.
They devour the foliaj^e and blossoms and frequently defoliate
the plants. They usually feed in colonies moving slowly across
the field and destroying the plants as they go.

As far as known, the larvie of blister-beetles feed on grass-
hopper eggs but the life history of most species has not been
studied. C. V. Riley has given a good account of the early
stages of the striped blister-beetle, but even in the case of this
species much remains to be learned. About two hundred
species of blister-beetles are known to occur in America north
of Mexico. Less than a score of these have been recorded as in-
jurious to cultivated plants, but it is quite probable that many
of the others may on occasion become destructive.

]\Iost blister-beetles contain a substance, cantharidin, which
has the property of blistering the skin. The spanish-fly of
CDmmcrce consists of the dried bodies of certain species of
blister-beetles.

The Striped B lister-Beetle

Epicaula triltala Fabriciua

The striped blister-beetle has long been known as an enemy
of the potato, on which it was formerly more destructive than

302

BLISTER-BEETLES

30^

it has been since the invasion of the Colorach^ potato beetle.
It is generally distributed from New England, Quebec and
Ontario to Montana and southward to Texas and Florida but
is most abundant in the central and southern states. The
beetle (Fig. 184) is ^ to f inch in length. In the typical form,
the head, prothorax and wing-covers are dull yellow or reddish
yellow. On the head there are two black spots; on the pro-
thorax two black stripes, and on each wing-cover two broad
black stripes. In the variety known as lemniscafa there are
three black stripes on each wing-
cover. In Illinois the beetles are to
be found from the first of June to the
first of September and are most abun-
dant during the last half of July and
the first part of August. They feed
ravenously on the foliage and blossoms
of their food plants but have a tend-
ency to be scattered more uniformly
through the fields than is the more
usual habit among blister-beetles.
They attack potato, tomato, beet,
eggplant, carrot, cabbage, turnip,
radish, bean, pea, melon, corn, buck-
wheat, clover, and in Oklahoma have been found very destruc-
tive to ripening tomatoes. They also feed on cotton, clematis,
arrow-leaf and pigweed.

In Missouri egg-laying begins in July and may continue
until October. The female deposits her eggs in clusters of
about 130 in small excavations in the ground which she hollows
out and then covers them with earth. The same beetle may
lay several batches of eggs in the course of her life. The egg
is about iV inch in length, smooth and shining, elongate, cylin-
drical, rounded at the ends and of a pale yellowish color. The
eggs hatch in ten to twenty-two days. The newly hatched

Fig. 184. — Tlic striped
tjli.ster-ljeoUe (X U).

304 MANUAL OF VEGETABLE-GARDEN INSECTS

larva is al^out ^ iiu-li in len<ith and yellowish brown in color;
the head is large and provided with a pair of strong piws. The
legs are long and slender and the body is elongate and tapers
toward the tip, which is i)rovi(le(l with two long seta'. On
hatching, the young larvtu run actively about and burrow into
the soil, seeking for grasshopper eggs. They possess great
vitality and can survive without food for at least three weeks.
As soon as an egg-pod is found, the larva gnaws its way into
the capsule and begins feeding on the eggs ; about eight days
after beginning to feed, the larva molts. The second stage
larva is white, has a smaller head, shorter legs, and the two
long setae at the tip of the body have been lost. When in its
natural position, the larva has its abdomen curled beneath.
The larva continues to feed on the grasshoi)per eggs and in
about a week molts a second time. The third stage larva*
have the mouth-parts and legs much more reduced, the body
becomes stouter and thicker and is strongly curved, with the
head proportionately smaller. The larva grows rapidly antl
takes on a yellowish color, becoming full-grown within the
egg-pod of the grasshopj)er. In about ten days after entering
the egg-pod the larva molts for the third time and about nine
days later becomes full-grown. In the fourth stage the body
is more distinctly yellowish. When fully fed, the larva leaves
the egg-pod and works its way some distance into the surround-
ing soil. It there constructs a smooth cavity in which it molts
again but does not coini)letely shed its skin, the latter being
attached to the posterior part of the bo(l,\-. In this stage the
insect remains in a dormant condition. The legs and mouth-
parts are much reduced and are not functional. The skin
becomes leathery and acquires a deep yellow color. It is about
g inch in length. In this condition the insect usually hiber-
nates, and in some cases may remain in this state during a
second and even sometimes a third winter. In the spring the
insect molts again. This time the larva resumes the form in

BLISTER-BEETLES

305

which it left the egg-pod but is somewhat smaller and paler.
After moving about in the soil for a few days, it transforms
to a pupa. The pupal stage lasts about two weeks. There
is only one brood annually, at least in Illinois and Missouri.
The striped blister-beetle is a striking instance of an insect
that is beneficial in one stage of its development and highly
destructive in another.

References

Riley, Trans. Acad. Sei. St. Louis, 3, pp. 544-562. 1878.
Iowa Agr. Exj). Sta. Bull. 1.55, pp. 377-380. 1915.

The Margined Blister-Beetle

Epicauta niarginata Fabricius

This blister-beetle (Fig. 185) is a little over ^ inch in length,
black, with the head and sides of the thorax ashy gray. The
wing-covers are black, the inner and
the outer margin with a narrow
stripe of gray. This beetle is dis-
tributed throughout the eastern
United States and occurs sparingly-
in Canada. The larva has been
found feeding on the eggs of the
differential locust. The first stage
larva is about tV inch in length and
similar to that of the stri])ed blister-
beetle.

The beetles are found from June
to October. They feed in colonies.
They have a special fondness for
beet, but also attack bean, potato, tomato, cal)bagc, pumpkin,
clematis, aster, pigweed, ground cherry and wild sunflower.

I'ld. ISTi. — I'lu" iiKirgincd
l)listci-l)iH-lli' (X 2^.

306 MAXUAL OF VEGETABLE-GARDEX IXSECTS

The Gray B lister-Beetle

Epicauta cincrea Forster

The gray blister-beetle (Fig. 186) closely resembles the ash-
gray species with which it has often been confused. It is
(listiiii^uislu'd by having the second segment of the antennse

less than one half as long as the
third. The ash-gray blister-beetle
is a duller, darker gray ; the gray
blister-beetle is a lighter gray with a
slight tinge of yellow. This latter
beetle has also been confused with
the margined species, some writers
even considering the two as merely
varieties of the same species. While
the gray blister-beetle is recorded as
occurring sparingly in the East, it
is much more abundant in the West
in Iowa, Colorado, Kansas, Nebraska
and Texas. It attacks bean, lentil,
lupine, potato and clover and in western Nebraska has been
recorded as feeding on the hornbean, locust and honey locust.
It has been reared from the egg-pods of the Rocky Mountain
locust. The egg is pale day-yellow in color, elongate elliptical
in (lutline, and about th inch in Icn^tii.

LSG. — The tiray blister-
beetle (X 'SI).

The Asii-Grav Blister-Beetle

Macrobasis unicolor Kirby

The species known as the ash-gray blister-beetle (Fig. 187) is
■g- to 3 inch in length. The ground color is black but the insect
is clothed with a grayish pubescence so that its general ap-
pearance is dark gray. The insect is distributed throughout

BLW TER-BEE TIES

307

Canada and the United States westward to Kansas and
Nebraska.

The life history of this insect has never been fully worked
out. The beetles appear in swarms in May or June and are
more or less abundant until autumn.
The female lays her eggs in irregular
masses in the ground an inch or so
below the surface. The beetles have
been reared from larvae feeding on the
eggs of the Rocky Mountain locust.
In Minnesota there are said to be two
generations annually, the adults of the
first brood appearing about the middle
of June, those of the second from the
middle of August to early in September.
These beetles are especially fond of
leguminous plants, pea, bean, soybean,
cowpea, clover, alfalfa, black locust,
honey locust, wild indigo, lupine and

astragalus. They also attack potato, tomato, sweet potato,
beet, radish, flax and several wild plants.

Fig. 187. — The ash-gray
blister-beetle (X 4|).

The Black Blister-Beetle

Epicauta pennsylvanica De Geer

This insect (Fig. 188) is i inch or less in length and of a uni-
form, dull black color. It is widely distributed throughout
the eastern United States and Canada east of the Rocky Moun-
tains. It attacks a large variety of plants, including potato,
tomato, carrot, mangel, cabbage, corn, onion, chrysanthemum,
pink, aster, clematis, passion flower, zinnia and alfalfa. It
also feeds on pigweed, thoroughwort, ragweed and meadow rue.

This blister-beetle usually becomes abundant a little later
in the season than the other common species. The egg is pale

308 MAX UAL OF VEGETABLE-GARDEX IX SECTS

clay-yelldw, cloiifjate elliptical and slightly less than ^ inch
in leno;th. Th(^ ecus are depositecl in clusters of eighty to over
one hundred in the ground in late
sunmier or fall. They hatch in two
or three weeks. The first stage larva
is black, about tV inch in length and
in structure resembles that of the
strii)ed bli.ster-beetle. The larvjp feed
on grasshopper eggs, adults having
been reared from larva? found in the
egg-i)o(ls of the Rocky Mountain locu.st.
There is only one brood annually.

On the Pacific Coast a closely related
l)lack blister-beetle, Kpicaiita puncti-
FiG 188 — The biuk fo^^-^ jNIaun, has been reported as
blister-beetle (X 3i). injurious to potato and aster.

Nuttall's B lister-Beetle

Canlharis nuttalli Say

The head and prothorax of Xuttall's i)lister-l)(>etle CFig. 189)
are green, often with coppery or purplish ., i..,^,^ ^„«.—
reflections, and the insect is from f to 1
inch in length. The wing-covers vary
from dark pur])lish green to a rich bronzy
purple. The antenn;e and legs are dark
greenish or bluish. The underside of the
body is dark green. This beautiful beetle
ranges from Saskatchewan southward west
of the Mississippi and east of the Rockies
to New ^Mexico. The life history has not
been worked out but the larvie are sup-
posed to feed on grasshopper eggs. The Fi<;. 189. -Nuttall's
beetles often appear in swarms and devour blLster-bceUe (x ij).

BLISTER-BEETLES

309

the foliage of beans, beets, alfalfa, vetch, oats and barley.
The beetles appear at irregular intervals, some years being
very rare. In the northern part of their range, they may be
expected from the middle of June to the last of July and some-
times continue until fall.

The Spotted B lister-Beetle

Epicaula maculata Say

The spotted blister-beetle (Fig. 190) is ■§■ inch or less in
length, light gray in color with the wing-covers marked wilh
numerous small round black spots where
the pubescence is lacking. This blister-
beetle ranges from western Canada
southward through ^lontana. South
Dakota, Kansas, Nebraska and Okla-
homa to New ]\Iexico and westward to
Washington, Oregon and California east
of the Cascade Mountains. The beetles
attack potato, bean, beet, cabbage,
spinach, alfalfa and clover. They have
also been recorded as feeding on lamb's
quarters and grease-wood. In British
C'olumbia the beetles are abundant from
the middle of May till the middle of
August. The early stages have not been described.

Fi<;. 190. — The spotted
blister-beetle (X 3).

The Two-Spotted B lister-Beetle

Macrobasis albida Say

This beetle (Fig. 191) is nearly an inch in length, uniform light
gray, with two elongate black spots on the prothorax. The
basal part of the anteniue is yellowish or reddish. This species
ranges from Kansas to Texas and westward to Arizona. It

310 MANUAL OF VECET ABLE-CARDEX IXSECTS

has been reported as injurious to potato, tomato, \)Vi\ and sugar-
beet.

A closely related species, Mdrrohasis lotKi'icoUis Leconte
(Fig. 192), lacking the two black spots on the ])roth()rax, has

Fic. 191. — The two-spotted
blister-beetle (X IJ).

Fig. 1'J2. — Macroliasis
lonyicolli.s ( X 2).

been recorded as very destructive to potatoes and alfalfa in
New ^Mexico.

MiscELLAXEors Blisti:i{-Bi:etles

The immaculate hlidcr-hcetlc, Macrohasis iininanilafa Say,
is uniform yellowish gray in color and is nearly an inch in length.
It has been reported as injurious in Kansas and Coloradc*. It
feeds on potato, tomato and cabbage.

The segmented bla-cic blister-beetle, Marrahasis scgmnitata Say,
is large and black, from f to an inch in length. It has been
recorded as injurious to beet, potato, tomato and cabbage in
Kansas. Its range extends into Mexico. The l)eetle is dull
black in color, usually with a narrow band of lighter hairs on
the front and hind margins of the ])rothorax. The underside
of the abdomen is ringed with a narrow band of light hairs on
the hind martrin of each segment.

BLISTER-BEETLES

311

The large black blistcr-bectlc, Lytta hispcrata Horn (Fifj. 193).

In southern California sugar-beets are sometimes seriously

injured by this shining blaek blister-
beetle, about f inch in length. The

dorsal surface often has a rich, bluish

metallic luster and there is a small red

spot on the middle of the face just

above the eyes.

The yanthcr blister-beetle, Epicauta

pardalis Leconte (Fig. 194), is a little

less than ^ inch in length, light silvery
gray and covered
with numerous
c )iifluent black
spots on which the
pubescence is lack-
ing. It has been reported as a serious
l)est of potatoes in Arizona, where it
appears in the fields about the first of
July.

The croie blisier-bcetle, Epicauta ror-

iv'na Leconte, is large and black,

^, nearlv an inch in length. It has been

Fig. 194. — The pan- ' ...

thpr blister-beetle reported as mjunous to i)otatoes m
^'^^*^- Arizona.

Fig. 193. — The large
black blister-beetle (X 2).

Means of CoxXtuolijnc Blister-Beftles

Blister-beetles are difficult to control because they are in-
jurious in the adult stage. Th(>y fly readily from on(> plant
to another and are not easily poisoned with arsenicals. In
the garden, screening choice plants with mos{|uito netting and
hand-picking the be(>tles into ])ans containing a little kerosene
are practical methods of prexenting injury. On potatoes and

312 MAMAL OF VEGETABLK-dARDEX INSECTS

other crops on which paris green and arsenate of lead can be
safely used, spraying is the most practical measure to be em-
ployed. The poison should be applied at the first appearance
of the beetles, using 1 pound of paris green or 3 or 4 pounds of
arsenate of lead (paste) to 50 gallons of water. One pound
of lime should be added to each pound of paris green to lessen
the danger of burning the leaves. The arsenicals may V)e
used to advantage scmiewhat stronger: provided the plants
are not injured. In some cases in which it is not possible to
use an arsenical poison, the beetles may be driven before the
wind into windrows of hay or straw along the edge of the field
and then burned.

CHAPTER XVII
FLEA-BEETLES

Among the most troublesome of garden pests are several
species of small, usually dark-cofored leaf-beetles which have
the hind femora enlarged for jumping. When alarmed they
spring suddenly into the air to a distance of a foot or more and
thus escape the pursuer. This habit of jumping has given the
insects the highly appropriate name of flea-beetles. Flea-
beetles, as a rule, eat out pits or holes in the leaves, causing the
death of the surrounding tissue. Badly injured leaves become
riddled with holes, turn brown and die. The beetles are most
destructive to young plants early in the season. In most
species the larvse feed on the roots, but in some cases they may
live as miners in the leaves or as borers in the petioles. Usually
the beetles hibernate in dry sheltered places, under the bark
of trees, under rubbish and in hedgerows. It often happens
that their injuries to cultivated crops are first apparent along
the edge of the field nearest to such shelter. Some species are
closely restricted to one or two food plants, while others attack
a large variety of ])lants in widely separated families. As
a rule, however, each species shows a decided preference for
some particular grou]). l^'or instance, one prefers the cabbage,
turnip, nnistard and their relatives, another is more or less
restricted to the ])()tato and other solanaceous plants, while
a third is partial to the beet, spinach, lamb's quarters and others
of the same family.

313

314 MAX UAL OF VEGETABLE-GARDEN INSECTS

The Potato Flea-Beetle

Epilrix cucumeris Harris

This insect is also known as tlie cucumber flea-})cetle because
it was first described from specimens feeding on that plant.
But, as it is an important pest of the potato and feeds only
sparingly on cucumbers, it is more api)ropriately called the
potato flea-beetle. This species is distributed throughout the

Ignited States and
(\uiada from the
Atlantic to the
Pacific and has
been reported from
Porto Rico. It is,
as a rule, more
abundant and de-
structive in the
more northern part
of its range. It is
second only to the
Colorado potato
beetle as an enemy
of the ])otato and
in many localities
has pro\cd itself,
on th(> whole, more
injurious. It also
attacks tomato,
eggplant, wonder-
berry {Solarium
nigrum), i)eppers, turni]), ra<lish, cabbage, celery, beet, water-
melon, cantaloupe, tobacco, cucumber, jx-tunia, bittersweet
{Solanuni Dulcamara), Jerusalem cherry, horse-nettle (Solanum

195. — Potato leaves injured by the i)otato
flea-beetle.

FLEA-BEETLES 315

carolinese), common nightshade, ground cherry (Physalis),
Jimson weed and sunflower. It has also been recorded as
injuring young corn plants. The beetles feed on both the
upper and under surface of the leaves, eating out small round
holes through the epidermis and parenchyma but usually
leaving the epidermis on the opposite side intact. This soon
dies and breaks away, leaving the foliage riddled wdth small
holes. Badly injured leaves first turn yellow, then brown,
curl up and die (Fig. 195).

