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Principal Insect Enemies

OF THE

We | = es one Mibra?
ASA C. MAXSON Bewtral b-
_ In Charge, Experimental Department ae

ULC

Published by —
AGRICULTURAL DEPARTMENT
| ‘THE GREAT WESTERN SUGAR COMP ‘
Pe DENVER, COLORADO }

1920

Principal Insect Enemies

OF THE

SUGAR BEE!

THE TERRITORIES SERVED BY

IN
The Great Western Sugar Company
BY
INSIN Ce MAXSON

In Charge, Experimental Department

Published by
AGRICULTURAL DEPARTMENT
THE GREAT WESTERN SUGAR COMPANY
DENVER, COLORADO

1920

PREFACE

Some damage is done by some pest somewhere every year, causing
some loss to individual farmers. Fortunately, we have been free so far
from pests damaging very large areas in any one year, and it is confidently
hoped that this will always be the case in the territory served by this Com-
pany. Nevertheless, it seems wise to have on hand. all the information
necessary to enable growers to apply proper measures in case of emergency.

There are available a number of bulletins and books published by the
Department of Agriculture, Agricultural Colleges and others, dealing with
insect pests damaging to sugar beets, but it has been thought of interest
and value to beet growers to have this information presented in one book
and with due regard to local conditions.

While it is hoped that this Bulletin will be of valuable assistance to
the grower of sugar beets by presenting the best known methods of pre-
venting injury and controlling insects which damage this crop, it seems
desirable to impress upon him the fact that there is no magical method, no
patent medicine, which can be quickly and easily applied.

Good farming, as taught by local experience, practiced con-
sistently every year, will produce bigger yields of beets and min-
imize the damage done by insects or beet diseases.

For the benefit of those wishing to study the subject more completely,
scientific names of insects, other invertebrate animals, and plants discussed,
have been given in the Appendix, pages 138 to 146, together with credit
for determination. Free use has been made of the literature of beet insects
and credit given where it has been quoted.

This Bulletin has been prepared by Mr. A. C. Maxson, Entomologist
in charge of the Company's Experimental Farm at Longmont, Colorado.

Credit is due Miss Caroline M. Preston for reproducing the insects
for the colored plates.

THE GREAT WESTERN SUGAR COMPANY

TABLE OF CONTENTS

Page

“FDA GRC ETOTO LS vie wy © Scan) bw Ryan ee ee Sta cv een l

Wutuncwomencwoulletinw-she we we ws Meee eee Mee ne eee 3
Key for Determining Insect Injury to Sugar Beets:

Feinats eal GI OMMONPINC Veh entra 0 ae ee Laika erie al 4

Tae TR Ga ea Se eit NBR ts ya TU 5

Wolonccaimlaces ymin tees tne pre mer ecg oases ae Il

CHAPTER I

SSREES ihe Geaenells Sea wie Sioa Ola aeeee Nee net Cae Nee tne tee nee 29

SCISUISIWERE 2 wig oS Re Ee I st Se 29

| DIPVSNO OBIS AEs 5 Gi ah Boia Soa keris ota RAS cl eye eh einer ce a co ees 29

Tire TELPaRGe sale: See le leteiyaees ee OIG. Bieta east Gene fe naar NeMageae a 30

“TEV Lea S <p GAS wR oneties es SIU ca 30

WHAG IPRS a eb te G/B et bc Ua ee 30

MMep NGO CARtee aor rest near aes G AY, Meats icin ha quiuhlchoase cles 30

Wiitcenteounentre Aye tee MOR Me ae ee ES coer 30

Blea Cat Omen ON Na aren Anh e oteerrs Shoe sos 3 Maceaynlac hee 31

IR@OE IR@SSISSS Bia co Ses GI eae OTE ey RU ee eee eae 31

IL@ait IFSC ise eB e vile eos eae a a me ae 31

PS viet OMI SEC Samia were ee aye ce ii hing Miele ce geithcuthen’s 31

UC Sila OMIIASCCES eet re Merrie. Me nitiernae ofilcues sss 31

Per moe Om Controller at) 104. oe eles es ene ie es 31

INeteuipaleNlepaodSers aia te gees Vee ei ne ald Phe 51k

GroppNorariomus nr ewe ee lene ci oe suite as 31

IP ON RaVes Le stone cic tae ke keansoib onc oa ee ee RS ee On ee By

LBS TP UBL ACCA aero iN eal eae eee eco he eg i ae eRe BD

| IUVAAITAVS? eee See amte6 8 6.18 tae A Ae 1 eel ee ET oy

(Clean Cuillsite sc gate bie srctgtes 0 cis ey Lace aaa eee eee 32

PGuinicialu\lethiods——inSeCuiclGesin sakes sase- toone oe ayn)

Controle icinemlnsectsmenmmnina Wek. ese oaks ee By)

Control of Sucking Insects—Contact Poisons.......... 33

RG welleat Sipe Weare eee are Pee gio bik ceeded Nase BB

\SVERVGRG 215. Se M Anglo. gt cats. Mesto 2 es een OOM te Sa 53

TSG EOA SIONS CN UNI ES hie clas, ee aa ee 33

(Care Of SorenierSae fs ink eee | Sieh Uk nee Opie ete tae Ae ie ee 34

IKIBVSSBCIK. (SOHN CIEE ioe eimai eure hae Ea een IR Ue ee 36

IFIIAG! SlOTENICR AS Cae 6 i Roca Ree an eC en 36

Fal OMe HAAG ONS ANA Cleantech ais keen eee ae oiay ee wo sin OF)

Pans Green, Caution Regarding the Handling of................... 37

Table of Contents

CHAPTER II
Page
Root ‘Feeders. sc sche cnt. Mane te ore OOO ee one ae 38
A. Biting Root Peeders35. se ee ee ee eee 38
1, Citeworms...:./0 4 eae se ee eee 38
anmWiestenapAemaya GU W Orn eee ea 4]
bx Pale Westernl Gutwonmlan eee eee 45
c) Naniegatedi@utworme sane ror nee eee 47
2. White Grubbs. so. toste nim 1 cairo ne ee eee 48
Bit Wir Worse 28 aes Bo stot albeit Ce ae ee DD)
IB. Sucking Root :Reedersie- a. ne ne er 55
|.<Sugar,Beet!Root-louses. e012 eee case eae D9)
2. sugar Beet, Nematodes 2 masini ic a ee 59
3 oot-knot Nematode om Gallwornmeeee ee eee 64
CHAPTER III
Leaf Féedersi sevice os dienes RO Sh oe eS ee 67
A. Biting eat: Peedersni es ieee eae er ee 67
|. Weaf-eating Catenpillarsiy: . oc ee ee eee 67
Al, SUletie BEBE WENO. 5obocccccucoscecocccu seco 67
b: TruesArmy Worm... 3.4.0. n5) oi eee 78
c:, Alfalfa Teooperniccers yaw ate ee ee 81
d: Alfalfa Webworm) gs0.%. Hack. ee eee 84
es ellow-bearm Caterpillars seen eee 86
f;. Zebra: Gaterpillar.. 2 eee, eee eee 87
2. eeat-eating. Beetles. 0 seen) gare ey 88
a. Larger Sugar Beet Leaf-beetle or Alkali-beetle...... 89
lpWiestennubecetalbeat-locetl emesis ea enn 90
c.. Plea-beetles 5 2 fe 5 a eee Oe eee 91
c= BandediBlea-beetlen y= a ee eee 92
¢-2.4 Potato Plea-beetle = eee ee oe 93
¢-3, llhnee-spottedtlea-ocet lena i eae 93
diSpinachCarsion-bectle an eee aa 94
e. (Bhister-beetles cA) Cee eee oe ne oe 96
3). GGrassHOPpens 222 28s sacetes ne ee een ee er 98
a. Two-lined: Hopper 26. eo. a ae cee eee 100
bps Differentiallltoppereeeneeer et een Ne TORS, « 100
ce. Red-leggedi Locust. heen ere ene ee ee 100
4: Field*Crickets 2.3.05 egtth a ene reese nae eee eae 109
).. Wéataminers 6. Sang ce eee OE eee 110
BL, IBESE Ge Sone a ILEANA, 4655 os0cn ss noscocooc: 110

Table of Contents

Leaf Feeders—Continued Page
IB, Suc einen bei PCa Giese ae acres eee eerie ea eters ec ee He
ep ANyolni Gl sworn lain taliCe nian dey. co: sus/aness Chere taretecee wieata aie 6 111
a, Gresn Peecreeiol clues aeeemia on cic > ectes oem amine 116
[pamlalaclwiseet-seed OuSCi i. Scns nee ne ee che ne ie = IN
2). WRG BAUS Faas a 3 ess ts Ponce Oa eee NET POO oils ee eae ee oar IN)
@, Pallse Claivaeloul Bibi oni sic rieinees ce ene irs Situs aieanieeL cones 119
ommlbanmished) lant-bUg a. sic a. <5 cease sceeceia ees 122
3. LGC |S) OARS Secyetote ota ery Cree eae eC Sertint teaee 23
A, Sulgpaic Bese Iai nojcieassgaseecge et an oop ocmore 123
be Clovenleatshoppeins 1.2/0: c0 acae hoasopeenee net 126
COM UECELISCES OO UMRMEC ier ce erralay Wames seis ect eoeeiomione. one 128
CHAPTER IV
EBA TCIAl, WMSQCIS sc. 5 thse cleo eeoeete Rick Seca eo a ener aa ee 129
(MMM AC ACIOUSMITISECES ony rstae ae ie A tcie, sect ale tieleis gin sae ee See 130
en Grotincdslscetlesmnn acetate Mele aalts nisin Ko esah cle meets 130
Bi, JENS Y TAMILS C8 5 On aoe ey laden fim eRe See Er aU 130
lomlpomnancien:bectlesumens sn yaaa aiula eles omtrce ea. 130
2. WNGSR SATIS ss Rae Biolole cae Oke a chee ee Se aaa 131
Bmelbacdy-pectlesionieady- UGS ese ee see ese oes e 132
AL, “SSNS VERWIGRS 2.5 A ocren eh lots eae on Re ee ern ay 1B
ARE NSSASS NaC SHIM vere y me thaliana Lleanpie Mee ce a ne ee 133
1D. AN@MOWSIAS OUI: a cpa) gu eLearn cen cea ee en ae 133
© SEMA SWOS s eer stbee asta in een ator eee ane ee Cena eee aa 133
Pe BACC “NMOS CMEC S Hes cee ie, TNod onl ax nitaseis Sebo) ae Ses ore 133
©, WERES cdc seciBi se SH OCG NG tec Re ner arel e a ne ra 134
Bl, DIGGERS OSE wonecce See ee eee 134
aaa SCOLMAAC HA ac Meron paces Sch oe aces 134
ABS DIG eLaWASPS av rerne cin tie oc eran ee eels aac 134
Ze3,. WMCACWVANSCEC WAGON. os cooecogeooosueovude 134
[Sys SOUCY NINERS) XS ac a eo see el a 135
je}, PEmaASIOIO INNSEES soa sone eee ee ee 135
Hemel clninetirmone ties ain seer ein Sls nhcc. aysrane lesen d Gale wines s 136
aa GAC OMICS ee ey PRON See ete cae ea ontecs ele sy neh ee E« 136
Bie Cra cissilics ee me wn he coh mats Adie oe skse Ae ace oars BW
ESCO TCNBS 5 Se bc aN MCPS eekly tea ace es tite nue ee A 138
Jil SNNGSIPBIOI ONY 3 eis ac cieta eneeiett fee A ena eine Nes Ae 147
LIGIER. 5 6.6 ov 0 dpi a alere seaeeNS EuaG Ns a enter anaes OP TIRADE, A 149

Fig.
Fig.
Fig.
Fig.
aie

paige

Fig.

Ivey,
Fig.
Fig.

Fig.
Fig.

Fig.
Fig.
ee
ige
Fig.

Fig.

LIST OF TEXT FIGURES

Page
1 Agood type of traction sprayer for fielduse. (Original)...... 33
2 Knapsack sprayer) Onicinal) ease ee ee 36
3°. Iland-sprayers, 7(@nginal) ae ae ls ee 36
3-a A Home-made sprayer....... PUR eR IMG estes tus ee Rann 37
4 Scales from wing of moth of western army cutworm, highly
magrinedy i (@ricinal) eee SS Nate ee ree Ne 42
5 Adult snapping-beetle, Alaus ocutatus. The larvae of this
beetle feed upon decaying wood. (Original)............ De

6 A sugar beet infested with sugar beet namatodes. The white

bodies of the female nematodes can be seen clinging to the
rootlets) (Original), Horns Gee oan: ao oe ee 60

7 A sugar beet affected with curly-top, showing the character-

istic dense mass of rootlets. (After C. O. Townsend,

Farmers’ Bulletin No. 122, U. S. Department of Agri-
culture) el See es cae Se OMAN 1) 60

8 Small sugar beets infested with the root-knot nematode. The

bead-like swellings on the small roots and the enlarge-

ments of the main root are caused by the nematodes.

(Oriteinal) oe ees 6 ee eee ae Ee ee en a 64
9 Sugar beet badly damaged by webworms................. 69
10 Sugar beets badly damaged by webworms................. 70
11 Field of sugar beets showing work of the sugar beet webworm.

(Origtinal ec Sse cs URE ee 7)
12 Result of spraying—left, unsprayed; right, eed HE 5. ne
13 A portion of the compound eye of a tiger-beetle, highly mag-

nified 4 (Originalie Geka eo cee eke nie ane ee 76
14 Cross section through burrow of the solitary wasp.

(Original) Jc ae he UR eee ea ica 78
15 Hopper dozer. (After Charles R. Jones, Bulletin No. 233,

Colorado Agricultural Experiment Station) .......... 102
16 Exposed grass roots, showing grasshopper eggs and larvae of

the ground beetle, Amara obesa. (Original)............ 106
17 Hair worm escaping from a parasitized ground beetle.

(Onigimaly eh aoe ee en el an oa ae 107
18 The hair worm shown in Figure 17, after it had escaped from

the beetle.”..(Originall) aii oe poe fees nse tenet eee 108
19 Grasshoppers killed by the fungous disease, Empusa grylli.

(Onigirial) leu aaa ac Acca re a se eee 109

Fig.

Saris.
Fig.

Fig.
Fig.

Big:

Fig.

Z|
De.

23
24

List of Text Figures

Page

An exposed colony of plant-lice on a common roadside weed.
(@yicinrall emer eta sets cae POE nn hate et. ais
Leaves of white ash curled by a plant-louse. (Original).....
Gall of sugar beet root-louse on leaves of narrow-leaf cot-
GoranOOc yes Oni cima) vo snns-os cae ae acessories oko
A common wingless aphid; honey tubes at “A"’. (Original). .
A branch of Euonymus species, showing star-shaped fruit.
(Cisieaiovell) 2 cae Buh 4 a een cs a 35 one
Sugar beet showing characteristic curling of leaves caused by
curly-top. (After Harry B. Shaw, Bulletin No. 181, U.
Su punecauiommolantalmaustry,)) yaar soda ass
Cross section of sugar beet, showing darkening of rings caused
by curly-top. (After C. O. Townsend, Bulletin No. 122,
U.S, IBUureat GF IPieioe IhaeUsGAy. oh snccokooeoemenens
Entrance to burrow of tiger-beetle larva. There is never any
loose soil at the entrance to these burrows. (Original)...
Same burrow as shown in Figure 27, with head of larva resting
on level with the surface, ready to seize a victim. (Orig-
rial Dee ote DO BO eis 2/ 58 8 oe CIE No AO ne OS ee
Nest of a mud-dauber, taken from rafter of an out-building.
(Giicimall pee eee co Mae NS Ee
A cabbage-worm killed by the larvae of a Braconid, the
cocoons of which are fastened to the window screen near
ike. (Over ta'e) Dc Se Ne ST Be vee nn ee

131

135

’
ee
fa
¥
.
i .
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i 2 4
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My

INTRODUCTION

The impression may be gained that the sugar beet is especially
liable to insect injury because of the bringing together of so much on the
subject. However, this is not the case. A study of crop insects shows
that most crops have an equal number of insect enemies and many have
more. It should be emphasized that everything known to good farming
practice in beet culture, such as rotation of crops, manuring, clean culture,
and timeliness of plowing and irrigating, tends to minimize damage by
insects.

OUTLINE OF THE BULLETIN

By knowing in advance the structural plan of the Bulletin, reference
can more readily be made to any desired part. Hence an outline is
given on page 3. Furthermore, the use of this Outline in conjunction
with the “Key for Determining Insect Injury to Sugar Beets” (pages 5
to 8) may aid in identifying insects. For example, if it is known that
damage is being done to the leaves of the beets and that the insects caus-
ing it are Biting” insects, and if it is known that they are not beetles or
grasshoppers, then it can, for practical purposes, be concluded that the
damage is being caused by either leaf-miners or caterpillars, and by
referring to the text cited, a conclusion can in most cases be drawn regard-
ing the particular insect causing the damage. If one of the suspected
insects has been caught, the Colored Plates (See pages 11 to 27)
will greatly facilitate its identification.

KEY FOR DETERMINING INSECT INJURY TO SUGAR BEETS

In order to facilitate the use of this Bulletin for reference purposes,
a short “Key for Determining Insect Injury to Sugar Beets’’ has been
constructed. (See pages 5 to 8.) If the nature of the insect damage is
known, reference to this “Key” should enable one to determine the gen-
eral class of insect doing the damage, if not the particular insect. By
looking up the descriptive pages cited in the Key’, and by checking
the Colored Plates against the suspected insect, if one has been
caught, a reasonably strong case can probably be established.

COLORED PLATES

It took the artist three seasons to complete the drawings from which
the Colored Plates were made. Every insect was drawn directly from
a live specimen, and the form and colors are true to life.

Some of these colored pictures were enlarged. In nearly all such
cases a small black and white outline at the left or right of the colored
picture shows the natural size of the specimen. The exceptions are
clearly noted on the title pages.

Pictures as well prepared as these carry descriptions much more

quickly and accurately than words, especially to persons not trained to
think in entomological terms.

Introduction

The main purpose of all this care in preparing these Colored Plates
is to enable the reader to identify, in the easiest and most positive manner
possible, any specimens he may have procured.

The title page opposite each plate gives the name of each specimen
and indicates the pages of the Bulletin on which it is discussed.

Additional help in locating the pages on which any individual insect
is discussed may be had from the Outline of the Bulletin (page 3), the
“Key for Determining Insect Injury to Sugar Beets’ (pages 5 to 8),
the Appendix (pages 138 to 146), and Index (pages 149 to 157).

THE APPENDIX

The Appendix (pages 138 to 146) contains an alphabetical list of the
popular names of insects and plants discussed, together with their scien-
tific names, credit for their determination, and illustration and page
references. The Appendix is mainly for the benefit of those wishing to
study the subject more fully than has been done in this Bulletin.

THE INDEX

The Index will be found at the back of the book, on pages 149
tomloy7e

THREE METHODS FOR LOCATING DESIRED TEXT

1. If you know the name of the insect, use the Index (pages 149
to 157).or the Appendix (pages 138 to 146) to find the pages of the
Bulletin on which it is discussed.

2. If you know the nature of the damage, but not the name of the
insect doing it, use the “Key for Determining Insect Injury to Sugar
Beets’ (pages 5 to 8) or the Outline (page 3).

3. If you have one of the suspected insects, but do not know its
name, use the Colored Plates (pages 11 to 27).

Use both Methods 2 and 3 when possible, to make identification
more positive.

In case of doubt as to the identity of an insect or other specimen,
or as to the nature of an injury, competent advice can always be obtained
by consulting the authorities of the Agricultural College, the County
Agents, or The Great Western Sugar Company's fieldmen.

REFERENCE FIGURES

The small elevated figures found occasionally throughout the text
after the mention of some insect, refer to the corresponding marginal
figure in the Appendix. The purpose of the reference is to connect the
particular species to its scientific name.

BIBLIOGRAPHY

The Bibliography (pages 147 and 148) contains a list of publications
on related subjects. Some of these have been drawn upon in the com-
pilation of this Bulletin, and credit given in the text.

Introduction

OUTLINE OF THE BULLETIN

INTRODUCTION
Outline of the Bulletin

Key for Determining Insect Injuring Sugar Beets

Colored Plates
CHAPTER |

Iimsectsmim General’... 5. .eecee cee ome eke

Root Feeders........ (NB iting ern eee

CHAPTER III
Wedimeccdenrs:. ... ».(a)) Biting. ... 0.04...

(Us) eSuclsineeperaet an.

CHAPTER IV

Beneficial Insects....(a) Predacious.......

(a) MRarasiticw nena.

APPENDIX
BIBLIOGRAPHY
INDEX

(a) Structure

(b) Development

(d) Methods of Control

(1) Cutworms

(2) White Grubs

(3) Wireworms

(1) Sugar Beet Root-louse

(2) Sugar Beet Nematode

(3) Root-knot Nematode or
Gallworm

(1) Caterpillars

(2) Beetles

(3) Grasshoppers

(4) Field Crickets

(5) Leaf-miners

(1) Aphids or Plant-lice
(2) True Bugs

(3) Leaf-hoppers

(1) Beetles

(2) True Bugs

(3) Lace-winged Flies
(4) Wasps

(1) Ichneumon-fiies
(2) Braconids

(3) Chalcis-flies

Introduction

EXPLANATION OF KEY FOR DETERMINING INSECT
INJURY TO SUGAR BEETS

The method of using the Key (pages 5 to 8) is illustrated below
by imagining a case of injury and following it through the Key until
we come to the point where we get a clue to the insect causing the damage.

Example: In going through the field while the thinners are at work,
we notice a beet here and there which is wilted and cut off just below
the surface of the ground. Take your Key and begin at “A.” This
says that the leaves of the plant are wilted while those of the surround-
ing plants remain normal. This is true of the plants we found, so we read
what comes under “1.”’ As our beet is cut off below the surface of the
ground “'|”’ fits our case, so we continue to “‘a’ and read: “Plants small.
Damage occurring before or shortly after blocking and thinning’. As the
thinners are at work in our field this again fits our case, so we pass on
to the single star (*). Here we read: ~ Plants cut off at or just below
the surface of the ground,’ etc. This is our case exactly, and at the end
we read: “Look for Cutworms.”’ Thus the Key indicates that cut-
worms are at work on our beets and refers us to pages 38 to 48 of the
Bulletin, where this insect is discussed.

Let us suppose that when we read the paragraph under the single star
(*) we found that this did not describe our beet. We would then pass
on to the double star (**), and if the beet we have has been injured by
any of the insects discussed in this Bulletin this paragraph should describe
the way it is injured.

If the injury was not indicated by a wilting of the leaves we pass
from the capital “A” to capital “ B’’, on page 6, and if this does not fit
our case we pass on through the capital letters until we do find the de-
scription. When we find it we pass through the other steps which are
indicated by figures, small letters, etc., until we come to the place where
the insect causing the injury is named.

While this Key may not fit all cases exactly, yet it should enable
one to determine quite closely what insect is causing the injury noticed.
Then if the discussion of this insect and the nature of its injury are read
and the insect, if one is secured, is compared with the pictures in the
Colored Plates, there should be little difficulty encountered in identifying
the culprit.

In case of doubt competent advice can always be obtained by con-
sulting the authorities of the agricultural colleges, county agents or the
sugar company’s fieldmen.

Introduction

KEY FOR DETERMINING INSECT INJURY TO SUGAR BEETS

A. Leaves of plant wilted while those of surrounding plants re-
main normal.

1. Plants cut off above the surface of the ground, at varying depths
below, or with portions of the root surface eaten away, leaving
shallow depressions or deep pits with darkened walls.

a. Plants small. Damage occurring before or shortly after
blocking and thinning.

* Plants cut off at or just below the surface of the ground.
Damage most apt to occur where beets follow alfalfa
or grain, timothy or abandoned crops, and on fields ad-
jacent to alfalfa.

Look for Cutworms (pages 38-48).

** Plants cut off an inch or so below the surface of the
ground. Tip of root as pulled from the ground dark,
almost black. Damage most apt to occur where beets
follow alfalfa, sod, pasture or meadow.

Look for: White Grubs (pages 48-52) ;
Wireworms (pages 52-54).

b. Beets larger. Damage occurring from time roots attain the
size of one’s finger until harvest.

* Plants always cut off above surface of ground or with
deep cavities pecked into the crowns. Damage most
apt to occur near standing alfalfa or waste land over-
grown with weeds or other tall growth.

Damage caused by Pheasants.
** Plants never cut off above the surface of the ground.

° Portions of root surface eaten away, leaving shallow
depressions with rough darkened surface. Root
often entirely eaten off several inches below the
surface of the ground. Damage usually occurring
where beets follow sod, pasture or meadow, or on
river bottom land.

Look for White Grubs (pages 48-52).

0° Portions of root surface eaten away, leaving small,
deep, dark-walled pits. Roots of large beets never
entirely eaten off. Damage most apt to occur
where beets follow alfalfa, sod, pasture or meadow.

Look for Wireworms (pages 52-54).

2. Plants not cut off. Portions of root surface not eaten away.
Leaves often dull, dark green, as though plants were suffering
from lack of moisture; or leaves yellowish green.

Introduction

a. Only young heart leaves wilted. Wilting usually most appar-
ent at tip of leaves. Later these tips become dry and brown.

Look for Tarnished Plant-bugs (pages
122-123).

b. Entire plant more or less wilted.

* Root either covered with whitish substance or with abnor-
mal development of fine roots or wart-like swellings.

° Root more or less covered with a white mould-like
substance. Many whitish-yellow lice mixed with
this substance. Lice present in nearly every
field regardless of previous crop. Damage more
apt to be severe in dry years than wet.

Sugar Beet Root-lice (pages 55-59).

°° Root with abnormal development of fine rootlets.
Many small pearly-white bodies clinging to these
rootlets. (See Figure 9, Plate III, Page 15 and
Figure 6, Page 60). In late fall many of these
bodies become rich brown in color. Injury most
apt to occur on old beet ground.

Sugar Beet Nematode (pages 59-64).

009 Roots with wart-like swellings. Rootlets with
small, almost round swellings resembling beads on
a string. (See Figure 8, Page 64). Injury most
apt to occur on old beet ground.

Root-knot Nematode or Gallworm
(pages 64-66).

** Root normal. Not as above.

° Damage usually most severe in fields near poor
stands of alfalfa overrun by shepherd’s-purse,
fanweed and other weeds of the mustard family.
Fields adjacent to waste land overgrown with
these weeds very apt to be damaged, also, as weeds
begin to ripen.

Look for False Chinch Bugs (pages 119-
121).

B. Leaves dull green, light yellow, or blotched with whitish ¢reen
or purple.

1. Leaves dull green, as though plants were suffering from lack of
moisture. In severe cases leaves become light yellowish green.
Plants making poor growth.

Look for: Sugar Beet Root-lice (pages
55-59) ;
Nematodes (pages 59-66).

Introduction

2. Leaves blotched with whitish green. Not abnormally curled.

Look for: Plant-lice (pages 111-116),
Leaf-hoppers (pages 123-128).