The potato flea-beetle is one of the smallest species of the
group. It is from re to ^ inch in length, black, with the
antennse and legs brownish yellow. The
hind femora and part of the middle and
front femora are black. The prothorax
has a deep transverse depression near the
hind margin (Fig. 196). The posterior
femora are greatly enlarged, giving the
insect the power to jump a considerable
distance. The beetles pass the winter in
sheltered places under rubbish and are

found in the spring on plantain and other ^'fle|-^beeUe\'x '1-4?^*°
weeds as well as on the foliage of apple,
wild cherry and maple. As soon as their cultivated food
plants come up or are transplanted into the field, they are
subject to attack. Tobacco and cabbage plants may be
seriously injured in the seed-bed. On Long Island the
beetles begin egg-laying the early part of June and in Maine
the latter part of the month. The egg is about tfo" inch in
length, elongate ellii)S()idal and white in color. The eggs
are deposited in the soil around the plants. At this time the
beetles are sometimes found four or five inches in the ground
but whether they enter the soil for egg-laying is not known.
The larva.' feed on the roots, tubers and underground stems of
the plant and are sometimes found on the piece of potato used

316 MAXUAL OF VEGETABLE-GARDEN IXSECTS

for seed. The full-grown larva is about i inch in length with
a brown head and yellowish brown thoracic shield. The
larvae are sometimes found with the front part of the body
inserted into the tuber, from which the remainder of the body
projects. The tissue surrounding the larva in the tuber be-
comes hardened and turns blackish. Under some conditions
the presence of the grub causes an abnormal growth on the
surface of the tuber about i to i inch in diameter, low, convex
and scurfy at the top. Tubers so aflected are called pimply
potatoes and their market value is considerably lessened.
The larvjB have also been found feeding on the roots of tomato,
eggplant and the common nightshade. When mature they
transform within small earthen cells to whitish pupae about
Tjr inch in length and in six to eight days transformation to
the adult takes place. On Long Island the beetles of the new
brood begin to appear in early Jidy and in Maine about the
middle of the month. Some of the beetles continue fecfling
until cold weather, when they go into hibernation. Nearly
all the females do not oviposit until the following spring, but
it is quite probable that a few of them soon after emerging
lay eggs from which there is produced a small second brood
of beetles in late summer or early fall. This second lirood
goes into hibernation with those of the preceding generation.

The beetles that have hibernated feed ravenously until the
eggs have been laid and then gradually decrease in numbers.
Thus, during late June and early July, they are much l(>ss abun-
dant in the field than earlier in the season or a little later when
the beetles of the new brood begin to appear. The dying off
of these over-wintered beetles has often misled growers into
thinking that they had been killed by spraying.

While the larvre are sometimes injurious to the tubers, this
type of injury is not common. The most serious injury is to
the foliage. Not only is the leaf surface greatly reduced by
the feeding of the beetles and the consequent killing of the

FLEA-BEETLES 317

leaves, but the punctures serve as points for infection by the
early potato blight fungus. The injury to the foliage also has
a direct influence on the size and quality of the tubers. Injury
by flea-beetles is most pronounced during dry seasons when
the plants are least able to withstand the loss of their foliage.
Tomato plants are most subject to injury when first trans-
planted.

Means of control.

On potatoes flea-beetle injury is best held in check by keep-
ing the plants well covered with bordeaux mixture. Frequent
and thorough spraying with this material not only makes the
plants distasteful to the beetles but also protects them from
infection by the potato blight fungus. Experience has shown
that spraying with paris green or arsenate of lead, as for the
Colorado potato beetle, is of little or no value in destroying
the potato flea-beetle, because the latter either avoids the
poison or eats so little of it as to be unaffected. Where an
arsenical is used in bordeaux mixture for the control of the
Colorado potato beetle, it is quite probable that many of the
flea-beetles are also poisoned, but it is a question whether
enough of them are killed to make it worth while to add the
poison for flea-beetles alone. It has been suggested that
sweetening the poison might make it more attractive but
experiments on Long Island have shown that repeated appli-
cations of sweetened arsenate of lead in bordeaux mixture are
injurious to the potato plants. When potatoes are thoroughly
sprayed every ten to fourteen days with bordeaux mixture
for the control of potato blight, a practice now commonly
followed by commercial potato-growers, it is possible to raise
a good crop in spite of the flea-beetle. Tomato plants are
most seriously injured by flea-beetles soon after transplanting
and should be kept well sprayed with bordeaux mixture until
the danger is past.

318 MAMAL OF VEGETABLE-GARDEN INSECTS

Cabbage plants are often seriously injured in the seed-bed.
This may be avoided by screening the beds as described for
the control of the cabbage root-maggot (page 35).

References

N. Y. (Geneva) Agr. Exp. Sta. Bull. 113. 1896.

Maine A^. Exp. Sta. Bull. 211. 1913.

Iowa Agr. Exp. Sta. Bull. 155, pp. 367-376. 1915.

The Western Potato Flea-Beetle

Epilrix subscrinita Leeonte

On the Pacific Coast, the potato flea-beetle is replaced by this
closely related species which may be distinguished by its bronzy

brown color (Fig. 197). It has been
reported from California to British
Columbia, where it is an important
pest of the potato, tomato, pepper
and eggplant. It also attacks the
bean. Among its wild food plants
are many common weeds. The
beetles spend the winter under rub-
bish. They appear in March and
April, feeding at first on weeds and
later on cultivated crops. The larva?
feed on the roots and tubers of potato
and also bore a short distance into the latter. The full-grown
larva is about | inch in length, slender, and white with a
brown head. In Oregon the larvt^ become mature in late
June, transform to small white pupte within earthen cells
early in July, and the beetles begin to emerge the latter part
of the month. These beetles soon lay eggs for a second brood
of larviP, which pupate in September, giving rise to another
brood in October. After feeding for a time on the foliage,

Fig. 197. — The western po-
tato flea-beetle (X 10).

FLEA-BEETLES 319

these insects go into hibernation probably in company with
some of the beetles of the previous generation. There are
probably two broods annually.

This western potato flea-beetle may be controlled by the
measures suggested for its eastern relative.

On the Pacific Coast potatoes are also attacked by another
flea-beetle, CJIyptina cerina Leconte.

Reference
Ore. Agr. Col. Bull. 91, pp. 11-13. 1913.

The Tobacco Flea-Beetle

Epitrix parvida Fabricius

This near relative of the potato flea-beetle ranges from Mary-
land to Michigan, Colorado and Wyoming and southward to
Texas, Florida, Central America and the West Indies. It
also occurs in California and Hawaii. This flea-beetle is a
serious enemy of tobacco but also attacks potato, tomato,
eggplant, and among wild plants feeds on horse-nettle, ground
cherry and Jimson weed. In California it has been known to
attack almond, orange and squash. In Hawaii it injures the
cape gooseberry. Its injuries to potato, tomato, and egg])lant
are similar to those inflicted by the potato and eggplant Hea-
beetles with which it is often associated.

The tobacco flea-beetle is about ts inch in length, yellowish
brown, usually with a darker band across the middle of the
wing-covers; the antennae and legs are also yellowish brown
except the femora, which are somew^hat darker. The trans-
verse depression near the hind margin of the prothorax is (^fly
faintly indicated (Fig. 198). The beetles emerge from hiberna-
tion in the spring and attack the i)lants as soon as they come up.
The eggs are probably deposited in the soil at the base of the

320 MAX UAL OF VEGETABLE-HARDEX INSECTS

plants. The egg is about -is inch in
lengtli, pale yellowish gray in color and
elongate oval in outline. The lar\:e feed
on the roots and stems below ground and
pupate in the soil an inch or so from
the surface. After about a month from
the time the egg was laid the beetle
appears. The number of generations
annually has not been determined but in
(^alifornia there are said to be several.
The tobacco flea-beetle can be controlled by the measures
suggested for the potato flea-beetle.

Reference
U. S. Div. Ent. Bull. 19, pp. 85-87. 1899.

Fn;. 198. — The tobacco
flea-beetle (X IS).

The Eggplant Flka-Bkktle

Epitrix fuscula Crotch

This species is also closely related to the potato flea-beetle.
It ranges from New Jersey through Illinois, Nebraska and
Utah to California and southward to
Georgia and Louisiana. In size and
general apjjearance, it closely resembles
the potato flea-beetle but all the femora
are black, the transverse depression near
tlie hind margin of the prothorax is less
distinct and the wing-covers are slightly
more hairy (Fig. 199). The beetles
come out of hibernation in early si)ring,
as early as March 20th in Indiana.
They show a decided preference for
eggplant but have also been found injurious to i)otato and
have been recorded as feeding on horse-nettle, hazelnut, poke-
weed, sugar-beet and strawberry.

Fi<i. 1U<). — The cgK-
plant fleii-bectlo (X 10).

FLEA-BEETLES

321

This flea-beetle may be controlled by the same measures as
suggested for the potato flea-beetle.

The Pale-Striped Flea-Beetle

Systena tceniala Say

This abundant and widely distributed flea-beetle is very
variable in coloration and sculpture. Several varieties have
been described, some of which are considered as distinct species

Fig. 200. — The pale-stiipod floa-
beeUe ( X 13) .

Fig. 201. — The pale-striped flca-
beetlc, variety blanda (X 13).

by certain writers. The beetle is about g inch in length ; the
antennjE and legs are reddish or yellowish brown ; the head
is reddish, and the thorax brownish. In the typical form the
wing-covers are black with two pale yellowish longitudinal
stripes. In the light-colored variety, hlaiida, the thorax and
wing-covers are paler and the wing-covers have the pale stripe
much broader, often leaving but little of the dark markings.
In some specimens the wing-covers are uniformly j)ale. All
gradations occur (Figs. 200 and 201).

322 MANUAL OF VEGETABLE-GARDEX IX SECTS

Tlic insect r;in<,'os from Xcw EniijlaiKl tlir()U<,'li Canada to
Calit'ornia and southward to (Icorj^da, Alal)aina and Mexico.
It lias hccn t'ouiid most dcstructixe to youn<j; liccts and recently
transplanted tomato j)lants. It also attacks potato, carrot,
parsnip, cantaloupe, cucuml)er, i)um])kin, cabbage, turnip,
radish, pea, bean, e<,'^q)lant, lettuce, summer savory, sweet
potato, peanut, corn and cotton. It feeds on a large number
of wild j)lants, among wliich are ])igweed, lamb's quarters,
j)urslane, ragweed, cocklebur, horse sorrel and wild solana-
ceous plants. It also sometimes injures newly set aster plants
and apple and pear nursery stock.

It is not definitely known where or in what stage the insect
passes the winter. The beetles a])pear on the plants in the
spring. In feeding they eat out small holes in the epidermis
and parenchyma but do not eat through the leaf. Young
l)eet plants are often killed in this way, it sometimes being
necessary to re])lant. The egg is about tV inch in length,
elliptical in outline, and yellowish in color. The eggs have
not l)i'en observed exce})t under cage conditions. Larv;e have
been found on the roots of lamb's cpiarters and probably occur
on se\eral other conunon weeds. A single larva was once
found on a s])r()uting corn plant. This may have been acci-
dental. The full-grown Iar\ a is elongate, about i inch in length,
white, with a yellowish head. The body is broadest ])osteriorly.
At Washington the eggs are laid during June and July and the
adults of the new brood begin to emerge in late July. The
number of generations annually has not })een definitely de-
termined but there is probably only one, at least in the North.
The insect j)robably hibernates as a larva, puj)ates in the
spring and transforms to the adult in May or June.

References

U. S. Div. Ent. Rull. 23, pp. 22-20. 1000.

111. Atjr. E.\p. Sla. Bull. 00, pp. 408-470. 10(X).

FLEA-BEETLES

323

The Red-Headed Flea-Beetle

^•^

Systena frontalis Fabricius

This species closely resembles the smartweed flea-beetle
from which it may be distinguished by its reddish head (V\^.
202). It ranges throughout the
Ignited States and Canada east of
the Rockies and south to Florida.
Outbreaks of this beetle are usually
more or less local but serious injury
may sometimes result. It attacks
potato, beet and bean, and in
Canada is sometimes destructi\'c
to the second crop of clo^■e^.
Young grape vines are occasionally
nearly defoliated by the beetles-.
They have also been known to
attack cranberry, rose mallow,
marsh mallow, Japanese honey-
suckle, weigela, aster and chrysanthemum. Among weeds
they are known to feed on smartweed, lamb's quarters and
pigweed.

The beetles have been found hibernating under the loose
bark of trees and in mullein rosettes. The early stages have
not been described.

Fig. 202. — The red-headed
flea-beetle (X 8).

The Smartweed Fle.v-Beetle

Systena hudsonias Forster

This elongate bluisli black flea-beetle is generally distributed
throughout the United States and Canada east of the Rocky
Mountains where it has been recorded as injurious to potato,
bean, corn, beet and cabbage plants in the seed-bed. It has

324 MANUAL OF VEGETABLE-GARDES IXSECTS

also been known to injure cranberries and grapes as well as
apple and pear grafts. The beetles feed on a wide variety of
weeds, including smart weed, pigweed, daisy, fleabane, ragweed,

plantain, catnip, dock and
goldcnrod.

The beetle is slightly more

than i inch in length, and bluisii

black in color, with the antennje

having the two basal segments

dark, the next three or four

light and the remainder dark

(Fig. 20:]). They are most

abundant in midsummer. The

inunature stages haw not been

described and the number of

broods occurring annually is not

known.

When attacking cabbage in the seed-bed, the injury is best

prevented by screening the bed with cheesecloth as is often

done for protection against the cabbage root-maggot (page 35).

Fig. 203. — The smart wochI flca-
bcctlc (X 11).

The Stiuped Cabbage Flea-Beetle

I'In/llolrctd riltnta J'abricius

The strii)ed cabbage flea-beetle shows a preference for crucif-
erous i)lants, attacking cabbage, radish, turnip, horse-radish,
water-cress, stock and wall-flower. It is also rec<)rde<l as injuri-
ous to tomato and strawberry. Its most important unculti-
vated food ])lant is the wild mustard, but it also feeds on
charlock, shc])hcr(rs jiurse and rocket. The insect ranges
throughout the I'nited States and southern Canada east of the
Rocky Mountains. The l)eetles hibernate in sheltered places
and aj)pear in the fields in the spring, in western Xew York
about the middle of May. The adult is about /o i^^h i" length,

FLEA-BEETLES 325

black, with each winti^-cover marked with a wavy yellowish
stripe, narrowed in the middle and incurved at each end (Fig.
204). The beetles are most destructive to cabbage plants be-
fore the fourth leaf has appeared or during the first week after
they come up. They gnaw pits in the leaves but do not eat out
holes except in very thin leaves. Young cabbage, turnip and
radish plants are often killcfl in this way. The females deposit
the minute, oval, whitish eggs at the base of the plant in irreg-
ular excavations gnawed out in the root near the crown. The
larv.ie feed on the roots of cabbage and
radish and in New York have been found
especially abundant on the roots of the
wild mustard. The larvje eat off the
smaller roots and riddle the main one
with tunnels, sometitnes excavating the
entire root. The full-grown larva is
about i inch in length, whitish with a
light brown head. In Illinois the larvae
are present in late Mav and June and Fig. 204. — The striped

, 1 p / I • « cabbage flea-beetle

give rise to a brood 01 beetles in August. (x 13).
The over-wintered beetles mostly dis-
appear in June and in the North turnips sowed after this date
are likely to escape injury. In North Carolina a second brood
of larvae has been observed on turnips in October. In Illinois
tliere is said to be but one generation annually but in Nortli
Carolina tliere are at least two.

Cabbage plants in the seed-bed are very liable to injury
by this flea-beetle. They may be ])rotected l)y screening the
beds with cheesecloth as reconmieiided for the cabbage root-
maggot (page 35).

Reference
Shimer, Amorioan Naturalist, 2, pp. 514-517. ISGO.

326 MANUAL OF VECETABLE-CARDEX IXSECTS

In California a closely related species, Phyllotrefa rnmosa
Crotch, ill which the yellowish stripe on the wing-cover has a
short branch just back of the middle, has been reported as in-
jurious to turnip, radish and mustard.

The four-spotted cabbage flea-beetle, Phyllotrda hipudulata
Fabricius, is sometimes found feeding on cabbage and turnip
in the Atlantic states. Its wild food j^lants are hedge mustard,
charlock and shepherd's ])urse. It has never been known to
cause any serious injury. In this species each wing-cover is
marked with two large yellowish spots.

In California cabbage, radish, mustard and turniij are some-
times attacked by a small, dark, metallic green flea-beetle,
Heviiglypfiis hdsdli.s- Crotch.

The Sinuate-Striped Flea-Beetle

Phyllolrela sinuata Stephens

This flea-beetle is often found in coinj)aiiy w ith the strii)cd
cabbage (Ica-bcetlc, feeding on cabbage, turnijj and radish.
The insect was ])r<)bably introduced from
Pvurope but is now widely distributed
throughout the United States and Canada.
The beetle averages somewhat larger than
the striped cabbage flea-beetle and the
yellowish stri])e on the wing-cover does
not turn inward toward the base, being
nearly ])arallel with the inner margin
(I'ig. 205). The eggs are deposited singly
on the u])])er surface of the leaf along the
lie egg is T^ inch in length,
dull greenish white, de|)resse(l, oblong
and glued to the leaf by one side. The
larxje have been found as miners in the leax'es of wild pepper-
grass, cress and rock cress. The young larxa- enter the leaf,

Fig. 205.— The .-sinuate- midrib,
striped flea-beeUe

(X 14).