3. Leaves blotched with purple (Figure 1, Plate VIII, Page 25).
Look for Leaf-hoppers (pages 123-128).

C. Leaves with portions of blade or stem eaten away. Sometimes
crowns of beets eaten also.

1. Leaves eaten full of small holes (Figure 1, Plate IV, Page 17).
Injury most apt to occur during spring and early summer.

Look for Flea-beetles (pages 91-93).

2. Leaves more or less completely eaten, or portions eaten from mar-
gins (Figure 11, Plate III, Page 15).

a. Leaves often more or less covered with a fine whitish web.
Damage caused by worms about one inch long when fully
grown. Worms-very active, throwing themselves from the
plant when disturbed. Often hanging from leaf by a single
thread of web, especially when young.

* Worm dark green, striped, several dark circular spots on
each segment of the body (Figure 6, Plate V, Page
19). Web when present usually on blade of leaf near
its base. Heart leaves usually eaten last. Excrement
of worms scattered over leaves in form of small dark
pellets.

Sugar Beet Webworms (pages 67-78).

** Worm lighter than webworm. A pink or flesh-colored
Simipemony cache side \(eicure- lb) Plate Vil; Page 21).
Web often among heart leaves. A long tube leading
from web to clods on the surface of the ground. Worm
usually concealed at end of this tube when not feeding.

Alfalfa Webworms (pages 84-85).
b. Leaves not webbed.

* Damage occurring during spring and early summer, while
beets are still small.

° Damage usually most severe on wet alkali land or
near such land.
Look for Alkali-beetles (pages 89-90).
°° Damage not associated with alkali land. Usually
most severe near alfalfa, ditch banks, fence rows

or waste land. Edges of leaves eaten. In severe
cases entire plant destroyed.

Look for Spinach Carrion-beetles (pages
94-95),

Introduction

** T)amage usually occurring during midsummer or later.

° Damage most severe on wet alkali land or near such
land. Tender portion of leaf eaten, only a net-
work of veins remaining, which soon become dry
and brown.

Look for Alkali-beetles (pages 89-90).

°° Damage usually most severe at borders of fieldinear
wild land, waste land, ditch banks and fence rows
where grasshoppers are numerous, or near alflafa
or waste land overrun with sweet clover, or near
grain fields.

Look for: Grasshoppers (pages 98-109) ;

Alfalfa Loopers (pages 81-
84);

Western Army Cutworms
(pages 41-45).

eee Tamage usually slight, only a beet leaf here and
there being eaten. Not confined to border, but
occurring throughout entire field.

Look for: Yellow-bear Caterpillars (pages
86-87) ;

Zebra Caterpillars (pages 87-88) ;
Variegated Cutworms (pages 47-48).

D. Leaves very much curled and distorted. Veins much enlarged,
often bearing cone-shaped points (Figure 5, Plate VIII, Page
25). Root small and stunted. Rootlets abnormally de-
veloped (Figure 7, Page 60). Crown often covered with a
sticky syrup-like substance. Curly-top (pages 124-125).

Look for Sugar Beet Leaf-hoppers (Pages
123-126).

COLORED PLATES

A BPW Ye

PLATE I

Page
Western Army Cutworm, Chorizagrotis auxiliaris Grt..... 41
Western Army, €utworm pupal aasseee eee eee eee eee
Western Army Cutworm, adult moth..=5.-.-..).. 54 leeaaes
Western Army Cutworm, wing of dark individual........ 41, 42
An Ichneumon-fly parasite of the Western Army Cutworm,
Amblyteles longula €ress)- (Enlarged) =. 5) easel
A Braconid parasite of the Western Army Cutworm—M ic-
rogastemspeciesn (eialane ed) aa ane ae te ee 43, 136, 137
Cocoon of Microgaster species (Enlarged).......... 44, 136, 137
Chalcis-fly parasite of cutworms, Berecyntus bakeri bakeri
Howard (Enlarged) e205 ita 44, 137
Pale Western Cutworm, Porosagrotis orthogonia Morr..... 45
Pale Westenn Cutrornan, aichullt maoda..sccccccsecnvccoce- 45 46
Eggs of Pale Western Cutworm (Enlarged)........... 42, 45, 46
Egg of Pale Western Cutworm (Natural size)......... 42, 45, 46
Wireworm cs 25: 2h: ee coe ee es I 3)
[ast seoment of Wireworm) (Enlarced) hae) eee 52, 53
Wireworm: pupals2-. | Ge 5G 5s. ear ee be 52, 54
Adult Wireworm, Hemicrepidius memnonius Herbst... .52, 53, 54
Adulte Wireworn) (Enlarged) yeaa 52, 54
Larva of adult Wireworm shown in Figure 17........... I 3
White Grubes oan 6 Pa eee eee 48, 51
A small white grub which feeds upon decayed vegetable
MACE eR ir 8R8 ascii Re eee 48,51
True: Army (Wormiy =. 2 ae ee 78, 80
Trué-Army Worn: eee cece hee nen 78, 80
Adule White Grub, Pisynusysibbosus De Go.) - eee 48,51
Rupa ofeirue Anmuye\Voniai. ease ne ear 78, 80
Adult True Army Worms. © 22 see see 78, 80

Note: In case of enlargement, a natural size black and
white outline drawing is shown beside the colored picture. Ex-
ceptions to this plan on Plate | are Figures 7 and 14.

FS Aiges els

fig. 23 41g. 25°

NON SPW Ww

17
18

PLATE II

Sugar Beet Root-louse, Pemphigus betae Doane Page
Newly hatched louse feeding on cottonwood leaf (See ‘“‘A”’).55, 58
INewlyanatchedilouses(2nlanecec)) Saari DD, D1
Wppemsideioteleat aktemecallilsecomesiclosed aaa eae yD), IS
Side-view sof young. caller ea oe ane ea 55,58
Fully: developed: gall eis ae hn sean ee DD) DO
Fullferowm'stem-mother(Enlayced) = a eS
Full grown second generation leuss ‘(Goin migrant)

(Enlarged) rcs es a ee DD, 3
Antennavofebictine Aq nlaneecl) aera aaa tener OD, IS
Wingless form of sugar beet root-louse found on beets dur-

iapesuraTMae res (alancec)) eta ee DES
A lady-beetle which feeds upon sugar beet root-lice (En-

large)" aye ict ke RCIA Ste Sha eae Sree 59, 115, 132
Antenna ofswanelessslouse (Ealanged) essa Da), De)
Antennalof winelessslouse. (enlagcec)) aa ent re ee Dd, DS
Antenna of true male sugar beet root-louse, Figure 16 (En-

eigen te) enn emiet neers Pio nee nrenia wk GMa oi 8s 5 60 5
A true bug, Authocoris melanocerus, which feeds on lice in

gall (Enlarged) iii 2) 2c ee ewe aaa eee! A ee 59, 132
Larva of lady-beetle (Figure 10), which also feeds on lice

widlle Ga locos (Balleirnweel). ooo cs cee sce wsoescce De WS, 132

True male sugar beet root-louse (Much enlarged. Note
minute representation of actual size at left of colored
PICUUTE aur hak ee Se elena ae aie en A 5, 57

Solitary egg laid by female sugar beet root-louse (Enlarged).55, 57

True female sugar beet root-louse (Much enlarged. Note
minute representation of actual size at left of colored
PICUUPE) Mieka tac aati te DD, 27

Note: Incase of enlargement, a natural size black and
white outline drawing is shown beside the colored picture. Ex-
ceptions) to) this) planyonw lately aneimicuness2ac-mlel le emmlS
and 17.

FLAT Li

PLATE III

Page

Beet leaf showing mines made by Beet Leaf-miner (Fig. 3), ;
andeggs) (Fig: 3-A)e mea oan ene ee ee INO, AU
Egesofseeelecat-miner (enlarged) aan eee ee 110, 111
Bectlbeateminers (Enlaneec)) septa ae aren eae 110, 111
Pupariumion Beet eat-miner (Enlarged) ees eee Oana

Adult Beet Leaf-miner, Pegomyia vicina Lintn.(Enlarged) 110, 111
Black Beet-seed Louse, Aphis euonymi Fabr. (Enlarged) 117, 118
Winged form of Black Beet-seed Louse (Enlarged)...... IW, Wks

Sugar Beet Nematode, Heterodera schachtii Schmidt (Adult
female, much enlarged. The nematode is almost

MICFOSCOPIC IN SIZE) Ec ee, 8 ee 59, 64
Young beet showing female nematodes on rootlets (Slightly

enlar eed): .uccee ei) oles pole ee iene ie ae aerate DS),
Adultemmalemmematodes (Muchmenlanzec)) hanna ara 59, 64

Zebra Caterpillar, Mamestra picta Harr, feeding on beet leaf .87, 88

Note: In case of enlargement, a natural size black and
white outline drawing is shown beside the colored picture. Ex-
ceptions to this plan on Plate III are Figures 2, 8, 9 and 10.

a —

(FL E UM

lie

PLATE IV

Worlkofitleasbectlesion ai bectll calmness nara a ee 89,91
Adult Banded Flea-beetle, Systena taeniata Say (Enlarged) 92
A flesh-fly parasite of grasshoppers, Sarcophage variacauda

Coq: (Enlarged): 2:7 oesenel oa Oe 105
Magcotofisicuress(2nlargcd) aaa 105
Adult Potato Flea-beetle, Epitrix cucumeris Harr. (En-

larged)) ok. oan Se eee eee es ae 93
Adult Three-spotted Flea-beetle, Disonycha triangularis

Say (Enlarged). ee kee eee eee 93
Ambinamatune temalessieldi Cricket yee eee 109, 110
Grasshoppervegs=pod)— 9 ya Stk le ee 104
Young Two-lined Hopper, Melanoplus bivittatus Say (En-

Teirgecd) sa scte Soc tae. oe ce eras al een oe 100, 105
Adultitemalemlino-linedilslop cena tae nee 100, 104
Outline drawing of tip of female's abdomen, Two-lined

FOP PEGS OWI ee OM1OOSICO Ine e ee 100, 104
Adult male Differential Hopper, Melanoplus differentialis

ethos, yellow :phase... ieee eee ene ney ae 7 100
Adult male Differential Hopper, black phase............. 100

Adult Red-legged Locust, Melanoplus femur-rubrum De G. 100

Outline drawing of last segment of male's abdomen, adult
Red=les ged! bocustvcs55 5 nate nae ee ee en 100
Hair Worm. A parasite of grasshoppers and other insects

—somewhat enlarged. See also Figures 17 and 18,
Pagesil0/fandsl0S eae ee och ae eee 107, 108

Note: In case of enlargements, natural size outline
drawings are shown beside the colored pictures. Excep-
tions on Plate IV are Figures 9 and 16.

PLATE

CM.PRESTON

MW FW WY —

—1 ©& we) CD Ny &

— —

12
13

PLATE V

Page
A half grown grasshopper with Locust Mites attached 105,106,107
Nounemnites(2nlarced) mane Bette iia a ees 106, 107
Beet leaf with young Sugar Beet Webworm at “A”....... 67,7)
Young Sugar Beet Webworm (Enlarged).................67,75
Portion of beet leaf with Sugar Beet Webworm moth eggs
(Shightly*enlarged) ins ace a a ee ee eee 67, 74
Full grown Sugar Beet Webworm (Enlarged)........ C7 Ale
Sugar Beet Webworm parasite, Cremnops vulgaris....... Hi, WO
Sucamibecee Webwonrmlcocooms en ee ere 67, 75
IPUjoe ©F Suyepie ISeee WOW OTT ocnccocncsscodeocseoceces OV, 7D

Last segment of Sugar Beet Webworm pupa (Enlarged). .67, 75
Adult Sugar Beet Webworm moth, Loxostege sticticalis

Bit gta tee Hen rs aM eM mene ane chee i cree ta 67, 68, 75, 85
Pupariumvoteng ures oes (Smlancec)) ar nee nae 77
A two-winged Tachina-fly parasite (Meteorus loxostegei

Vier.) of the Sugar Beet Webworm (Enlarged) ..... Th
A Braconid reared from a Sugar Beet Webworm (Enlarged)

TG, NO, 37
Yellow-bear: Caterpillar’ 22 (a eee eee 86, 87

Adult Yellow-bear Caterpillar, Diacrisia virginica Fab... . .86, 87

Adult female Locust-mite (Trombedium locustarum Riley)
and.ecos (Ee nlanced) aa eewye ey ea eee ee 106, 107

Adulemmaleleocust-mites(2nlagced) hasan OOmlOm
Note: In case of enlargement, a natural size black and

white outline drawing is shown beside the colored picture. Ex-
ceptions on Plate V are Figures 2, 3, 4 and 10.

Figl7 SES ee

CO NY OY SV oS Ww OO —

PLATE VI

Page
Alfalfa Wielbwornie (ralane eel) pense een 83, 84
Rupavoie Alfalfa Wiebwonmsy sence Taree ero 84, 85
Last Segment of Alfalfa Webworm pupa (Enlarged)...... 84, 85
Adult Alfalfa Webworm, Loxostege commixtalis Walker 75, 84, 85
Alfalfa Looper. . Pi Snake Re cael 5 emma. 3 See eS
Cocoon of Vite ieee Rt lea ee wate es coe AR 81, 83
Fupa:of -Alfaltag Bb copera: awit eee 81, 83

Adult Alfalfa Looper, Autographa gramma_ californica
SPO Y Clee cep sto laces anata ot ar ere ae 81, 83

Itoplectis atrocoxalis Cress, male. An _ Ichneumon-fly
PALasiverontmerAltaltanlBoope Gy a a aan 83, 136

Itoplectis atrocoxalis Cress, female. An Ichneumon-fly
JORIASIIES OH Cae ANIA ILOO SEP. .2cccc cc ccccancoscse 83, 136

An undetermined Tachina-fly parasite of the Alfalfa Web-
wornas(Enilanged) esse 22a oa ae yim ar eer ear etree 85
A“ Reobbersthy ice x cet oak Medea ae een a 78

Syrphus-fly, Syrphus paulxillus Will. (Enlarged) Its larvae
féed:on (Beet Rootzlicessaee eres Sa eee DQ), ING

A two-winged fly (Chloropisca glabra Meign.) whose larvae
are found among Beet Root-lice (Enlarged). ........ 59

A Solitary-wasp (Odynerus annulatus Say), which places
webworms in its nest as food for its young.......... Wd, NBD

A full grown larva of the Digger-wasp (Fig. 18), surrounded
by¢skinsofia cutwonme- tart ore orl ae eee 45, 134

Cutworm with egg of the Digger-wasp (Fig. 18) attached
Hear Meal 3c uihn NCE eA eerie eee, Aree serge 45, 134

A Digger-wasp (Sphex luctuosa Snw.) carrying a cutworm
THEO IES DULETOW oe aes ee eet ee i ee er 44 134

Note: In case of enlargement, a natural size black
and white outline drawing is shown beside the colored
picture. Exception on Plate VI is Figure 3.

PLATE VZ

FigI5

CWPRESTON 119.16 fig 18

Fig.

oO NN F&F WY NY

CON

PLATE VII

Page
arvavofeAlkalicbeetler(Enlayced) ia ae OO nO 0)
RuparoteAlkaliciseetlen(2nilance cl) pease 89, 90
AlKalizbeetlereg ou (Eialang ec) ernie ea ae 89, 90
Allkali-bectlevegessaboutmaturalisizess = ee 89, 90

Adult Alkali-beetle, Monoxia puncticolis Say (Enlarged). .89, 90
Adult Western Beet Leaf-beetle, Monoxia consputa Lec.

(Enlarged) cc.c:e) 30) ele ae ee 90
VariesatediGutwormy.\esen ernie en tere ee ee 47, 48
Black Blister-beetle, Epicauta pennsylvanica De G. (En-

larged a Ac ainues ns Aad 6 eer ee eee 96, 98
Ash-gray Blister-beetle, Macrobasis unicolor Kby. (En-

IN ok 16) nana mM an SIO rE SRE oo dee by Gigois' na d-0 6 0,< 96, 98
Spinach Carrion-beetle, Silpha bituberosa Lec. (Enlarged) . .94, 95
Spinach) @arrion-beetlellanval(Enlarced) = sere eee 94,95
Winter larva of a Blister-beetle (Enlarged)............. 96, 97
The final larval stage of a Blister-beetle (Enlarged)...... 96, 98
Pupa of the Lady-beetle, Figure 10, Plate II, Page 21 (En-

langed): (ns Stack oid oe aor ie eae eae eae 59, 132

Adult Variegated Cutworm, Peridroma margaritosa Haw.. .47, 48

Note: In case of enlargement, a natural size black and
white outline drawing is shown beside the colored picture.

PLATE W

Fig.

NOM BW

10
I]

PLATE VIII

Page

Sugar beet leaf discolored by feeding of insects shown in
Faeuress Sani ioc ar asst cen oe eae 128

Eggs of Green Peach-aphis, Myzus persicae Sulz. (En-
large etic aces eres 0 ite pene Oma One eee eee 116, 117
7 Nyimpheofisioune 4. (Enlarged) see eee 128
Adult Leaf-hopper, Eutettix strobi Fitch (Enlarged)....... 128
Sugar sect leateattected ny Cunly=topnes = as a eee 123, 124
INynaphiorm Ricune 74 (Sialarecc)): a ee 123), 12

Sugar beet Leaf-hopper (Eutettix tenella Baker), which
carries the disease known as Curly-top (Enlarged). . 123, 126

Clover Leaf-hopper, Agallia sanguinolenta Prov. (En-

lanced) Ree ey Steere eh ai oes hse nae 126, 127
Wingless Green Peach-aphis (Enlarged)................. 116
WingediGreen Peach-apiais) (Pnlanced) a a ee 116
INympohvor False ChinchiSue; (Enlayeec)) a IN), ZT

Adult False Chinch Bug, Nysius ericae Schill.(Enlarged).119, 121

Note: In case of enlargement, a natural size black and
white outline drawing is shown beside the colored picture. The
only exception to this on Plate VIII is Figure 2.

—- OO OAOAN DN FW WY

pe pa
nA & WY wp

PLATE Ix

Beneficial Insects Page
Leia OF Inigay Inluiateee, Saowyin tin JWI Do. .5 20 cescc see 130
Mienydaumters Calosomarcalidum aloes ae Aan)
IN. COunanorn (Girowinel IBSS0S. ose sccc2kesesccccscsscsnecn 130
A cutworm killed by Chalcis-fly parasites.............. 44, 137
luarvasol Tiger=beetlet i ac tanes.. ciate a0 ee eae ae eter Bal
Adult Tiger-beetle, Cicindela vulgaris Say............... Bley
Adult Tiger-beetle, Cicindela purpurea Oliv............ Be 132
Esgsvompugsshownenulsicunesi! 2yainc tl Sra
No GUS SOwior ita |e UIES C, sanUelN GollavaeeCl, . ssc css cecce 133
A half grown nymph of the bug shown in Figure 12...... 133
A newly hatched nymph of the bug shown in Figure 12 (En-

Lar Ged). al eS ios ace co Ma cei) Cee ee 133
A predacious bug, Perillus claudus, yellow phase......... 133
A predacious bug, Perillus claudus, red phase............ 133
Eeosiofleady-beetlershow mun i oumen |) anny)
Adult Lady-beetle, Hippodamia convergens CGuer (En-.

103 foi 3el) eae me ern Mn ony Mat TONER E err ctr don So uince (ose WWD, WS2
Egosiof Waceswinged Rily,, showntintial tunes OR ann ioe
Cocoon made by larva (Figure 18) of Lace-winged Fly,

Shown, in PigureslOe 3) gett a eee eee eee 133, 134
Larva of Lace-winged Fly, shown in Figure 19. Often

Called > Atphis-lionien(Enlarced) sane Ome ermleer
Adult Lace-winged Fly. Commonly called ~ Golden-eye”’

(Eplargedh) 25 ahs ee career trs Ue een Or INO, 33
Larva of Ground Beetle, Figure 22 (Enlarged). It feeds

ON /PFASSHOP Pere POSe.... Nees le ean eee ee 106, 130

Pupa of Ground Beetle, shown in Figure 22 (Enlarged). 106, 130
Adult Ground Beetle, Amara obesa Say (Enlarged)... .. 106, 130
Wanvaror Bady-pcctlesmicunesl os (2 mlancec) manner lemon
Pupakotlwady-beetlemiaicuneslom (2alaneec) hen 132

Note: In case of enlargement, a natural size black and
white outline drawing is shown beside the colored picture. Ex-
ceptions on Plate IX are Figures 9, 11, and 22.

F
iy

PILI WIE AE

Fig R4

C M. PRESTON

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CHAPTER I

INSECTS IN GENERAL

Knowledge of the structure, development, classification and methods
of control of insects in general will enable the reader to understand better
the text dealing with any individual insect. The purpose of the brief
discussion in this chapter is to give that preliminary setting.

STRUCTURE

All adult insects have the head, thorax (chest) and abdomen more
or less distinctly separated. Attached to the front of the head are two
antennae, or feelers, as they are popularly called. The mouth parts are
formed for biting or sucking. Those of biting insects, such as grasshop-
pers, flea-beetles and alkali-beetles, consist of hard, sharp-edged jaws.
Sucking insects, such as the false chinch bug, plant-lice and others, have
the mouth parts prolonged into a long, straight beak which is often jointed.
In the case of moths and butterflies the larvae have biting mouth parts
while those of the adults are in the form of a slender proboscis, which is
carried coiled beneath the head. In the adult stage there are always
three pairs of legs attached to the thorax. These three pairs of legs are
present in the immature stages of beetles, the true bugs, moths and but-
terflies, while the young of the two-winged flies, bees, wasps and others
are legless. Aside from the true legs, which are located near the head,
caterpillars have from two to twelve fleshy leglike organs on the ab-
domen. These are called prolegs or props. These prolegs are furnished
with both hooks and suction pads. Most adult insects have one or two
pairs of wings, which are also attached to the chest.

Insects breathe through small openings or spiracles in the abdomen.
From these openings the air is carried through tubes called tracheae, lead-
ing to the various parts of the body.

Spiders, ticks and mites are not insects, but belong to a group of
invertebrate animals which have the head, thorax and abdomen closely
united and possess four pairs of legs in the adult stage; however, in the
immature stages some have but three pairs.

DEVELOPMENT

In the course of their development most insects undergo remarkable
changes in form. These changes constitute what is known as insect
metamorphosis.

One order of insects develops without change in form or without
metamorphosis. The young when hatched from the egg have the same
form as the adult. A common representative of this group is often seen
floating in dense masses on water. Another is sometimes seen hopping
about on the snow during warm days in early spring in northern latitudes.

The insects belonging to another class undergo considerable change
in form during their development, but the young resemble the adults

a 29

Insects in General

quite closely; therefore the metamorphosis is said to be incomplete.
Grasshoppers, plant-lice and the true bugs are common examples of this
class. [he young of these insects are called nymphs.

The early forms of many insects, like the butterflies, moths, flies,
bees and beetles, differ so from the adults that there is no resemblance
whatever between the two. These insects pass through at least four
stages, the egg, larva, pupa and adult, each differing in form from the
other. For this reason their metamorphosis is said to be complete.

The Egg .

The egg is the first stage in the development of any insect. The eggs
of some insects, like the plant-lice, remain in the abdomen of the mother
until the young are fully developed and hatched. Insect eggs vary
greatly in form, as can be seen by referring to the figures given in the
Colored Plates.

The Larva

The larva is the form of an insect immediately following the egg. It
is then in the stage of growth, and many of our common insects damage
crops more severely during this period of their lives than at any other
time. Larvae differ greatly in form in the different orders. The larvae
of moths and butterflies are called caterpillars; those of flies are called
maggots; those of some beetles are called grubs and others worms.
Caterpillars are often called worms also. The legless larvae of bees,
wasps and related insects are sometimes called grubs.

The Pupa

The pupa is the third or resting stage. The larva becomes a pupa
when it has completed its growth. In this stage the insect has very little
or no power of movement, being unable to do more than wriggle the tip
of the abdomen at most. The pupa of a butterfly or moth is called a
chrysalis; the hardened larval skin within which the pupa of some two-
winged flies is formed is termed a puparium.

The Adult
The adult is the fourth and final stage in an insect’s development.
No further growth takes place after this stage is reached. Only enough
food is taken by the adult to sustain life; in fact some adults do not feed
at all, their mouth parts having been lost through disuse. The prin-
ciple function of the adult is that of reproduction.

The Integument

The skin or integument of an insect is composed of a tough, horny
substance called chitin (pronounced ki-tin). At certain periods dur-
ing the larval stage this becomes so hard that it cannot stretch and soon
becomes too small for the growing insect. In the meantime a new skin
is forming underneath the old one, which splits open. The insect then
frees itself from its old coat. This process is called molting. The new
skin is at first soft and stretches to accommodate the increasing size of the
insect. Soon, however, it becomes hardened and must in turn be cast off.
Thus, in the course of their development insects shed their skins several
times. After reaching the adult stage molting ceases and all growth
stops.

30 ®

Insects in General

CLASSIFICATION

The insects that injure agricultural crops can be roughly grouped
into two classes: those that feed upon the roots and underground parts of
plants, or “root feeders;’’ and those that feed upon the leaves and other
parts of plants above the ground, or “leaf feeders.”

Each of these groups can in turn be divided into two other classes:
insects which bite their food, or “biting insects,’’ and those which suck
their food, or “sucking insects.”

Both classifications are most important from the viewpoint of insect
control.

The mouth parts of the biting insects consist of an upper and lower
lip between which are two pairs of jaws with which portions of the food
plant are bitten out and masticated. Attached to these jaws are slender,
jointed organs used in guiding the food to the mouth or as sense organs.

The mouth parts of sucking insects are modified into a long, jointed
tube or beak and several hair-like bristles which are enclosed within it. In
feeding, the beak is placed against the surface of the plant while the
bristles or piercing organs are forced into the tissue. The plant juice is

_then sucked up through them by a pumping motion of the mouth.

METHODS OF CONTROL

There are two general methods of insect control, the cultural or
natural method, and the artificial method.

The natural method consists of handling the soil or the crop in
such a way as to prevent or reduce insect injury, and in fighting injurious
insects with their natural enemies.

The artificial method consists of the application of any substance
to a crop for the purpose of killing attacking insects or making the plants
so distasteful to them that they will not feed upon them.

Natural Methods of Control

Application of the natural methods of control depends largely upon
the habits and life history of the insect to be controlled. For example,
in the case of the grasshopper we know that its egg stage is passed in the
ground during the fall and winter. Fall plowing, harrowing and discing
will kill the grasshopper in the egg stage.

Crop Rotation

Crop rotation is one of the principal factors in insect control. Many
insects feed upon only one crop or those closely related botanically.
It is evident, therefore, that if the same crop is planted on a field for
several years in succession the insects attacking it are likely to accumu-
late in and about it until serious damage results. The length of rotation
necessary to insure against injury by an insect or other crop pest, depends
upon the pest in question. For example, the corn root worm can be con-
trolled by alternating corn with any other crop; while white grubs and
wireworms require a three or four year rotation; and the sugar beet
nematode a much longer rotation.