FLEA-BEETLES

327

where they eat out a mine of the blotch type, often being
numerous enough to kill the plant. The full-grown larva is
about i inch in length, orange, with the head, pronotum and
anal segment dark brown. The other segments are marked
with numerous brown spots. When mature, the larva descends
to the ground, where in an earthen cell, it transforms to a
white or yellowish pupa. In May and June in Missouri the
life cycle from egg to adult requires about three weeks. This
species has not been recorded as causing any very serious in-
jury. This may be explained in part from its being frequently
mistaken for the striped cabbage flea-beetle.

Reference
Riley, U. S. Ent. Kept, for 18S1, pp. 304-308.

The Western Cabbage Flea-Beetle

PhjjUntrefa pusilla Horn

Along the eastern slope of the Rocky Mountains from Dakota
to Mexico and in New Mexico and southern California, the
wavy-striped flea-beetle is replaced
by this pitchy black, slighth' bronzy
beetle from tV to iV inch in length
(Fig. 20()). It has been recorded
as injurious to cabbage, radish,
turnip, horse-radish, mustard, rape,
pea, sugar-beet and corn. It also
feeds on hedge mustard and the
bee plant. The beetles hi})ernate
and are most destructive to the
young })lants soon after coming
out of hibernation. The early
described.

Fi(

, 2()(). — 'I'lic western cab-
IkiKc n<'a-l)cctlo (X 16).

stages have not been

328 MAMAL OF VECETABLE-GARDEX IX.SECTS

The Horse-Radisii Flea-Beetle

Phyllotrcla armoraciw Koch

Imported from Europe about 189o, this horse-radish pest
is now present in the northern states from New York and New-
Jersey to Iowa and Nebraska. It has also been found at
Montreal, Canada. In some localities it has already proved
itself a serious enemy of horse-radish, making it necessary to
replant the beds yearly. In contrast
to the habits of many other flea-
beetles, this insect has a very re-
stricted list of food plants, includini;
only marsh cress in addition to horse-
radish. Tlic winter is passed by the
beetles in dry sheltered places. The
at hilt (Fig. 207) is about \ inch in
length, oval, strongly convex, black in
color, with each wing-cover yellowish,
except a narrow black stripe along
the outer margin and a wider one on
the inner margin, the latter broadest
at the middle. The antenniv are
The legs arc yellowish except the
hind femora and all but the tip of the front and middle
tibise, whicii arc black. The beetles appear on the plants
early in the spring and eat out holes in the leaves and
cavities in the midribs. The female deposits her smooth,
oval, orange eggs, about irV inch in length, in clusters of twenty
or more, loosely attached t<> the petioles of the young leaves.
Egg-laying begins in late A])ril or May and may continue until
August. Each female usually lays several batches of eggs and
the total number laid by a single individual may exceed 4rMl.
The eggs hatch in a week or two. On hatching, the young

Fig. 207. — The horse-
radish flea-beetle ( X 9) .

yellowish at the base

FLEA-BEETLES 329

larva enters the petiole, where it burrows through the tissue,
often causing the death of the leaf. Its presence is indicated
by brownish, dead areas where the larva has come near the
surface. The mature larva is nearly i inch in length, slender,
pale yellowish white, with the head, thoracic shield and anal
plate dark brown. From seven to over nine weeks are required
for the larva to reach maturity. It then descends to the ground,
where it transforms to a small white pupa in an earthen cell
and in ten days to two weeks the beetles emerge. There is
only one brood annually. The beetles are more destructive
early in the season and the larvie later. The foliage is injured
to such an extent that the roots do not develop and the crop is
consequently shortened.

Control.

The plants may be made distasteful to the beetles and some
of them poisoned by thorough spraying with bordeaux mixture
containing 4 or 6 pounds of arsenate of lead (paste) in 50 gallons.
When the pest is abundant, several ap])lications at intervals
of two or three weeks may be found necessary. In some cases
it is advisable to change the location of the beds yearly to new
land in order to escape attack by the beetles.

Reference
U. S. Dept. Agr. Bull. 535. 1917.

The Spinach Flea-Beetle

Disonycha xanlhomchrna Dalman

So far as known, this flea-beetle has 1)c(mi injurious only to
beet, spinacli and salt-bush. Its wild food plants include
lamb's c|uarters, pigweed and chick-weed. The insect is dis-
tributed throughout the United States and Canada east of the
Kockv Mountains.

330 MANCAL OF VEGKTABLE-GARDEX IXSECTS

The beetle is about 3^ inch in length, greenish black in color
with the prothorax yellow (Fig. 208). The insect hibernates
in the adult stage and appears in the field early in the spring.
The female deposits her elongate, ellij)tical, orange eggs, from
21) to iV inch in length, on end, in clusters of about thirtx' on
the ground at the base of the plant. Each female may lay
several batches of eggs at intervals of a few days. The lar\a
escapes through a slit in the side of the egg near the base. The
young larva is nearly ^ inch in length, uniform light gray and

armed with numerous black
sj^incs which are white at
the tip. The young larvjii
crawl to the ])lants and feed
on the underside of a leaf,
at first gnawing off only the
surface but later eating out
lioles. When alarmed, the
larvse fall to the ground,
where they remain hidden
until the danger is past.
The young larv.ie have the
iiabit of feeding in colonies
but when older become scattered. After the tops are killed,
they may feed on the roots. The mature larva is a little more
than 3 inch in length, leaden gray, with head and mouth-parts
brownish. When feeding on b(>ets, it acquires a purplish color.
The larva b(>comes full-grown in ten days to a month. It
then enters the ground and transforms to a grayish pupa in a
slight earthen cell near the surface. In six to nine days the
transformation to the adult takes jilace and after waiting a
(lay or two to bccunic hardened the beetle cmergi's. At
Washington there are two g('iierati(»iis annually. Egg-laying
by the new brood of beetles begins the latter part of July
antl continues until September.

Fig. 208.

The spinacli floa-l)Octlc

(X 7i).

FLEA-BEETLES 331

Reference
U. S. Div. Eat. Bull. 19, pp. 80-85. 1899.

The Yellow-Necked Flea-Beetle

Disonycha mellicollis Say

This beetle is found from New Jersey, Indiana and Colorado
southward to Florida and Texas. It is closely related to the
spinach flea-beetle, from which it maybe distinguished by having
all the femora reddish or yellowish. It has been recorded as
injurious to beets and spinach in Texas and Florida. Its wild
food plants are amaranth and purslane. The beetles come out
of hibernation early in the spring and deposit their blood-red
eggs, similar to those of the spinach flea-beetle, in clusters of
forty or fifty on the leaves or on the ground at the base of the
food plants. The eggs hatch in four to ten days. The larvoe
feed on the underside of the leaves, injuring the plant in much
the same way as do those of the spinach flea-beetle. They
become full-grown in about eleven days and are then dull
yellowish red. Pupation takes place in the ground and the
beetles emerge in about five days.

Reference
U. S. Bur. Ent. Bull. 82, pp. 29-32. 1909.

The Three-Spotted Flea-Beetle

DisonycJia triangularis Chevrolat

This closely related species ranges through the United States
and Canada east of the Rocky Mountains. It has been re-
ported as injurious to beets, mangels and sugar-beets. Its
wild food plants are lamb's quarters and spiny pigweed. The
beetle is ^ to | inch in length, bluish black; the pruthorax is

332 MAM'AL OF VFJiETABLE-CARDEX INSECTS

yi-ll()\v, inark(Ml with three black
spots arranjivd in a triani:;le (Fi^.
209). The insect hibernates as a
beetle in sheltered i)laces. The early
stages have not been described.

Tin: Larger Striped Flea-Beetle

Disonycha crenicollis Say

Fig. 209. — The three-spotted ™, . . • i t- • i

flea-beetle (X 5). 1 his species occurs ni the I nited

States east of the Rockx Mountains,

ranging from New York to Nebraska and south to Mexico.

The beetle is ab;)ut \ inch in

length, yellow, with two black

spots on the prothorax and

has eacii wing-cover marked

with a narrow marginal and

sntnral, and a broader median

black stripe (Fig. 210). It

has been found on beet, melon

and strawberry in Illinois. It

hibernates in the adult con- ^ " jm^' ;^'

dition and the earl\' stages ,, ,,,,, „,, , . • ,«

"^ Ik;. L'lO. — I he larpor striped flea-

are unknown. beetle (X 4J).

The Sweet Potato I-'i.ka-Bkktle

Ch(F(ncticmn coufinis Crotch

Although this lira-beetle is widely distributed throughout
the I nited States east of the Bocky Mountains and has also
been taken in ("alifornia, it has attracted most attention by
its injuries to the sweet potato in New .Jersey. In some local-
ities and in cci'tain seasons, it has prmcd itself the most im-

FLEA-BEETLES 333

portant insect enemy of that crop. It has been observed feed-
ing on sugar-beet, corn, wheat, oats, timothy, bhie-grass, buck-
wheat, red clover, raspberry and box elder.

The beetle is about re inch in length, pitchy black with a faint
bronzy reflection. The antennre and legs, except the hind
femora, are reddish yellow (Fig. 211). The winter is passed
by the beetles in rubbish, especially along hedgerows and
woodlots. In New Jersey they appear on the sweet potato
plants as soon as transplanted in ]\Iay. They do not eat holes
through the leaves but eat out grooves or channels in the
upper surface, usually beginning along
the more prominent veins. Later a large
part of the surface may be eaten off; the
leaf wilts, turns brown and dies. Young
plants are often killed in this way or so
badly stunted that they do not produce a
good crop. In New Jersey the beetles
are most abundant in jNIay and the first
part of June, when they begin to leave Fig. 211. — The sweet
sweet potato, and by the first of July J''^*=\*° flea-beetle
very few are left. On leaving the sweet
potato, they migrate to bindweed, which is often found grow-
ing as a weed in the fields or along the fences. It is on this
plant that the larvfe have been found feeding on the fine
roots but not tunneling the larger roots. When full-grown,
the larva is ab[)ut § inch in length, white, with a l)rown-
ish head. The whitish pupse are found in earthen cells in the
ground. The beetles of the new brood begin to appear in late
July but do not return to the sweet potato in large numbers until
the following spring. There is only one generation annually.

Control.

Fortunately this fiea-beetle does not attack sweet potato
plants in the seed-bed to any appreciable extent. Most of the

334 MAXi'AL OF VEGETABLE-GARDEX IXSECTS

injury to the youn^ plants may be avoided by dipping; them
before transplanting in arsenate of lead (paste). 1 i)ound in
10 gallons of water. Dippintj is much more effective than
spraying the plants because both sides of the leaves are covered
with the poison. Flea-beetle injury may also be avoided, in
large measure, by late planting.

Reference
X. J. Agr. Exp. Sta. Kept, for 1908, pp. 343-348.

The Desert (Ohn Flea-Beetle

ChcEtocnema edypn Horn

In the semi-arid rc<;ions of the Soutinvcst, beans are some-
times seriously injured by this small, shining black flea-beetle,
a little less than iV i'lch in length. Its food plants are grasses,
grains and corn but it occasionally attacks cantaloupes and
sugar-beets. The beetles appear in the field about the middle
of February and begin egg-la\ ing in about a month. The
minute, bean-shaped, whitish eggs, about ^ inch in length, are
deposited at or near the surface of the ground on or near the
food plant. The eggs hatch in three to fifteen days with an
average of five or six. The larv;e feed on the roots, often caus-
ing considerable damage to the roots of alfalfa, barley, oats,
wheat and corn. They become full-grown in a little over three
weeks. The mature larva is whitish, elongate, slender, and
from \ to ^ inch in length. When mature, the larva constructs
an oblong, earthen cell within which it transforms to a shorter
thickened form known as the prepupa and a few days later to
a delicate, soft, whitish pupa. The pupal period varies from
three to twelve days with an average of about six. There are
three generations annually and in some years a partial fourth
may develop. The beetles go into hibernation in Xtnember
under rubbish and clumps of grass in waste places.

FLEA-BEETLES 335

Reference
U. S. Dept. Agr. Bull. 43G. 1917.

The Hop Flea-Beetle

Psylliodes punctulata Melsheimer

Although this flea-beetle is best known as a destructive
enemy of hops in the Northwest, it is widely distributed
throughout the northern United States and southern Canada
from the Atlantic to the Pacific and also attacks several garden
plants, including beet, rhubarb, potato, tomato, turnip, radish,
cabbage, cucumber, watermelon, mustard and clover. Its
wild food plants are numerous, including
hedge mustard, lamb's quarters, pigweed,
dock, sorrel, tumbleweed and nettle.

The hop flea-beetle is about -j^ inch in
length and bronzy black in color. The
antennae are brownish, pale at the base.
The legs are reddish yellow with the middle
and front femora black and the hind pair . . .

bronzy (Fig. 212). The beetles hibernate ^ ^*^^^
under anv convenient shelter, such as cracks ■^'*^'^^";r'7^^!!?'^

' . flea-beetle (X lU).

and crevices of posts or poles, in the hollow
stems of plants, under grass or weeds, and in the soil itself.
In British Columbia they emerge in March or April and soon
begin feeding on the foliage of their food plants, eating out
pits, but usually do not perforate the leaf. The injured area
soon dries, however, and may break away, leaving a hole
through the leaf. The foliage is often riddled in this way and
in the case of hops the leaves are reduced to mere shreds.

The fcniidcs enter the soil to lay their eggs on the roots of
the hop. The egg is about te inch long, elliptico-cylindrical,
and yellowish in color. They are found at a depth of one to

^36 MANUAL OF VEGETABLE-GARDEN INSECTS

t\V() iiK-lics in the s )il. 'V\\v c^ijjs liatcli in al)i)iit tliriH' wooks
or a little less, (irpciHliiii; on the tciiiperatui-e, and tlic Noiuii;
larva hcjjjins tVediui;- on the roots. Although the larva' have
only been found on hop roots, they undoul)tedly feed on other
plants. They l)ee;)ine fuli-urown in al)out three weeks. They
are then about I inch in len^^th, white, with the head, thoraeic
shield and anal plate darker. After reaehinj; maturity, the
larva becomes somewhat shorter and thicker and rests in a
dormant condition for nearly two weeks before transformins:^
to the white ])ui)a. rni)ation takes place in the soil but not
in an earthen cell. The pupal i)erio(l averages about sixteen
days. There are two <ijenerations annually. From eggs de-
posited in the early s))ring by over-wintered beetles, a new
brood of adults is i)r.iducc(l the last of May or early in June,
and another brood ap])cars the last of July or the hrst of August.
The latter go into hibernation with the advent of cool weather.

References

U. S. Hur. Ent. Bull. (Ui, pp. 71-92. 1909.
U. S. Bur. Ent. Bull. 82, pp. 33-58. 1910.

]\Ie.\n.s of CoxTROLLixr, Flea-Beetles

It is usually' difficult to ])rc\(Mit injury by flea-beetles because
the attack is made by the adults, most of which feed only
slightly on the surface of the leaf and are more or less resistant
to i)ois()ns. They also avoid the poison and attack the leaves
where the spray has not been api)lied. The attack is usually
most severe on young plants early in the season when the
beetles are most voracious after their long winter's fast and
when the j)lants are least able to withstand injury. Contact
in.secticides have been found of little value because of the
difficulty of hitting the insects, since the beetles jump from the
plants at the slightest alarm only to return when the danger

FLEA-BEETLES 337

is passed. Bordeaux mixture has been found the most efficient
and inexpensive deterrent for most flea-beetles. The presence
of this material on the leaves makes them distasteful to the
beetles. When combined with paris green, 2 pounds in 100
galbns, or arsenate of lead (paste) at the rate of 4 or 5 pounds
to 100 gallons, it makes the most effective treatment. As
bordeaux mixture is used on many plants for the prevention of
fungous diseases, its use serves a double purpose. In some
cases in which the plants are started in seed-beds and then trans-
planted into tlie field, dipping the plants in arsenate of lead
(paste), 1 pound in 10 gallons of water, before setting has been
found the most effective way of protecting from flea-beetle
attack. When the injury is done to the plants in the seed-bed,
it is sometimes found advisable to screen the beds with cheese-
cloth or tobacco-cloth as described under the cabbage root-
maggot on page 35. Special methods of treatment applicable
to certain species will be found in the account of these forms.

CHAPTER XVIII
UNCLASSIFIED PESTS

Some of the insects and insect-like animals are so miscel-
laneous in their feeding that they cannot be associated clearly
with any one crop. A few of these are treated together here.
Some of them are very troiil)lesome and are difficult to combat.

The 1v()ot-1v\()T Nematode

Helerodcra radicicola Greef

A great variety of plants is subject to serious injury from
the attacks of minute nearly trans])arent worms that bore into
the roots, causing gall-like knots or outgrowths to develop.
In England these are known as eel-worms. The swellings on
the roots are produced by the i)lant in its attemj)t to repair
the injury caused by the presence of the worm. The normal
growth of the root tissue is disturbed, with the result that the
sap-tubes are distorted and unable to carry their load of raw
plant-food up to the leaves. Badly infested plants take on a
weak, unhealthv appearance, become stunted and sometimes
die.

The root-knot disease is j)revalcnt throughout the troj)ics,
.sub-tropics and the warmer parts of the temperate zone. In
the United States it is occasionally foiuid as far north as New
York, Michigan and Nebraska but is of little importance except
in the southern states and in central mikI southern California.