Other insects deposit their eggs upon certain crops or in the soil
where these crops are growing or have grown. Loss can be avoided by
ons such crops with Sener which are not attacked by this class
of insect

Insects in General

Plowing

Many insects pass certain tender stages of their development in
the ground or on plants in the fields. Plowing infested fields at the pro-
per time will do much toward destroying such insects.

Late Planting

Injury can sometimes be prevented by timing the planting of crops
so that they will not come up until danger of infestation is passed.

Burning

Many insects spend the winter in hibernation beneath the trash or
crop refuse on and about fields. If this waste matter, dead weeds and
grass about fence rows and ditch banks is burned during the fall or winter,
many insects will be destroyed which would otherwise damage crops the
following spring.

Clean Culture

Nearly all injurious insects fed upon wild plants before the land
was broken up and planted to crops. If weeds are allowed to grow in
a crop or about the fields, ditch banks, fences or roadsides, they attract
these insects to the vicinity. After the wild food plants have been
destroyed, the insects turn their attention to crops and much damage
results. Clean cultivation is always profitable from the standpoint of
insect control as well as for other reasons.

Artificial Method of Control—Insecticides

What substance to use and how to use it in artificial control depends
upon whether the insects are biting or sucking insects. There are
two general classes of insecticides, those which kill after they are eaten
(stomach poisons), and those which kill by coming in contact with the
insects (contact poisons). The first is used against insects which bite
their food, and the second against those which suck it.

Control of Biting Insects

In the control of most biting insects poisonous substances such as
Paris green and arsenate of lead are used. ‘These are applied either as a
spray mixed with water or dry. In the latter case the poison is mixed
with low grade flour, air slaked lime or some other fine powder and dusted
onto the crop. The*poisons are often mixed with some substance which
the insects will eat, and this poisoned bait, as it is called, is scattered
over infested fields.

In the control of some biting insects it is necessary to kill them while
in the egg stage. This is done by spraying with oils which can be mixed
with water or with lime-sulphur wash (See page 115). These oils are
petroleum products rendered soluble by the addition of vegetable oils
and are known by the trade name of “miscible oils.”

Many biting insects devour the entire leaf in feeding, while others
feed on the under side of the leaves only, eating all but the upper surface.
In applying stomach poisons it is very essential that the location of the
insects while feeding be known. If they feed on the under side of the
leaves the sprayer must be adjusted so that the poison is applied to the
lower surface.

Insects in General Sprayers

Sometimes arsenical poisons burn the leaves of plants, especially
if the application is heavy. This is due to free arsenious acid in the
material used. The addition of a little quick lime to the water in which
the poison is mixed will prevent this burning. When lime has been
added the solution must be carefully strained to remove particles of lime
which would otherwise clog the nozzles.

Control of Sucking Insects—Contact Poisons

In the control of sucking insects the contact poisons kill the insects
either by corroding their bodies or by clogging their spiracles, thus
causing strangulation. Black-leaf 40 (See page 114), kerosene emulsion
(See page 114), the so-called insect powders and soluble oils are standard
remedies for sucking insects. As the name implies, these substances
must come in actual contact with the insect to kill it.

Repellents

A repellent is any substance the presence of which on plants makes
them so distasteful to insects that they will not feed upon them. Mix-
tures containing tobacco preparations or soap, especially whale oil soap,
are effective as repellents.

SPRAYERS

A. TRACTION SPRAYER

For field use any one of the many makes of traction sprayers (Fig.
I, Page 33) is recommended.

Fig. 1. A Good Type of Traction Sprayer for Field Use
33

Sprayers

Such a machine should embody the following features:

A. A tank of sufficient capacity to permit of spraying large fields
without having to fill it in the center of the field. A tank holding 50
gallons is large enough for practical purposes.

B. A revolving agitator within the tank to keep the poison in
suspension.

C. A force pump to maintain a pressure at the nozzles in order to
produce a fine mist-like spray. This pump should be driven by the
wheels of the sprayer.

D. A pressure gauge.
E. A large air chamber.

F. An adjustable safety valve to prevent bursting the rubber hose
connections.

G. An adjustment whereby the machine can be adapted to variable
distances between rows without changing piping, hose connections or
nozzles.

A means of adjusting the wheels to varying widths of rows.

CARE OF SPRAYER
Remove Rust Scales

There are certain soluble acids in Paris green which act upon the iron
parts of the sprayers, especially the iron piping. This action produces
large quantities of rust which falls away from the pipe in scales. These
scales will clog the nozzles unless the piping and other metal parts are
thoroughly cleaned.

Remove Dry Paris Green
There is always some Paris green left in the piping, tank and nozzles.
This is apt to cause the same trouble when you start the sprayer as the
rust scale mentioned. The barrel, or whatever kind of tank there is on
your machine, should be thoroughly cleaned.
Repair Hose Connections
Be sure that all hose connections are in good repair.
Clean Nozzles

Often times the nozzles become clogged with dry Paris green. There-
fore all nozzles should be taken apart and thoroughly cleaned.

Examine Pump

The pump is one of the most important parts of a sprayer. Too
much pains cannot be taken in seeing that the pump is in perfect con-
dition. Remember that the pump will not work properly if not properly
packed.

Examine Valves

Next to the packing, the valves are most important. A steady
pressure cannot be maintained if the valves are not in perfect condition.

Sprayers
Clean Relief Valve

The relief valve which regulates the pressure should be examined,
since, if this fails to work, the hose connections are very apt to be blown
off.

Neckyoke and Eveners

Most beets are planted 18 or 20 inches apart or 16 and 24 inches.
In either case three rows of beets should be between the wheels and the
wheels 60 inches apart. The eveners and neckyoke should be 60 inches
long, so that the horses walk in front of the wheels. Less damage will
be done to the crop from broken leaves and crushed crowns if your
machine is equipped in this way.

Setting the Nozzles

The nozzles should be so placed as to make it possible to spray thor-
oughly all surface between the end nozzles. There are so many styles of
nozzle equipments and frames that it would require too much space to
explain in detail the setting of all. Let it be sufficient to say that four
single nozzles should not cover more than 5 rows of beets and 6 single
nozzles 7 rows. If the double nozzles are used, 4 pairs will cover 8 rows
and 6 pairs 12 rows. In spraying very small beets the nozzles should
be placed directly over the rows.

Testing the Pump

Before attempting to do any spraying, test the spray pump thor-
oughly. The pressure regulates the kind of spray your machine throws
(fine or coarse), also the amount of water applied to an acre of ground.
Eighty pounds pressure produces the fine mist-like spray required
for best results.

Test Your Sprayer

It is the poison applied to an acre of beets and not the water which
kills the worms. Quick and satisfactory results are secured by the use
of 4 pounds of Paris green per acre. Unless you know how much water
your sprayer applies to an acre, you cannot know how much poison to
use in a tank of water. For example, if a sprayer equipped with 4 double
nozzles and producing a pressure of 80 pounds will cover an acre with 50
gallons of water, you should mix 4 pounds of Paris green with 50 gallons
of water. If the pressure falls very much below 80 pounds, less water
will be applied to an acre and more Paris green will have to be added to a
50-gallon tank of water.

To test your sprayer fill the tank with water, put the pump in gear,
then drive along the road and measure the distance traveled in discharg-
ing all of the water through the nozzles. Multiply this distance, meas-
ured in feet, by the width of the number of beet rows you spray; say 5
twenty-inch rows or 8.3 feet, and divide this by 43,560, which is the
number of square feet in an acre. This will give you the part of an acre
you spray with one tank of water. Many failures in spraying are due
to using too little poison, and much loss in money results from using too
much. Avoid this by testing your machine. From the above you can
determine the amount of Paris green to use with a tank of water to
apply the 4 pounds per acre.

KNAPSACK SPRAYER

Fig. 2.

HAND SPRAYER

The hand sprayer (Fig.
3, Page 36) is suitable for
spraying house plants, or a
very small fruit or vegeta-
ble garden. It can also be
used to apply repellents to
live stock. Where one has
only occasional use for a
sprayer to spray a few
plants this type is recom-
mended because of its small
cost.

Sprayers

Knapsack Sprayer

Fig.

For use in gardens or
for spraying berry
bushes and ornamental
shrubs, the knapsack
sprayer (Fig. 2, Page
36) is very convenient.
This sprayer can be
placed on the ground or
carried as shown in the
figure. Where the gar-
den or the number of
plants to be sprayed is
small this sprayer is not
so well adapted to the
work as the hand
sprayer.

Hand Sprayer

Sprayers Paris Green

The accompanying picture (Fig. 3-a) illustrates a home-made spray-
er, costing approximately $25.00. This machine was successfully used
during the 1919 growing season in the Fort Collins, Colorado district.
Any hand-power spray pump may be used.

A HOME-MADE SPRAYER

Fig. 3-a. A Home-made Sprayer

CAUTION

Since Paris green is a poison, due care should be exercised in
handling it.

Be careful not to get Paris green on the hands, face, or other
parts of the body, or to rub the face or body with the hands if any
of the green should get onthem. The safest plan is to wear gloves.

The poison is absorbed into the pores of the skin and causes
a severe rash or breaking out. This absorption is more rapid
when one is perspiring.

Inhaling the dry poison may cause local poisoning of the
nasal passages.

Long continued handling of Paris green with bare hands may
result in systemic poisoning which is accompanied by typical
internal arsenical poisoning symptoms.

The average person will become poisoned locally only after
long and continuous contact with Paris green, but some individ-
uals are much more susceptible than others. This susceptibility
cannot be determined beforehand, hence the increased need for
caution.

In measuring Paris green use a long handled dipper.

Always use a wooden paddle for mixing it.

Destroy all cans or paper containers in which Paris green is
received, after emptying them. Children may be poisoned by
playing with them.

Root Feeders . Cutworms

CHAPTER II

ROOT FEEDERS

Taken as a class, those insects which inhabit the soil and feed upon
the roots and other underground parts of plants are among the worst
enemies of field, orchard and garden crops.

Living and feeding, as they do, below the surface of the ground the
greater part of their lives, the root feeders are seldom observed at work in
the field.

The effect of injury by root feeders upon the leaves and other visible
parts of plants is often attributed to many causes but the right one, and its
association with the insect is often not suspected until much damage has
been done, if at all.

Their subterranean habits, together with ‘he rapidity with which some
forms multiply, and the ease with which others are disseminated over
large areas, make them, with few exceptions, extremely difficult to
control.

Furthermore, the study of the habits, life history and control of many
root feeders is attended by peculiar difficulties, because of which our knowl-
edge of them is often so meager that we are unable to apply effective means
of control when some insect of this class suddenly appears in damaging
numbers in our fields.

Probably the best known and most destructive root feeders are the
cutworms, whi e grubs, wireworms, corn root-worms, the corn root-louse
and the sugar beet root-louse. To this may be added the sugar beet nema-
tode and other closely related eelworms.

A. BITING ROOT FEEDERS

(Cutworms, White Grubs, Wireworms)
1. CUTWORMS

The name “cutworm’ is applied in a general way to all of the hair-
less larvae (caterpillars) of a group of moths or millers called ~owlet
moths,’ from the fact that they fly mostly at night and have eyes that
shine in the dark. :

Probably no other insects are more dreaded in those sections where
they cause large annual crop losses, than are the various cutworms.
Like the evil gnomes of old, who sallied forth on moonless nights to
wreak vengeance upon some hapless wayfarer, the cutworms come forth
from hiding, and, under cover of darkness, despoil the farmers’ crops;
or, like the “sappers’’ of an invading army, these invaders of our fields
tunnel from plant to plant, leaving a trail of death and destruction in
their wake.

NATURE OF INJURY

If, in walking through a beet field, dead and wilted plants are seen; if
stools of grain in grain fields are dying or the stand is becoming thin; or

Cutworms

if alfalfa starts very slowly or makes an indifferent growth in the spring,
the fields should be examined for cutworms.

If cutworms are causing the injury the dead and wilted beets or dying
stools of grain will be found cut off at the surface of the ground, or just
below it. Should these plants still be attached to their roots, there being
no evidence of their having been partially gnawed off, cutworms are not
responsible for the plants dying. In case the plants have been killed for
some time the dead and dried leaves may have been blown away, leaving
the ground bare. In this case the stubs of the plants will be found if the
soil is removed to a depth of one-half inch or so.

When the slowness in starting or indifferent growth of alfalfa is due
to cutworms many new shoots will be found wilted and dead. These
will be gnawed off near the crown of the plant. As in the case of beets
and grain, shoots that are not at least partially gnawed off have not been
killed by cutworms.

While the foregoing is usually sufficient evidence that cutworms are
or have been injuring a crop, yet the real proof is in finding the worms.

WHERE TO LOOK FOR THE WORMS

Most cutworms, like the moths which produce them, are nocturnal
in habit. They lie hidden beneath trash or just below the surface of
the soil during the day, coming forth toward dusk and during the night
to feed. When very numerous and during cloudy, damp days, they
sometimes move about quite freely in the early part of the day.

In infested fields the worms will usually be found buried in the soil
near some plant which has been recently cut off. In alfalfa they will be
found buried near the crowns of the plants or under the trash scattered
over the field. Many times they accumulate under boards and other
objects lying on the surface of the ground. Careful watch should be
kept for worms before planting as damage can best be avoided by de-
stroying them before the crop is sown.

METHODS OF CONTROL
Poisoned Bait; Kansas Mixture

The best known method of killing cutworms is the use of poisoned
bait. A poisoned bran mash known as Kansas Mixture seems to give
the best results. The formula for use against cutworms is as follows:

20 lbs. bran or shorts;
1 Ib. Paris green;
2 qts. molasses (any cheap grade or beet molasses) ;
2 lemons or oranges (lemons preferred) ;
3 gals. water.

How to Make Kansas Mixture

Thoroughly mix the bran or shorts and the Paris green dry. Chop
the lemons or oranges, rind included, very fine. If a food chopper is
available, use this. Add the molasses and chopped fruit to about one-
half of the water and stir until the molasses is dissolved. Add this
mixture to the bran and Paris green and mix evenly. The rest of the
water should then be added a little at a time, stirring the mixture while
doing so, and until the whole mass is evenly moistened. When this

Cutworms

has been done the bran should be just moist enough to stick together,
but not so wet that it will not crumble freely. In this condition it
can be evenly and thinly scattered over the field to be treated.

How to Apply the Bait

The poisoned bait should be scattered broadcast over the infested
field. ‘This can be done by hand, care being taken to prevent large lumps
from being left in the field unbroken. If the bait is thinly and evenly
scattered there is no danger of poultry or livestock being poisoned by
eating it. If properly scattered a mixture made of 20 pounds of bran
will cover 2% acres.

Time to Put Out the Bait

Since the cutworms, as a rule, do not begin feeding until late after-
noon or early evening, the bait should not be spread until about sun-
down. If spread earlier in the day, especially if the weather is hot and
dry, the bait will become dried out before the worms begin feeding.
In this case the results are apt to be disappointing. It is claimed that
cutworms feed much more freely on shorts when dried out than on bran.*

Treating Fields Before Planting

Infested fields should be treated with poisoned bait before plant-
ing. If properly applied one application of Kansas Mixture is sufficient
to rid a field of cutworms. After being treated in this manner a field
can be planted with safety.

Other Poisoned Bait
Freshly cut clover or alfalfa thoroughly sprayed with Paris green
and water (1 lb. Paris green to 25 gallons water) and spread over infested
fields is often substituted for Kansas Mixture. It is very doubtful if
this is as satisfactory as the poisoned bran mixture. This method
should be avoided because of the danger of poisoning live stock.

Rolling
Rolling is sometimes recommended for killing cutworms. How-
ever, it is a doubtful method and one which is very apt to be disappoint-
ing in its results. Unless the surface of the field is very smooth and
‘compact, rolling is a waste of time for this purpose. If done at all it
must be done at night when the worms are moving on the surface. Gen-
erally speaking, rolling is not to be recommended.

Discing
Discing is even less effective than the roller, for destroying cut-
worms, and is not recommended.

Plowing,

Deep fall plowing will often give good results, especially if the soil
is thoroughly disced before plowing and the surface well worked down
afterward.

Replowing of infested fields in the spring, if the plowing is deep
and the surface thoroughly worked afterward, has given good results
when the season is not too far advanced for the planting of early matur-
ing crops.

*E. H. Streckland, **Control of Cutworms in the Prairie Provinces,’ Circular No. 6, Department of
Agriculture, Dominion of Canada (1916).

Cutworms Western Army Cutworm

Late Planting

Late planting may sometimes be resorted to as a means of prevent-
ing loss by cutworms. However, before resorting to this means the
best plan, if one is in doubt as to the identity of the particular cutworm
in question, is to send some of the worms to the State Entomologist,
to the Experimental Department of The Great Western Sugar Company,
Longmont, Colorado, or to some one else familiar with these insects and
qualified'to give advice regarding them. If this is done much time and
many dollars may be saved. Before resorting to late planting read
carefully what follows about the different species of cutworm, especially
the Pale Western Cutworm.

(a) WESTERN ARMY CUTWORM
(Figs. 1, 2, 3 and 4, Plate I, Page 11)

The name “western army cutworm ”’ has been applied to this species
because under favorable conditions it becomes very numerous and at
such times travels en masse in much the same way as the true army worms.

It is also often called the “alfalfa cutworm,’’ because of its prefer-
ence for this crop. In Northern Colorado it seldom injures crops unless

they are planted on recently broken alfalfa land or in fields adjoining
infested alfalfa fields.

DESCRIPTION
The Worm

Figure 1, Plate I, Page 11 represents a full grown western army
cutworm, natural size. This worm is marked with various shades of
brown above, while the lower part is a dirty white. There are usually
several dark spots on each segment of the body. Each of these bears
a short, stiff bristle. These bristles are not always easily seen with the
naked eye. Some individuals are much darker than in the figure, while
others are lighter. This is the most common cutworm in alfalfa fields.

The Pupa

Shortly after the cutworm becomes full grown it burrows into the
soil to a depth of about two inches. The next few days are spent in
wriggling and twisting about, making a cosy cell in the soil.

Rapid changes now begin to take place in the worm. It gradually
shortens and changes from its original color to a dirty, whitish yellow.
The skin, which has become much shrunken and wrinkled, now cracks
open, exposing a yellowish brown object within. A few more twists
and turns and the pupa (Fig. 2, Plate I, Page 11) frees itself from the
skin which covered the worm.

The Moth

The change from worm to pupa is only the beginning. During the
next two or three weeks nature is at work within the brown walls of
the pupa forming a body, legs and wings and hundreds of feather-like
scales (Fig. 4, Page 42) to cover them. When all is complete, our ugly
cutworm has taken on still another form. The brown walls of the pupa
burst open and after much pulling and straining the moth emerges.
At each side of its body hang two crumpled objects. As we watch these
they begin to expand and lengthen. In a very short time they have

Western Army Culworm

developed into delicately colored wings. The cutworm has now reached
the fourth or perfect stage, the moth.

These moths (Fig. 3, Plate I, Page 11) are easily recognized by the
light stripe on the forward edge of the fore wing. A few individuals
as Ee aa the fore wing being colored as shown in Figure 4, Plate

, Page 11.

Fig. 4. Scales from Wing of Moth of Western Army Cutworm,
highly magnified

LIFE HISTORY

Our knowledge of the life history of the western army cutworm is
incomplete. However, recent investigations conducted by Prof. R. A.
Cooley, Entomologist of the Montana Experiment station,* have de-
termined some of the more important points.

Prof. Cooley and his associates draw the conclusion that the west-
ern army cutworm is single brooded in Montana. This is probably
true of Northern Colorado as well.

The eggs are deposited, so far as is known, on bare ground, on clods
of earth, stubble and dead roots on the surface of the soil. Each female
moth is capable of laying several hundred whitish, ribbed, and more
or less globular eggs similar to those which are shown much enlarged
on Plate I, Page 11, Figures 11 and 12. The greater part of the egg
laying is done during September and October.

The eggs hatch in about ten days under ordinary conditions, but a
longer time is required if the weather is cool or the season advanced

** Observations of the Life History of the Army Cutworm,” Journal of Agricultural Research, Vol.
VI, No. 23 (1916).

Western Army Cutworm

when they are laid. The young worms feed during the fall until winter
comeson. As arule little or no damage is noticed as a result of this fall
feeding. With the coming of cold weather the worms become dormant,
in which condition they remain until the coming of warm weather in the
spring, when they resume feeding.

In seasons of normal temperatures the worms feed until about April
15th or May Ist. If the season is cold and backward the feeding period
is prolonged. Under such conditions the worms have been known to
feed until well into May.

Advantage can be taken of our knowledge of the feeding
habits of this worm in the sowing of our crops. In case we have
an infested field it can safely be planted to an early maturing crop by
waiting until the worms have ceased feeding, which is normally about
the middle of April in the latitude of Denver. Farther north, planting
should be delayed until about May Ist to 10th.

The moths begin to appear in numbers about June 15th. From
this time until the fore part of July they are most abundant. They
often become a nuisance in dwellings, causing much annoyance by
flying about the lamps. When very numerous the moths will be found
under any object which affords concealment during the day. Old gar-
ments hanging on the sides of out-buildings seem to be favorite hiding
places. The moths live until fall, when egg laying begins.

NATURAL ENEMIES

There are a number of parasitic and predacious insects which prey
upon the western army cutworm. The most important of these are:
Ichneumon-flies, Braconids, Chalcis-flies and ground beetles and certain
species of digger-wasps. Several species of birds destroy great numbers
of cutworms also.

Ichneumon-flies, Braconids and Chalcis-flies sting their eggs into
the cutworms, using for this purpose a long slender organ called an
ovipositor. ‘This ovipositor is located at or near the tip of the abdomen.
After the eggs have been placed in the body of the cutworm the little
grubs hatch and immediately begin feeding. These grubs subsist
upon the body fluids and fatty substances of the cutworm but do not
destroy its vital organs until they are fully grown.

Ichneumon-fly

The larva of the Ichneumon-fly *® (Fig. 5, Plate I, Page 11) does
not kill the worm, which changes into a pupa before the parasite’s work
is finished. The moth never develops in a parasitized pupa, however,
for the pupa is killed by the parasite, which gnaws its way out when it
is fully developed. Instead of a moth coming forth to lay more eggs to
infest our fields, the wasp-like Ichneumon-fly emerges, and if a female
it deposits its eggs in other cutworms, thus carrying on the good work
of ridding our fields of these pests.

Braconid

The larvae of the Braconid 2 (Fig. 6, Plate I, Page 11) kill the worm
before it changes to a pupa. When fully grown the grubs gnaw their
way out of the worm and proceed to spin about themselves little silken

(229-2) See explanation of “Reference Figures,’ page 2.

Western Army Cutworm

cocoons (Fig. 7, Plate I, Page 11) in which their development is com-
pleted. These cocoons are sometimes fastened to the dead worm,
sometimes to grasses or other plants, where they cling in clusters.

Chalcis-fly

The little Chalcis-fly * (Fig. 8, Plate I, Page 11) is one of the most
interesting parasites which attack the cutworms. The parasitized
worms die before changing into pupae. A single worm killed by this
parasite has been known to contain over 2,000 of these little flies. The
parasites complete their development in the dead worm. Figure 4,
Plate IX, Page 27 shows a parasitized worm just before the emergence
of the parasites, the pupa of which completely fill the skin of the cut-
worm and can be seen through it as little oval bodies.

Digger-wasp

The digger-wasp ® (Fig. 18, Plate VI, Page 21) is another very in-
teresting natural enemy of cutworms. The figure represents one of these
insects carrying an army cutworm to its burrow. So interesting are
their habits that the writer is giving the story of the capture and sub-
sequent entombing of a cutworm by a digger-wasp.

On warm days in early summer these blue-black wasps can be seen
hurrying over the ground, in and out of every hole, under every clod
and into every possible place where a cutworm could hide. In its search
many short flights are made and when running the wings are jerked
nervously, while every movement of the hunter is indicative of the
greatest haste.

When a cutworm is found it is immediately paralyzed, apparently
by being stung. This does not kill it but renders it helpless, in which
condition it remains until destroyed by the larva of the wasp.

The next act in this tragedy of nature is the finding of a suitable
place to leave the worm while a site for the home of the young wasp is
found. Always, so far as observed, the worm is left on some high place,
such as the top of a large clod of earth or in a fork of some plant an inch
or two above the ground.

Dame wasp (for it is always the female that catches the cutworms)
does not believe in the old adage, “Never catch a bird until you have a
cage for it,’ as the worm is always secured before the burrow is dug.
The worm having been left in some place of prominence, the search for
a suitable location to dig a burrow begins. Mrs. Fossores (for this
is one of her names) does not consider “any old place’ good enough
for a home for her young. One wasp was seen to start seven burrows
before finding a place entirely to her liking. The eighth location proved
satisfactory and the burrow was completed. Several of the unsatis-
factory attempts were made where the soil was soft and the digging easy;
however, an easy job did not seem to be what the wasp was looking for.
The location finally selected was in a hard beaten pathway where the
digging was very difficult. Thirty minutes were consumed in the con-
struction of the burrow. The wasp rested but once during this period
and then for but a very short time, when she lay flattened out on the

warm soil in the sunshine.

(4-8) See explanation of “Reference Figures,” page 2.

Western Army Cutworm Pale Western Cutworm

When the nest was completed the wasp wandered about for several
minutes and finally went to the worm, grasped it by the throat and
carried it in almost a straight line to the mouth of the burrow, where
it was laid with its head toward the opening. She then entered the
burrow, turned around, came out, and grasping the worm, backed into
the burrow again, dragging it after her. After a few seconds, during
which time the egg was fastened to the worm, the wasp reappeared,
turned its head away from the mouth of the burrow, and, standing on
her four hind legs, clawed dirt into it with her front feet. Every little
while she turned around to ram the dirt into the opening with her head.
This was continued until the mouth of the burrow was completely filled.
The surface of the soil was left in such a condition that it was only with
the greatest difficulty that the writer could locate the burrow.

The egg, shown fastened near the head of the worm in Figure 17,
Plate VI, Page 21, gradually changes into a maggot. The forward end
of this maggot, which contains the mouth, is long and pointed and during
the entire feeding period remains embedded in the body of the worm.
As the larva increases in size the worm shrinks until, when the grub is
fully grown, nothing but its empty skin remains, as shown in Figure 16,
Plate VI, Page 21. When the young wasp has exhausted its supply of
food its head is withdrawn from the empty skin of the worm.

The next day or so is spent in lining its burrow with a silken cocoon,
within which the grub changes to the pupa-and finally into the adult
wasp.

Birds

Birds are among the most effective natural checks of cutworms.
The meadow lark is probably one of the most valuable, its food in May
being about 24% caterpillars, the greater part of which are cutworms.
Blackbirds of all species, and robins, destroy large numbers of cutworms,
as do many other ground feeding species.

(b) PALE WESTERN CUTWORM
(Figs. 9, 10, 11 and 12, Plate I, Page 11)

The pale western cutworm !2 is a western species which until
1911 was not known as seriously injurious. Reported outbreaks have
all occurred in the Great Plains and Rocky Mountain areas of the United
States and the prairies of Western Canada.