338

UNCLASSIFIED PESTS 339

It is especially troublesome in irrigated districts and in
greenhouses even in districts where it does not occur in the
open.

Different species of plants vary greatly in their degree of
susceptibility to the root-knot disease. Among vegetable
crops those most susceptible to injury are potato, tomato,
eggplant, celery, beet, carrot, lettuce, pepper, endi\e, canta-
loupe, cucumber, watermelon, squash, pumpkin, lentil and
salsify ; the following also are sometimes seriously attacked :
asparagus, onion, cauliflower, cabbage, kale, collard, turnip,
pepper, bean, pea, radish, spinach and sweet potato. In some
localities potato tubers become badly infested and acquire a
warty appearance. Infested potatoes are unsuitable for market
and should ne^'er be used for seed.

The organism that causes the root-knot disease is not an
insect but a nematode worm. The young are produced inside
the old gall, from which they escape through cracks or by work-
ing their way through the tissue. In this stage the worm is
about T? inch in length, slender and eel-like in form. The
young worms can live for several months in moist earth and
are able to move readily about among the soil particles. When
one of these worms finds a young and tender rootlet, it breaks
its way through the tissue by means of a spear-like organ located
in the mouth and then passes a short distance into the sub-
stance of the root. The worm then becomes inactive, swells
up and the female finally assumes a pear-sliaped form. The
male becomes broadly spindle-shaped and then molts but
remains within the discarded skin. It then assumes a ^•ery
elongate form and becomes coiled in three or four folds within
its cyst. It finally escapes and, passing through the tissue of
the root, finds a female with which it mates before she has
beconu^ fully mature. Tlie fully dexclojx'd encysted females
are pear-shaped, about 2V i>i<'b i" lengtii and a little more than
half as broad and when the gall is broken open appear as little

340 MANUAL OF V EGET ABLE-GARDEN INSECTS

jjcarly white p;l()bules ombedde^l in the tissue. Eaeh female
is capable of producing about 500 eggs, which are laid at the
rate of ten or fifteen a day. The eggs form a mass often as
large as the female and are surrounded by a gelatinous sub-
stance. "^I'he eggs are ellipsoidal or sometimes kidney-shaped,
about twice as long as broad and \ary greatly in size, being
from about ttt to ^o inch in length. Sometimes the eggs
hatch while still within the body of the mother. The female
begins to lay eggs about twenty-five days after entering the
root. The winter is passed in the larval stage in the galls and
in the surrounding soil.

The galls produced on different species of plants are variable
in size and shape, but as a rule the amount of enlargement
de})ends on the number of worms entering a root near the same
point. Plants growing in light sandy soil are more subject
to injury than when on lieavy land. The worms cannot sur-
vive a thorough drying of the soil as is the case with many
related forms and are killed if the soil remains saturated with
water for a long time.

Means of control.

Vegetables susceptible to the root-knot disease should not
be planted on land known to be infested. To free fields of the
root-knot nematode, they should be planted for one or two
years to some crop not susceptible to the <lisease and which
has a sufficiently rank growth to crowd out all weeds that might
harbor the pest. Certain varieties of cowpeas, particularly
the Iron, are not susceptil)le and are sometimes uscfl for this
purpose. After the cowpeas are harvested, the ground should
be plowed and sowed to some winter grain such as rye or wheat.
The next season another crop of cowj)eas should be sown to
be followed again by grain the second winter. Under certain
conditions velvet beans or Florida beggarweed may be used
instead of cowpeas. Care should be taken not to allow weeds

UNCLASSIFIED PESTS 341

to grow in the field at any time wliile attempting to eradicate
the disease, since many of them serve as hosts for, the
worms.

Where greenhouse soil has become infested by the root-
knot nematode, it should either be renewed with fresh unin-
fested soil or may be sterilized with live steam under pressure.
This is performed by having the beds equipped with lines of
pipe running through the soil in which at intervals are small
holes about re inch in diameter for the escape of the steam.
The beds are covered with straw or with some other material
and the steam is applied until the soil is thoroughly sterilized.
This may be determined by placing potatoes in the soil near
the surface and when they are found to be cooked the steam
may be turned off. Rows of tiles are sometimes used instead
of pipes, the steam escaping through the joints.

More or less satisfactory results can be obtained in shallow
beds by applying a weak solution of formaldehyde, 1 part of
the 40 per cent commercial solution in 100 parts of water,
using 1 to li gallons for every square yard of surface.

Recent experiments in Florida indicate that land may be
freed of root-knot nematodes by the application of com-
mercial sodium cyanamid at the rate of 1000 to 5000 pounds
to the acre. This material should be applied dry and then
worked into the soil. The land should then be irrigated and
the crop should not be planted until several weeks later de-
pending on the amount of material used. Sodium cyanamid
is too expensive for use on large areas but may be emplo.>ed
to advantage on seed-beds and on plots under intensive
cultivation.

References

Ala. Agr. Exp. Sta. Bull. 9. 1S,S<).

Mass. (Hatch) Afrr. Kxp. Sta. Bull. 5.^). 1S98.

U. S. Bur. Plant Ind. Bull. 217. 1911.

342 MAMAL OF VEGETABLE-GARDEN INSECTS
The SrGAR-Bp:p:T X?:matode

Ilcterndcra schachlii St'liinidt

This near relative of the root-tcnot nematode has been known
for many years as an important enemy of the sngar-heet in
Europe and has recently seriously infested sugar-beets in the
western United States. It also infests other kinds of beets,
as well as cabbage and related croj)s. Its life history is similar
to that of the species last treated, the most important differ-
ence being that there is a resting stage in which the eggs may
survive in the soil for at least six years. The sugar-beet nema-
tode is, therefore, a nnuh more difficult i)est to eradicate,
since to rid land by crop rotation it would be necessary to keep
it free from all susceptible crops for a period of se\eral years.

Millipedes

There are several species of millipedes injurious to sprouting
seeds, seedlings and root-crops, such as radishes, turnips,
carrots, parsnips and beets (Fig. 213). They sometimes eat
out holes in potato tubers and often infest the heads of cabbage,
cauliflower and lettuce. Seed beans are attacked underground
and the millipedes may eat off the tender shoots. Sprouting
corn and peas are injured in a similar way. The millipedes
often bore into melons, cucumbers, squashes and tomatoes
where they touch the ground.

Millii)cdes are not insects but belong to a closely related
class of animals. They are elongate, more or less cylindrical
creatures, having a distinct head and a l)ody consisting of a
series of similar segments which is not divided into a thorax
and abdomen. Each segment, excepting the first four, bears
two pairs of legs.

It is often stated that the mouth-parts of millipedes are not
fitted for feeding on healthy plant tissue, but a dissection of

UNCLAStilFIED PESTS

343

these ortjans has convinced the writers that they are well
adapted for this purpose. It is true that milHpedes prefer
decaying vegetable matter but it is also well known that they
will attack healthy roots when their favorite food is not avail-
able. Under such conditions they select, wherever possible,
a part that has already been injured by some insect or that is
affected with some disease. Roots or
tubers that have been eaten into often be-
come infected with fungi or bacteria, causing
decay.

Numerous species of millipedes belonging
to several genera have been found injurious
in America but their life history and habits
do not appear to have been carefully
studied.

The greenhouse millipede, OrtJwnwrpha
gracilis Koch, is of tropical origin and is
common in greenhouses in Europe and
America. In this form the body is some-
what flattened and the segmentation is
very distinct. On the side of each seg-
ment is a thin horizontal plate which in
the posterior segments is acutely pointed
behind. The full-grown millipede is nearly an inch in
length, chestnut-brown above, with the lateral plates
yellowish.

The commonest millipedes that are injurious in the field
belong to Julus and related genera. Thes(> forms are elongate,
cylindrical and usually piceous in color with the legs and under
parts pale. When at rest they are usually coiled in a circle.
Reproduction is by means of eggs, which the female deposits
in a mass co\tTed with jjcllcts of earth ghuMJ together to form
an egg-cocoon, "^riie eggs are laid in the spring and again in
the fall and hatch in about two weeks. The voung ditfer from

Fi.i. 213. — A car-
rot injured hy
slugs and milli-
pedes.

344

.i/.l.\7'.lL OF VEdETAHLK (iAliDEX IXSECTS

the adults in size and in having a smaller number of body
segments and fewer legs.

In New York a common and troublesome species is Julus
cocrulcocinctits Wood. It is nearly an inch in length and has

been found in-
jurious to peas,
beans, tomatoes,
melons and many
other vegetables
(Fig. 214).

NO satisfactory
nu'tho<l for the
control of milli-
jx'des under field
or garden condi-
tions has been
devised. In the
garden they may
be trapped under ])ieces of boards or slices of vegetables
laid on the ground. In the greenhouse they may be traj)ped
in the same way or by using lumps of dough sweetened with
molasses. Lime or tobacco dust applied around the plants
will have a tendency to keep the pest away.

Fig. 214. — .\ niillipprlo, Julus coerulcocinctus (X ')).

White Grubs

Lachnnstcrna (several species)

Vegetable crops are often seriou.sly injured by large white
curved grubs that are found in land that has recently been in
sod. These grubs (Fig. 215) are the larval form of the large
brown June beetles or June bugs (Fig. 21()) that come blundering
around lights on summer evenings. In the Initcfl States
there are nearly one hundred species, but the greater j)art of
the injury is caused by a relatively small number.

UNCLASSIFIED PESTS

345

Fig. 215. — A white grub
(X U).

The parent beetles are most abundant in May and June.
They feed at night on the leaves of ^'a^ious trees, but at day-
break they desert these and return to the fields. The females
burrow into the soil to a depth of two
or three inches and there deposit their
eggs singly or in small groups. Each
female is capable of laying from fifty
to one hundred eggs. The eggs are
oval, white, and have a diameter of
about T2 inch. They lie in small cells
composed of soil particles glued to-
gether with a sticky substance secreted
by the beetle. The eggs hatch in ten
days to several weeks. The young grubs feed throughout the re-
mainder of that season on the roots of grasses a short distance
below the surface of the ground. With the approach of cold
weather, they burrow deeper into the soil and hibernate at a
depth of ten or twelve inches. The following spring they re-
turn to the grass roots, on
which they feed through-
out the season. The
grubs of some species
reach maturity at the
end of the second sum-
mer, but in the case of
our more common species
the grubs are not full-
grown at that time. In
th(> latter case, the grubs
again descend into the
soil for hibernation and
return to the grass roots in the spring of the third year. After
feeding for a period, they become full-grown in June or July.
The grub then constructs an oval earthen cocoon in which it

Fig. 216. — Two species of June beetles,
the adults of the white grub Lachnoslerna
ilicis and L. hirticula.

346 MAMAL OF VECETABLE-aARDEX I \ SECTS

transforms to a dolicatc whitish pupa. The insect remains in
this condition until the latter part of the summer and then
transforms into a beetle. It remains in the earthen cell until
the following .spring, when it emerges from the ground. While
certain species emerge the second spring after the eggs are
laid, and a few do not emerge until the fourth spring, the
greater number of the injurious species do not emerge until
the third spring. For instance, in the last case the young
grubs that hatch from eggs laid in the spring of 1918 feed until
the fall of that year, hibernate during the winter of 1018-19,
feed again through the summer (jf 1919, hibernate again as
grubs during the winter of 1919-20, complete their growth,
pupate, and transform to beetles that season and hibernate
as beetles during the winter of 1920-21 ; the beetles emerge
in the spring of 1921. It will be seen from the foregoing ac-
count that the grubs are most destructive during the second
season, because it is then that they feed for the longest period
and make their greatest growth. The first year the grubs
feed only during the latter i)art of the season and arc very small.
The third summer they feed only during the early part of the
season and only enough to prepare themselves for pupation.

In case infested sod land is broken up and planted to vege-
table crops, the white grubs are forced to concentrate their
feeding on the latter. Corn, potato, beet and other root crops
are esp(>cially liable to attack; in fact, there is scarcely a vege-
table crop that is not subject to injurv when grown on infested
land.

Trops liable to injury by white grubs should not be planted
on land known to be infested. Much trouble may be avoided
by adopting a short rotation of crops in which land will not be
left in sod for more than two or three years. White grubs are
likely to be abundant in old strawberry beds and when these
arc plowed up they should be treated the same as sod land.
l)U(kwhcat, alfalfa, clover and other leguminous crops are not

UNCLASSIFIED PESTS 347

relished by white grubs and may be used as iutermediate crops
between sod and vegetables. As ])re^'iously stated, the grubs
do the greatest injury during the season following that in which
the eggs are laid. Observations in Illinois have shown that the
beetles prefer to lay their eggs in ground that is well covered
with vegetation. Pasture land, wheat, and oats are chosen
in the order named. Clover is a relatively immune crop,
very few eggs being laid in fields where there is a heavy stand.
These facts should be kept in mind when planning a rotation
of which vegetable crops are a part.

In some parts of the country, white grubs appear in more or
less definite broods and are destructive in three-year cycles.
In localities where this tendency is well developed, this knowl-
edge may be utilized to avoid injury.

WiREWORMS

Several Species of Elateridce

Many vegetable crops are liable to attack by wireworms es-
pecially when planted on land previously in sod. Wireworms
(Fig. 217) are elongate, hard-
shelled, brownish larvae, the im-
mature stages of medium-sized,
dull-colored, snapping beetles or
click-beetles. Thev are under- „ ,_ . .

. ' n- \ I'lc. 21/. — A wireworm, Mono-

ground msects that eat oil the crepidius ih-idus {x M).

smaller roots, bore into tubers

and fleshy roots and destroy germinating seed. The beetles
appear in May and June, and the females dejjosit their eggs
in the soil. The beetles are from i to |^ inch in length, dull
grayish brown in color, and have the peculiar habit of snap-
ping themselves into the air when laid on their backs. The
larvie feed on the grass roots for several seasons, the various
species difi'ering in the length of their life cycle from three to

=i . 1 i.fcti»

348 MAM'AL OF VEGETABLE-GARDEX IXSECTS

Fig. 218. — A potato infested
with wheat wireworni-s.

six years. The wireworms reach maturity early in July.
They are then from 1 to U inches in k-ngth, dependint; on

the species. They transform to
deUcate whitish pupse in earthen
cells within six inches of the
surface of the ground. Trans-
formation to the beetle takes
place in three weeks to a month,
the beetles remaining within
the earthen cell until the follow-
ing spring. There are many
species of wireworms that ma\'
attack \egetables but only the
most important can be treated
here.

The wheat wireworm, Agrioiea
maticiis Say, is about an inch in length when full-grown, pale
yellow in color, cylindrical in form and may be recognized by
the two dark spots at the base of the
last segment of the body. This species
feeds normally on the roots of grasses /
>()(1 is broken up will
seriously injure corn,
wheat, potato, car-
rot, turnip, bean,
cucumber and cab-
bage. Injured po-
tatoes are shown in
Figs. 21 S to 220.

The adult of the wheat wireworm is
about ;V inch in length, dull reddish brown,
Ficj. 220. — The .same darker oil the head and thorax. The
potato cut open to beetles are to be found in the field from

show the burrows

made by wireworni.s. Ai)ril to Juiie. The female enters the

but

Fit;. 21!). — Potato injured
1)V the wheat wireworm.

UNCLASSIFIED PESTS 349

ground to deposit her eggs. The larvae become about half-
grown by the end of the season ; they resume feeding the
following spring and become nearly full-grown by the second
winter. They reach maturity in July of the third summer
and construct earthen cells in which they transform to small
whitish pupae and a little later change to beetles. The beetles
do not emerge the same season but remain in the pupal cells
till the following spring. Three years are required for the
completion of the life cycle.

The corn wireworm, Melanotus conmumli Gyllenhal, is 1^
inches in length when full-grown, cylindrical, reddish brown in
color and the last segment of the body is provided with three
lobes. The beetle is about ^ inch in length and of a dull red-
dish brown color. In this form the life cycle may require six
years for its completion. Corn wireworms are most trouble-
some on heavy, poorly drained soils.

The sugar-beet wireworm, Limonius calif nrnicu.s Manneheim,
has been reported as injurious to sugar-beet, lima bean, po-
tato, corn and alfalfa in California. The beetle is a little less
than ^ inch in length, and brown to dusky black in color.
The adults appear in the field in early spring and after re-
maining in a sluggish condition for some time the females
burrow into the ground to deposit their eggs. ]\Iost of the
eggs are laid between the middle of April and the middle of
]\Iay and hatch in a little less than a month. Three years are
spent in the larval state. The full-grown wireworm is about
I inch in length and shiny, waxy, yellowish brown in color.

The confused wireworm, Limonius coufiisus Leconte, has
been recorded as attacking potato, tomato, onion, cabbage,
radish, horse-radish and corn in Illinois. A related species,
Limonius ngonus Say, is treated as a tomato pest on page 173.

The corn and cotton wireworm, Uoristonotu.s uhlerii Horn,
is sometimes injurious in the South to corn, oats, rye, cowpeas,
peanuts, cotton, tobacco, sweet potatoes and watermelons.

350 MANUAL OF VEGETABLE GARDEX IXSECTS

This species is an exception to the general rule and is most
destructive on light sandy soil in the higher parts of fields.
The beetle is ^ to ^ inch in length and brownish red in color.
The larva is very slender, soft and has the body apiJurcntly
competed of twenty-six segments.

Control.