Unlike the western army cutworm, this species does not occur in
alfalfa to any extent. Fall grain, crops planted on weedy fallow land
and those following grain are most apt to be injured. Seldom are crops
following cultivated crops injured unless they are adjacent to infested
fields. ‘This is especially true of crops following sugar beets and potatoes.

DESCRIPTION
The Worm

The full grown worm (shown natural size, Fig. 9, Plate I, Page 11)
is a dirty, pale gray color. After eating its fill of green food it takes on
an olive tinge. The head and part of the first segment of the body back

of it are light brown. There are usually two dark lines on the head as

(7) See explanation of “Reference Figures.” page 2.

Pale Western Cutworm

shown in the figure. ‘The small dark spots on the segments of the abdo-
men, each bearing a short stiff bristle, are usually plainly visible.

Just beneath the skin of the back is an organ which fulfills the
offices of the heart in the higher animals. This shows as a dark line
in the center of the back running nearly the whole length of the worm.
If watched closely it will be seen to pulsate in true heart fashion when
the worm is alive.

The Pupa

The pupa resembles that of the western army cutworm so closely
that Figure 2, Plate I, Page 11, will suffice for both. Aside from some
minor structural differences the only difference is in the size. The pupa
of the species under consideration is slightly smaller than that of the
western army cutworm.

The Moth

Figure 10, Plate I, Page 11 represents the moth, natural size. The
whole insect is lighter than the moth of the western army cutworm.
The colors are chiefly delicate shades of tan and brown. These moths
fly more freely during the day than those of the preceding species. On
warm afternoons in fall they have been seen feeding on the blossoms of
“rabbit brush” in quite large numbers.

LIFE HISTORY

The life history of the pale western cutworm is essentially the same
as that of the western army cutworm. The only important differences
| are in the dates when feeding ceases and the changes from worm to pupa
| and pupa to moth take place. For a description of how and where these
| changes take place read those parts of the discussion of the western
army cutworm under the heads “The Pupa’’ and“ The Moth’ ‘(Page 41).
This cutworm is single brooded in Northern Colorado. ‘The eggs,
shown very much enlarged in Figures 11 and 12, Plate I, Page 11, area
little less than 31; of an inch in diameter. The eggs are laid during
September and October, and so far as known are deposited either in
cracks in the soil, on lumps of soil or on the surface of the soil. Seldom,
if ever, are they deposited on green plants. Dry, fallow land and stubble
fields are ideal locations for egg laying.

During open, warm falls some eggs may hatch before winter sets in,
but field observations indicate that the greater part of the eggs do not
hatch until spring. As soon as hatched the worms begin feeding and
continue to feed until the last of June or the first or second week of July.
Because of this late feeding habit late planting cannot be re-
sorted to as a means of preventing loss, as no profitable field
crop can be planted at this late date.

The worms remain in their earthen cells for two or three weeks
before the change to the pupa takes place. In about four weeks more
the moth emerges.

NATURAL ENEMIES

Little is known of the natural enemies of the pale western cutworm.
In all probability it is held in check by some of the same parasitic and
predacious insects and birds as the western army cutworm.

Variegated Cutworm

This is one of the most universally distributed of all cutworms. It
is known over practically the whole agricultural world with the possible
exception of Africa. At one time or another damaging outbreaks of
this worm have occurred in nearly every part of its range. While, so
far as the author knows, no serious outbreak has occurred in the sugar
beet growing sections of the West which come within the scope of this
Bulletin, yet it is always present in our fields and may at any time appear
in such numbers as to do considerable damage.

This worm is a very general feeder, attacking almost any green
plant. It seems to prefer cultivated plants, and feeds sparingly upon
weeds, grasses and grains.

NATURE OF INJURY

The feeding habits of the variegated cutworm differ in some respects
from those of the preceding species. In California it is reported as
damaging young sugar beets in April.* At this time the worms spent
the day buried in the soil, coming out to feed during the night and early
morning. The beets were eaten off near the surface of the ground in true
cutworm fashion. During the same season a later brood of worms fed
upon the leaves, entirely stripping the plants of foliage. The roots were
also damaged to some extent. Large numbers of these worms have been
observed in Northern Colorado on the third cutting of alfalfa.

METHODS OF CONTROL

While the author has had no experience in the control of this cut-
worm, it would seem that during the early part of the season, before
the worms have acquired the climbing habit, the poisoned bait so suc-
cessfully used against the western army and pale western cutworms
would be equally successful in the control of this species.

In the case of later broods or when the worms are feeding upon the
leaves, spraying with Paris green will give satisfactory results, according
to Mr. G. E. Bensel.* In his work in California Mr. Bensel used 2 pounds
of Paris green to 50 gallons of water. To this about | lb. of molasses .
was added to make the poison adhere to the leaves. Two or three
applications were required, at a cost of about 90 cts. per acre, to check the
worms. A traction sprayer should be used in order to secure an even
application and an economic use of the poison.

Large lantern traps were also used to catch the moths in Ventura
Co., California, with very satisfactory results.

DESCRIPTION
The Egg

The eggs resemble those of other cutworms. They are deposited
in clusters of from a few to as high as 50 or 60 on the twigs of trees and
leaves of various plants.

*G. E. Bensel. “Control of the Variegated Cutworm in Ventura County, California.’ Journal of
Economic Entomology, Vol. 9, No. 2 (April, 1916).

Variegated Cutworm White Grubs

The Worm

The worm (Fig. 7, Plate VII, Page 23) is variable in color, ranging
from a very pale to almost a dark brown. Some light individuals have
a greenish tinge. The upper part is mottled with various shades of
brown and in the darker worms some black. On each side is a con-
spicuous yellow stripe and above this a dark stripe broken into a row
of crescent spots, as shown in the figure. The most characteristic mark-
ing is the row of yellow spots in the center of the back on the forward
half of the body.

The Moth

The moth, like the worm, varies in color. The one shown in Figure
15, Plate VII, Page 23, is of the dark type, the other extreme being very
much lighter, while all gradations of color between the two occur. Like
the moths of most cutworms, the adult variegated cutworm flies princi-
pally during the night when it is attracted by strong lights. Advantage
of this fact is sometimes taken in applying control measures.

LIFE HISTORY

As is likely to be the case with insects which range over so large
a territory, the seasonal history of the variegated cutworm varies with
the locality. It is known to pass the winter in every stage from the egg
to the adult moth, depending upon the latitude. In Northern Colorado
it probably passes the winter in the pupal stage or as a partly grown
worm. ‘There are two, possibly three, generations produced annually
in the latitude of Northern Colorado. The damage is done largely by
the first and second broods. The third brood, when produced, usually
comes too late to do any great damage during the fall. However, these
late hatched worms may hibernate over winter, in which case damage
may be done the following spring.

2. WHITE GRUBS
(Figs. 19, 20 and 23, Plate I, Page 11)

White grubs are the larvae of several species of rather robust beetles
commonly known as May beetles or June bugs. These beetles often
enter houses at night, being attracted by the lights. At such times
they fly awkwardly about, their wings making a loud humming noise.
Their flight usually ends abruptly as they collide with the wall or some
object in the room and fall heavily to the floor.

These insects belong to a large family, some species of which are
scavengers, while others feed upon living plants. The latter do much
damage to crops, especially in the Mississippi Valley and eastward.

The Sacred Beetle of Egypt belongs to this family. This beetle
was held in high veneration by the ancient Egyptians. It was placed in
the tombs with their dead. The members of this group we know as
“tumble-bugs,’’ from their habit of rolling about large balls of dung in
which their eggs are laid. To the Egyptians this ball was symbolic of
the earth and the beetle of the sun. The thirty joints of the feet were
taken to represent the days of the month. It was supposed that all of
these beetles were males. This was taken to symbolize a race of warriors,

White Grubs

a superstition which reached as far as Rome, where the soldiers wore
images of the beetles as sets in their rings.

The grubs of some species lie on their backs in the soil. This is
responsible for a myth of the Cherokee Indians* which runs something
like this:

In the old days the beasts, birds, fishes, insects and plants could
all talk and they and the people lived together in peace and friendship.
As time went on the people became so numerous that they began to crowd
the poor animals until they became cramped for room. Worse yet,
man invented bows, knives, blow-guns, spears and hooks and began to
kill the birds, animals and fishes for food and to tread upon the smaller
creatures, such as frogs and worms, out of pure contempt. So the animals
decided to hold a council to determine upon measures for their common
safety.

The bears met first. After each had complained about how man
killed their friends, ate their flesh and used their skins for robes, it was
decided to begin war against man at once. Some one asked what weapons
man used. ~ Bows and arrows,’ was the answer. The bears decided
to try fighting man with his own weapons. One bear got a fine piece of
locust wood for the bow. Another sacrificed himself for the good of his
friends that his entrails might be used for bow strings. But, alas, it was
found that the bears’ long claws spoiled the shot. Some one proposed
that their claws be trimmed. This was done and the arrow flew straight
to the mark. The leader, a large white bear, objected, saying that all
bears needed claws in order to climb trees. “It is better to depend
upon teeth and claws that nature gave us, for it is evident that man’s
weapons are not for us.”’

The deer held council next and decided to send rheumatism upon the
hunter who killed one of them unless he took care to ask their pardon
for the offense.

Next the fishes and reptiles held council and decided to cause man to
dream of snakes twisting about him in slimy folds or of eating decayed
fish so that he would sicken and die.

Finally the birds, insects and other small animals came together in
council. The grubworm was chief of the assembly. After all had made
complaint about the cruelties of man they began to name the different
diseases with which he should be afflicted. As disease after disease was
named, the grubworm became so happy that he finally shook for joy and
fell over backward and was unable to rise but had to wriggle off on his
back, as the grubworm has done ever since.

When the plants heard what had been done by the animals they
decided to defeat their evil designs. So each tree, shrub and herb, down
even to the grasses and mosses, agreed to furnish a cure for some one of
the diseases. [hus came medicine.

NATURE OF INJURY

White grubs never appear above ground but live and feed below the
surface. They are naturally grass-land inhabitants, being most common
in pasture and meadow land, where they feed on the roots of the grasses.

*Myths of the Cherokee,’ Nineteenth Annual Report of the U. S. Bureau of Ethnology (1898).
49

White Grubs

Sugar beets, potatoes and corn are among the field crops most seriously
damaged. Garden truck and strawberries often suffer heavily, also.

In the case of potatoes and sugar beets deep pits are eaten into the
tubers and roots. If sugar beets are damaged when the plants are small
the root is eaten off two or three inches below the surface of the ground.
The plant, of course, wilts. If it is pulled the tip of the root at the point
where it is eaten off will be dark in color, sometimes almost black. Wire-
worm injury is so similar to this that the two are easily confused. Later
in the season when the beets have attained some size they may not be
entirely eaten off but portions of their surface will be eaten away. Beets
attacked at this time of the year usually wilt, especially in the heat of
the day. Such beets are easily pulled because the grubs have destroyed
most of the smaller roots. When removed from the soil, the surface
will be found pitted, the pits being dark in color and rough on the surface.

The adults (beetles) of many of the injurious June bugs feed upon
the leaves of various trees, mainly cottonwoods and willows in the beet-
growing areas covered by this Bulletin. Injury by white grubs has been
noted only in river bottoms where natural sod and the trees mentioned
above are both common. Crops following sod or crops in which
much ¢grass was allowed to grow are most apt to be injured.

METHOD OF CONTROL

There is no known method by which an infested field can be freed
of white grubs without injury to growing crops. However, measures can
be taken which will reduce the injury or prevent future losses.

Pasturing with Hogs

When practical, pasturing with hogs will rid land of grubs. There
is one drawback to this method, however. This lies in the fact that the
giant thorn-headed worm, an internal parasite of swine, passes one stage
of its life in certain white grubs. Hogs eating these grubs become in-
fested and grubs eating the excrement of such animals become infested
in turn. If no hogs have been pastured on land for at least three years,
grubs in it will not contain this parasite, and hogs pastured on such land
will not become infested.

Rotation

White grub losses can be reduced by practicing a proper system of
rotation. Since the beetles usually deposit their eggs in fields of grass or
small grain, sugar beets, potatoes or corn should not follow these crops in
localities where grubs occur unless the ground is known to be free from
them. Alfalfa, clover, buckwheat, peas and small grain are not damaged
to the same degree as the crops mentioned above.

Plowing

Fall plowing, if done early, is a great help in destroying this pest.
As the grubs burrow deep into the soil as cold weather comes on, to be
effective, fall plowing must be done not later than October. Fall plow-
ing is much more effective if followed by the disc or harrow. Plowing
infested land in July or August. will destroy many beetles, as the change
from pupa to-adult takes place about this time and the newly trans-
formed beetles are easily killed.

White Grubs

LIFE HISTORY

The life histories of the May beetles are not very well known. Few
records exist of the raising of beetles from the egg. In all probability
most, if not all, of the injurious species occurring in the beet growing
sections of the arid West have a three year life cycle. It is possible that
the same species may complete its development in two years in the South,
in three years in the northern tier of states, and require four in Canada.

In general, the life cycle of the white grub is as follows: The beetles
lay their eggs in the soil in early summer. As soon as the young grubs
hatch they begin to feed. At this time they seem to prefer decaying
vegetable matter, although when very numerous they are known to
attack and damage growing crops. Feeding continues until the approach
of cold weather, when the grub burrows deep into the soil, where it spends
the winter in hibernation. Usually the damage done during the first
season of the grub’s life is slight.

With the return of spring the grubs come toward the surface, where
they begin a season-long campaign against the farmers’ crops. It is
during this second year of their lives that the grubs do the most damage.
At this age the grub appears as-in Figure 19, Plate I, Page 11.

Again with the coming of winter the grub burrows into the soil,
returning to the surface the following spring to feed a few weeks. The
change from grub to pupa takes place about the first of June. After
remaining in this resting stage for several weeks the adult beetle emerges
from the pupa. The beetles do not leave the soil until the following
spring, however. Digging their way out of the soil during May, the
peculcs proceed to feed, mate and deposit the eggs for another generation
of grubs.

Figure 23, Plate I, Page 11 represents the adult of a common white
grub which sometimes occurs in fields in our river bottoms.

Figure 20, PlateI, Page 11 is the grub of a small species which is
found in newly broken alfalfa ground and is often mistaken for the young
grubs of injurious species. So far as known it feeds only upon rotting
vegetable matter and not upon crops. ~ .

NATURAL ENEMIES

The white grub is preyed upon by many birds, animals and insects,
which materially aid in holding it in check. The U. S. Biological Survey
has found this insect in the stomachs of 60 species of common birds. Of
the feathered enemies of the white grub the crow and the crow blackbird
are no doubt the most important. Both of these birds will follow the
plow in grub infested fields and search out the grubs exposed. The
number of grubs which a crow blackbird will eat at one time is almost
beyond belief. It has been reported* that one bird ate 20 grubs in about
two minutes.

Skunks are very fond of white grubs. Meadow lands are often so
thoroughly worked over by these animals that hardly a square yard over
large areas does not contain one or more of the shallow holes from which
a grub has been taken.

cay Davis, “Common White Grubs,"’ Farmers’ Bulletin No. 543, U. S. Department of Agricul-
ture si

White Grubs Wireworms

Parasitic and predacious insects, while they destroy many of the
grubs, and beetles as well, are of less importance seemingly than the bird
and mammal enemies of this pest. In the Farmers’ Bulletin mentioned,*
Mr. Davis names two wasps, " Tiphia inornata Say.,"’ and “Elis sexcincta
Fab.," and a parasitic fly, “Pyrgota undata.’ The first two destroy
the grubs and the last preys upon the beetles.

3. WIREWORMS
(Figs. 13, 14, 15, 16, 17, 18, Plate I, Page 11)

Few boys and girls grow to manhood and womanhood on the farm
without becoming familiar with the “snapping-beetles,"’ “‘skip-jacks,”’
or — click-beetles,’’ as adult wireworms are called. (Figs. 16 and 17, Plate
eaceslilivandiicupmizacens)

Many a dull moment has been en-
livened by the acrobatic performances of
these trim, slender bodied beetles which
drop as if dead, when touched. With
their legs closely folded against their
bodies they feign death until they think
all danger is past, when they are off for
cover as fast as they cantravel. If they
happen to fall on their backs they will
spring into the air several inches, turn
over, land on their feet, and are off at
a run. This springing is accompanied
by a sharp snap or click, therefore the
names ~snapping-beetles’’ and “‘click-
beetles.

There are over 500 species of these
insects found in the United States.
The larvae of many of these live in the
decaying wood of stumps and fallen trees.
Many others are denizens of the soil.
Among the latter are the injurious forms.
These are most apt to be found in pasture
and meadow lands or wherever grass is

Fig. 5. Adult Snapping-beetle, Alaus
i oculatus. The larvae of this beetle allowed to grow about the fields. A few

Pe acai cea De ae coGy species are known to be predacious, feed-

ing upon other insects and often upon their own kind.

NATURE OF INJURY

During the early part of the season, especially about the time the
beets are being blocked and thinned, here and there a beet will be found
which is apparently dying. The leaves will be wilted, many times the
outer ones being dead and dry. When such beets are pulled they will be
be found gnawed off an inch or two below the surface of the ground.
The end of the beet as it comes from the soil will usually be dark, almost

*J. J. Davis, “Common White Grubs,” Farmers’ Bulletin No. 543, U. S. Department of Agriculture
(1913).

Wireworms

black. This wilting of the leaves, associated with the darkening of the
tip where it is gnawed off, are characteristic of wireworm injury; how-
ever, the work of white grubs is very similar in the early part of the season.

Many times beets eaten off by wireworms will throw out new roots,
especially if the soil is moist. Such beets develop a short sprangly root
as arule. If the soil is dry and the weather warm the injured plants
usually die. This results in a poor stand if the injury is severe.

Wireworm injury to sugar beets is not so severe in the Great Plains
States as it is farther edst and in California. In the latter state the
damage is especially severe and is due to the sugar beet wireworm, which
is very numerous in the beet fields of some parts of that state.

This wireworm also damages alfalfa, corn and beans.

METHODS OF CONTROL

Because of the great similarity between the habits and life history of
white grubs and wireworms, many of the same methods of control may
be used against both.

Rotation

As already stated, wireworms are most likely to be found in abund-
ance in pasture and meadow lands. When such lands are broken up
and planted to field crops those least apt to be badly injured should be
put in the first season. Row crops, such as sugar beets, corn or
potatoes, suffer most severely on infested ground. While the
small grains are sometimes severely injured they are not.as a rule so
badly damaged as corn and root crops.

Short rotations in which the land is not allowed to remain in grass
for any length of time will prevent the increase of wireworms, as the
females prefer grass lands as places to deposit their eggs.

Plowing
Early fall and late summer plowing will kill many newly transformed
beetles and pupae, especially if the surface is thoroughly worked with the
disc or harrow. :

Seed Treatment
Sometimes wireworms injure seed corn before it germinates, thus
causing an almost total loss of stand in severe cases. Treating the corn
before planting by coating it with gas tar and dusting with Paris green
will almost entirely prevent loss, according to tests conducted by Dr. H.
T. Fernald in Massachusetts in 1908 and 1909.

Poisoned Bait
Many poisoned baits have been tried, but with very little success.

DESCRIPTION
The Worm

Wireworms vary in form and color as well as size. The species most
injurious to sugar beets resemble Figure 13, Plate I, Page 11. This is
the larva of the “click-beetle’’ (Fig. 16, Plate 1). Figure 14, Plate I, is
an outline drawing of the last segment of the body of this worm. The
notch in the center is characteristic of many of our injurious wireworms.
Figure 18, Plate I represents another species often found in our fields.

Wireworms

The Pupa

The pupal stage (Fig. 15, Plate I) is spent in an oval cell in the soil.
The figure represents the pupa on the beetle shown in Figure 16, Plate I.

The Beetle

The beetles of this group are characterized by the freely moving joint
between the thorax and abdomen and by their power to spring into the
air when placed on their backs.

Our most common species ® (Fig. 16, Plate 1) isdark brown. Figure
17, Plate I, represents a smaller, lighter colored species. The drawing
to the right of the colored figure is the natural size of this beetle.

LIFE HISTORY

The life history of the soil-inhabiting species of wireworms is very
similar to that of the white grubs. The eggs are laid in the soil.
Usually meadows, pastures or other grass covered lands are selected by
the females as places to deposit their eggs.

Two or three years are required for the worms to reach maturity.
Feeding takes place each season. When mature the worm forms an oval
cell in the soil in which the change to the pupal stage takes place. This
change occurs during the summer months. In the course of a few weeks
the adult beetle emerges from the pupa.

Most of the newly transformed beetles remain in the soil until the
following season. However, a few leave their pupal cells soon after
emerging. During the following winter these beetles hibernate under
dead leaves, crop refuse or other material which furnishes suitable pro-
tection against the cold and moisture.

NATURAL ENEMIES
Ground Beetles

Wireworms are unusually free from attack by parasitic insects, but
the predacious ground beetles destroy many of them. Several species
of the Genus Calosoma, one of which is represented in Figure 2, Plate
IX, Page 27, and their larvae, feed freely on this pest.

Birds

Many species of birds are very effective in destroying the beetles.
The ill-famed crow is a noted wireworm destroyer. The food of the
California shrike, or butcher-bird as it is sometimes called, is known to
consist largely of adult wireworms during certain seasons of the year and
where these are abundant. From 90% to 95% of the food eaten is
composed of these beetles at such times, according to observations
recorded by John E. Graf, in Bulletin No. 123, Bureau of Entomology,
U.S. Department of Agriculture.

Skunks

Skunks, which’ are so effective in the destruction of white grubs,
devour large numbers of wireworms as well as the adult beetles. In
1914 the writer examined a quantity of excrement of the little, spotted
skunk. No evidence of any other animal food aside from insects was
found. Over 10% of the insects eaten were wireworms and click-beetles.

(®) See explanation of ‘Reference Figures,’ page 2

Sugar Beel Root-louse

B. SUCKING ROOT FEEDERS

I. SUGAR BEET ROOT-LOUSE
(Figs. 1 to 9, 11 to 13, 16 to 18, Plate II, Page 13)

Because of its universal distribution in the sugar beet growing sections
of the West and the difficulty of controlling it, the sugar beet root-louse
presents one of the most serious insect pest problems with which the
beet growers and factory people have to contend.

NATURE OF INJURY

Visible effects of root-louse injury on the above-ground parts of the
sugar beet do not appear until the number of lice becomes very great.
At such times the color of the beet leaves changes from a dark to a yel-
lowish green. This change in color alone must not, however, be taken
as proof that a crop is being greatly damaged by root-lice. Sugar beets,
especially when grown on light soil or watered too heavily, will turn
light in color in the latter part of the season when not infested with root-
lice. When the lice become very numerous the beet leaves wilt as though
the crop were suffering from lack of water. Often the beets become so
shrunken as to be loose in the ground and very much wrinkled. Such
beets are very limber and can be bent almost double without breaking.

The above is descriptive of exceptional cases. Whether effects are
visible or not, if lice are present, on the surface of the roots and in the
soil surrounding them will be found a whitish, mold-like substance.
Intermingled with this and covered by it will be seen many small, wingless
lice of a yellowish white color (Fig. 9, Plate II, Page 13), and if the season
is ee advanced some darker winged lice (Fig. 7, Plate II, Page 13) as
well.

The effect of lice on live stock is so well known that no one expects
a lousy animal to make normal growth or put on fat. The loss of blood
and possibly the irritation caused by the feeding of the lice stunt it and
produce a very scrubby and inferior animal. The effect of lice on a sugar
beet may be compared with that of lice on livestock. The lice take up
' the sap of the beet and the feeding irritates it. The combined effect of
these two things is a small, stunted beet and one low in sugar content.
Of course quite satisfactory yields and sugar contents are possible even
though the beets are lousy. Nevertheless, nothing is more certain than
that had they not been lousy both would have been higher.

Carefully conducted tests show that infested beets contain from 2%
to 1% less sugar than uninfested beets in the same field. Also, the purity
of juice of such beets is from 1% to 2% lower than uninfested beets.
The average infestation reduces the yield by more than | ton per acre.
In very severe cases the beets are killed or made worthless for factory
purposes.

METHODS OF CONTROL

There is no known means of entirely preventing sugar beet root-
louse losses. However, if the crop is properly handled they can be
greatly reduced.

Sugar Beet Root-louse

Irrigation

It has been shown by Mr. J. R. Parker of the Montana Experiment
station*, that the sugar beet root-louse does not multiply so rapidly in
moist as in dry soil. Experiments conducted by him on The Great
Western Sugar Company's farm at Edgar, Montana, and on the Gov-
ernment Reclamation Project at Huntley, Montana, show that fields
irrigated during the migration of the lice from the cotton-wood
trees to the beet fields are much freer from root-lice at harvest
than fields not irrigated until later.

Migration begins about the 10th of June and is at its height about
the 20th of the month in the latitude of Denver, Colorado. In the lati-
tude of Billings, Montana, the height of migration is probably reached
six to eight days later. Since the losses due to this insect are propor-
tional to the number of lice present and feeding on the crop, anything
which reduces their number reduces the loss as well. Frequent irriga-
tions during the growing season reduce the infestation and also increase
the yield of beets.

In a leaflet issued by Mr. Parker and circulated by The Great West-
ern Sugar Company at Billings, Montana, the results of several years’
work in thescontrol of the sugar beet root-louse, show that there are 56.2,
46.6 and 25.6 beets out of every 100 infested where two, three and five
irrigations respectively were applied.

The sugar content was 15.8%, 17.1% and 17.2% for two, three and
five irrigations respectively.

The gross returns per acre were $82.27 for two, $85.61 for three, and
$96.07 for five irrigations.

To some, early irrigation may seem like “jumping from the frying
pan into the fire,”’ since it is quite generally believed that early watering
is detrimental to sugar beets. Quite to the contrary it has been found
that irrigating as early as June 22nd produces better results in yield and
per cent of sugar in the majority of years. It is a fortunate coincidence
that early irrigation gives best results in just the years which are favor-
able for the development of root-lice; i. e., years when the winter and
early summer are dry.

Through experiments conducted on The Great Western Sugar Com-
pany’s Experimental Farm at Longmont, Colorado, it has been found
that, as an average of six years tests, irrigating as early as June 22nd to
25th has produced a yield of 14.66 tons per acre and 16.05% sugar, while
beets irrigated the first time July 5th to 10th gave a yield of but 14.23
tons per acre and a sugar content of 15.84%. Both the early and late
irrigated beets were watered three times each season. The gross re-
turns were $87.29 per acre for the early and $83.80 for the late
irrigated beets, without any greater expenditure of labor or water
for the increased returns due to early irrigating.

Fall and Spring Irrigation; Plowing

Fall or early spring irrigation will no doubt destroy most of the fee
in the soil. However, if the destruction of the lice is the only reason

* Life History of the Sugar-beet Root-louse, Pemphigus betae,’ Journal of Economic Entomology.
Vol. 7, No. 1 (1914).

Sugar Beet Root-louse

for this irrigation it is doubtful if the results will warrant the use of the
water. During the process of plowing and working down the seed bed,
the majority of the hibernating lice are destroyed.