Wireworm injury to vegetable crops can be prevented in
large measure by })racticing a short rotation of crops in which
the land is not left in grass for more than two, or at most, three
years. Peas and buckwheat are relatively immune to wire-
worm attack and may sometimes be used to advantage between
sod and corn or other susceptible crops. Deep and thorough
cultivation of the soil in late July and August will break open
the i)upal cells and destroy the pupje and recently transformed
adults, thus reducing the number of beetles the following
spring. Late fall-i)lowing is of little value in destroying
wireworms.

In the garden poisoned baits are sometimes u.sed for killing
the wireworms as well as the beetles. Small bunches of clover
or other succulent ])lants are dipped into paris green water
and then placed in the field covered with earth or pieces of
boards. Sweetened corn-meal dough poisoned with paris green
or other arsenical may be used instead of the clover. These
baits should be distributed after the ground has been fitted but
before the croj) is j)lanted and should be kept fresh by frequent
renewals.

(iHAssnoprERS

Nearly all vegetable crops are subject t^* injurx l)y \arl()us
species of grasshoppers when grown in localities where these
insects are abundant. (irasshopjxTs arc most likely t > be
destructive in regions where the soil is sandy and where there
are large areas of waste land. l)ecause it is in such situations

UNCLASSIFIED PESTS 351

that they find conditions ni(;st snitable for depositing their
eggs.

An effective and practicable method of destroying grasshop-
pers is by the use of a poisoned bait made according to the
formuhi given on page 299.

The Red-Spider

Telranychus telarius Linnaeus

It has often been pointed out that the common name of this
pest is inappropriate because it is neither a spider nor is it al-
ways red, but as this name has been in use for many years it
would seem unwise to designate it as the spider mite as has
been suggested recently. The red-spider is a mite belonging
to the class Arachnida. On hatching, this mite is provided
with three pairs of legs but before reaching maturity acquires
a fourth pair. The mouth-parts are adapted for piercing the
epidermis of the leaf on the juices of which the animal feeds.
The red-spider attacks a great variety of plants both in the
greenhouse and in the open. Of the former, roses, chrysan-
themums, violets and carnations are particularly liable to in-
jury while of the latter, arbor-vitse, juniper, lilac, snowball and
red sage should be mentioned. In the nursery some cherries
may be attacked. The red-spider is also an important enemy
of cotton and sometimes becomes troublesome on okra, cu-
cumber, melon, egg{)lant, bean, tomato, pepper, sugar-beet,
hops and orchard trees. Bramble fruits are especially liable
to attack. The red-spider is almost cosmopolitan in its dis-
tril)uti()n, occurring wherever suitable food plants are found
and being most abundant in those regions where the climate is
dry. The mite is usually most troublesome in seasons of
drought or in greenhouses where the moisture is deficient.

The full-grown female red-spider (Fig. 221) is a little less
than sV i'i<-'^^ i'> h'^^'th ; the male measures about ■;\- inch.

352 MANUAL OF VECIET ABLE-GARDEN INSECTS

The mite varies greatly in color from greenish through yel-
lowish to orange or reddish ; some are brownish. Usually
the body is marked with one to three pairs of black spots. In
some cases the spots are confluent and the mite appears black.
The eyes are red. The legs are pale and in the male the two
front ])airs are usualix' tinged with reddish. Seen from above
tiie mite's body is broadly ovate in out-
line. It is not di\ided into three regions
as in insects. The mouth-parts consist
of a pair of sharp needle-like protrusile
bristles and a j)air of shorter fixed spines.
In feeding the mite pierces the epidermis
of the leaf with its mouth-parts and
through the puncture extracts the juices
of the i)lant. This mite covers its feed-
ing grounds with a maze of delicate
silken threads. The silk is produced by
glands opening near the tip of the body.
The claws at the tip of the legs are
especially adapted to enable the mite to
travel over the web.

The female deposits her spherical, jx'arly
white eggs, about -^^^ inch in diameter,
singly on the underside of the leaves, to
which they are usually attached by strands
of silk. As the eggs develop they take on a reddish hue and
the eyes of the embryo become evident as small red spots.
Each female is capable of la>'ing from 50 to 100 eggs over a
period of nearly a month. The eggs hatch in three to eight
days. On hatching the young mite is provided with only
three pairs of legs ; it is about y-Vt^ inch in length and the
body is nearly spherical in outline when viewed from above.
The young mite soon begins feeding near the egg-shell and
in about three da\s molts its skin. In the .second stage

Fiu. 221. — The red-
spidor (X GO).

UNCLASSIFIED PESTS 353

the mite is provided with four pairs of legs ; it is nearly
gV int'h in length. It feeds actively and in about three
days molts again. The third stage nymph averages -j^ inch in
length. In this stage the mite develops the habit of spinning
a web. In about three days the mite molts for the third and
last time and assumes the adult condition. It is thus seen that
in the course of its development the mite passes through three
immature stages and reaches maturity in nine or ten days after
hatching from the Q^g. In about three days the females
begin egg-laying. The number of generations produced an-
nually varies with the length of the season and with the con-
dition of temperature and moisture. When the weather is
dry and hot the time elapsing from the laying of the egg to the
time at which the mature female lays her first egg may be only
nine or ten days, but in the cooler weather of the spring and
autumn this period may be lengthened to over a month. Ob-
servations of the mite on cotton in South Carolina have shown
that breeding from the first egg laid by the females of each
generation as many as seventeen generations may be produced
annually but owing to the fact that the mites may continue
egg-laying for a montli or more several of the later generations
must be only partial. Under greenhouse conditions breeding
may be continuous throughout the year.

The injury caused to most plants by the red-spider is indi-
cated by small light-colored spots on the leaves, the result of
the death of the plant cells around the feeding punctures. \Mien
numerous these spots coalesce and the leaves take on a whitish
appearance. Injured plants usually become paler or take on a
reddish cast and finally the leaves may shrivel and die.

Control.

In the greenhouse the red-spider may be held in check by
watering the plants frec|uently with a nozzle tliat gives a stifl"
srray without delivering enough water to drench the beds.

2 A

354 MAX UAL OF VEGETABLE-GARDEN INSECTS

Liberal watering of plants in the open will also liave a heiieficial
effect on preventing red-spider injury. " IJIack Leaf 40" to-
bacco extract, 1 part in KMK) parts of water in which soap has
been dissolved at the rate of i pound to 5 gallons will also be
found useful in freeing the plants of the pests. The tobacco
extract is also effective when combined with the oil emulsions
or with bordeaux mixture. The mites may also be held in
check by dusting ^he plants with finely ground sulfur.

Rkference
Ore. Agr. Exp. Sta. Bull. 121. 1914.

Slugs

Slugs are closely related to snails, from which they differ in
having the shell reduced to a thin plate or wanting altogether.
The commonest species injurious to vegetables in the eastern
Tnitcd States is the gra\' field slug, Agriolimax agrc.siis Liniuvus

(Fig. 222) and has appar-
ently been introduced from
Kurojx'. It is about \\
^^^^^^"^""^ inches in length when fully

Fi;;. 222. — The may fu-hl siuf? (X \\). extended, spindle-shaped in

outline, ashy gray in color
mottled with darker gray. On the head are two pairs of
fleshy tentacles; the upper pair is the longer and bears
the eyes at the tip. When at rest or when disturbed the
tentacles are withdrawn and the body contracts into a dull
gray lump. Slugs are found in cool, moist situations. During
the day they are hidden away under stones or boards and
come out to feed only at night or on damp cloudy days.
Their bodies are kept moist by a slimy secretion a trail
of which is left behind wherever the\- go. The.se glistening
snail tracks are often seen on boards left lying on the ground.

UNCLASSIFIED PESTS

355

Fig. 223. — A cluster of eggs of the gray
field slug ( X 3) .

When irritated as by an

application of lime, they

throw out a copious quan-
tity of this protective

secretion. The slug's

mouth is provided with a

tongue-like organ thickly

studded with minute sharp

teeth by which the animal

is able to rasp off tender

plant tissue. Slugs are

hermaphroditic, both male

and female organs being present in the same individual. The

eggs are deposited from spring till late fall in loose clusters of

thirty or forty in moist
ground, under stones or
other shelter. The eggs
(Fig. 223) are nearly
spherical, translucent and
about tV inch in diameter.
They hatch in three to ten
weeks depending on the
weather. If dried they
shrink considerably but
regain their size when
moistened. The time re-
quired for a slug to reach
maturity depends on condi-
tions of moisture and food
and varies from six weeks
to nearly a year. They are
said to live for several years.
„ „„. ^ ... , , , • , Shigs are most troublc-

JbiG. 224. — beedhng bean iilants injured .

by slugs. some ni seasons or abun-

356 MAXIWL OF VECET ABLE-GARDEN IXSECTS

Fig. 225. — Base of a oabhaKC loaf ridillecl by sIur-s.

flant moisture and on heavy soil that does not dry ont qnickly.
They .sometimes eat out holes in potato tubers and in the roots
of radishes and carrots (Fig. 213). Corn and tobacco seedlings

are sometimes destroyed and they

may cause serious injury to bean

.^^^ plants (Fig. 224) by eating into

«^ the stems, devouring the buds and

riddling th(> leaves with holes.
They may also bore into the un-
^ rij)e |)()ds. The leaves of celery,

lettuce, cabbage, cauliflower, radish
Fig. 226 — \ i luia- ""*^^ *'^^ sprouts of potatoes are

jured by slugs, frequently attacked (Fig. 225).

UNCLASSIFIED PESTS 357

Slugs often bore into ripening tomatoes but sometimes attack
them while still green (Fig. 226) and are often found resting
in cavities eaten out in ripening strawberries.

A smaller, nearly black species, AgrioJimax campestris Bin-
ney, is often associated with the gray field slug. It closely
resembles that form in habits and inflicts similar injuries.

Control.

Slugs may be killed by using the poison bait recommended
for the control of cutworms on page 299, or by poisoning sliced
potatoes with paris green or other arsenicals. Dusting the
plants and the surrounding ground with air-slaked lime or land
plaster will have a tendency to keep them away. Bordeaux
mixture also has a deterrent effect and on some crops may be
used to advantage. In some cases the plants may be sprayed
with arsenate of lead either alone or in combination with
bordeaux mixture.

The Yellow^ Bear Caterpillar

Diacrisia virginica Fabricius

Many vegetables are occasionally subject to attack by large
hairy caterpillars which from their shaggy appearance and
clumsy gait have received the suggestive names of yellow and
woolly bears. The yellow bear is widely distributed from
Nova Scotia to California southward to ^Mexico and (^uba.
The caterpillars are very general feeders attacking asparagus,
bean, pea, beet, salsify, cabbage, cauliflower, radish, turnip,
carrot, celery, eggplant, onion, ])arsnii), corn, peanut, canta-
loupe, pumpkin, squash, potato, rhubarb, sweet potato, water-
melon, grasses, alfalfa, grape, currant, gooseberry, raspberry,
canna, dahlia, hollyhock, hyacinth, morning-glory and various
other plants.

358 .\fA.\UAL OF VECETABLE-nARDEX IXSECTS

IIil)criiati()n takes place in the |)U[)al state and tiie moths
emerge from early spring to June. The moths have an expanse
of \^ to 2 inches. The wings are i)ure white; the front wings
marked with a small black dot near the center ; the hind wings
usually with three black dots. The head and thorax are clothed
with white down; the abdomen is white with two orange
bands and three rows cjf black spots. The eggs are deposited
in clusters of fifty to sixty or more on leaves. The egg is
spherical, about -^ inch in diameter and shining white to golden
yellow in color. The eggs hatch in seven days. The young cater-
pillars feed at first in colonies on the underside of the leaves,
skeletonizing them, but later scatter and riddle the leaves,
leaving only the ribs. They become mature in about four
weeks. The full-grown caterpillar is from 1^ to 2 inches in
length, covered with fine soft hairs intermingled with larger
ones and varying from pale yellow to deep reddish brown,
shading to blackish in front. They then leave their food plants
and seek shelter unrler the loose bark of trees, under boards
or similar situations, where they construct cocoons mostly com-
posed of hairs from their bodies fastened together with a few
threads (jf silk. The reddish brown pupa is about f inch in
length. The pupal period lasts from one to two weeks. In
the northern United States there are two broods annually.

Coiiirol.

The larger caterpillars feed in exposed situations and are
readily controlled by hand-picking. The smaller ones are
easily poisoned by spraying with arsenate of lead (paste), 2^
pounds in oO gallons of water.

References

Rilpy, .3r(l Ropt. Ins. Mo., pp. 0S-G9. 1871.
Dickerson, Moths and Butterflies, pp. 192-195. 1901.

UNCLASSIFIED PESTS 359

The Salt-Marsh Caterpillar

Estigmene acrcra Drury

Nearly a century ago, T. W. Harris made a careful study of
the life history and habits of this insect, which he named the
salt-marsh caterpillar because of its injuries to hay grown on
the salt marshes of the Massachusetts coast. This name has
been retained though somewhat misleading, as the caterpillars
are not confined to salt marshes but also feed on a great variety
of grasses and garden crops including cabbage, beans and peas.
The insect is distributed throughout North America from
Hudson Bay to Central America.

Hibernation takes place in the pupal stage and the moths
emerge in late May and June. The moth has an expanse of
If to 2^ inches. In the female the wings are white and marked
with numerous small black spots. In the male the hind wings
and under surface are yellow and spotted as in the female.
The abdomen above is orange with three rows of black spots ;
the tip is white. The yelknv, nearly spherical eggs, about ^V
inch in diameter, are laid in patches about the middle of June,
a single female laying as many as 1200 eggs. The eggs hatch
in about a week and the young caterpillars feed at first in
colonies but soon scatter. They reach maturity in about
seven weeks, that is, about the middle of August. The cater-
pillar is then about If inches in length and covered with long
mouse- and fox-colored hairs arising from large tubercles,
twelve tubercles to a segment. The nearly mature caterpillars
are often seen wandering about in search of food or places in
which to pupate. The cocoons are hidden away in any sheltered
place and are liirgely ('oinj)()sed of tlie caterpillar's hairs inter-
w^oven with silk and lined with a layer of silk. The pui)al
period in the sunnncr lasts from two ti) three weeks. In Xew
England there are two generations annually.

3G0 MAXi'AL OF VEGETABLE-GARDES INSECTS

This caterpillar may he c:)iitr()lle(l hy the same measures as
suggested for the preceding species.

Reference
Harris, Mass. Agr. Rept. and Jour. 7, pp. .3'22-33;3. 1823.

CHAPTER XIX
INSECTS AND INSECTICIDES

In order successfully to prevent insect injury to any crop,
it is necessary to take into consideration various factors, as
for instance : the life history of the insect ; its habits and struc-
ture in its various stages ; the method and rate of reproduc-
tion ; how, when and on what part of the plant it feeds, both
in its immature and adult condition ; where and in what stage
it passes the winter ; and its susceptibility to the action of
poisons and contact insecticides, as well as the effect of these
substances on the plant concerned. In order to devise a
practical means of control, it is also necessary to take into
consideration the conditions under which the plant is grown,
the methods of propagation, cultivation and harvesting as
well as the commercial value of the crop.

In the preceding chapters, an attempt has been made to
give the more important facts known touching on these points.
In the present chapter are presented some general considera-
tions in regard to the structure and development of insects
that are of interest from the standpoint of control, followed
by a discussion of the more important insecticides used against
vegetable insects.

Structure of Insects

Insects possess an external skeleton or shell composed of a
series of segments or rings which is divided hito three well-

361

362 MANUAL OF VEGET ABLE-GARDEN INSECTS

(lofiiiod refjions, — head, thorax and ah(h)men (Fig. 227). The
head bears a pair of antennjie, a pair of compound eyes and often
three simple eyes or ocelH. On the thorax are borne three pairs
of legs and in tlic adult condition two pairs of wings, except

Antenna Sucking Bedk.

Head

"nioMx-<

Abdo

-Fbie Wing

__-3I^Le9

Yu:

17. — \'oiitr:il \i('\v of :i sf|uash-l)tiK.

in the flies, when the hind pair is represented by a pair of knobbe<l
appendages known as poisers. The legs (Fig. 228) consist of a
series of segments named as follows, beginning with the one
nearest the body: coxa, trochanter, fcnnu", tibia and tarsal
joints.

INSECTS AND INSECTICIDES

363

Coxa.

TrochoiTiter —

Femur — —

The wings are modified in various ways ; in the butterflies
and moths they are usually covered with scales ; in the beetles
the front wings are hard and horny and are known as wing-
covers under which the hind wings
are folded when in repose. In many
true bugs the front wings are of a
leathery texture except the tip, which
is membranous.

In the female the abdomen is often
provided with a sharp ovipositor by
means of which she is able to insert
her eggs into the tissue of plants.

How insects feed.

The mouth-parts of insects are
adapted for feeding in various ways
and on all kinds of plant tissue. In
order to make intelligent efforts to
control insects, it is necessary to
know exactly in what way they take
their food. For purposes of control,
insects may be roughly divided into
three classes as follows :

1. Chewing insects: In this group
the mouth is provided with a pair
of hard horny jaws or mandibles
(Fig. 229) with which the insect is
able to bite off portions of plant
tissue, which are then swallowed.
Beetles and caterj)illars belong to
this class. It is usually possible to
kill such insects by poisoning their
food. Arsenic in some form is „ „„„ , ^ , ,■ ,

I'iG. 228. — LoK of a hhstcr-

generaliy employed tor this purpose. beetle.

TibiCb-

Tarsus

364 MANUAL OF VEGETABLE-GARDEN INSECTS

2. Sucking insects: This term is usually applied to insects
which have the mouth-parts modified to form a beak con-
taining four bristles united into a slender tube with which
they jnmcture the tissues of the plant and suck out the juices

(Fig. 230). riant-lice and
other true bugs possess this
type of mouth-parts and are
controlled by the use of con-
tact insecticides.

3. Lapping insects : In
some flies the mouth-parts
are developed into a tongue-
like organ with which they
are able to lap or lick up
liciuids but which is not fitted
for piercing plant tissue (Fig.
231). Sweetened arsenical
baits have been used success-
fully for the control of some
insects belonging tt) this class.

How insects breathe.

Insects breathe through a
series of openings called
spiracles extending along the
side of the body. These open-
ings connect with tubes called
tracheje which, subdividing
again and again, extend to all parts of the body. Some
contact insecticides, such as soaps, are supposed to clog the
spiracles and kill the insect by suffocation ; others, like the
oils, are said to penetrate the thin walls of the tracheie and
thus reach a vital part ; and it is thought that the fumes of
nicotine arising from the spray applied to the insect are

Fig. 229. — A gras.shopper feeding,
showing the biting type of niuuth-
parts.

INSECTS AND INSECTICIDES

365

carried through the trachese to the nervous system where
they cause death by paralysis.

^m>p

Fig. 230. — A tarnished plant-bug feeding, showing the sucking type of

mouth-parts.

The developvient of iiwects.

Most insects, with the exception of some scale insects and
certain forms of plant-lice, reproduce by means of eggs. The
newly hatched insect usually
bears little resemblance to the
adult. As it increases in size,
its skin becomes too small, a
new skin is formed beneath the
old one and the latter is dis-
carded ; this is known as molt-
ing. The period between two
successive molts is called an
instar. The number of instars
varies in different insects from Fig. 231. — Head of the onion mag-
three to six or seven ; five is the ^f fly. showing the lapping type

' of mouth-parts.

more common number. In some

insects the change from the immature condition to the winged

adult takes place without any material change in form ; in

366 MANUAL OF VEGETABLE-GARDEX INSECTS

others the transformation is abrupt and striking. In the
former case the insect is said to have an incomplete meta-
mc^rphosis ; in the latter a complete metamorphosis.

Incomplete metamorphosis.

In this type of development, the immature stages resemble
the adult in form. The wings develop externally as pad-like
outgrowths of the "thorax but do not become functional till
the adult stage is reached. The immature forms are known
as nymphs. In this type of development, the life cycle of the
insect consists of three stages, viz., the e^^, the nymph (three to
five in.stars) and the adult. The true bugs and grasshoppers
have incomplete metamorphosis.

Some authors refer to the early nymphal stages of plant-lice
as larva' and to the last nymphal stage, in which the wing-pads
are present, as pupii". According to this system in the thrips,
the first two nymphal stages are called larv?e, the third stage
a prepupa and the fourth a pupa. These terms are somewhat
confusing and are not followed in the ])resent work. It is
preferable to restrict the terms larva and j)upa to the early
stages of insects having a complete metamorphosis. The
various stages of an insect with incomplete metamorphosis
are shown in Fig. 232.

Complete meta morphosis.

In this case the immature stages of the insect bear little or
no resemblance to the adult. The wings develop internally
in pockets formed by an infolding of the body-wall of the thorax.
The immature stages are known as larva\ The larva molts
five or six times, and when full-grown transforms to an inactive
pupa, often in a cocoon or earthen cell prepared In' the larva.
The pupa is a resting stage in which the organs of the larva
are more or less broken down and made over into those of the
adult. In the pupa, the antennse, legs and wings of the adult

Fig. _32. — The various stages in the development of Idiocerus scurra, a leaf-
hopper on poplar, an insert with incomplete metamorphosis. 1 to 5 fir^t
to fifth nymphal stages ; 0. a<lnlt ; 7. e^'t,^ (All e..lar^e,l hut not in the'same
proportion.)

368 MANUAL OF V EGET ABLE-G ARDEX IXSECTS

are usually evident, closely applied to the body and covered
by the pupal skin. When the remarkable internal structural
changes in the pupa are coni|)lete, the adult win<;ed insect
emerges. In this type of devel()j)ment there are four stages,
viz., egg, larva (five to six instars), pupa and adult. Butter-
flies, moths, beetles and flies have complete metamorphosis.
The four stages of an insect with com])lete metamorphosis
are illustrated in Figs. 93 to 97 of the tomato worm.

The larvffi of flies are commonly known as maggots ; those of
butterflies and moths as caterpillars, and the larva' of beetles
as grubs. The pupa of a butterfly or moth is often called a
chrysalis.

Insecticides

Injuries to vegetable crops by insects may be prevented by
various cultural })ractices. such as clean farming to reduce
hibernating shelter and to destroy the weeds antl other wild
{>lants on which injurious species breed, and from which they
spread to cultivated cr()])s, and by a proper system of rotation
in which the same crop is not i)lanted on the same land for a
series of years and in whicli crojjs that arc attacked by the same
insects do not succeed each other. In some cases, collecting
and destroying crop remnants is of great importance in pre-
venting injur>- in the same or near-by fields the following year.
Taken all in all, clean farming in combination with a i)roper
crop rotation is the most important and j)ractical method of
])rcvcnting loss from insect attacks to vegetables.

In the case of some crops, cultural practices can usually
be relied on to prevent serious insect injury, but with most
crops recourse must be had to special applications of materials
that either poison the insects or kill them by coming into con-
tact with their bodies. Such substances are known as insec-
ticides.

Insecticides arc usually divided into two classes, internal

INSECTS AND INSECTICIDES 369

poisons and those that kill by contact. The former are used
against chewing insects and kill by being taken into the diges-
tive tract ; the latter are not eaten but a^re applied directly
to the insect's body and produce death in various ways, either
by suffocation, by corrosive action or by fumes that penetrate
the breathing pores of the insect.

Insects infesting stored seeds and tubers may be killed by
fumigating with poisonous gases.

Arsenic.

White arsenic, arsenious oxid (AS2O3), is a white powder.
It is the cheapest form in which arsenic can be obtained. It
is soluble in water and therefore very injurious to foliage.
Sodium arsenite, a cheap and efficient insecticide, may, however,
be prepared from it by the following method :

Sal soda 2 pounds

Water 1 gallon

Arsenic 1 pound

Mix the white arsenic into a paste and then add the sal soda
and water, and boil until dissolved. Add water to replace any
that has boiled away, so that one gallon of stock solution is
the result. Use one quart of this stock solution to fifty gallons
of bordeaux mixture. This material is little used, except for
potato spraying, and should always be applied in combination
with bordeaux mixture and even wdien so used care should be
taken that there is enough lime in the mixture to neutralize
the caustic action of the asenic.

Paris green.

Pure paris green, ']Cu(As02)2 • Cu(C2H302)2, is composed
of copper oxid, CuO, acetic acid, ITCoILjOo, and arsenious oxid,
AS2O3, chemically combined as coj)per-aceto-arsenite as follows:
2b

370 MAXUAL OF VEdErABLE-GARDEX IXSECTS

Copper oxid . 31.29 jkt cent

Arsenious oxid ^S.d') per cent

Acetic acid 1 ().()(') i)er cent

The commercial grades often contain impurities and vary
somewhat from the above. By the National Insecticide
Law of 1910, par is green must contain at least 50 per cent of
arsenious oxid, and must not contain arsenic in water-sohil)le
form equivalent to more than iU per cent of arsenious oxid.

Paris green is most widely used for spraying potatoes and is
usually combined with bordeaux mixture. When used in
water, an equal weight of lime should be added to neutralize
any soluble arsenic present and thus prevent burning of the
foliage. For many purposes paris green is now largel\' re-
placed by arsenate of lead, which is less likely to burn the leaves
but is a little slower in its effect on the insects.

Paris green is sometimes applied in the dry form and may
tlicn be dihitcd with liydrated lime or land ])laster.

London purple.

London puri)le is an arsenite of lime obtained as a by-product
in the manufacture of aniline dyes. Its composition is variable,
the arsenic content varying from 30 to 50 per cent. It is a finer
powder than paris green and, therefore, remains longer in sus-
pension in water. It is used in the same way as paris green,
but owing to the presence of much soluble arsenic, is likely to
cause foliage injury. This can be averted by the use of lime as
advised under paris green. Ivondon purple is now little used as
an insecticide.

Arsenate of lead.

Arsenate of lead lias practically replaced paris green for
spraying orchard trees and its use on vegetable crops is rapidly
becoming more widespread. It contains less soluble arsenic

INSECTS AND INSECTICIDES 371

and, therefore, does not have as great a tendency to burn the
foliage ; it adheres better to the leaves but is a little slower
in its action on the insects.

Chemically, arsenate of lead may be either triplumbic arse-
nate, Pb3(As04)2, or plumbic hydrogen arsenate, PbHAs04.
The commercial product usually consists of a mixture of these
tw'o forms, the proportion depending on the method of manu-
facture employed. The triplumbic arsenate of lead is prepared
by combining normal sodium arsenate, Xa3As04, with either
lead acetate, Pb(C2H302)2, or lead nitrate, Pb(X03)2. If any
di-sodium hydrogen arsenate, Na2HAs04, be present, there is
then formed some of the plumbic hydrogen arsenate. Arse-
nate of lead is sold in two forms, a thick paste and a fine powder.

Under the National Insecticide Act of 1910, arsenate of lead
paste must not contain more than 50 per cent water and must
contain the arsenic equivalent of at least 12i per cent arsenic
oxid, AS2O5. The water-soluble arsenic must not exceed an
equivalent of f of one per cent of arsenic oxid. Some of the
commercial preparations contain a larger percentage of arsenic
than required by the law. In the best grades of arsenate of
lead paste, the chemical is in a finely divided condition, and
thus when diluted for use remains in suspension for a consider-
able time. If the paste contains less than 50 per cent water,
it is likely to be lumpy and requires considerable time and labor
to get it into condition for use.

Powdered arsenate of lead is usually considered to contain
twice as much arsenic as the paste. It is often stated on theoret-
ical grounds that powdered arsenate of lead does not adhere
as well to the foliage as the paste form, but practically there is
little if any difference. The powder is more convenient to use,
it mixes more readily with water and broken packages are not
injured by drying out or by freezing. In the preceding chapters
the quantity of arsenate of lead to be used has been gi^•en in
terms of the paste form but in most cases the powdered form

372 MAX UAL OF VEGETABLE-GARDEN INSECTS

may be used with equally good results and only one half the
quantity is necessary.

Zinc arsenite.

Arsenite of zinc, Zn(As02)2, is a li^'ht fluffy powder and eon-
tains the equivalent of 40 per cent arsenious oxid. It is some-
times used as a substitute for arsenate of lead. It has a greater
tendency to burn the foliage when used in water but is fairly
safe if combined with bordeaux mixture. It is probable that
foliage injury by zinc arsenite is due to the solubility of this
poison in water containing a small quantity of carbonic acid ;
the latter is usually present on the leaves, being derived from
the respiration of the plant. One pound of zinc arsenite is
equivalent in eflfectivcness to about three pounds of arsenate
of lead paste.

Calcium arsenate.

Commercial calcium arsenate consists of a \ariable mixture
of acid calcium arsenate, ('aIIAs04, and basic calcium arsenate,
Ca3(As04)2. It is sold in two forms — a thick paste and a
powder. It may be used as a substitute for arsenate of lead
and is considerably cheaper, rnfortunately, when used alone
there is some danger of burning the foliage. This may be
overcome by adding an equal weight of quicklime, or by using
it with bordeaux mixture. Calcium arsenate contains a larger
percentage of arsenic than arsenate of lead and it is, there-
fore, not necessary to use so large a quantity.

II cU chore.

Hellebore is a light brown powder made from the roots of
the white helleliore jilant {\'cratrum. alhiini), one of the lily
family. It is applied both dry and in water. In the dry
state, it is usually apjilied without dilution, although the ad-
dition of a little flour will render it more adhesive. In water.

INSECTS AND INSECTICIDES 373

4 ounces of the poison are mixed with 2 or 3 gallons, and an
ounce of glue, or thin flour paste, is sometimes added to make
it adhere. A decoction is made by using boiling water in the
same proportions. Hellebore soon loses its strength, and a
fresh article should always be demanded. It is much less
poisonous than the arsenicals, and, therefore, may be used on
vegetables soon to be eaten. It is of especial value in the home
garden.

Soaps.

Soap solutions are often used as contact insecticides for
killing plant-lice and other small, soft-bodied insects. The
so-called whale-oil or fish-oil soaps are most widely used for
this purpose. The commercial brands are usually by-products
and contain many impurities ; furthermore, many of them
contain an excess of free or uncombined alkali and are con-
sequently very likely to injure young and tender foliage. An
excellent fish-oil soap may be easily prepared at home by the
following formula :

Caustic soda 0 pounds

Water i gallon

Fish-oil 22 pounds

Completely dissolve the caustic soda in the water, and then
add the fish-oil very gradually under constant and vigorous
stirring. The combination occurs readily at ordinary sunnner
temperatures and boiling is unnecessary. Stir briskly for about
twenty minutes after the last of the oil has been added.

Sulfur.

Snlfur is commonly sold in two forms, — flowers of snlfur
and flour of sulfur. Flowers of sulfur or sublimed sulfur is a
fine, impalpable yellow powder insoluble in water, and is
formed by condensing sulfur vapor in a large chanibcr of brick

374 MANUAL OF VEGETABLE-GARDEN INSECTS

work. If the sulfur vaj)<)r is condonsed to the licjuid form in
a cold receiver, roil sulfur is formed. Flour of sulfur is made
by grinding roll sulfur to a fine powder.

In the form of a powder or dust, sulfur is especially \aluable
against red-spider. For this })urpose it is often diluted with
hydrated lime and may he apjjlied mixed with water at the
rate of 1 pound in '.] gallons, in which a little soap has been
dis.solved to help keej) the sulfur in suspension. The sulfur
settles quickly and should be agitated constantly during spray-
ing. The sulfur will remain in suspension longer if first made
into a paste with water containing 2 of one per cent of glue.

l-.uiiilsion.'i.

Ennilsions are sprays in which oils are suspended in water
in the form of minute globules, a condition brought about by
the addition of soap. They form an important class of contact
insecticides useful particularly against j)lant-lice and other
soft-bodied insects.

Kerosene emulsion is one of the oldest of contact insecticides.
It is prepared by the following fornuda :

Soap i pound

Water 1 gallon

Kerosene 2 gallons

Dissolve the soap in hot water; remove from tlie fire and
while still hot add the kerosene. Pump the liquid i)a(k into
itself for five or ten minutes or until it becomes a creamy mass.
If proi)erly made the oil will not separate on cooling.

For killing plant-lice on foliage, dilute with 10 to 15 parts
of water. The strength of oil emulsions is frequently indicated
by the percentage of oil in the diluted li(iuid :

For a 10 per cent emulsion add 17 gal. water to 3 gal. stock emulsion.
For a 1 ") per cent emulsion add 10 \ gal. water to 3 gal. .stock emulsion.
For a 20 per cent emulsion add 7 gal. water to 3 gal. stock emulsion.
For a 25 per cent enuilsion add ."> gal. water to 3 gal. stock emulsion.

INSECTS AND INSECTICIDES 375

Carbolic acid emulsion is sometimes used against root-
maggots.

Soap 1 pound

Water 1 gallon

Crude carbolic acid 1 pint

The soap is dissolved in hot water, the crude carbolic acid is
added and the mixture is agitated into an emulsion. For use
against root-maggots, this stock solution should be diluted with
30 parts of water.

Tobacco.

Tobacco is one of the most useful insecticides. The poisonous
principle in tobacco is an alkaloid, nicotine, which in the pure
state is a colorless oily fluid, slightly heavier than \\ater, of
little smell when cold and with an exceedingly acrid burning
taste even when largely diluted. It is soluble in water and
entirely volatile. It is one of the most virulent poisons known ;
a single drop is sufficient to kill a dog.

Commercial tobacco preparations have been on the market
for many years. The most important of these are "Black
Leaf 40" and Xicofume.

"Black Leaf .40" is a concentrated tobacco extract contain-
ing 40 per cent nicotine in the form of nicotine sulfate. Its
specific gravity is about L25. In this preparation the nicotine
is in a non-volatile form, it having been treated with sulfuric
acid to form the sulfate. "Black Leaf 40" is used at strengths
varying from 1 part in 500 parts of water to 1 part in IGOO
parts. It can be satisfactorily combined with other sprays,
as, for instance, bordeaux mixture, arsenate of lead and the
various soaj) solutions. When used with wat(T, 4 to S p<nuids
of soaj) should l)e added to each 100 gallons to make the mixture
spread and stick better.

Nicofume is a tobacco extract containing 40 per cent of

376 MANUAL OF VECET ABLE-GARDEN INSECTS

nicotine in the volatile form. It is intended j)rimarily for use
in greenhouses. Strips of paper soaked in this j)rei)aration are
smudged in greenhouses to destroy aphids.

Tobacco is also used in the form of a dust for the same pur-
pose. It is especially valuable against root-lice on asters and
other plants. Tobacco extracts can be made at home by
steeping tobacco stems in water, but as they vary greatly in
nicotine content and are sometimes likely to injure tender
foliage, it is better to buy the standardized extracts.

Bordeaux mixture.