Rotation

While quite a number of lice live over from season to season in the
soil of old beet fields, yet they are of little importance as compared with
the lice from the narrow-leaf cottonwood trees as a source of infesta-
tion. For this reason rotation is of very little avail in preventing
losses. The results of a survey covering 80,000 acres, made in 1916,
showed that 83 beets out of 100 were infested with root-lice where sugar
beets were grown on old beet ground and 82 out of 100 where they fol-
lowed all other crops. This proves conclusively that rotation will not
prevent root-louse losses. The presence of lice in the soil in the spring
is no reason why such fields should not be planted to beets provided
they are otherwise fit.

The results of the survey mentioned above show quite conclusively
that the destruction of all narrow-leaf cottonwood trees within the beet
growing sections will reduce the damage done by the sugar beet root-
louse. Therefore, the cutting of these trees is strongly to be recom-
mended. However, it will not entirely free beet fields of this pest, since
many lice reach them from the foothills and canyons.

DESCRIPTION AND LIFE HISTORY

Mention has already been made of winged lice on the beet roots in
the fall. During warm, sunny autumn days swarms of these little
winged lice leave the beet fields and fly to the narrow-leaf cottonwood
trees.

About every narrow-leaf cottonwood with the rays of the sun
glistening on their wings, thousands of lice sway in and out among the
branches. One by one they alight to go hurrying up and down as if
fearful lest the oncoming winter overtake them before suitable homes
for their young have been found.

In deep crevices and under loose pieces of bark these winged migrants
from the beet fields deposit their minute, yellowish young. These are
of two kinds, tiny little females (Fig. 18, Plate II, Page 13), and still
smaller males (Fig. 16, Plate Il). (Note the minute representation of
the actual size of these lice, shown at the left of the figures.) Almost
microscopic in size, mouthless and living but a few days, their sole object
in life is to produce the solitary egg which each female lays. This accom-
Bees the female dies, the male having died shortly after mating took
place.

Figure 13, Plate II, Page 13, is the antenna of Figure 16, Plate II,
Page 13, greatly enlarged.

The eggs, one of which is shown very much enlarged (Fig. 17, Plate
II), are about »; of an inch long and one-fourth as broad. Snugly
tucked away in some crevice of the bark they remain until the warm
days of spring cause the buds to swell, when from each egg a small, dark
louse (Fig. 2, Plate I], much enlarged) emerges. As soon as hatched
this little louse starts in search of an opening bud. When one is found

Sugar Beet Root-louse

it crawls in among the expanding leaves and begins to feed upon the
upper surface of one close to the midrib. This feeding causes a depression
to form and the leaf to turn light in color (Fig. 1-A, Plate I1).

In the course of a few days this depression has become a swelling on
the under side of the leaf (Fig. 4, Plate II), which is now entirely closed
on the upper side (Fig. 3, Plate II). In this gall, as the swelling is called,
the little louse is securely protected from inclement weather and the
sharp-eyed birds as they flit among the branches. Both the gall and the
louse increase in size for some time, until the former appears as in Figure
5, Plate II, and the louse, which is called a stem-mother, as shown in
Figure 6, Plate II.

This rotund stem-mother gives birth to several living young daily
during the next month or six weeks. If opened about the middle of
June the gall will be found to contain many pale lice all surrounded by
a whitish substance. This waxy material is secreted by glands and
escapes through what are called wax-pores, which are arranged in rows
across the body of the insect. [hese appear as light, round spots on the
backwm: (icon late):

The young of the stem-mother do not resemble her in form, being
slender of body and at first wingless. As they grow older wing pads
appear on their shoulders. After shedding their skins several times,
growing darker with every succeeding molt, the last larval skin is shed
and a delicately winged louse (Fig. 7, Plate Il) emerges. The antenna
of this winged louse is shown in Figure 8, Plate II.

About the time the first winged lice appear the mouth of the gall
begins to open. Through this opening the winged lice escape and fly
or are blown by the wind far and wide among the beet fields, where they
settle on the beets and deposit their young, which immediately descend
to the ground and take up their abode on the beet roots. All the young
of the winged migrants from the cottonwood trees are wingless and when
full grown appear as shown in Figure 9, Plate II.

The antenna of the wingless lice which are found on the beet roots
is shown in Figures 11 and 12, Plate II.

These wingless lice give birth to still more wingless lice. This goes
on until several generations and hundreds of lice have been produced on
the beets. Then with the return of fall some of the lice on the beet roots
develop wing pads like those of the young of the stem-mother in the gall.
After acquiring wings these lice are known as the fall migrants.

These migrants return to the narrow-leaf cottonwoods and there
deposit their young. Thus we have followed the lice from the galls on
the cottonwood trees to the beet fields and back again to the cottonwoods.

Not all of the lice become winged in the fall, however. Some wing-
less ones remain over the winter in the soil, where they hibernate in
earth-worm burrows and other openings. Thus we see that nature has
provided two means of carrying the beet root-lice over the winter: the
hibernating lice in the soil, and the eggs in the crevices of the cotton-
wood bark.

Sugar Beet Root-louse Sugar Beet. Nematode

NATURAL ENEMIES

While in the galls a bug* (Fig. 14, Plate II, Page 13) preys upon
the lice. In the beet fields the little lady-beetle 11 and its larva (Figs.
10 and 15, Plate II, Page 13) feed upon the root-lice. This larva,
which is not very much larger than a good sized louse, secretes a white,
waxy substance with which its body is covered, making it resemble to
a remarkable degree one of the lice upon which it feeds. The pupa of
this beetle (Fig. 14, Plate VII, Page 23) is surrounded by the cast larval
skin and white flocculent coating.

The larvae or maggots of the Syrphus-fly !4 (Fig. 13, Plate VI, Page
21) do their part in destroying this pest.

__ Every season large numbers of the lice are killed by a fungous dis-
ease.** This fungus develops within the lice and finally causes their
death. Were it not for these natural checks the damage caused an-
nually by the beet root-louse would be far greater than it is now.

Slender, yellowish-white maggots are often seen among the lice on
beet roots. These are the larvae of a small, striped flyt (Fig. 14, Plate
VI, Page 21). Recent investigations} show that these maggots are
very effective in destroying the beet root-lice. During the latter part
of the season small, oval, brown bodies will be seen among the lice also.
These have often been mistaken for the eggs from which the lice hatch.
Instead of being root-louse eggs they are the thickened larval skins
within which the maggots change into the flies mentioned above.

2; SUGAR BEET NEMATODE
(Figs. 8, 9 and 10, Plate III, Page 15)

Quite early in the history of the beet sugar industry in Europe it
was noticed that the yield of sugar beets was steadily dropping off in
certain districts. In spite of the efforts of the growers to maintain the
yield by using fertilizers, and in spite of their increasing knowledge of
the handling of the crop, the tonnage secured was so unsatisfactory that
the growing of sugar beets was discontinued on many fields.

Many theories were advanced in explanation of this condition. The
most prevalent and generally accepted of these attributed the trouble
to an exhaustion of the mineral plant foods of the soil.

It was noticed that those fields where beets had been grown con-
tinuously for several years were most affected. This led the Germans to
give the name “ Riibenmiidigkeit,’ or “beet weariness,"’ to this malady.

A German scientist named Kiihn was first to associate the soil in-
habiting eelworm or nematode (Heterodera schachtii) with this trouble.

The sugar beet nematode so far has been found only in a few well
defined localities within the territory in which The Great Western Sugar
Company operates.

*Authocoris melanocerus.

**Empusa aphidis.

ae opece glabra.

R. Parker, “Life History and Habits of Chl i labra Meign.,” i
Beeay Wor xXt Nes 4 ry its o oropisca glabra Meign., Journal of Economic Ento-
(72-14) See explanation of ‘Reference Figures,”’ page 2.

Sugar Beet Nematode

Fig. 6. A Sugar Beet infested with Sugar Beet Nematodes. The white bodies. of
the female nematodes can be seen clinging to the rootlets.

Fig. 7._A Sugar Beet affected with Curly-top, showiog the characteristic dense mass of rootlets. (After C. O.
Townsend, Farmers’ Bulletin No. 122, U. S. Department of Agriculture.)

Sugar Beet Nematode

NATURE OF INJURY

The young sugar beet nematodes search out a beet root, and by
piercing it with their strong spear-like mouth parts, embed themselves
within the tissue. They then begin to feed upon the juices of the beet.

Effect on Roots

The presence of the nematodes causes an irritation of the roots.
Because of this irritation, and because the sap is consumed by the nema-
todes, the roots are unable to carry the water and plant food to the beet,
and the growth of the plant is interferred with.

In an attempt to overcome this trouble the beets send out many
new rootlets from the root seams at each side of the main root. In
Europe these beets have been called “bearded roots” or “hunger roots.”
Such beets (Fig. 6, Page 60) resemble the “ whiskered beets’ suffering
ae a severe attack of the disease known as ' Curly-top”’ (Fig. 7, Page
60).

If carefully removed from the soil, the rootlets of infested beets
will have many minute, pearly-white bodies clinging to them (Fig. 9,
Plate III, Page 15). These are the mature female nematodes.

In extreme cases the weakened roots become infested with fungi and
bacteria which cause them to rot or the plants die because of lack of
nourishment.

Effect on Leaves

The presence of nematodes becomes apparent in the appearance of
the leaves as the season advances. The foliage of the infested plants
turns light in color, becoming a yellowish green, or they have the dull,
gray-green color of beets suffering from lack of water. The leaves wilt
and finally lie flat on the ground, failing to recover during the night.
The outer ones finally die. The growth of the inner leaves is seriously
interfered with, and in severe cases they die also. If the beet does not
succumb to the attack, the new leaves produced fail to attain normal
size and are often much curled and distorted. Late in the season, beets
which have survived the attack are often a darker green than their
uninfested neighbors.

Effect on Sugar Content
Not only is the size of the roots and leaves of the beets affected
but the sugar content is greatly reduced as a result of the nematode
attack. For example, moderately infested beets contained 11.35%
sugar and badly infested ones only 8.4% in a field where healthy plants
had a sugar content of 14.9%.*

HOW NEMATODES SPREAD
By Their Own Movements

Sugar beet nematodes have the power of increasing by their own
movements the area infested. In certain stages of their development
and under favorable conditions they can travel considerable distances
in the soil. The ravages of this pest have been known to be extended
from 50 to 75 feet each season in this way.*

*Harry B. Shaw, “Control of the Sugar-Beet Nematode,’ Farmers’ Bulletin No. 772, U. S. Depart-
ment of Agriculture (1916).

Sugar Beet Nematode
Carried by Irrigation Water

Irrigation water passing over infested areas carries many nematodes
to uninfested localities with the soil washed away from these areas.

The use of factory waste water for irrigation purposes has resulted
in spreading this pest over large areas in those localities where the nem-
atodes exist.

Carried by Implements, People and Live Stock

Nematode infested soil is often carried from infested to uninfested
fields on the farm implements used in their cultivation.

The wagons used in hauling a crop from infested fields or in hauling
manure onto such fields often carry the nematodes to other fields.

Work animals or stock allowed to run on infested land, as well as
people, spread this pest by carrying the eelworm in the soil clinging to
their feet.

In Manure of Animals

The sugar beet nematode does not pass through the digestive organs
of sheep alive. ‘There seems to be no evidence that this is true of other
farm animals. It is therefore quite possible that nematodes may be
carried in the manure of other animals, and if beet tops on infested land
are to be pastured, sheep should be used for this purpose.

METHODS OF CONTROL

The fact that the sugar beet nematode is a really formidable
pest, if allowed to spread, cannot be too strongly impressed upon
the minds of all beet growers, especially as it occurs in damaging
numbers in several beet growing sections of the United States,
including a small area in Colorado.

Since there are no known methods of entirely freeing the soil of
nematodes which can be used in field practice, the adoption of proper
precautions to prevent their introduction into new fields is of the greatest
importance. Once this eelworm is established, the prevention of its
spread is no less important than the establishing of a system of crop
rotation which will check its multiplication.

How to Prevent Spread of Nematodes

(1) No waste water should be allowed to run from infested to un-
infested fields.

' (2) In infested areas, factory waste water should not be used for
irrigation purposes unless first properly treated with lime.

(3) All implements used in working infested land should be very
carefully cleaned by removing all soil from them before they are used in
uninfested fields. This includes the cleaning of wagon wheels.

(4) The feet of persons and work animals should be thoroughly
cleaned before going from infested to uninfested fields.

(5) Live stock should not be allowed to run on infested land unless
it is to be confined there until removed to market.

(6) Beet tops from infested land should not be removed but should
be pastured on the land where grown.

(7) The manure of animals fed on beet tops from infested land
should not be used on uninfested land.

Sugar Beet Nematode

How to Check Multiplication of Nematodes

Field Surveys

All suspected fields should be thoroughly examined, so that the
exact location and extent of infested areas may be known. That such
surveys of suspected lands be made is of the greatest importance.

Local Treatment

If the infested areas are small, local treatment may be all that is
necessary. All plants on the area should be pulled, together with those
from a_ strip several feet wide all around it. These should be destroyed
by burning on the spot.

A trench about one foot deep and one foot wide should then be dug
around the infested spot and this filled with quick-lime. The surface
of the infested area should be covered with lime an inch or two deep and
this thoroughly mixed with the soil. Frequent mixing of the limed soil
will add to the effectiveness of the treatment.

Pasturing with Sheep

Pasture the beet tops grown on infested land to sheep, rather than to
other stock, as the nematode in the tops eaten will thus be destroyed, and
will not be returned to the soil through the manure.

Rotation

The sugar beet nematode infests the roots of many weeds and cul-
tivated crops. The following list of plants known to be subject to attack
is taken from Farmers’ Bulletin No. 772 of the U. S. Department of
Agriculture.

Alfalfa Dandelions Pinks
Allseed Foxtail, Green Potatoes
Barley Hemp Radishes
Beans, Dwarf Pea Hops Rape
Beans, Lima Kale Rutabaga
Beets, Garden Kohl-rabi Rye
Beets, Sugar Lentils Sorghum
Cabbage Lupine, Yellow Spinach
Cabbage, Chinese Meadow-grass, Annual Sunflower
Cauliflower Meadow Oat-grass, Tall Timothy
Celery Mustard Turnips
Clover, Crimson Oats Vetch
Clover, White Parsnips Wheat
Corn Peas, Garden

Cress Peas, Sweet

In the above mentioned bulletin the author lists the following crops
as being available for Colorado and neighboring states for rotation on
infested land:

Cow Peas Asparagus

Soy Beans Lettuce

Sweet Clover Cantaloupe

Rye Barley

The Millets Wheat

Tomatoes Cucumbers
Potatoes

Potatoes are often slightly injured.
63

Sugar Beet Nematode Root-knot Nematode or Gallworm

DESCRIPTION AND LIFE HISTORY

In the course of its development the sugar beet nematode passes
through four forms or stages: the egg, two larval stages, and the adult.
The Egg
Each adult female produces from 300 to 400 eggs. These are color-
less and broadly oval or kidney-shaped. They are extremely small,
being only about 34, of an inch long.
The Larval Stages

The young nematodes, or larvae, are very active, threadlike creatures.
Being colorless and almost microscopic in size, they are seldom noticed

in the field.

It is in the first larval stage that the nematodes enter the tissue of
the beet roots. The first larval skin is cast shortly after entering the
beet and the larva takes on a more robust form.

The Adult

With a second molt the nematode becomes an adult male (Fig. 10,

Plate III, Page 15), or female (Fig. 8, Plate III, Page 15).
The Brown-cyst Stage

As cold weather approaches’ or conditions become unfavorable for
the development of the females, certain individuals pass into a resting or
preservation stage which is known as the brown-cyst stage.

In the cyst form the female passes the winter or the period of un-
favorable conditions protecting the eggs until conditions become favor-
able for further development. With the change of conditions the eggs
begin to hatch. They do not all hatch at once, however, but may con-
tinue to do so ror long periods that may extend over several years.

3. ROOT-KNOT NEMATODE OR GALLWORM

This nematode, which is very closely related to the sugar beet nem-
atode, seriously interferes with the growing of sugar beets in some
localities.

This nematode has been
found in the Sterling, Brush,
Ft. Morgan and Scottsbluff
districts.

NATURE OF INJURY

The roots of infested plants
present a very characteristic
appearance. The presence of
the females and larvae in a
root is indicated by irregular
swellings (Fig. 8, Page 64),

Fig. 8. Small Sugar Beets infested with the a 3
Root-knot Nematode. The bead-like swellings caused by the irritation set
on the small roots and the enlargements of the
main root are caused by the nematodes. up by these eelworms.

Root-knot Nematode or Gallworm

METHODS OF CONTROL
Prevent Spread of Nematodes
In order to prevent the spread of this pest, the same precautions
should be observed as in the case of the sugar beet nematode (See page 62).
Potatoes grown on infested land should not be used for seed, as the
nematodes pass the winter within the tubers.

Such plants as tomatoes, cabbage, strawberries, kale, sweet potatoes,
asparagus and horse-radish should not be taken from infested soil and
transplanted in nematode free fields.

Nematode Eradication
There is no practical means of entirely eradicating the gallworm in
large fields. In the case of hotbeds and greenhouses soil fumigants can
be used, but these are too expensive for field use.

Rotation
The most practical method of reducing the numbers of nematodes
is to rotate with such crops as are not attacked. Mr. C. S. Scofield*
gives the following list of crops as suited for planting on infested soil:

Barley Sorghum
Oats Milo
Wheat Kafir
Rye Timothy
Corn Red Top

The value of growing the resistant crops named above is strikingly
illustrated by the results of a survey of five large areas in which all sugar
beet fields infested with the root-knot nematode were located and a record
secured of the crop grown on all fields, both infested and uninfested the
year previous. It was found as the per cent of resistant crops grown
increased, the per cent of infested beet fields decreased. These figures
are given in the following table:

% of total
Total fields % of total growing nematode
Area examined infested resistant crops
A 366 58.47 5.19
B 480 51.87 6.66
G 768 US. 9.77
D 671 2.08 12.09
E 676 1.03 28.06

LIFE HISTORY

During the greater part of their lives these worms remain embedded
within the tissue of the roots of their host plants.

Upon reaching maturity the fertilized females begin the production
of eggs. Some of these hatch within the body of the parent, the young
ultimately escaping into the surrounding tissue of the host plant. Others
are laid at the rate of ten or fifteen daily.*

*~ The Nematode Gallworm on Potatoes and Other Crop Plants in Nevada,” Circular No. 91, Bureau
of Plant Industry, U. S. Department of Agriculture (1912).

Root-knot Nematode or Gallworm

Shortly after the larvae hatch they escape from the root of the host
plant and spend a time in the soil. Soon they search out the root of a
suitable plant and burrow into it, where they feed upon its sap, causing
the characteristic swellings already mentioned.

The nematode gallworm lives from season to season embedded in
the tissue of the host plant either in the egg or larval stage. The life of
the adult is only a few weeks under favorable conditions.

Plants and crops subject to severe infestation which should never
be planted on infested land:*

Beet Pumpkin Cowpea
Carrot Potato Rape
Celery Salsify Soy bean
Cucumber Squash Catalpa
Egg plant Tomato Cherry
Lettuce Watermelon Elm
Muskmelon Clover Peach

Plants subject to attack but not seriously injured by nematode
gallworms: These should not be planted on infested land as they will
serve to keep the worms alive.*

Alfalfa Cauliflower Kale

Vetch Garden pea Onion

Sweet clover Horseradish Radish
Asparagus Strawberry Spinach
Cabbage Lima bean Sweet potato

Crops suited for planting on infested land :*

Barley Corn Kafir
Oats Sorghum Timothy
Wheat Milo Red top
Rye

*C. S. Scofield, “ The Nematode Gallworm on Potatoes and Other Crop Plants in Nevada,” Circular
No. 91, Bureau of Plant Industry, U. S. Department of Agriculture (1912).

Leaf-eating Caterpillars Sugar Beet Webworm

CHAPTER III

LEAF FEEDERS

Either because they feed exposed to the view of the most casual
observer or because their work is such as to attract general attention,
the leaf-feeding insects are much more universally known to the layman
than the root-feeding insects. Ina general way the methods of controlling
this class of insects are common knowledge also. However, this knowl-
edge is of a superficial nature; that is, it is general instead of specific.
This lack of knowledge of the particular insect involved has led to much
waste of money, energy and material, either because the wrong remedy
has been applied or the right one was not applied in the correct way or
at the right time.

A. BITING LEAF FEEDERS

(Caterpillars, Beetles, Grasshoppers, Crickets, Leaf-miners)

1. LEAF-EATING CATERPILLARS

The young of moths or millers and butterflies are known by the
general name of caterpillars. In size, shape, color and body covering
they differ greatly in different species.

Some are but a fraction of an inch in length, while others attain a
length of six or seven inches. For the most part caterpillars are cylindri-
cal, being several times as long as thick. Some are grub-like in form and
others resemble dead leaves or twigs in shape and color. The bodies of
many are bare, those of others are covered with long hairs. In some
species these hairs are connected with poison glands. If these cater-
pillars come in contact with the bare hands or face the sensation is very
similar to that caused by the sting of nettles, only more severe. Some
caterpillars are really formidable in appearance because their bodies are
covered with large spines or spine covered tubercles.

In the kinds of food eaten, caterpillars are as variable as in shape,
size or color. Some bore in the wood of trees, others feed upon hair,
wool, horn and like substances. A few feed upon scale insects and the
larvae of borers. Several species attack growing fruits, while others
destroy stored fruits and grains. The species with which we are most
concerned, and which are discussed in the following pages, feed upon the
leaves of plants. Among this class are to be found some of the worst
enemies of cultivated crops.

(a) SUGAR BEET WEBWORM
(Figs. 3, 4, 5, 6, 8, 9, 10, 11, Plate V, Page 19)
The sugar beet webworm is one of the most destructive leaf-eating
insects attacking the sugar beet. Like many of our most injurious insect

pests, it was introduced into this country from the Eastern Hemisphere,
appearing first on the Pacific coast. In 1869 it damaged beets in Utah.

Sugar Beet Webworm

Since that time it has spread over the entire sugar beet growing areas of
the country.

The worst outbreaks of webworms which have occurred in the ter-
ritories in which The Great Western Sugar Company is operating took
place in 1918 and 1919. During the season of 1918, the June and August
paged: both caused great damage. Some fields were injured by both

roods.

An accurate statement of the acres damaged in 1918 and the degree -
of damage was reported by the fieldmen of The Great Western Sugar
Company. These reports show that 31,000 acres were injured. The
first brood injured 5,500 acres and the second 25,500 acres. Over 7,000
acres were damaged to the extent of two tons per acre, over 7,000 acres
to the extent of one ton per acre and nearly 15,000 acres to the extent of
% ton per acre. The total loss to the growers and the industry was not
less than 26,450 tons of beets. These at $10.00 per ton, the price in 1918,
represents a money loss of $264,500. Over 16,000 acres were sprayed
with Paris green at the average rate of 4 pounds per acre, and much loss
thus prevented. This required 84,000 pounds of Paris green, much of
which was furnished the growers at a reduced cost per pound by The Great
Western Sugar Company.

This loss could have been very much more reduced if all growers had
realized in time that there was danger and had had themselves properly
prepared. Too late spraying was responsible for much of the loss.

As this bulletin goes to press the campaign against the first brood
of 1919 is drawing to aclose. This brood, which is the largest known in
the history of sugar beet growing in the United States, covered practically
all beet growing areas in Colorado, Nebraska, Montana and Wyoming.

In order to assist the growers in combating it The Great Western
Sugar Company purchased several hundred traction sprayers and dis-
tributed about 700,000 pounds of Paris green in its territories. Had it
not been for this assistance the loss to the growers would have far exceeded
that caused by both broods of 1918.

NATURE OF INJURY

Webworms injure sugar beets by destroying the leaves. This re-
tards the growth, thus reducing the yield and sugar content. All other
things being equal, the loss is quite proportional to the loss in leaves.
The greater the amount of leaf surface destroyed, the greater the loss.
On the other hand, the losses depend somewhat upon the time of season
when the damage is done, also upon the weather condition immediately
after it is done.

Small beets may be killed outright if the leaf surface is so small that
the worms attack the crowns. Larger beets may have their leaves
entirely eaten off but recover by putting out new leaves. (See Fig. 9,
Page 69, and Fig. 10, Page 70.)

The first indications that a crop may be injured by the sugar beet
webworm is the appearance of the moths (Fig. 11, Plate V, Page 19) in
the field. These moths are active and easily disturbed during the day.
When present they will be noticed flying ahead of the cultivator or of
one walking through the field. Their flights are short and jerky and they
usually alight on the under side of a leaf or on the ground. Catch one

Sugar Beet Webworm

ot the moths and compare it with the figure. If it is the same then look
for the eggs, continuing to do so for several days. Call the attention
of the Sugar Company's fieldman to the moths and get his advice.

The eggs will be found on the under side of the beet leaves, on lamb’s-
quarters or on Russian thistle if these weeds are growing in the field. Of
a pearly-white color and about the size of a small pin-head, they are not
easily seen unless careful search is made for them.

Fig. 9. Sugar Beet badly damaged by Webworms

Even though no eggs can be found, do not assume that all danger is
past. Often the eggs are overlooked and the first indication you have
that your crop is infested is the presence of newly hatched worms hang-
ing from the under side of the leaves by a short web. These can best
be seen by getting down near the*ground and looking up and down the
rows. Both the worms and web are light colored and not very easily
seen unless the light is just right. Looking away from the sun makes
them more easily discerned.

Picking leaves at random over a field and noting the number of eggs
or young worms present is a very good way of estimating the possibility
of damage in the near future. Great care must be taken not to under-

-estimate this possibility, however. One or two worms or eggs on
one-half to three-fourths of the leaves indicate the presence of enough
worms seriously to injure the crop later. As some of the worms drop
from the leaves when they are broken off, the worms seen do not represent
all present.

Sugar Beel Webworm

Very often a few eggs in one part of a field indicate that in some
other portion there are many more. Not infrequently the moths lay eggs
by the hundreds and thousands over a very small area. This is quite
as apt to be in the center of the field, or at least some distance from the
border, as near the edge of the field. All weedy spots should be carefully
examined and the weeds removed as soon as possible, as these are often
the places where the injury starts and spreads to the entire field.

It is hard for a person who has not seen a severe outbreak of web-
worms to realize that what appears to be but a few small worms is capable
of causing the loss of several dollars worth of beets. This fact has been
the cause of a great deal of the loss in the past.

If eggs or young worms are found it is time to get your spray
machine out, or your neighbor’s if you do not have one of your
own, and provide a supply of Paris green ready to apply as soon as
the eggs begin to hatch.

“As the young
worms feed entirely
on the under side
of the leaves for
several days after
they leave the eggs
and do not eat away
the upper surface, .
their presence is not
suspected, many
times, until they
are so far developed
that much damage
is done before they
can be controlled. :

Winkeim mrs
hatched the worms
are so small that
their capacity for
doing damage is
limited. As they
increase insize their
appetites become
almost insatiable. The rapidity with which they will completely strip a
beet field of leaves is almost beyond belief. Each worm will eat several
times its own weight of beet leaf every day. So rapid is their work that
although there is no apparent injury today, tomorrow or the next day
large spots in the field may be completely defoliated.