Bordeaux mixture is widely used on potatoes and many
other plants for the prevention of fungous diseases. In addi-
tion to its fungicidal properties, it also acts as a deterrent to
many insects, especially flea-beetles. Arsenate of lead, paris
green and "Black Leaf 40" may be used in combination
with it.

Bordeaux mixture is ])repared by mixing a solution of copper
sulfate, C''uS04, and milk of lime (calciuni hydroxid) according
to the following formula :

Copper sulfate 4 pounds

Lime 4 pounds

Water 50 gallons

In some cases a weaker mixture is used, containing ^) pounds
of copper sulfate and lime respectively. These formulas are
often abbreviated thus : 4-4-50 and 3-3-50.

When needed in large ciuantities, bordeaux mixture is most
conveniently i)repared by using stock solutions of copper
sulfate and milk of lime and storing them in tubs on an elevated
j)latform from which the desired (|Uantity of each can be easily
drawn off into the spray tank.

The rt'(|uire(l (|uantity of co])per sulfate sli mid be dissolved
in water in the proportion of one jjound to one gallon. This

INSECTS AND INSECTICIDES 377

may be mcist easily accomplished by suspending; the copper
sulfate crystals in a sack near the top of the water. A solution
of copper sulfate is heavier than water. As soon, then, as the
crystals begin to dissolve, the solution will sink, bringing
water again in contact with the crystals. In this way, the
crystals will dissolve much sooner than if placed in the bottom
of the barrel. In case large quantities of stock solution are
needed, two pounds of copper sulfate may be dissolved in each
gallon of water, making the stock solution twice as strong.

Slake the required quantity of lime in a tub or trough. Add
the water slowly at first, so that the lime crumbles into a fine
powder. If small quantities of lime are used, hot water is
preferred. When completely slaked or entirely powdered,
add more water. When the lime has slaked sufficiently, add
water to bring it to a thick milk or to a certain number of gal-
lons. The amount required for each tank of spray can be
secured approximately from this stock mixture, which should
not be allowed to dry out. Hydrated or prepared lime of
good quality may be substituted for the stone lime. Place
the required quantity in the barrel or tank and add water.
No slaking is required. Do not use air-slaked lime.

To make a 5-5-50 bordeaux mixture, take 5 gallons of stock
solution, containing one pound of copper sulfate to a gallon
(or one half as much of the stronger solution) for every 50
gallons of bordeaux mixture required. Pour this into the
spray-tank. Add water until the tank is about two thirds full.
From the stock lime mixture add the required quantity. Stir
the mixture and add water to make 50 gallons. Experiment
stations often recommend the diluting of both the copper sul-
fate solution and the lime mixture to one half the required
amount before putting them together. This is not neces.sary,
and is often impracticable for connnercial work. It is preferable
to dilute the copper sulfate solution. Never pour togetiier
the concentrated stock mixtures and dilute afterward. Bor-

378 MANUAL OF VEGETABLE-GARDEN INSECTS

(leaux mixture of other strengths as recommended is made in
the same way, except that the amounts of copper sulfate and
lime are varied according to the requirements.

It is not necessary to weigh the lime in making bordeaux
mixture, for a simple test can be used to determine when enough
of a stock lime mixture has been added. Dissolve an ounce of
yellow prussiate of potash in a pint of water and label it
"poison." Cut a V-shaped slit in one side of the cork so that
the liquid may be poured out in drops. Add the lime mixture
to the diluted copper sulfate solution until the ferrocyanid
test solution will not turn brown when dropped from the bottle
into the mixture. It is always best to add a slight excess of
lime.

Sticker.

The foliage of onions, cabbage and some other plants is so
smooth that it is difficult to make a spray adhere to it. The
following preparation will be useful for this purpose:

Resin 2 pounds

Sal soda (crystals) 1 jjound

Water 1 gallon

Boil in an iron kettle in the open one to one and one half
hours, or until the liquid takes on a clear brown color. Add
this amount to each 50 gallons of bordeaux mixture.

Fumigation.

Two gases are in common use for killing insects, hydro-
cyanic acid gas and carbon bisulfid. The former is much used
for the destructicm of vermin in houses, for fumigating nursery
stock and for the destruction of greenhouse insects, particularly
the white-fly and plant-lice. The latter is more generally u.sed
for killing insects infesting seeds and tubers in storage.

Hydrocyanic acid gas is generated by i)lacing either potas-
sium cyanid (KCX) or sodium cyanid (Xa('X) in dilute sul-

INSECTS AND INSECTICIDES 379

furic acid. The ingredients are combined in the following
proportions :

Potassium cyanid (98 per cent) . 1 ounce avoirdupois

Sulfuric acid 1 fluid ounce

Water 3 fluid ounces

Potassium cyanid is a white, deliquescent, highly poisonous
substance. The commercial article is usually in the form of
rather hard irregular lumps which are readily soluble in water.
Because of its tendency to draw moisture from the air, it is
usually sold in tight tin cans or drums. Small amounts may
be kept in glass fruit-jars. For fumigation purposes, only
potassium cyanid that is at least 98 per cent pure should be
used.

The sulfuric acid need not be chemically pure, a good com-
mercial grade being entirely satisfactory.

When sodium cxanid is used, the proportions are as follows :

Sodium cyanid 1 ounce avoirdupois

Sulfuric acid 1| fluid ounces

Water 2 fluid ounces

When pure, sodium cyanid contains 53 per cent cyanogen
(CX), which is about 33 per cent more than is present in potas-
sium cyanid. It is customary to indicate the strength of sodium
cyanid in terms of potassium cyanid ; that is, pure sodium
cyanid is said to be 133 per cent pure. This means that 100
pounds of sodium cyanid will yield as much cyanogen as 133
pounds of potassium cyanid. For fumigation purposes, sodium
cyanid should be at least 124 per cent pure and should not
contain more than one per cent of common salt, as its presence
causes the decomposition of the hydrocyanic acid gas. Owing
to its higher cyanogen content, only three fourths as much
sodium cyanid is recpiired for fumigating a given space as of
potassium cyanid.

380 MANUAL OF VEGETABLE-GARDEX IXSECTS

In gencnitinjj; the fjas, the projx'r ))r<)ee(lure is to place the
water in an earthen jar of suitable size. Butter crocks are
convenient for this purpose. The acid is then added to the
water, <;enerating considerable heat. The water should never
be poured into the acid, since the .steam produced will cause a
vigorous bubbling and the acid may be spattered on the operator.
After the acid has mixed with the water, the proper (juantity
of cyanid is placed in the liquid. The rai)idity with which the
gas is generated will depend on the temperature of the liquid
and on the size of the lumps of cyanid.

For destroying white-fly on tomatoes and cucumbers grown
under glass, potassium cyanid should be used at the rate of 1
ounce (or sodium cyanid, f ounce) to .'^000 cubic feet of space
contained in the house and the fumigation should continue
all night. Fumigate only on dark dry nights when there is no
wind. The house should be as dry as practicable and the
temperature not above 00 degrees F.

Carbon bisulfid is often used for fumigating peas and beans
infested with weevils and potatoes infested with the tuber-
moth. Carbon bisulfid (CS2) is a thin liquid that volatilizes
at a low temperature, the vapor being \-ery destructive to
animal life. It is very inflammable and care should be taken
not to bring it in contact with fire or with a lighted lamp.
One should not smoke while fumigating. In fumigating peas
and beans infested with weevils the seed should be i)laced in a
tight box or barrel to which a cover has bi-cu fitted as nearly
air-tight as possible. Carbon bisulfid is used at the rate of |
to 1 ounce a bushel. In larger (luantities in specially con-
structed fumigating chambers, the weevils can be killed by
using the liciuid at the rate of 3 pounds to 1000 cubic feet. The
material is placed in a shall:)W dish on the top of the seed. The
l)ox should then be co\ered tightl\' and the fumigation con-
tinued for twenty-four to thirty-six hours.

In fumigating jxitatoes t;) destroy the tuber-moth, the

INSECTS AND INSECTICIDES 381

material should be placed in tight bins lined with tarred paper
and with the seams painted. The carbon bisulfid is used at
the rate of 2 pounds for each 1000 cubic feet and the fumigation
is continued for forty-eight hours.

The carbon bisulfid is placed in shallow tin pans on top of
the material to be treated. The vapor is heavier than air and
will be gradually diffused through the mass. Fumigation with
this material is more effective if the temperature is kept near
70 degrees F. At lower temperatures the insects are less active
and much more difficult to kill.

INDEX

Acidia f r atria, 199.
acrcea, Eatigmene, 359.
Acroisternum hilaris, 42..
Adelphocoris rapidus, 195.
adonidis, Entomoscelis, 50.
adusta, Scaptomyza, 45.
aenea, Choetopsis, 249.
wruginosa, Phcedon, 258.
agonus, Limonius, 17.3.
agrestis, Agriolimax, .354.
agrejtis, Chorizagrotis, 287.
Agriolimax agrestis, 354.

campestris, 357.
Agriotes mancus, 348.
Agromyza maura simplex, 208.

pusilla, 46.

simplex, 208.
Agrotis ypsilon, 265.
albida, Macrobasis, 309.
albilinea, Leucania, 298.
alternata, Rhynchagrotis, 298.
^na.sa andrewsi, 120.

armigera, 119.

tristis, 116.
andrewsi, Anasa, 120.
annexa, Feltia, 273.
Anomis erosa, 253.
Anthonomus eugenii, 255.
Aphiii brassiccB, 22.

go.snypii, 135.

maidi-radicis, 218.

pseuduhrassiccB, 27.

rurnicis, 76.
Apple leafhopper, 154.
arctica, Hadena, 281.
argus, Chelymorpha, 238.
Argus tortoise beetle, 238.
armigera, Anasa, 119.
armoracia, PliitcUn, 14.
armoraciae, Phyllotrvta, 328.

Army cutworm, 287.
Army-worm, 288.
Army-worms, 260.
Arsenate of lead, 370.
Arsenic, 369.

Ash-gray blister-beetle, 306.
asparagi, Crioceris, 201.
asparagi, Tetrastichus, 204.
Asparagus insects, 201.

miner, 208.
atomaris, Paragrotis, 298.
Autographa brassicce, 8.

falcigera, 191.
auxiliaris, Chorizagrotis, 287.

balteata, Diabrotica, 115.
Barred-winged onion fly, 249.
basalis, Heiniglyptus, 326.
Bean aphis, 76.

insects, .54.

ladybird, 67.

leaf-beetle, 65.

leaf-roller, 81.

thrips, 69.

weevil, 57.
Beet army-worm, 294.

insects, 90.

leafhopper, 92.
Belted cucumber beetle, 115.
Bernisia inconspicua, 242.
6e^<E, Pemphigus, 102.
liicolor, Coplocycla, 237.
f)i piiiirlalis, Pacfiyzancla, 101.
bipu.^lulata, Pliyllotreta, 320.
Bisulfid of carbon, 380.
bivittata, Cassida, 230.
Black army cutworm. 275.
Black blister-beetle, 307.
Black Leaf 40, 375.
Black-legged tortoise beetle, 237.

383

384

INDEX

Black onion fly, L'oO.
lilack swallow-tail hutlorfly, \S(\
bhinda, Si/.sliiut, .'12 1.
Blistcr-bcctlos, :j()2.
Bordeaux mixture, 876.
borealifi, Epilachna, 133.
brachyurus, MancascUus, 257.
brassicae. Aphis, 22.
brassiccB, Aidograplia, S.
brasnicce, Phorhia, 29.
BreathiriK of insects, 364.
brevicornis, Tychca, 104.
Bri.stly cutworm, 2JS5.
Broad bean weevil, 61).
Bronzed cutworm, 2!S6.
Brown fruit-chafer, 231.
Bruchus chinetisis, 63.

oblectus, bl .

pisorum, 54.

quadrimaculalus, 61.

rufimanus, 00.
brunnea, Colaspis, 67.
Burdock Ixirer, 100.

Cabbage aphi.s, 22.

curculio, 49.

insects, 3.

leaf-miners, 43.

looper, 8.

root-maggot, 29.

seed-stalk weevil, 50.

webworm, 16.
Calcium arsenate, 372.
Calico-back, .3,S.
californicii.s, Lunonius, 349.
campe-striti, Aijrioliinns, 357.
Cantharis nultnlli, 30.S.
Caradrina cxiaua, 294.

flavimaculata, 294.
Carbolic acid emulsion, 375.
Carton bisulfid, .3,S0.
Carrot beetle, 1.S5.

insects, 1<S1.

rust-fly, 181.
Cassida hiiitlaln. 230.

nigriprx, 237.

pnltidula, 177.
cataphracla, Papaipcma, 160.

Celery insects, 181.

leaf-tyer, 189.

looper, 191.
rcparuni, Phorbia, 243.
cirina, Gli/plina, 319.
Ciroloma trifurcata, 6.5.
Ccutorhyncfius quadridens, 50.

rapac, 49.
Chatocncma confinis, 332.

cctypn, 334.
ChcetopsiK aenca, 249.
Chiiytnurpha argus, 238.
Chewing insects, 363.
rhinensis, Bruchits, 03.
Chorizagrotis agreslis, 287.

auxiliari.s, 287.

intru/ercns, 287.
cincrea, Epicauta, 306.
rincrcola, Ogdoconta, 83.
r;//-/, Hallicus, 77.
cltKlophtftiruK, Eriophyes, 174.
rtandcslina, Xortua, 263.
Clay-backed cutworm, 274.
Clover cutworm, 284.
c-nigrum, Xocliia, 262.
cicruleociitctiDi, Julus, .344.
Colaspis brunnea, 67.
Colorado corn root-worm, 227.

potato beetle. 142.
Coiniiion asparagus beetle, 201.

stalk-l)r)rer, 1.57.
communis, Mclanoliis, 349.
roncavus, Li jus, 251.
confinis, Clicelorncma, .3.32.
f\)nfu.sed wireworm, 349.
ronfusus, fjimoniiis, .349.
roinuxn. Dinlirolica, 116.
ronsimtn, Monoxin, 96.
Coploryrlu hirolor, 237.

signifera, 238.
Corn and cotton wireworm, 349.

ear- worm, 211.

in.sects, 211.

root-a|)his, 218.

wireworm, 349.
ciirrupta. Epilachna, 67.
rorrina, Epirnuln, 311.
Cowpea weevil, 6.3.
rrtnicollis, Disonyrha. 3.32.
Crioccris asparagi, 201.

INDEX

385

Crioceris — Cont.

duodccirnpunctata, 205.

quatuordecimpunctata, 207.

quinquepunctata, 207.
Cross-striped cabbage worm, 14.
Crow blister-beetle, 311.
Cucumber flea-beetle, 314.

insects, 109.
cucumeris, Epitrix, 314.
cucurbitae, Macrosiphum, 139.
Cutworms, 260.
Cyariid of potassium, 379.

of sodium, 379.
Cylas formicarius, 239.

Dargida procinctus, 298.
Dark-sided cutworm, 268.
decemlineata, Leptinotarsa, 142.
Depressaria heracliana, 197.
Desert corn flea-beetle, 334.
detersa, Paragrotis, 298.
devastairix, Hadena, 279.
Development of insects, 365.
Diabrotica balteata, 115.

connexa, 116.

duodecimpunctata, 113, 222.

longicornis, 225.

soror, 114.

trivittata, 113.

virgifera, 227.

vittata, 109.
Diacrisia virginica, 357.
Diamond-back moth, 12.
Diaphania hyalinata, 131.

nitidalis, 127.
DialrcBa zeacolella, 228.
DiuKy cutworm, 271.
Di.soni/rha crctiirolUs, 332.

mdlicollis, 331.

triangularis, 331.

xanthonielcBna, 329.
ducens, Fellia, 271.
duodecimpunctata, Crioceris, 205.
duodecimpunctata, Diabrutica, 113, 222.

Eastern field wiroworm, 173.
ectypa, C/twlocnema, 334.

Eggplant flea-beetle, 320.

insects, 177.

lace-bug, 178.

tortoise beetle, 177.
Elasmopalpus lignosellus, 229.
Empoasca mali, 154.
Emulsions, 374.
Enlomosceiis adonidis. 50.
Epicauta cinerea, 306.

corvina, 311.

lemniscata, 303.

maculata, 309.

marginala, 305.

pardalis, 311.

pennsylvanica, 307.

i7'«a<o, 302.
Epilachna borealis, 133.

corrupta, 67.
Epitrix cucuyneris, 314.

fuscula, 320.

parvula, 319.

suhacrinita, 318.
ericce, Nysius, 47.
eridania, Prodenia, 297.
Erinose of the tomato, 174.
Eriophyes cladophthirus, 174.
erosa, Anomis, 253.
Estigmene acrcea, 359.
Eudamus proteus, 81.
eugenii, Anthonomus, 255.
Euphoria inda, 231.
euschistoides, Euschistus, 232.
Euschistus euschistoides, 232.

variolarius, 232.
Eutettix tenellus, 92.
Evergestis rimosalis, 14.

straminalis, 19.
exigua, Caradrina, 294.

falcigera, Autographa, 191.
Fall army-worm, 292.
False ciiinch-bug, 47.
fascialis, Ilyuunia, 99.
fasciatus, Hcliothrips, 69.
Feeding of insects, 303.
Feltia anncxa, 273.

ducens, 271.

gladiaria, 274.