These spots very often occur in the center of the field, thus they are
overlooked unless it happens that the grower is cultivating or irrigating
at the time.

Fig. 10. Sugar Beets badly damaged by Webworms

Sugar Beet Webworm

Careful watch should be kept of the beets during the last half
of June and the latter part of July and early August. Examine
the under side of the beet leaves every day or so.

If young worms are present small pits will be eaten into the lower
surface of the leaves. In case such pits occur the little whitish-yellow
worms should be found not far away. If the worms are several days old
they will be greenish in color, appearing more like the full grown worm
(Fig. 6, Plate V, Page 19). At this age they will be found on both sides
of the leaves. The edges of the leaves will be eaten away, leaving them
ragged, or the entire leaf will be eaten with the exception of the heavy
veins. Ihe young leaves at the heart of the beet are usually the last
eaten.

Fig. 11. Field of Sugar Beets showing Work of the Sugar Beet Webworm. Bare
areas were weedy when eggs were laid. Balance of field was free from weeds.

Sometimes the worms will be concealed in webs spun over the leaf,
usually near its base. In case small, roundish, dark colored pellets
are seen on the leaves, a webworm or some other leaf-eating caterpillar
is present. The culprit should be located and his identity established.

METHODS OF CONTROL
Destruction of Weeds

The sugar beet webworm moth shows a particular liking for lamb’'s-
quarters and Russian thistle as plants on which to deposit its eggs. For
this reason if these weeds are abundant in a field of beets the crop is apt
to be damaged by webworms if the moths are at all numerous in the
vicinity. Volunteer alfalfa is also a menace to the crop.

The effect of allowing weeds to grow in a crop of beets is strikingly
illustrated by the cut on page 71 (Fig. 11).

Sugar Beet Webworm

At blocking and thinning time this field was quite free of weeds
except a Strip running entirely across the picture from right to left
and indicated by the bare spots at either side. The hand labor began
thinning before the webworms appeared, cleaning out the rows, including
the center portion of the weedy strip, but leaving the weeds in the sec-
tions at each end represented by the bare spots. They then moved to
another part of the field. In the meantime the webworm moths deposited
thousands of eggs on the weeds left.

When the labor returned to this part of the field both the weeds and
the beets among them were stripped of their leaves. The beets on that
part of the weedy strip that had been cleaned out earlier were not dam-
aged. The worms were just moving to the beets surrounding the weedy
patches, but a thorough application of Paris green applied according to
the instructions given later killed them and no further damage was done.

Furrow Trap

Weedy ground bordering a beet field is very often as bad as weeds in
the field. As soon as the worms have destroyed the weeds on which they
hatch, hunger compels them to search for food. At such times they
travel in armies, devouring whatever green thing comes in their way.
A furrow plowed about the field and a small stream of water kept running
in it will prevent the advancing worms from entering it. Newly cut
alfalfa thoroughly sprayed with Paris green placed in the path of the
oncoming army will destroy the worms by thousands.

Irrigation

In case both the moths and worms escape your observation and
you are not aware that your crop is being damaged until a large por-
tion of the leaves are eaten, the damage can sometimes be lessened by
applying water to the crop, thus stimulating the growth of beets. This
is especially true if the season is dry.

Poison

After the webworms have appeared in a field the only way to prevent
loss is to kill them by spraying with some poison. Paris green seems
best for this purpose. Being prepared for quick action as soon as
the proper time comes to begin the fight is extremely important.
Have all your forces mustered, all equipment in working order
and a good supply of Paris green on hand. When the time
comes strike and strike hard, working as rapidly as possible.

The most vulnerable period of the webworm’s life is during the first
few days after it leaves the egg. There are two reasons why this is the
best time to fight this enemy of the beet crop:

(1) If killed when young the worms will not have time to do much
damage, which means that they will not eat as much leaf before
dying as they would if they were older.

(2) It requires less poison to kill the young worms.

However, do not think that because less poison is needed to
kill the young worms that less should be used, for this is not the
case. Too diluted a poison will mean an unnecessary consumption of
leaves to bring about the death of the worms.

Sugar Beet Webworm

Paris green gives more satisfactory results and works more quickly
than any poison yet used for killing sugar beet webworms.

In using this poison apply not less than 4 pounds per acre.
(For the method of determining the amount of poison applied per acre,
see “Test Your Sprayer”’ on page 35).

A good type of traction sprayer, when properly adjusted, should
apply about 50 gallons of water to the acre. If too little water is used
the beet plants are apt to be burned; if too much is used much poison
is wasted.

Arsenate of lead acts very much more slowly than Paris green,
therefore seldom gives satisfactory results. This poison can be secured
in two forms, dry and as a paste containing 50% water. These are not
recommended except in case Paris green cannot be secured. When
used, not less
than 8 pounds
of the dry or 16
pounds of the
paste should be
applied per acre.
If the worms are
large, arsenate of
lead is not recom-
mended, as it acts
too slowly.

Best results are
only secured
when the poison
is applied with a
pressure sprayer
which will main-
tain a pressure of
80 pounds. Such
a machine pro-
duces the fine
mist-like spray
which is necessary
in order to place

the poison on the

under side of the Fig. 12. Result of Spraying—Left, Unsprayed;
leaves Right, Sprayed

The effect of spraying at the proper time, with the proper equipment
and with the proper amount of Paris green, is clearly shown in Figure
12, Page 73. The left of the cut shows the unsprayed portion of the
field and the right the sprayed portion.

See caution regarding the handling of Paris green, given on
page 37.

WHY GROWERS DO NOT SPRAY

Beet growers have innumerable excuses for not spraying, few of
which will stand the test.

Sugar Beet Webworm
Cost Too High ,

The cost is one of the reasons most frequently given for not spraying.
It costs not to exceed $3.00 an acre to apply Paris green with labor at
$3.00 per day and Paris green at 50 cents per pound. One thorough
spraying may save the grower $20.00 worth of beets. Even though a
moderate amount of damage is done in spite of the spraying, a saving of
one ton or $10.00 an acre can be made.

Spraying Interferes with Haying

Some growers will not spray because it is haying time when the
worms appear. Two men and one team can handle at least 15 acres a
day and should do 20 to 25 acres. Ifa grower has 25 acres he can spray
it in one day and save one or two tons of beets per acre or $250.00 to
$500.00 in a day by spending a day’s time and $75.00 for labor and poison.
This is not a bad interest on his investment.

Fear of Poisoning Stock

The fear of poisoning stock by feeding sprayed beet tops often keeps
a grower from spraying. As sprayed beet tops have been fed for many
years without killing stock, this excuse seems to have no foundation.
The fact that only a portion of the leaves present when the spraying is
done ever enter the feed lot, because they have died and fallen off, to-
gether with the fact that the poison is very easily washed off by showers,
would seem to reduce the question of poisoning stock to the very remotest
of possibilities—so remote in fact that it need not be considered at all.

Fear of Breaking Beet Leaves

The fear of breaking off some of the beet leaves with the spray
machines and team often keeps growers from spraying. The presence
of a very few worms in a field will reduce the leaf surface of a crop much
more than all the leaves that will be broken off during the spraying.
The fact that there is only a hole here and there in the leaves makes the
damage appear slight, but it does not take many such holes to equal the
area of a whole leaf, although the loss is not nearly so apparent as when
the whole leaf is broken off.

Hard to Realize Danger

It is often very hard for growers to realize that there is going to be
any damage. The worms are small and inconspicuous, which makes
their numbers appear insignificant as compared with the foliage of the
beets. If in doubt yourself and the Sugar Company representative
advises spraying, remember that this man has no interest in your spend-
ing more money on your crop unless by so doing you can produce a
better crop.

DESCRIPTION
The Egg
The eggs of the sugar beet webwormmoth (Fig. 5, Plate V, Page 19) are
about the size of a small pin-head, of a pearly white color when first laid,
becoming yellowish as the young worm develops within. When depos-
ited singly they appear as shown at “A” of the figure. They often

Sugar Beet Webworm

occur in groups of from two to five or six or even more, when inthey are
placed in rows, the eggs overlapping as shown at “B”’ and “

The Worm

Figure 3, A,’ Plate V, Page 19 shows a young webworm, natural
size, on a beet leaf. Figure 4, Plate V, Page 19 shows this same worm
much enlarged. As they grow larger these worms become darker,
appearing more like the full grown worms.

The full grown worm is shown enlarged in Figure 6, Plate V, Page
19. They are not very variable in color, although some individuals
are somewhat lighter than the figure. The most characteristic marking
is the dark line in the center of the back with the row of dark circles on
either side, each with a small bristle in the center. These circles are
grouped in pairs. When disturbed the worms jerk their bodies violently
from side to side, often throwing themselves from the leaf.

The Pupa and Cocoon

The cocoon (Fig. 8, Plate V, Page 19) is composed of silk which is
produced by the worm. These silken tubes, which are often 1} to 2
inches long, reach to the surface of the soil. When removed with the
earth adhering to them they appear like small earthen rods. The light
portion of the figure shows where the soil has been scraped away, re-
vealing the cocoon beneath.

The pupa (Fig. 9, Plate V, Page 19) is very active. When disturbed
it will twist and squirm about in very much the same manner as the worm.
At the tip are eight curved spines, four on either side, as shown in Figure
10, Plate V, Page 19.

The Moth

The moth (shown natural -size, Fig. 11, Plate V, Page 19), with
its delicate shades of gray, brown and tan, harmonizes so well with the
colors of the soil that when resting on the ground it is hard to distinguish
from its surroundings. When at rest its wings are folded over the body
so that the moth is triangular in form like the outline drawing to the left
of Figure 4, Plate VI, Page 21. When disturbed the moths fly up, mak-
ing short, jerky, zigzagging flights.

LIFE HISTORY

The first webworm moths appear during the latter part of April and
early May. About the first of June the moths of this first brood of the
season are most numerous.

After mating takes place each female deposits several hundred eggs
on sugar beets or on lamb’s-quarters, Russian thistle, alfalfa and other
plants growing in the field and along the ditch banks and fence rows.

At the end of from three to five days hundreds of hungry little worms
hatch and begin their work of destruction.

Feeding continues from two to three weeks, the amount eaten
daily increasing very rapidly until the worms are full grown. During
the last two or three days before they enter the soil to pupate, the amount
eaten is appalling.

Sugar Beet Webworm

When full grown the worms burrow into the soil and by much
wriggling and twisting about form a long cell extending from the surface
to a depth of 1} to 2 inches. When the cell is completed the worm pro-
ceeds to line it with silk, which it spins into a tough, leathery cocoon.

After the cocoon is completed the worm begins to shorten and be-
comes very much wrinkled. All this time the pupal case has been form-
ing just under the worm's skin, which breaks and the pupa wriggles its
way out.

ho
Sates

YS + re

Fig. 13. A Portion of the Compound Hye of a Tiger-beetle, highly
magnified. (See page 131)

While in the pupal stage legs, wings, antennae and a long proboscis
with which the moth will suck the nectar from the alfalfa and other
flowers upon which it feeds, two compound eyes, each composed of many
smaller ones (See Fig. 13), and a covering of feather-like scales, are
formed. After all this is completed the moth comes forth.

These moths from the first brood of worms mate and the females lay
the eggs for the next brood. These worms pass through the same changes
as the first until they enter the soil. All make cells like those of the first
brood worms and line them with silk. Only a small portion of them
pupate in the fall, however. The greater number remain unchanged in
their cells until the following spring. With the coming of warm weather
they change to the pupa and after ten days or two weeks, to moths, which
are the first moths to appear in the spring.

Sugar Beet Webworm

The worms which pupate in the fall become moths in about ten or
twelve days. After breaking out of the silken cocoons these moths mate
and the females lay eggs for a third brood. When full grown, the worms
of this brood enter the ground, where they remain in their cocoons, as
worms, until spring.

How wisely Nature has provided for the carrying of the beet web-
worm over the winter! For fear that an early winter overtake the last
brood in the fall and they perish, a part of the second brood is set aside
as a sort of sinking fund against such a calamity. There is a considerable
overlapping of the broods, so that the eggs and several sizes of worms may
be present at one time.

NATURAL ENEMIES
Ichneumon-flies

The dusky winged parasite ° (Fig. 7, Plate V, Page 19) is one of the
most common enemies of the sugar beet webworm. The larva of this
parasite develops within the webworm, but does not kill it until after it
has entered the ground and spun its cocoon. ‘Then instead of the moth,
the parasite emerges from the cocoon.

This parasite has four dusky wings. Near the center of each of the
forward pair is a partially clear area. The body is dark reddish or bay
and the legs have dark bands which give them the appearance of being
ringed.

Braconids

The little wasp-like parasite * (Fig. 14, Plate V, Page 19), which is a
ee frequently emerges from a cocoon instead of the webworm
moth.

Tachina-flies

The Tachina-fly ** (Fig. 13, Plate V, Page 19) fastens its eggs onto
the webworm and when the maggots hatch they burrow into it. At first
the webworm appears to be little disturbed by the maggots, but as the
latter increase in size their feeding weakens the worm, which finally dies.
When fully grown, the maggots change to pupae inside the puparium
(Fig. 12, Plate V, Page 19). The adult fly breaks open the end of the
puparium, as shown in the figure, and escapes.

Solitary Wasp

One of the enemies of the sugar beet webworm belongs to a group of
wasps known as solitary wasps. (See page 135.)

This wasp ® (Fig. 15, Plate VI, Page 21) places its eggs in
tunnels, one of which is shown in cross section in Figure 14, Page 78.
These tunnels are dug in the soil about the borders of fields.

The mouth of the tunnel is always built up a half inch or so above the
surface of the soil. When the nest is completed several webworms are
caught and after being stung, which paralyzes them, they are placed at
the bottom of the tunnel. After a single egg is deposited among the
worms a wall is built so as to make a small cell at the lower end of the
tunnel. The chimney-like mouth is next filled with mud. The larva
which hatches from the egg feeds upon the webworms until ready to
change to the pupa. This change takes place in the burrow, from which
the adult wasp escapes by digging its way out.

(3-9_13-16, See explanation of ~ Reference Figures,” page 2

Sugar Beet Webworm True Army Worm

Fig. 14. Cross Section through Burrow of the Solitary Wasp

Robber-flies

There is a family of flies commonly known as robber-flies (Fig. 12,
Plate VI, Page 21), the members of which prey upon other flies, as well
as upon bees and their near relatives, small flying beetles and moths.
These flies will often be noticed resting on the ground or some object
which furnishes a clear view of the surroundings, patiently waiting for
some victim to appear. Their heads are joined to the body by a freely
moving neck so that they can be moved at will. While waiting for some
ill-fated fly to appear the head is moved about following the flight of
passing insects in really human fashion.

These flies capture their victims by pouncing upon them in true bird
of prey fashion. Holding the victim with their long legs, the beak is
thrust into its body and the contents sucked up. One of these flies was
observed to capture and feed upon a webworm moth.

(b) TRUE ARMY WORM
(Figs. 21, 22, 24 and 25, Plate I, Page 11)

The true army worm is one of those insects which, while always
present in small numbers in our fields, commonly escapes, unobserved,
because of its seclusive habits. However, when for any reason the natural
checks become abnormally scarce or favorable weather conditions prevail
in connection with a plentiful food supply, it multiplies very rapidly,
overrunning our fields in vast hordes, often traveling in such large num-
bers that the very earth seems to move. All follow the same general
direction, destroying crops as they go, and leaving nothing but the
riddled remains of what a few days before gave promise of a bountiful
harvest. : a

True Army Worm

NATURE OF INJURY

In the case of leaf-eating insects the damage done is usually pro-
portionate to the amount of leaf surface destroyed. However, the true
army worm is an exception to this rule. When feeding, these worms
have the habit of climbing grass and grain stalks and gnawing off the heads.
When grain is in the shock, especially if harvested a little green, the heads
are often gnawed off also. For this reason the damage greatly exceeds
that of most insects of this class in that the army worm destroys much
more than it actually eats.

Sugar beets are seldom damaged except where they lie in the path of
the moving worms or next to infested small grain or grass crops. When
attacking this crop the worms overrun the leaves, at the same time eating
irregular areas out of their margins. In case of severe injury all of the
leaves with the exception of the coarse stems may be destroyed. The
roots are seldom, if ever, eaten. The army worm usually appears so late
in the season that few beets are killed.

METHODS OF CONTROL
Spraying

When the nature of the crop attacked is such that poison can be
applied in the form of a spray, without danger of poisoning either live
stock or human beings that use the crop as a food, the army worm can be
effectively controlled by spraying with Paris green or lead arsenate.
The same proportions of poison and water should be used as in the control
of the beet webworm; i. e., 4 pounds of Paris green or 16 pounds of arsenate
of lead paste to the amount of water used in spraying an acre. Remem-
ber that the sprayer should be adjusted so as not to apply more than 100
to 125 gallons per acre.

Poisoned Bait

When the food supply has become exhausted and the worms have
started across country in search of new pasturage, the poisoned bait
recommended in the control of cutworms will prove most effective. (See
pages 39 and 40.) This should be scattered in the path of the worms.
Several strips of a rod or so wide with about the same distance between
them will give the best results. As the worms are most active during
the latter part of the afternoon this is the best time to put out the bait;
peer: if the army is on the move earlier, the poison should be scattered
earlier.

Furrow Trap

This consists of a furrow plowed across the path of the advancing
worms. The soil should be thrown toward the worms so as to leave the
perpendicular side of the furrow opposite them.. Post holes should be
bored in the bottom of the furrow every few feet. As the worms enter
the furrow they will attempt to climb up the perpendicular side. Many
failing in this will wander up and down the furrow in search of a place
where they can climb out. In this way many will fall into the post holes.
The worms thus trapped can be killed by crushing them with a piece of
wood or by pouring a small quantity of kerosene into each hole. Some-
times the post holes are not used. In their stead a small log or heavy

True Army Worm

post is hauled up and down the furrow to crush the worms. The furrow
in connection with the poisoned bait makes a very effective combination.

DESCRIPTION
The Eg¢

The eggs have a smooth shining surface. When first laid they are
of a pearly white. As the young worm develops the color changes to a
creamy flesh color, gradually becoming darker until just before the young
worm emerges, when it is a dull gray.

The moths appear to prefer the dense growth of grass or grain which
commonly grows on old stack bottoms or about manure piles or the
droppings of animals in pastures, as places to deposit their eggs. Injury
to small grain is often first observed where this heavy growth occurs
on old stacking grounds.

The eggs often occur in clusters of a hundred or more. Usually
they are deposited in the sheath of grass and grain leaves, sometimes
between two leaves which happen to be fastened together. Egg laying
takes place during the night. A single female moth has been known to
lay 254 eggs, and as many as 800 developed and undeveloped eggs have
been taken from the abdomen of one moth.*

The Worm

In from eight to ten days after the eggs are laid, the young worms
appear. As they emerge from the egg they are whitish with brown heads.
The first act of the newly hatched worm is to eat the shell of the egg from
which it has just escaped.

During the course of their development the worms shed their skins
several times. As soon as the worm has cast off its old coat it proceeds
to devour it as if attempting to cover up its trail.

The full grown worms (Figs. 21 and 22, Plate I, Page 11) are variable
in color, some being considerably lighter than the figures. The figures
are so lifelike that a description of the coloring is not necessary. When
disturbed the worms curl up as shown in Figure 21. This is not char-
acteristic of the army worms alone, however, as many caterpillars, espec-
ially cutworms, have the same habit. When fully grown the army worms
enter the soil, where they form a cell in the same way as the cutworms.
In this cell the worm spins a thin, silken cocoon within which it changes
to the pupa. :

The Pupa

The pupa (Fig. 24, Plate I, Page 11) of the army worm does not
differ greatly from that of the cutworms already mentioned. At first it
is a light creamy yellow. When fully colored it is of a rich mahogany
brown. At the tip there are four spine-like appendages as shown in the
figure. After spending-from two to three weeks in the pupal stage the
moths appear.

The Moth

The moth (Fig. 25, Plate I, Page 11) is a night flyer and is seldom
seen on the wing during the day unless the weather is cloudy and damp.

*Davis and Satterthwait, “ Life History Studies of Cirphis unipuncta, the True Army Worm,” Journal
of Agricultural Research, Vol. VI, No. 21 (1916).

True Army Worm Alfalfa Looper

The most characteristic marking is the white spot near the center of each
fore wing. The last part of the army worm’s Latin name, © unipuncta,
is derived from this spot and means one point.

LIFE HISTORY

So far as known, the army worm passes the winter, in the north-
ern half of the United States, as a partially grown worm or larva.
The first moths appear during May or June, depending upon the season
and the locality. The cooler the season and the farther north we go the
later they appear.

The eggs are laid soon after the moths emerge, and the young worms
appear during June. These feed for about three weeks and then change
to pupae, in which form they remain from eight to eleven or twelve days,
when the adult moths come forth.

The second brood is in the egg stage about the middle of July, in the
worm stage during the latter part of July and early August, in the pupal
stage during the latter part of August, and the moths issue between the
the last of August and the 8th or 10th of September.

The third brood of worms hatches during the latter part of Septem-
ber and early October. These worms spend ‘the winter as partially
grown larvae and complete their development the next April.

In the southern part of the country a fourth generation may occur.

NATURAL ENEMIES
Parasitic Flies

Several species of parasitic flies destroy the army worm. Two
species, ‘“‘Archytus apicifere Walk’ and a “‘Winthemia’* species (near
militaris Walsh) have been bred from parasitized army worms taken
in Boulder County, Colorado.

Birds

Birds, especially blackbirds, meadow larks and other ground feeding
species, render valuable service in destroying these worms.

Ground Beetles

Ground beetles and their larvae also devour large numbers of army
worms.

The first authentic record of this insect as a crop pest** states that
during June, 1895, considerable damage was done to alfalfa near Grand
Junction, Colorado, by the caterpillars. Again in 1914 reports of injury
by this insect came from the same locality. The same year the looper
also appeared in large numbers in the Yellowstone Valley in Montana
and in adjoining territories, where considerable damage was done to both
alfalfa and sugar beets. The latter were damaged only in those instances
where the worms migrated from alfalfa fields or the sweet clover growing
on waste land.

*Determined by C. H. T Townsend.

**J. A. Hyslop, “ The Alfalfa Looper,” Bulletin No. 95, Part VII, Bureau of Entomology. U. S.
Department of Agriculture (1912).

Alfalfa Looper

NATURE OF INJURY _

The injury to sugar beets is similar to that caused by other leaf-
eating caterpillars. “The destruction of the leaves reduces the yield and
sugar content of the crop.

Both the leaves and blossoms of alfalfa are eaten. This reduces the
yield and quality of hay. The destruction of the blossoms reduces the
yield of seed where the crop is grown for seed production.

METHODS OF CONTROL

As this insect seldom if ever attacks sugar beets until its favorite
food plants (alfalfa and sweet clover) are exhausted, such attacks can be
anticipated and preventive measures employed to protect the crop.

Furrow Trap

In case sugar beets adjoin infested alfalfa or waste land overgrown
with sweet clover the furrow trap recommended for the control of the true
army worm (page 79) can be used with good results. The furrow should
be thrown away from the beets so as to leave the perpendicular side next
to them. If water is available a small stream in the furrow will add to
its effectiveness.

Poisons

Where the loopers are feeding on alfalfa or sweet clover growing on
ditch banks or fence rows about beet fields these plants should be sprayed
with Paris green or arsenate of lead, using 2 to 3 pounds of the former or
8 to 12 pounds of the latter if the paste is used, or 4 to 6 pounds of the dry
form, to 50 gallons of water.

If the caterpillars have entered a beet field, spray the beets, using
the proportions of poison and water given above.

Bunches of freshly cut green alfalfa or sweet clover, sprayed with
Paris green and placed in the furrow, where the furrow trap is used, will
kill many of the loopers.

Mowing

Where alfalfa is being damaged it should be mowed at once. The
longer it stands the poorer the quality will be. After the hay is removed
the stubble should be sprayed to destroy the worms and protect the new
growth.

If strips of alfalfa are left uncut at intervals through the field the
loopers will congregate on these and can then be killed by spraying the
standing alfalfa. When the worms have been destroyed the alfalfa on
the strips can be removed. ‘This hay should not be fed unless heavy
rains have washed off the poison.

Close watch should be kept of the worms after the infested hay is
cut to prevent their migrating to adjoining crops.

DESCRIPTION
The Egg

The eggs are pale yellow, hemispherical in shape, rounded at the base,
the apex with a rounded depression, and are finely creased vertically.*

*J. A. Hyslop, “The Alfalfa Looper,” Bulletin No. 95, Part VII, Bureau of Entomology, U. S.
Department of Agriculture (1912).

Alfalfa Looper

The eggs are deposited on the food plants. Moths have been ob-
served in the act of laying at three o'clock in the afternoon.*

The Caterpillar

These caterpillars differ from all others discussed in this Bulletin
in having but three prolegs on each side of the posterior half of the body.
By comparing Figure | and Figure 5, Plate VI, Page 21, this difference is
made more apparent. It will be noticed that Figure | has four legs just
back of the center, and one at the tip of the body, and that Figure 5, which
represents a full grown alfalfa looper, has but three including the one at
the tip.

The alfalfa loopers vary greatly in color.

The darker parts of different individuals range from a dark olive
brown to pale greenish brown. The figure represents one of the lighter

type.
The Cocoon

The cocoon (Fig. 6, Plate VI, Page 21) is made of several leaves of
the host plant held together by loosely woven silk threads. Sometimes
the cocoons are constructed among dead leaves and trash on the ground.

The Pupa
After the worm has completed its cocoon it changes to the pupa
within it. The pupa (Fig. 7, Plate VI, Page 21) is very similar to those
of the cutworms and army worms.

The Moth

The adult (Fig. 8, Plate VI, Page 21) is one of our most beautiful
moths. The figure is so true to life that no description is necessary.
The silvery spot near the center of the fore wing is characteristic of this
and related moths.

LIFE HISTORY

This insect probably passes the winter in hibernation in the pupal
stage. During the latter part of May and early June the eggs for the first
brood of worms of the season are laid.

The length of the egg stage is not definitely known. The worms
feed for about two weeks, at the end of which time the cocoon is made
and the change to the pupal stage takes place. This lasts about ten to
twenty days during ordinary summer weather.

The first adults of the second brood appear during late June and early
July. There are two and possibly three generations each season.

NATURAL ENEMIES

The alfalfa looper appears to be a favorite host of many parasites.
The Ichneumon-fly 8, shown in Figures 9 and 10, Plate VI, Page 21, was
reared from alfalfa loopers taken at Edgar, Montana, and several other
species have been reared from alfalfa loopers by Mr. Hyslop.

Many of the caterpillars succumb to a bacterial disease. The in-
fected worms become dark in color soon after dying. The dead worms

*Mr. Koebels, Bureau of Entomology Notes, No. 95-K.
(8) See explanation of “Reference Figures,’ page 2.

Alfalfa Looper Alfalfa Webworm

hang limp from the host plant at first, but finally the body becomes so
decayed that it drops to the ground.