386

INDEX

Feltia — Coiit.

jaculifcra, 271.

malefida, 272.

subgothica, 271.

vencrabilui, 298.
fennica, Xoctua, 27.5.
ferrugalis, Phhjclcenia, 189.
Five-spotted asparagus l>cetlp, 2(}7.
Fire-bug, 38.
Fish-oil soap, .'57;?.
Jlaveola, Scaploinijzn, 44.
flaciinaculala, Caradrina, 294.
Flea-beetles, 31.3.
Jlexa, Triioxa, 2.50.
formicarius, Cylas, 239.
Four-spotted bean weevil, 01.

rabbage flea-beetle, 32G.
Fourteen-spotted asparagus beetle,

207.
fratria, Acidia, 199.
/rontalin, Systena, 323.
frugiperda, Laphijgma, 292.
Fumigation, 378.
fusciceps, Phorbia, 30.
fuscula, Epilrix, 320.

Garden flea-hopper, 77.
Garden springtail, 1.39.

webworm, 18.
(largaphia solani, 178.
gibhonuH, fjigi/rus, 18.5.
glddlaria, Fe'.lia, 274.
(Jlassy rut worm, 279.
(iluptlna ccrina, 319.
Golden tortoise beetle, 237.
gossijpii, Aphia, 135.
gracilis, Orthomorpha, .343.
graminum, scaplomyza, 45.
graminum, Toxnptcra, 13.5.
Granulated futworm, 273.
Grape folas|)is, 07.
firapholiln nigrirnnn, 79.
Gras-shoppcrs, .350.
Grass-worm, 292.
Gray blister-beetle, 306.
Ciray field slug, 3.54.
CJray hair-streak, 84.
Greasy rut worm, 205.

Green clover worm, 85.
Greenhouse millipede, 343.
Green .soldier-bug, 42.

Hadrna arctica, 281.

dcva-slatrix, 279.
I I alt ic us citri, 77.
Harlequin cabbage bug, 38.
Hawaiian beet webworm, 99.
Heliophila unipuncta, 288.
Hcliolhis obsolete, 211.
Heliothrips fasciatus, 09.
Hellebore, 372.
Hf'llula undalis, 10.
IIcmigbjptuH basal is, .320.
hcrucliana, Dcprcssaria, 197.
Helerodera radicicola, 338.

schaclii, 342.
hilaris, Acroslernum, 42.
hirticula, Lachnosterna, 345.
histrionica, Murgantia, 38.
Hop flea-beetle, 335.
Horislonotujs uhlrrii, 349.
Horned squash bug, 119.
Horse-radish flea-lx;otle, 328.
hortensis, Sminlhunui, 1.39.
hiulsonias, Systena, 323.
hyalinata, Diaphnnia, 131.
Hydroc\-anic acitl gas, 378.
Ilymcnia fasciails, 99.

pcrsprctalis, 100.
hyoscyami, Prgnmyia, 90.

Jdiocerus scnrrn, 307.
ilicis, Larhnoslcrna, 345.
immaculala, Macroba.iis, 310.
Ininiaculate blister-l>eetle, 310.
Imported cabbage leaf-miner, 4.5.

cabbage worm, 4.

turnip leif-miner, 44.
incniispirua. licniisia, 242.
imla. Euphoria, 231.
Insecticides, 30.S.
inspcrala, Lytla, .311.
insnlsa. Paragrnli.s, 298.
introfcreii.s, Chorizag rolls, 287.

INDEX

387

jaculifera, Feltia, 271.
Jalysus spinosuii, 172.
Julus coeruleocinctus, 344.

Kcrosono einvilsion, 374.

Lachnostcrna hirticuln, 345.

ilicis, 34.5.
lactucm, Rhizohius, 258.
Laphygma frugiperda, 292.
Lapping insects, 364.
Large black blister-beetle, 311,
Larger corn stalk-borer, 22<S.
striped flea-beetle, 332.
sugar-beet leaf-beetle, 95.
latiusculus, Listronotus, 199.
Lead arsenate, 370.
legitima, Mamestra, 22.
Lema nigrovittala, 149.

trilineata, 149.
Irmniscata, Epirauta, 303.
Leptinotarsa dcccmlineata, 142.
Lcptoglossus opp<mtus, 122.

phyUopua, 121.
Lesser corn stalk-l)orer, 229.
Lettuce insects, 258.

root-louse, 258.
Lcucania albilinea, 298.

unipuncta, 288.
lignoscllus, Elasmopnlpufi, 229.
Ligyrus gihhnims, 185.
Lima bean vine-borer, 87.
Lirnonius agonui^, 173.
callfornicus, 349.
confusus, 349.
LiMronotus latiusculus, 199.
Hindus, Monocrepidius, .347.
Lixus concavus, 251.
London purple, 370.
longicollis, Marrohasis, 310.
lonoirornis, Diabrotica, 225.
Losses Caused by insects, 1.
Lii.rostrgc. siinilniis, 1 8.

sticticnlis, 97.
Lygus prntcnMi's, 192.
L//^/a iuspcrnid, 311.

INI

Macrohasis alhida, 309.
immaculaia, 310.
longicollis, 310.
segmentata, 310.
unicolor, 306.
Macrosiphum cucurhitcB, 139.
pisi, 71.
solanifolii, 150.
maculata, Epicauta, 309.
ynaculipennis, Plutella, 12.
maidi-radicis, Aphis, 218.
malefida, Feltia, 272.
?na/i, Empoasca, 154.
Mamestra picta, 21.
legitima, 22.
rcnigira, 285.
subjuncta, 283.
trifolii, 284.
Mancasellus brachyurus, '2'i7.
inancus, Agriotcs, 348.
margaritosa, Peridroma, 276.
marginata, Epicauta, 305.
Margined blister-beetle, 305.
Melanotus communis, 349.
melinus, Uranotes, 84.
Melilia satyriniformis, 124.
mellicollis, Disonycha, 331.
Melon aphis, 135.
insects, 109.
leaf-bug, 121.
worm, 131.
tnrssoria, Paragrntis, 268.
Metamorphosis of insects, 300.
Millipedes, .342.
minians, Nephelodes, 286.
minutus, Nysius, 48.
Monocrepidius lividus, .317.
Monoplilola nubilella, 87.
Monoxia consputa, 96.

puncticollis, 95.
Mottled tortoise beetle, 238.
Murgantia histrionica, 38.
Myzus persicce, 105.

N
Native cabbage leaf-miner, 45.
nrbris, Papaipema, 160.
Negro-ljug, 19().

388

INDEX

Xephelodes minians, 286.
Nezara viridula, 43.
Nioofunie, 37.j.
nigricaiui, Grapholita, 70.
nigripcs, Cassida, 237.
nigrocittala, Lema, 149.
nitela, Papaipenia, 157.
nitidaliJi, Diaphania, 127.
Noctua clandestina, 2G3.

c-nigrum, 2G2.

fi'nnic.a, 27.5.
Northern leaf-footed plant-l)Ug, 122.

tomato worm, 109.
nubilella, Monoptilota, 87.
nuUalli, CatilhariJi, 308.
Nuttall's blister-beetle, 308.
Nysius ericcB, 47.

minutu.'i, 48.

obsoleta, Heliolhis, 211.
obtectn-x, Bruchus, hi.
ochroganter , Paraorolia, 207.
Ogdoconta cinercola, 8.3.
Okra caterpillar, 253.

in.serts, 253.
oleracea, Ponlta, 7.
Onion insects, 243.

maggot, 243.

thrips, 245.
opcrridtlla, Phlhorimcea, 102.
opposiliix, Leploglotisus, 122.
oniithogalli, Prodrnia, 295.
orthogonia Porosagrotin, 298.
Orthomorpha gracilis, .343.

Parhj/zanrla fiipunctnli.'^. 101.
Pale-striped flea-lx'etlc, 321.
pall id ul a, Cassida, 177.
Panther blister-lx?etle. 311.
Papnipcma ralaphracta, 100.

nehria, 100.

nitela, 1.57.
Papilio piilj/Trncs, 180.

zolicaim, 1)S9.
Paragrotis atomarix, 298.

detrrsa, 29S.

insidsa, 298.

Paragrotis — Conf .

mf.'isoria, 268.
ochrogaster, 267.

pcrcxccllcnji, 298.
scandcns, 278.

tessellaia, 270.
pardalis, Epicauta, 311.
Paris green, 369.
Parsley stalk-weevil, 199.
Parsnip in.sects, IM.

leaf-miner. 199.

webworm, 197.
parvula, Epitrii, 319.
Pea aphis, 71.

insects, 54.

moth, 79.

weevil, 54.
Pegomyia hyoscyami, 90.
Pemphigus betce, 102.
penn.syhanica, Epicauta, 307.
Pepper insects, 255.

weevil, 255.
pereicellens, Paragrotis, 298.
Peridroma margaritosa, 276.
persiccE, Myzu.s, 105.
perspcctalis, Hymenia, 100.
Phoedon cBruginosa, 258.
phaseoli, Tychea, 104.
Phlegethontius quinquemaculata. 169.

sella, 171.'
Phlyctfpnia femigalis, 189.
Phorhia brassicce, 29.

ceparum, 243.

fu.sciceps, .30.

planijmlpi-s, 37.
Phthorimwa operrulella, 102.
phyllopu.s, Leploglossus, 121.
Phyllotreta armtiracia, 328.

bipu.stnlata. 326.

pujiilla, 327.

ratnosa, .326.

s'inuata, 326.

ri7/a/a, 324.
Pickle worm, 127.
picta, Mamcstra, 21.
PiliXToris tripunctata, 241.
pi'.f/, Macrosiphum, 71.
pisnrum, Brurhus, .54.
placida, Rhynchagrotis, 298.
planipalpis, Phorbia, 37.

INDEX

389

Plathypena .scahra, 85.
Plutella armoracia, 14.

maculipennis, 12.
Pnyxia scahiei, 161.
polyxenes, Papilio, 186-
Pontia oleracca, 7.

protodicc, 7.

rapcB, 4.
Porosagrotia orthoyonia, 1298.

vctusta, 282.
Pota.ssium cyanid, 379.
Potato aphis, 150.

flea-beetle, 314.

insects, 142.

scab gnat, 161.

stalk-weevil, 155.

tuber moth, 162.
Potherb butterfly, 7.
pratensis, Lygiis, 192.
procinctus, Dargida, 298.
Prodenia eridania, 297.

ornithogalli, 295.
proteus, Eudamus, 81.
proiodice, Pontia, 7.
pseudobrassicce. Aphis, 27.
Psila rosce, 181.
Psyliiodes punctulala, 335.
pulicarius, Thyrcocoris, 190.
puncticollis , Monoxia, 95.
punctulata, Psyliiodes, 335.
Purple-backed cabbage worm, 19.
pusilla, Agromyza, 46.
pusilla, Phyllotrcta, 327.
Pycnoderes quadrimaculatus, 121.

quadridens, Crutorhynchus, 50.
quadrimaculatus, Brux-.hiis, 61.
quadrimaculatus, Pycnoderes, 121.
quatuordecimpunctata, Crioceris, 207.
quinquemaculala, Phlegethontius, 169.
quinquepunctata, Crioceris, 207.

radicicola, Hctcrodera, 338.
ramosa, Phyllotrcta, 326.
rnpce, Ceutorhynchus, 49.
rapw, Pontia, 4.

rapidus, Adclphocoris, 195.
Red-backed cutworm, 267.
Red-headed flea-beetle, 323.
Red-spider, 351.
Red turnip beetle, 50.
renigera, Mamestra, 285.
Rhizobius lactuccB, 258.
Rhubarb curculio, 251.

insects, 251.
Rhynchagrotis altvrnata, 298.

placida, 298.
rimosalis, Evergcstis, 14.
Root-knot nematode, 338.
/•06<E, Psila, 181.
rufimanus, Bruchus, 60.
rumicis, Aphis, 76.

Salsify insects, 255.
Salt-marsh caterpillar, 359.
satyriniformis, Melittia, 124.
scabiei, Pnyxia, 161.
scabra, Plathypena, 85.
scandens, Paragrotis, 278.
Scaptomyza adusta, 45.

flaveola, 44.

graminum, 45.
schaclii, Heterodera, 342.
scurra, Idioceru-'i, 367.
Seed-corn maggot, 36.
srgmcntata, Macrohasis, 310.
Segmented black blister-beetle, 310.
Semi-tropical army-worm, 297.
Serpentine leaf-miner, 46.
sexta, Phlegethontius, 171.
Shagrecned cutworm, 272.
signifera, Coptocycla, 238.
similalis, Loxostege, 18.
simplex, Agromyza, 208.
simplex, Agromyza maura, 208.
sinuata, Phyllotrcta, 326.
Sinuato-stripod flea-beetle, 326.
Slugs, 854.

Smartweed flea-beetle, 323.
Sminthurus hortensis, 139.
Soaps, 373.
Sodium arsenite, 369.

cyanamid, 341.

cyanid, 379.

390

INDEX

solani, Gargaphia, 17s.
solanifolii, Macro.-iiphum, l.")().
soror, Dinhrntirn, 114.
Southern r-ablKifjo butterfly, 7.

beet web worm, 101.

corn root-worm, 22L'.

leaf-footed plant-lnit', ll-'l.

tomato worm, 171.
Spanish-fly, 302.
Sijof'kled cutworm, 2,S.'3.
Spinaeh aphis, lO.'j.

flea-beetle, .329.

insects, 90.

leaf-miner, 90.
spinnxns, Jalysua, 172.
Spotter! Ijlister-beetle, 309.

cutworm, 2f)2.

beet webworm, 100.
Spotted-legged cutworm, 2.S2.
Sf|uash aphis, 139.

bug, lit).

iiLsects, 109.

ladylnrd, 133.
S(|uash-vinc borer, 121.
Sticker, 37S.
sticlicali.s, LoToslrgr, 97.
Stink-bugs, 232.
straminalis, Evcrgcstis, 19.
Striped blister-liectlc, 302.

cabbage flca-l)eetle, 321.

cucumber beetle, 109.

cutworm, 270.

green bean caterpillar, S3.

tortoi.sc beetle, 236.
Structure of iasects, 3G1.
subgothica, F cilia, 271.
suhjuncta, Mamestra, 283.
suhscrinila, Epitrix, 318.
Sucking in.sects, 304.
Sugar-beet nematode, 342.

root-lou.se, 102.

webworm, 97.

wireworm, 349.
Sulfur, 373.
Sweet potato flea-beetic, 3.32.

insects, 235.

leaf-roller, 241.

weevil. 239.

white-fly. 242.
Syslena blanda, 321,

Si/slcna — Cord,
frontalis, 323.
Initlfiimia.-^, 323.
laniata, 321.

lahaci, Tlirip.s, 24."i.
Iwniala, Syslena, .321.
Tarnished planl-hiig, 192.
tvlarias, Ttlrani/chuN, '.i'll,
tcmllu.s, EuUitix, 92.
Terrapin-bug, 3S.
tcsnellala, Paragroti.s, 270.
Tctrani/chu.s tclariiis, 3.")1.
Tclra.'stirhu.s asparagi, 204.
Three-lined potato l)eetle, 149.
Three-si>otted flea-beetle, 331.
Thrips (abaci, 245.
Tliyrcocori.s pulicariun, 190.
Tobacco, 375.

dust, 376.

flea-beetle, 319.
Tomato insects. 168.

stilt-bug, 172.

worms, 16S.
Tortoise beetles, 2.3.').
Toxuptrra graminum, 1.3.").
Iriangiilari.s, Disonycha, 331.
Trichobaris (rinolata, 155.
trifolii, Manic-slra, 284.
Irifiircala, Ccrotoma, 65.
trilincata, Lcma, 149.
Irinolala, Trichobaris, 155.
tri punctata, Pilocrocis, 241.
Iristis, Anasa, 116.
Trituxa jlrxa, 250.
Iriiiltata, Diahrotira, 11.3.
Turnip aphis, 27.
Twelve-spotted asparagus beetle, 205.

cucumber l>eetle, 113.
Two-spotted blister-beetle, 309.
Tychra brrvicornin, 104.

})hascoli, KM.

iihlerii, Horitttonotus, 349.
undalis, Helhda, 16.
unicolor, Macrobaais, 306.

INDEX

391

unipuncta, Hdiophila, 288.
Uranutes melinus, 84.

Varlogatcd outworni, 270.
variolarius, Euschistus, 232.
venerabilis, Feltia, 298.
vetusta, Porosagrotis, 282.
mrgifera, Diabrotica, 227.
virginica, Diacrisia, 357.
viridula, Nezara, 43.
vittata, Diabrotica, 109.
vittata, Epicauta, 302.
vittata, Phyllotrcta, 324.

Water-cress insects, 257.

leaf-beetle, 258.

sowbug, 257.
Well-marked cutworm, 263.
Western army-worm, 287.

beet leaf-beetle, 96.

cabbage flea-beetle, 327.

corn root-worm, 225.

cucumber beetle, 113.

Western potato floa-bcotle, 318.

radish maggot, 37.

twelve-spotted cucumber beetle, 114.
Whale-oil soap, 373.
Wheat wireworm, 348.
White cutworm, 278.
White grubs, 344.
Wireworms, 347.

xantliumdwna, Disunycha, 329.

Yellow bear caterpillar, 357.
Yellow-headed cutworm, 281.
Yellow-necked flea-beetle, 331.
Yellow-striped army-worm, 295.
UPsiloH, Agrotis, 265.

zcacolclla, Diatraea, 228.
Zebra caterpillar, 21.
Zinc arsenite, 372.
zolicaon, Papilio, 189.

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Full text of "Manual of vegetable-garden insects"

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