(d) ALFALFA WEBWORM*
(Figs. 1, 2, 3 and 4, Plate VI, Page 21)

During the summer of 1914 the alfalfa webworm ! appeared in
large numbers in Northern Colorado, where it did considerable damage
to first cutting alfalfa. While they appear to prefer this crop and sweet
clover, the worms caused some anxiety among sugar beet growers by
feeding upon the leaves of sugar beets.

NATURE OF INJURY

When attacking alfalfa the worms spin masses of whitish web at the
tips of the plants, inclosing the new, tender leaves and blossoms. This
web furnishes protection for the worms while they feed upon the inclosed
parts.

Injury to sugar beets is similar to that caused by the sugar beet web-
worm. Some of the leaves will be found partially covered by a web which
terminates in a long tube extending to the ground, the lower end being
among the clods on the surface. When but few worms are present there
is usually only one to a plant.

METHODS OF CONTROL
Poison

This worm can be controlled on sugar beets by spraying with any
arsenical poison. The same amounts of poison should be used as for the
control of the sugar beet webworm (pages 72 and 73), and should be
applied in the same way.

Mowing ;
In case alfalfa is being damaged it should be cut at once, cured and
put up to prevent loss. After removing the crop the stubble can be
sprayed. (See “Mowing,” page 82.)

Irrigation

Irrigating after the worms have entered the ground to pupate will
seal them in, preventing many moths from emerging when mature.

DESCRIPTION
The Worm

Although closely related to the sugar beet webworm, this worm
(Fig. 1, Plate VI, Page 21) is easily distinguished from it by its coloring.
The central portion of the back is occupied by a light stripe tinged with
flesh color. On either side of this there is a dark stripe about the same
width. Along the upper and lower margins of these dark stripes there
are several dark circular spots, each bearing a hair-like bristle. With
the exception of those segments next to the head and at the tip of the
body, each segment has three of these spots, two on the upper border of

*This is a local name applied to this insect in Northern Colorado. This insect should not be con-

fused with “ Loxostege similaris Guen,”’ which is also called the alfalfa webworm. (See Bulletin 109, Okla-
homa Agricultural Experiment Station, February, 1916).

(4) See explanation of “Reference Figures,’ page 2.

Alfalfa Webworm

the dark stripe and one on the lower. Just below the dark stripe is an-
other light, more or less flesh-colored one, and below this the body is
dusky, but not so dark as the other dark portions. There are several
dark circles within the dusky portion, each bearing a bristle. The lateral
portions of the first segment back of the head are dark. The head is
mottled with dark brown on a lighter ground color.

The worms are very active. If their webbed retreats on alfalfa are dis-
_ turbed they throw themselves to the ground or run rapidly down the

stems.

When on sugar beets they will be found concealed at the end of the
long, silken tube already mentioned, among the clods near the crown of
the plant. If the soil is disturbed the worms run rapidly to the web
among the leaves, and if disturbed here they descend to the end of the
tube again just as rapidly. They appear to travel backward as freely as
forward.

The Pupa

When fully grown the worms enter the soil and spin a cocoon very
similar to that of the sugar beet webworm, but more loosely made, in
which they change to the pupa (Fig. 2, Plate VI, Page 21). The pupa is
very much like that of the beet webworm, but can be readily distinguished
from it by the eight spatulate (spoon-shaped) appendages at the tip (Fig.
3, Plate VI, Page 21), those of the sugar beet webworm being curved and
pointed.

The Moth

In warm weather the moths appear in about six or eight days after
the worms change to pupae. By comparing the figure of this moth (Fig.
4, Plate VI, Page 21) with that of the sugar beet webworm (Fig. 11,
Plate V, Page 19), the differences are clearly brought out. It will be
noticed that the under wings of the alfalfa webworm are much darker
than those of the sugar beet webworm moth and that the markings of the
upper or fore wings are darker as well as different inform. Flying in the
field the two are very hard to distinguish from each other.

LIFE HISTORY

So far as known to the writer, there are no published accounts of the
life history of this insect. In general it is probably quite similar to that
of the sugar beet webworm. The injury to alfalfa referred to above
occurred during the last of June. The moths of this brood appeared July
14th. During August another brood of worms appeared. This second
brood was not so numerous and did less damage than the first. In all
probability, in the latitude of Denver, the winter is passed in the larval
or pupal stage.

NATURAL ENEMIES

An undescribed Tachina-fly, ® (Fig. 11, Plate VI, Page 21), was
reared from caged worms.

Birds and poultry no doubt do much to hold this insect in check.

(75) See explanation of “Reference Figures,” page 2.

Yellow-bear Caterpillar

(e) YELLOW-BEAR CATERPILLAR
(Figs. 15 and 16, Plate V, Page 19)

The yellow-bear caterpillar is always in evidence, in small numbers,
on Russian thistle, lamb’s-quarters and other weeds along the fence
rows, ditch banks and roadsides. Asarule they are not numerous enough
to cause noticeable damage to crops. Occasionally, however, they become
so numerous that the wild food plants are not sufficient for their support.
At such times the caterpillars attack whatever growing crop happens to
be nearest at hand. Such an outbreak occurred during August and Sep-
tember, 1909, in the Arkansas Valley in Southern Colorado.*

NATURE OF INJURY

When young the worms eat only the surface of the leaves but as they
become older and larger the margins of the leaves are eaten away and holes
are eaten into them. When very numerous, crops are completely defoli-
ated by these caterpillars, or in the case of sugar beets the stems, midribs
and young heart leaves only are left untouched. Severe attacks on sugar
beets result in a lowering of the yield and sugar content of the crop.

The yellow-bear is one of the most genéral feeders among the whole
list of crop pests. The following list of plants injured is given by Mr.
Marsh in the bulletin already referred to:

Sugar beet Radish Squash
Stock beet Celery Watermelon
Table beet Carrot Cantaloupe
Rhubarb Parsnip Sweet potato
Cabbage Egg plant Corn
Cauliflower Potato Lima bean
Turnip Pumpkin String bean
Asparagus Dahlia Amaranthus
Pea Cherry Chenopodium
Peanut Gooseberry Helianthus
Alfalfa Blackberry Solanum rostratum
Hollyhock Raspberry Verbesina
Morning-glory Currant Ambrosia
Canna Grape Russian thistle
Hyacinth Dock (Rumex) Spanish needle

METHODS OF CONTROL

Poison

In his work in the Arkansas Valley of Colorado, Mr. Marsh exper-
imented with both Paris green and arsenate of lead. It was found that
arsenate of lead, even where applied in quantities as high as 8 pounds to
100 gallons of water, was of little value in the control of the yellow-bear
caterpillar. Paris green used at the rate of 10 pounds to 100 gallons of
water to which 10 pounds of lime was added to prevent injuring the
leaves killed practically all caterpillars in three days.

From the results of this work it appears that this worm is very resist-
ant to arsenical poisoning, the ordinary amounts being practically value-
less in its control.

*H. O. Marsh, “Biologic and Economic Notes on the Yellow-bear Caterpillar,’ Bulletin No. 82,
Part V, Bureau of Entomology, U. S. Department of Agriculture (1910).

Yellow-bear Caterpillar Zebra Caterpillar

DESCRIPTION
The Egg

The eggs are laid in clusters on some green plant. In the Arkansas
Valley Mr. Marsh found large numbers of eggs on rhubarb, which appears
to be a favorite food plant.

The Caterpillar

Unlike the cutworms and the other caterpillars so far considered in
this Bulletin, the yellow-bear is completely covered with a coat of tawny
hair. This varies from a reddish brown in the darker individuals to a light
yellow or straw color in the lighter ones. Figure 15, Plate V, Page 19
represents one of the lighter type. The body of the caterpillar is most
often pale yellow or straw color with a darker stripe running lengthwise
on either side.

The Pupa

The pupa is more robust than that of the cutworms already men-
tioned. Instead of entering the ground to pupate the worms seek some
secluded place such as underneath boards and other objects lying on the
ground or among the dead leaves and trash about the borders of fields
and on ditch banks. Here the caterpillar forms a loose cocoon composed
almost entirely of its own hairs held together by threads of silk, within
which it changes to the pupa and later to the moth.

The Moth

The adult yellow-bear (Fig. 16, Plate V, Page 19), sometimes known
as the Virginian tiger-moth, is one of our most delicate night fliers. Pure
white with dark spots on the wings and three rows of black dots on the
body alternating with two yellow stripes, this moth presents a striking
contrast to the dusky winged cutworm moths.

LIFE HISTORY

This moth spends the winter in the pupal stage concealed under
trash along fence rows and ditch banks and on other waste ground. The
moths appear in early summer to deposit the eggs for the first brood of
worms, which become mature about the last of July. The second brood
appears during August and becomes fully grown about the first week of
September. These worms pupate after spinning the loose cocoon already
mentioned and remain in this form until the next spring.

NATURAL ENEMIES

The natural enemies of the yellow-bear appear to be peculiarly few.
Because of their covering of hair few birds feed upon them. Certain
Tachina-flies destroy a few worms and in some localities many die of a
fungous disease.*

(@) ZEBRA CATERPILLAR
(Fig. 11, Plate III, Page 15)

This is one of our most striking caterpillars. When resting on a
beet with its bright colors contrasted with the dark green of the leaves
it is almost a thing of beauty.

*Botrytis bassiana Bals.

Zebra Caterpillar ; Leaf-eating Beetles

NATURE OF INJURY

The zebra caterpillar bears the distinction of being the first insect
reported as damaging beets in the United States.* While it seems to
prefer vegetable crops, especially beets, and cabbage, turnips, and other
cruciferous plants in general, yet it feeds upon field crops and even the
leaves of trees and shrubs.

METHODS OF CONTROL

Dr. Chittenden* states that this insect yields readily to sprays of
arsenicals. Paris green or arsenate of lead, the former at the rate of 2 to
3 pounds and the latter at 4 to 6 pounds dry or 8 to 12 pounds of the
paste, to each 100 gallons of water, will give satisfactory results.

DESCRIPTION
The Egg

The eggs are deposited in clusters of from several to as many as a
hundred or more, usually on the under side of the leaves of the food plants.

The Caterpillar

At first the worms are whitish in color with dark heads and several
dark spots scattered over the:-body. While small they feed in compact
groups, but after several days the skin is shed and the caterpillars take on
the colors of the adult worm (Fig. 11, Plate III, Page 15) and gradually
become scattered. When disturbed the worms coil up and fall to the
ground.

The Moth

The moth is about the size of the adult western army cutworm (Fig.
3, Plate 1, Page 11). The fore wings are a chestnut brown shaded with
purplish brown. The hind wings are whitish with pale brown margins.

LIFE HISTORY

The zebra caterpillar passes the winter in the pupal stage in the
ground. The first moths appear in May and June. In moderate tem-
peratures the eggs hatch in about six days. The worms feed four or five
weeks and then change to pupae, in which form they remain for about
sixty days. The moths of the second brood appear in late August or
September. The second brood of worms feeds during the fall, the change
from worm to pupa taking place before winter sets in.

NATURAL ENEMIES

This caterpillar appears to be especially attractive to the various
parasitic insects infesting caterpillars in general. Many are killed by
fungous diseases, while birds no doubt destroy them in large numbers.

2. LEAF-EATING BEETLES

There is a family of variously colored beetles of small or moderate
size, the members of which are called “ leaf-beetles’’ because they feed
upon the leaves of plants in both the adult and larval stages, with a few

*Dr. F. H. Chittenden, “A Brief Account of the Principal Insect Enemies of the Sugar Beet,”’ Bulle-
tin No. 43, Division of Entomology, U. S. Department of Agriculture (1903).

Leaf-eating Beetles Larger Sugar Beet Leaf-beetle or Alkali-beetle

exceptions where the larvae are root feeders. The Colorado potato-beetle
is the best known representative of this family.

Several leaf-beetles feed upon sugar beets and under certain con-
ditions do considerable damage to the crop. The principal species of
this family, together with other leaf-eating beetles attacking sugar beets
in the Great Plains area, are discussed in the following pages.

(a) LARGER SUGAR BEET LEAF-BEETLE OR ALKALI-BEETLE
(Figs. 1 to 5, Plate VII, Page 23)

In Northern Colorado this beetle is known as the “alkali-beetle™
or ~ alkali-bug’’, from the fact that it breeds most freely on the weeds
growing on low, damp ground where the alkali is brought to the surface
by seepage. In some other parts of its range it is known as the “French

bug”’.
NATURE OF INJURY

Both the larvae and the adults damage sugar beets. Injury usually
occurs on the border of fields next to waste land which is damp and con-
tains an excessive amount of alkali. The adults are very active on the
wing and often appear in swarms in the center of fields or at considerable
distances from low wet ground. When few in number their work appears
very similar to that of the flea-beetles only that the holes in the leaves
are larger. (See Fig. 1, Plate IV, Page 17). In severe cases nothing but
a-network composed of the larger veins of the leaves is left and the leaf
becomes brown and shriveled.

METHODS OF CONTROL
Spraying or Burning Weeds

When beets are planted near low, damp ground the weeds on this
waste land should be watched closely in early summer. If alkali-beetles
and their larvae appear in numbers the weeds should be sprayed with
Paris green or straw should be scattered among them and burned.

The destruction of the beetles and larvae at this time will prevent
their migrating into the beet fields and will also reduce the number of
eggs laid later.

Spraying Crop

In case the beetles and larvae have already begun to damage beets,
Paris green should be applied as a spray, using 4 pounds to 100 gallons of
water. Many times it happens that only a small portion of the field is
being damaged, making it inconvenient to use a team and power sprayer.
In such case a knapsack sprayer (See page 36) can be used to advantage.

Paris Green Applied Dry

Good results have followed a dry application of Paris green. If to
be applied in this way mix at the rate of 1 pound of the poison to 10
pounds of low grade flour or finely pulverized air-slaked lime. This
mixture can be dusted over the beets by using a sack made of coarse cloth
or a tin shaker with the bottom perforated with rather small holes. Best
results are secured if the dusting is done early in the morning when the

Larger Sugar Beet Leaf-beetle or Alkali-beetle Western Beet Leaf-beetle

dew is still on the beets. Never attempt to apply the dry poison when
the wind is blowing. Always spray or dust the beets some distance be-
yond where the insects are feeding.

DESCRIPTION
The Egg

The brownish gray eggs (Fig. 3 enlarged and Fig. 4 about natural
size, Plate VII, Page 23) are usually placed in clusters on the under side
of the leaves of the food plants. Russian thistle and saltbush, both of
which abound on alkali ground, are favorite plants on which to deposit
the eggs.

The Larva

The young alkali-bug is sluggish in its movements. In color it is a
dirty gray at first, becoming darker with age. When fully grown it ap-
pears as in Figure 1, Plate VII, Page 23. At this time the ground color
is an olive brown. The entire body is covered with blunt tubercles
each bearing several short, stiff hairs. These tubercles are yellowish in
color, giving the larva a spotted appearance.

The Pupa

The pupa (Fig. 2, Plate VII, Page 23) is what is known as a © free
pupa’ because the legs and other parts of the insect are encased separ-
ately, in contrast with the pupae of the cutworms and other related insects.
The pupal stage is passed in a small oval cell in the soil. At first the pupa
is a uniform yellowish brown as shown in the figure, but just before the
adult emerges the color becomes darker.

The Beetle

The adult alkali-beetle (Fig. 5, Plate VII, Page 23) often occurs in
swarms. In color it varies from a light brownish yellow to almost black.
Sometimes the wing covers are quite distinctly striped, the dark color
being concentrated near the center of each. The figure represents an
intermediate color type:

(b) WESTERN BEET LEAF-BEETLE
(Fig. 6, Plate VII, Page 23)

As the name indicates, this beetle is a Western insect. It is more
common on the Pacific coast than in the Rocky Mountain regions. It
first attracted attention in the years 1900 and 1901 in Oregon.*

This beetle (Fig. 6, Plate VII, Page 23) is very similar to the “larger
sugar beet leaf-beetle’’ in coloring but is only slightly more than one-half
aslarge. Its habits appear to be similar to those of the preceding species.

NATURE OF INJURY

The only cases known to the writer where this beetle has injured
sugar beets have been near low, damp ground, the beetles alone damaging
the crop. The early stages have not been observed by the writer.

*Dr. F. H. Chittenden, “A Brief Account of the Principal Insect Fonemics of the Sugar Beet,”’ Bulle-
tin No. 43, Division of Entomology. U. S. Department of Agriculture (1903).

Western Beet Lea f-beetle Flea-beetles

METHODS OF CONTROL

The same control measures employed against the preceding species
should be used in case this insect attacks sugar beets in sufficient num-
bers to damage the crop.

The individuals of one group of leaf-beetles are characterized by hav-
ing the joint of the hind legs next to the body much enlarged. This
enables them to jump long distances. The habit these beetles have of
making sudden leaps whenever disturbed suggested the popular name
“ flea-beetle which is applied to the members of this group.

Most flea-beetles are small, but some species are of moderate size.
The color is variable, some species being dull black or brown; others are
shining black, often with a metallic sheen; some are deep shining blue;
while in others parts of the insect are red or yellow or striped.

These active little insects are familiar objects to every person en-
gaged in either gardening or farming, appearing in swarms on crops dur-
ing spring and early summer. Several species attack sugar beets, often
threatening serious damage.

NATURE OF INJURY

The work of flea-beetles is quite characteristic. The leaves of the
plants attacked are eaten full of small holes popularly known as “shot
holes” (Fig. 1, Plate IV, Page 17). The leaves of the seedling beets are
sometimes completely destroyed. In severe cases the plants may be
killed. Usually, however, plants which appear dead will put forth new
leaves in the course of a week or ten days.

METHODS OF CONTROL
Destroy Weeds

Flea-beetles, in both the adult and larval stages, feed upon many of
our common weeds. Clean culture, especially keeping down all weeds
along fence rows and ditch banks, will effectively check the multiplica-
tion of this pest. Poverty-weed is a favorite food plant of the banded
flea-beetle. (See page 92).

Spraying

Beets are usually attacked while still quite small. For this reason
spraying is seldom advisable, since the plants will often be stripped of
their leaves before the beetles have eaten enough poison to kill them.

Scattering

The beetles are easily disturbed and the swarms readily scattered
either by the hand labor while thinning or by the cultivator in cultivating.
In case the beetles appear in a field before the beets are thinned, it is al- ,
ways advisable to disperse them before this work is done. This can be
accomplished by cultivating the field. If pieces of rope or strips of can-
vas are fastened to the frame of the cultivator so as to drag on the ground
the insects will be more completely scattered.

Flea-beetles Banded Flea-beetle

Irrigation

The beetles dislike damp ground. Advantage can be taken of this
fact, especially in dry years. If the beets are irrigated the insects will
usually leave the field. The irrigation will stimulate the young beets so
that they will outgrow the damage more quickly and completely. In
case irrigation is resorted to great care should be exercised to prevent
flooding the field as flooding young beets is injurious to them.

Poison

In cases where the use of poison is advisable Paris green mixed as
recommended in the control of the alkali-bug (page 89) should be used.
If the area to be treated is not too large, Paris green applied dry, mixed
with ten parts of low grade flour, will give very satisfactory results,
especially if the plants are small.

According to Dr. Chittenden,* Paris green mixed with Bordeaux
mixture gives better results than the Paris green and water spray. Asa
rule spraying the upper surface is sufficient, but for some species attack-
ing truck crops the under surface must also be sprayed.

(c-1) BANDED FLEA-BEETLE
(Fig. 2, Plate IV, Page 17)

About the time early beets are ready to block and thin, swarms of
banded flea-beetles (Fig. 2, Plate IV, Page 17) often appear in the fields.
Seldom is the whole field affected at one time, however. The beetles
being very active, the same swarm may appear in several places in a field
within a short time, thus causing considerable damage. Poverty-weed
is a favorite food plant of this beetle. LDamage to beets is most apt to
occur in fields where this weed is growing.

DESCRIPTION
The Egg

Dr. Chittenden, in the bulletin already referred to,* states that the
eggs are laid in June and July: They are about one-fourteenth of an inch
long, elliptical in form and of a light buff-yellow color.

The Larva

The larva is a slender, whitish grub. The body is narrowest at the
head, gradually widening toward the opposite end. The extreme tip of
the body tapers abruptly, ending in a prolonged process which bears
several stiff hairs. In this stage the flea-beetles feed upon the roots of
some crops and weeds.

The Adult

The adult beetle (Fig. 2, Plate 1V, Page 17) is slightly more than one-
eighth of an inch in length. The color is somewhat variable. A char-
acteristic marking is the yellow stripe on each wing cover. The figure
represents one of the darker colored individuals.

*Dr. F. H. Chittenden, “A Brief Account of the Prineipal Insect Enemies of the Sugar Beet, Bulle-
tin No. 43, Division of Entomology, U. S. Department of Agriculture (1903).

Banded Flea-beetle
Potato Flea-beeile Three-spotted Flea-beetle

LIFE HISTORY

The life history of this beetle is imperfectly known. It is thought
that the winter is passed in the larval stage only. The adults are most
numerous in June and July, during which months mating and egg laying
take place. There is no positive evidence of a second brood.

(c-2) POTATO FLEA-BEETLE
(Fig. 5, Plate IV, Page 17)

Not infrequently swarms of the potato flea-beetle appear in fields of
sugar beets, causing considerable damage to small areas. At such times
the injury to the crop is similar in every way to that caused by the striped
flea-beetle and the same remedies should be applied.

This insect’s liking for potatoes is indicated by its common name
“potato flea-beetle,”’ while its habit of attacking cucumbers and related
plants suggested the second part of its scientific name, “ cucumeris.

DESCRIPTION
The Larva

The larvae are small, whitish grubs which feed in the roots of several
common wild plants all belonging to the same family as the potato. The
roughened condition of potatoes known as “pimply”’ potatoes is caused
by the larvae burrowing into the tubers.

The Adult
The adult beetles (Fig. 5, Plate IV, Page 17) are a dull black with
the exception of the legs and antennae, which are yellowish. The wing
covers are clothed with very fine hairs and their surface is covered with
small punctures which are arranged in rows. The thorax has a deep,
curved depression across the posterior margin, as shown in the figure.
The nel outline drawing at the left of the figure is the natural size of
the adult.

LIFE HISTORY

The eggs are deposited on the roots of the host plants during May
and June by the adult beetles, which have spent the winter in hibernation
under dead leaves and other trash along ditch banks, fence rows and
roadsides.

The larvae tunnel into the roots of the host plants, where they feed
until fully grown. The mature larvae form small, oval cells in the soil,
near the roots of the plants within which they fed, and change to pupae.

(c-3) THREE-SPOTTED FLEA-BEETLE
(Fig. 6, Plate IV, Page 17)

The three-spotted flea-beetle (Fig. 6, Plate IV, Page 17) is conspicu-
ous in beet fields in early spring mainly because of its size and coloring.
It is one of the largest flea-beetles and is readily distinguished by the
yellowish-red thorax bearing three black spots.

Lamb’s-quarters and related plants, such as Russian thistle and sugar
beets, appear to be favorite food plants of this species.

Seldom, if ever, does this beetle occur in great enough numbers to
require the application of remedial measures.

Spinach Carrion-beetle

(d) SPINACH CARRION-BEETLE
(Figs. 10 and 11, Plate VII, Page 23)

The spinach carrion-beetle belongs to a family of insects the greater
part of whose members feed upon decaying animal matter. These
beetles are common objects under the carcasses of dead animals lying on
the ground.

A few species of this family, however, feed upon vegetable matter,
and some on fungi, while others, like the species under discussion and
its near relative, the black carrion-beetle (Schwarze Aaskafer) of Ger-
many, feed upon sugar beets and other crops and upon field weeds.

From field observations it seems quite probable that the growing of
sugar beets is not responsible for the presence of this pest in a neighbor-
hood, but that its presence is due to some of its favorite host plants being
in the vicinity.

The following plants make up the menu of this beetle: Lamb’s-
quarters, green-berried nightshade, spinach, and sugar beets. Squash

and pumpkin vines are sometimes damaged. The adults also feed upon
alfalfa.

If none of the weeds upon which it feeds are growing in a neighbor-
hood the spinach carrion-beetle is not apt to occur in injurious numbers.

NATURE OF INJURY

Both the adult beetles and the larvae feed upon sugar beets. The
edges of the leaves are eaten, the injury being quite characteristic in its
appearance. According to Prof. R. A. Cooley,* the gnawed margins of
the leaves are ragged, often showing a thin projection of crushed tissue.

Injury to sugar beets most often occurs near roadsides, ditch banks,
fence rows, and grain and alfalfa, from which the insects migrate into the
beet fields.

Sugar beets are seldom injured after they have attained any size.
The greatest damage occurs about blocking and thinning time, when
many plants may be completely gnawed off.

METHOD OF CONTROL
Clean Culture

Much can be done to control this pest by destroying the weeds upon
which it feeds. However, the work should not end here. The beetles
hibernate in the soil along ditches, fence rows and roadsides. If all weeds
are burned from these waste lands and the soil thoroughly disced or
plowed in the fall, few beetles will select these bare spaces for hibernation.
If the weeds and trash are left, these places are inviting hibernating
grounds, especially if a few of the host plants already mentioned are
growing on them.

Poisoned Bait

In the article* already referred to, Prof. Cooley states that the
poisoned bran mash so effective in the control of cutworms (See “ Kansas
Mixture,” page 39) is very effective against the carrion-beetle when

** Spinach Carrion-beetle,” Journal of Economic Entomology, Vol. 10, No. 1 (1917).
94

Spinach Carrion-beetle

spread on waste land, about ditches and fields. As the beetles and larvae
feed principally at night the poisoned bait to be most effective should
be put out late in the day.

DESCRIPTION
The Egg

The eggs, which are laid in the soil, vary from almost spherical to
ovalinform. The size is also variable. The smaller ones are about 5%
of an inch long and the larger ones 3%; of an inch long. ‘The color is a
creamy white, and the surface is polished and glistening. Prof. Cooley
has observed that the eggs increase in size after being laid.

The Larva

The newly hatched larva is about 3; of an inch long and black in
color. When fully grown the larva appears as shown in Figure 11, Plate
VII, Page 23. The color is a shining black. The head of the insect
represented by the figure is bent downward, making it appear as
though the first segment of the thorax were the head. The young car-
rion-beetles are flat, and the body, which is composed of plates each
terminating in an acute angled corner at each side, has the appearance
of being notched on the margin.

The Pupa

The pupa is white and soft. The legs; antennae and wings are free.
At the sides of the body there are several long hairs and at the tip are
two fleshy prongs also terminated by long hairs.

The Adult

The adult beetles (Fig. 10, Plate VII, Page 23) are uniformly dull
black. The wing covers are ribbed lengthwise. The Latin name of the
beetle, “ bituberosa,"’ meaning © with two tubercles,’ was suggested by
the tubercles at the end of the two outside ridges.

LIFE HISTORY

Egg laying begins about the middle of May and continues until
nearly the middle of July. The females seem to prefer moist soil as a
place to deposit their eggs, which are laid from one to two inches below
the surface. Prof. Cooley reports as high as 75 eggs from one female,
the average of several being 39. The eggs hatch in from three to six
days.

The larval stage lasts about 24 days, at the end of which time the full
grown larva enters the ground, forms an oval cell and pupates. The
pupal stage lasts 23 to 26 days, the insect completing its development
from the egg to the adult in about 55 days.

After emerging from the pupae the adults spend the remainder of the
season in the soil, coming out occasionally tofeed. They spend the winter
in hibernation about the margins of fields, on ditch banks and roadsides,
coming forth as soon as the frost leaves the ground in the spring. There
is no evidence of more than one brood each season.

Blister-beetles

(e) BLISTER-BEETLES
(Figs. 8, 9, 12 and 13, Plate VII, Page 23)

In nearly all lists of insects attacking the sugar beet mention is made
of several species of blister-beetles. The economic status of some of our
common species is difficult to determine, as the larvae, by destroying
grasshopper eggs, render a real service to agriculture, while the adult
beetles damage certain crops by feeding upon their leaves.

A powder made of the dried bodies of the adult beetles is uséd in
the treatment of certain diseases and injuries. When applied to the flesh
in a paste form blisters are produced. This led to the beetles being
called blister-beetles. The powder made from the dried bodies of a
European species is known in the commercial world as Spanish-fly.

NATURE OF INJURY

The injury to crops (which is the result of the feeding of the adult)
is similar to that caused by other leaf-eating beetles.

These beetles are strong fliers, often appearing in swarms on sugar
beets, potatoes and other crops, where they feed most ravenously for a
time. Disappearing as suddenly as they come, they leave only the riddled
remains of the crop.

At such times applications of poisons are of little avail because of
the great numbers of beetles and because of their voracity. Only the
promptest action and most thorough application of whatever remedies
are employed against them will be effective.

METHODS OF CONTROL
Poison

As already stated, the use of poison is seldom effective. If poison
is used, 2 to 2} pounds of Paris green or 4 to 5 pounds of dry arsenate of
lead, or 8 to 10 pounds of arsenate of lead paste, should be used in the
quantity of water necessary to spray one acre. This varies from 50 to
100 or 125 gallons in the different types of sprayers.

Mechanical Measures

As the beetles are very active and readily put to flight, driving them
from a field is often the most effective means of preventing losses. This
can be done by several persons, armed with brush or small branches of
of trees, driving the beetles ahead of them. Always work in one direc-
tion, taking as wide a strip across the field as possible, and going with the
wind.

According to Dr. Chittenden*, a windrow of dry straw or hay placed
along one side of the field can be burned after the beetles have been driven
onto it, thus destroying them.

When small areas or gardens are attacked the beetles can sometimes
be knocked into pans containing a small quantity of water covered with
a thin film of kerosene. This method 'is not suited to large fields.

When the beetles are not very numerous they can be dispersed and
serious damage prevented by using the cultivator equipped as suggested
for scattering flea-beetles, i. e., with pieces of rope or strips of canvas
attached to the frame so as to drag on the plants.

**A Brief Account of the Principal Insect Enemies of the Sugar Beet,” Bulletin No. 43, Division ot
Entomology, U. S. Department of Agriculture (1903).

Blister-beetles

DESCRIPTION AND LIFE HISTORY

The blister-beetles are especially interesting because of the feeding
habits of their larvae and because of the fact that they pass through more
stages in the course of their development than any of the other beetles
discussed in this Bulletin. There are six stages, the egg, three larval,
the pupal and the’ adult.

Mention has already been made of the fact that the larvae of some
species feed upon grasshopper eggs. The seasonal history of these may
be summarized as follows:

The Egg

The eggs, which are small and oval in form, are very delicate. They
are deposited in loose clusters in holes in the ground which have been
excavated by the female blister-beetle. After the eggs are laid they are
covered with loose soil which the beetle scratches over them with her feet.

The places chosen for egg laying are just those warm sunny spots
chosen by the female grasshopper for the same purpose. Thus we see
that the newly hatched blister-beetle finds an abundance of food close
at hand when it emerges from the egg.

The First Larval Stage

When the larva escapes from the egg its head is large and the jaws
are well developed. Its legs are comparatively long and the body slender.

As soon as the body walls become hardened by exposure to the air
the active larva starts in search of a grasshopper egg-pod. When one is
found the larva gnaws its way into it and begins feeding upon the eggs.

At the end of its first meal of uncooked omelet, which may last for
three or four days, the larva spends the next few days resting, and about
the eighth day after beginning to feed the first molt takes place and the
second larval stage begins.

The Second Larval Stage

In this stage the body is Pauehia more robust and the legs are much
Ces than before. After feeding for about a week another molt takes
place

The legs and mouth are now rudimentary and the body resembles
that of the white grub.

After about six or seven days the skin is once more shed and what is
known as the ultimate stage of the second larva is begun. In this stage
the larva feeds more voraciously.

After a week of almost continuous feasting the larva leaves the re-
mains of its repast and burrows a short distance into the soil, where a
smooth cell is formed.

Within this cell another change takes place. About the third or
fourth day the skin splits over the head and is gradually worked backward
but is not entirely shed. The mouth and legs are now quite rudimentary,
being represented by small tubercles. The skin becomes quite rigid and
takes on an orange yellow color (Fig. 12, Plate VII, Page 23). This is
the pseudopupa or coarctate larva.

The winter is spent in this form. In the spring the hard coarctate
larval skin is cast off and the third larval form appears.

Blister-beetles Grasshoppers

The Third Larval Stage

In this stage (Fig. 13, Plate VII, Page 23) the larva is robust of body,
anid while the mouth parts and legs are well developed, it does not appear
to feed.

After burrowing about in the soil for a time the third larva changes
to the pupa.

The Pupa

The pupa is white at first, becoming darker as the time for the
emergence of the adult approaches. The legs, wings and antennae are
free, as in the pupa of the alkali-beetle.

The pupal stage lasts from five to six days, when the adult beetle
appears.

The Adult

The adult blister-beetles are slender, rather soft bodied insects. In
fall they are common objects on the flower clusters of goldenrod and
other plants.

The black blister-beetle (Fig. 8, Plate VII, Page 23) feeds upon
Russian thistle and goldenrod blossoms, as well as potatoes and other
crops.

The ash-gray blister-beetle (Fig. 9, Plate VII, Page 23) is quite
common in alfalfa fields in Northern Colorado, where it feeds upon the
leaves of the alfalfa.

3. GRASSHOPPERS

During the early seventies the rich prairie soils of western Minnesota
attracted many homesteaders, so that by the summer of 1876 (which is
known as one of the worst grasshopper years in the history of American
agriculture), the vast expanse of these prairies was dotted with claim
shanties, tree claims and green fields.

The first of June of this memorable summer all crops gave promise of
a bountiful harvest. Then vague rumors of great hordes of Rocky
Mountain locusts, which were destroying crops to the southwest, caused
much apprehension among the settlers, many of whom had spent their
last dollar in the planting of their crops, fully expecting the harvest to be
sufficient for their future needs.

About June 20th great swarms of hoppers began flying over, coming
from the northwest and always traveling to the southeast. At times the
swarms were so large and the hoppers flew in such dense bodies that one
could look directly toward the sun without hurting the eyes. The light
was dimmed as though a thin cloud obscured the sun.

The suspense of the homesteaders had almost reached the breaking
point when the wind changed and the long dreaded thing happened.
Suddenly, about ten o'clock in the forenoon of July 5th people were
startled by a loud, rushing sound like that of an approaching storm.
Upon going outside a sight long to be remembered met their eyes.

From the sky, like huge snow flakes, millions of Rocky Mountain
locusts were dropping to earth. This living shower lasted for about
half an hour, when it ceased as suddenly as it began.

Grasshoppers

The ground was literally covered with a seething, kicking mass of
hoppers three to four deep. Gradually this struggling horde became
quiet, resting in regularly arranged rows and layers. In this position
they remained for about four hours, when the work of devastating the
fields began. Their work was rapid and thorough and the destruction
complete.

The writer's father describes the work of these hoppers in a corn
field as follows:

“ After having rested for about four hours those hoppers next to the
corn stalks began to feed upon them near the ground. As this weakened
them the stalks fell and were immediately attacked by other hoppers.
Stalk after stalk fell, until about sundown, when feeding ceased for the day,
less than a hundred stalks remained standing in a 44 acre field. When
the hoppers left this field not a vestige of the crop remained excepting the
stumps of the corn.”

Garden truck, with the exception of peas, was also completely de-
stroyed. Root crops such as beets and turnips were eaten leaf and root.
Where each plant stood only a hole in the ground remained. As they
devoured these roots the ravenous hoppers fought for a place until their
bodies and extended legs resembled a bundle of sticks set on end in a
small bowl.

The third day the hoppers rose and started in a southeasterly direc-
tion. They disappeared as suddenly as they came, leaving only bare
_ ground and disheartened farmers behind over an area one hundred miles
square.

Nothing more was seen of the hoppers until early August, when a
second but smaller swarm settled on the cropless country covered by the
earlier one. This second swarm found little but the prairie grasses to
feed upon. However, this furnished sufficient food for them until they
had honeycombed fields and prairie with their egg pods.

The following spring the whole country was a hopping mass of young
Rocky Mountain locusts. Then began the fight to destroy this growing
army and save what crops had been sown.

All the young hoppers traveled in one direction. Whichever way
they started in the morning was the direction for the day. While they
were still small, trenches were dug in front of them into which they fell
and in which they were buried.

The hopper dozer played its part in the fight against the young hop-
pers as they became larger and more active. By constant fighting some
crops were partially saved, at an enormous cost of time and hard work.

About the first of June the hoppers, having acquired wings, took
flight for parts unknown.

With the exception of very local outbreaks, which have been quickly
brought under control, the Rocky Mountain locust has never since ap-
peared within the bounds of the vast territory devastated during 1875 to
1877. In those parts of its range where it was most numerous during
these years it is almost unknown at the present time.

Thus one of the most destructive insects of the Western Hemisphere
came, devastated vast areas of crops and passed on, never since to appear
in anything like the same numbers in any part of its former range.

Grasshoppers

While the Rocky Mountain locust has almost ceased to be a pest,
there are several other species of grasshoppers which frequently occur in
great numbers and do much damage to crops within restricted areas.
Three of these species—the two-lined hopper, the differential hopper and
the red-legged locust—are worthy of special mention.

(a) TWO-LINED HOPPER
(Figs. 9, 10 and 11, Plate IV, Page 17)

The two-lined hopper, together with the two following species, often
occurs in large numbers in the Great Plains area.

It is easily distinguished from our other injurious species by the two
light lines beginning at the eyes and extending along the back and meet-
ing at the tip of the wings.

The females, one of which is shown, natural size, in Figure 10, Plate
IV, Page 17, are larger than the males. The color of both sexes is yellow-
ish or tan color, with darker, almost black markings. Some of the males
are much darker than the females, there being very little yellow visible
on these dark individuals. However, the light lines mentioned above
are always clearly discernible.

(b) DIFFERENTIAL HOPPER
(Figs. 12 and 13, Plate IV, Page 17)

Many times the differential hopper outnumbers the preceding one.
Since the passing of the Rocky Mountain locust it has been one of the ,
principal injurious forms in the Great Plains area.

This hopper occurs in two colors, with many intermediate shades.
Figure 12, Plate IV, Page 17 represents a male of the light or yellow
phase, while Figure 13, Plate IV represents the opposite color extreme.

In size this hopper resembles its near relative, the two-lined hopper.
However, in all its color variations, it can be distinguished from the two-
lined hopper by the lack of the two pale lines on the back.

The red-legged locust may be taken as representative of a group of
small or medium sized species which have in the past been responsible
for widespread damage to crops.

In general appearance and size the red-legged locust resembles the
Rocky Mountain locust already referred to, the lesser migratory locust,
and the California devastating locust.

It is very difficult to give a popular description of this grasshopper
that will make it possible for one not trained in entomology to distinguish
it from the other three species mentioned in the preceding paragraph.

Figure 14, Plate 1V, Page 17 represents an average male, natural
size. [he females are somewhat larger. The color of this hopper is
variable, being brownish, shaded with almost black in the darker indi-
viduals. In the light individuals, the lighter portions are yellowish
brown.

The slender part of the hind legs is usually reddish, although in some
specimens it is yellowish or even pale green.

100

Grasshoppers

NATURE OF GRASSHOPPER INJURY

Grasshoppers belong to that group of leaf-feeding insects which bite
their food. The crops attacked are often completely defoliated, and in
the case of root crops such as sugar beets, turnips and others the roots
are often eaten as well. The crowns of sugar beets are often completely
destroyed and as a consequence the beets soon die, as they cannot develop
new leaves.

Young alfalfa is often destroyed by grasshoppers, especially where
the ripening of the grain used as a nurse crop forces them to seek other
green food.

When attacking oats, grasshoppers have the peculiar habit of gnaw-
ing off the kernels, which they seldom if ever eat.

When other food fails, shade trees and shrubs are attacked and
stripped of their leaves.

During recent years grasshopper injury has usually occurred near
wild land or waste land about the borders of fields, roadsides, ditch banks
and fence rows, which are favorite breeding grounds of all grasshoppers.
With the passing of the Rocky Mountain locust the migration of large
swarms of grasshoppers from long distances appears to be a thing of the
past.

METHODS OF CONTROL
Kansas Mixture
The most effective remedy employed in the control of grasshoppers

is the poisoned bran mash known as © Kansas Mixture,”’ which is made of
the following ingredients:

Sane Mere be cot retard ob ees Quay Abts 3 W 5% 25 Ibs
and Seaneenind yee ayhjecyhie eo eae reek l= as.
IMIGIASS eStart aa ea ssnts 2 qts.
ILQIRTONRS a chs cacao 5
\NV GN ia Gl OY ACE Me sttes wea ener ae Pane 3 gals.

It will be noted that the formula for use against grasshoppers is
slightly different from that given on page 39 for use against cutworms.

How to Prepare the Mixture

In preparing this mixture proceed in the following manner: Thor-
oughly mix the bran and Paris green while dry until the whole has a uni-
form greenish color. Take about two gallons of water and add to this
the molasses and lemons after the latter have been finely ground, rind and
all. Stir this mixture until the molasses is completely dissolved, then
pour it over the bran and Paris green. Mix until evenly moistened,
then add water a little at a time until the mash is just wet enough to stick
together well but yet dry enough to crumble readily when being spread.

When to Apply the Mixture

Grasshoppers spend the night on weeds and other plants well up
above the ground. Not until after the sun rises and they have become
warmed do they become active and begin feeding. After their night's

fast the hoppers are hungry, so that if the poisoned bran is scattered
before they begin feeding in the morning the best results are secured. If

101

Grasshoppers

the mixture is put out in the evening it loses much of its odor during the
night and is less effective as a result. When put out after the hoppers
have filled up in the morning they are less hungry and do not eat so freely
of the bait as earlier in the morning. Then by the time they are ready
for another meal the sun has dried it more or less, which makes it less
appetizing.

Also, apply the remedy in the early part of the season, while the
hoppers are small. “It is the early bird that catches the worm."’ Like-
wise it is the early farmer that gets the hopper.

How to Apply the Mixture

The Kansas Mixture should be thinly broad-casted over the ground.
The most satisfactory way is to sow it by hand, using the same motion
as in sowing grain or grass seed by hand. Care should be exercised to
prevent leaving large lumps in the spreading, as these are apt to be eaten
by live stock or poultry and cause their death. The mixture made with
quantities, according to the formula given, is sufficient to cover 44 to 5
acres. If thinly and evenly applied to this area there is no danger of
either live stock or poultry being killed by feeding on treated land.

Where to Apply the Mixture

The poisoned mash should be scattered on waste land, borders of
fields or other places where the hoppers congregate for the night.

The Hopper Dozer

During the years 1875 to 1877 many devices for destroying grass-
hoppers, especially the wingless, young hoppers, were invented and cov-
ered by patent rights. The inventors of some attempted to use sulphur
fumes to kill the hoppers, others crushed them between rollers, and still
others used the principle of the vacuum cleaner to suck the hoppers into
their machine.

Fig. 15. Hopper Dozer (After Chas. R. Jones, Bulletin No. 233, Colorado Agricufvural
Experiment Station)

102

Grasshoppers

Of this assortment of mechanical hopper killers only the hopper
dozer (Fig. 15, Page 102), as we know it today, has survived. This de-
vice has long been recognized as effective in destroying grasshoppers, but
its usefulness is confined to low standing crops, mown meadows, stubble
fields and relatively flat ground. Where the ground is rolling or hilly the
“live hopper machine” takes the place of the dozer.

The hopper dozer consists of a sheet-iron pan about 4 inches deep
and 12 to 16 feet long by 23 to 3 feet wide. This is separated into com-
partments by cross partitions, making the compartments about square.
These cross partitions are to prevent the liquid used in the pan from run-
ning to either end when the dozer is used on slightly rolling ground. This
pan is placed on runners made of 2x4 or 2x6 lumber. At the back and
ends of the pan is an upright sheet of tin or oilcloth 2} or 3 feet high,
against which the hoppers fly and are knocked or slide down into the pan.

When in operation the pan is partially filled with water covered
with a thin film of kerosene. As the hoppers accumulate in this liquid
they are skimmed off. If this is not done the falling insects are prevented
from becoming coated with the oil and water, which is necessary in order
to kill them. The dozer is drawn by horses, one hitched at either end.

A dozer of this sort can be built on the farm, and should be constructed
for $6.00 to $7.00 when normal prices prevail.

The Live Hopper Machine

This device, which is of more recent origin than the dozer, is espec-
ially adapted to use on rolling or hilly land where those devices which
employ liquids cannot be satisfactorily worked.

The live hopper machine consists of a box about 2 feet wide, 2 feet
deep and 16 feet long, with bottom and ends of wood, and top and back of
fine screen. The remaining side of the box is partially closed by a curved
sheet iron or tin deflector about three feet high and extending along its
entire length. The deflector reaches to within about three inches of the
bottom of the box, the lower edge being curved backward into it. Just
in front of this is a narrow strip of tin fastened to the bottom of the box
directly under the bent-in portion of the deflector and curved outward
and upward to a height of about six inches. Thus a curved mouth is
produced along the entire length of the box. The hoppers flying against
the deflector slide down into this mouth. The narrow strip of tin men-
tioned prevents the hoppers from escaping by hopping off of the machine
in front. Once in the mouth of the box, the light coming through the
screen attracts them and the hoppers enter it in an attempt to escape,
and are imprisoned.

At each end of the box is a door which is used in removing the hop-
pers from the machine after they have been killed by being sprayed with
kerosene.

The machine is placed on runners and drawn by horses in the same
manner as the dozer.

Harrowing and Discing

Even though the hopper dozer is used and the Kansas Mixture ap-
plied, many grasshoppers will reach maturity and many eggs will be laid
each fall. In order fully to round out the season's work against the grass-

103

Grasshoppers

hopper plague, all waste land should be thoroughly harrowed or disced.
This harrowing and discing will break up the egg pods and scatter the
eggs where exposure to the air and weather will destroy them.

Many eggs will be deposited in alfalfa fields. The practice of reno-
vating this crop with some one of the various makes of alfalfa renovators
not only destroys many grasshopper eggs, but benefits the crop as well.
Early spring or fall renovating is most effective in destroying grasshop-
per eggs.

Plowing

Next to harrowing and disking, plowing egg infested land is one of
the most effective cultural means of preventing hopper losses. Plowing
alone does not destroy many of the eggs, but if the soil is plowed to a
depth of four to five inches and the surface thoroughly worked with the
harrow, a very small proportion of the young hoppers will succeed in
making their way to the surface.

Clean Culture

Our injurious species of grasshoppers prefer weedy or grassy land as
places to deposit their eggs. If all waste land about fields, ditches and
fences is kept free of vegetation, few eggs will be deposited and adjoining
fields will be comparatively free from injury.

Poultry

Poultry, if allowed to run at large, will rid considerable areas of
grasshoppers. Turkeys are more valuable for this purpose then hens, as
they range farther and spend more time in the fields. A small flock of
turkeys is a double source of profit to the farmer.

LIFE HISTORIES OF GRASSHOPPERS

The life histories of our most injurious species of grasshoppers are
very similar.

The mature females usually select some dry sunny location covered
with a growth of weeds or bunches of grass for depositing their eggs. The
eggs are deposited in holes in the soil which are lined with a glue like
substance secreted during egg laying. When this becomes hardened it
protects the eggs from excessive drouth, moisture, and possibly to some
extent, from predacious insects or egg parasites.

In making these holes the female presses the tip of her abdomen,
armed with four hard, curved and pointed plates (See Figs. 10 and 11,
Plate IV, Page 17), against the soil. By alternately opening and closing
these plates the soil is forced aside.

When the hole is filled with eggs it is sealed with more of the glue-
like secretion. This egg cluster inclosed within its impervious case is
called an egg pod. Figure 8, Plate IV, Page 17 represents one of these
egg pods removed from the soil. A portion of the covering has been re-
moved near the upper end, exposing the eggs. The eggs are of a yellow-
ish or olive yellow color, about one-fourth of an inch long, cylindrical,
and slightly curved. Most females deposit two egg clusters, the total
number of eggs laid varying from 50 to 100 or more.

All of our injurious grasshoppers pass the winter in the egg stage.
There are several species, however, that hatch in the fall and hibernate
in an immature state, completing their development the next summer.

104

Grasshoppers

Their presence about fields during warm weather in winter is responsible
for many reports of early hatching of grasshopper eggs.

Hatching begins during late May and early June and extends over a
considerable period of time. Those eggs deposited on sunny, south
slopes and in other protected locations hatch first.

The young grasshoppers or nymphs (Fig. 9, Plate IV, Page 17) re-
semble the adults but lack the wings of the latter. During their develop-
ment they shed their skins several times. With each molt they resemble
’ the adults more closely. Just before the last molt they appear as shown
in Figure 1, Plate V, Page 19. At this time the wings are represented
by four pads on the back of the insect.

During the process of molting, grasshoppers cling to some plant to
which the cast skin often remains fastened for some time.

With the last molt the grasshopper becomes an adult with fully de-
veloped wings. Mating soon takes place and egg deposition begins,
usually, about the middle of August and continues until cold weather
kills the grasshoppers.

NATURAL ENEMIES
Flesh Flies

The larvae of several species of flies belonging to a family popularly
known as “ flesh flies’ are parasitic upon grasshoppers.

Figure 3, Plate IV, Page 17 represents a flesh fly 7 which was
reared from the two-lined hopper. The larva or maggot of this fly is
shown in Figure 4, Plate IV.

The flesh flies here referred to are viviparous, which is to say that
they give birth to living maggots instead of laying eggs.

Mr. E. O. G. Kelley* describes the manner in which one of these
flies places its larvae upon the host hopper substantially as follows:

While the hoppers are on the wing the female flesh flies strike them
on the under side of the lower wing, at the same time depositing a tiny
maggot near its margin. When struck the hopper drops to the ground.
The maggots were observed by this author to crawl along the margin of
the wing to its base and then to enter the hopper’s body through some
natural opening or tender tissue. Once within the hopper the maggots
feed upon its body fluids until mature. The hoppers usually live until
the maggots are nearly full grown. However, these parasitized hoppers
are apt to be sluggish and inactive several days before their vitals are
destroyed and they die. When mature the maggots leave the dead
hopper, burrow into the ground or conceal themselves underneath trash,
change to pupae and later into adult flies.

The flesh flies are foremost in the list of insect enemies of the grass-
hopper and are of the greatest value to agriculture. They seldom appear
in buildings in numbers, being denizens of the fields where their good
work is done.

Ground Beetles

Several species of beetles commonly known as ground beetles (See
page 130) are known to feed upon grasshopper eggs as well as the grass-
hoppers, especially in their immature stages.

: sone New Sarcophagid Parasite of Grasshoppers,” Journal of Agricultural Research, Vol. II, No. 6

(7) See explanation of “Reference Figures.” page 2.

105

Grasshoppers

The egg-eating Amara (Figs. 20, 21 and 22, Plate IX, Page 27) be-
longs to this family and is of especial interest because of the good work
its larvae did in destroying eggs of the Rocky Mountain locust in the
territories overrun by this insect in 1876 and 1877.

Wherever grass-
hopper eggs are plen-
tiful, the larvae (Fig.
20, Plate 1X, Page
27) of this beetle will
be found. These
whitish yellow grubs
with brown heads
and dark shields on
each segment of the
body burrow among
the roots of grasses
(Fig. 16, Page 106),
where the female
grasshoppers have
deposited their eggs,
and destroy them in
large numbers.

The change from
larva to pupa (Fig.
21, Plate Xen Pace
27) takes place dur-
ing early May and
the adult beetles
Fig. 16. Exposed Grass Roots, showing Grasshopper (Fig: 22) Place eg

Eggs and Larvae of the Ground Beetle, Amara obesa Page 27) emerge two

or three weeks later.

Blister-beetles

The part which the larvae of blister-beetles play in the destruction
of grasshopper eggs has been discussed on page 96. However, the good
work of these larvae is partially offset by the adult beetles feeding upon
crops.

Locust Mites

The locust mite (Figs. 1, 2, 17 and 18, Plate V, Page 19) is one of the
most interesting as well as important enemies of the grasshopper. This
little creature, which is closely related to the “chiggers’’ so common in
some parts of the country, is not an insect but belongs to the same class
of invertebrate animals as the spider.

The animals of this class, which includes the scorpions, harvestmen,
spiders, mites, ticks and others, differ from the true insects in having four
pairs of legs instead of three pairs in the adult stage and in having the
head and thorax grown together. However, the immature stages often
have but three pairs of legs.

During those years when the Rocky Mountain locust overran the
country west of the Mississippi river the ground was, at times, almost
red with locust mites.

106

Grasshoppers

The adult female (Fig. 17, Plate V, Page 19) deposits her eggs, a few
of which are shown above the figure, in clusters of from 300 to 400. These
are placed below the surface of the soil, often to a depth of 1} to 2 inches.
The adult male, which is smaller than the female, is shown in Figure 18,
Plate V, Page 19.

In due time the minute, orange-red larvae, one of which is shown
much enlarged in Figure 2, Plate V, Page 19, emerge. These larvae
possess but three pairs of legs. However, they are very active and soon
become attached to a grasshopper as shown in Figure |, Plate V, Page
19. Usually the young mites are found under the wing pads when there
are but a few on an individual.

These mites are sometimes mistaken for the red eggs of some parasite.

The bodies of the young locust mites become distended in true tick
fashion after feeding on a grasshopper and drop to the ground, moving
about with difficulty in this condition. After secluding themselves
under trash or among the clods on the surface of the soil the change to the
pupa and from the pupa to the adult takes place. The adults, which
feed upon the eggs of grasshoppers, spend the winter secluded beneath
any object which furnishes protection from the weather.

Hair Worms

The hair worms or hair
snakes (Fig. 17, Page 107,
Fig. 18, Page 108, and Fig.
lo, Plate IV, Page 17) are
still believed by some to
be animated horse hairs.
Even those knowing the fal-
lacy of this old belief do not
always know the relation of
these worms to other living
creatures. The majority of
those hair or ~ Gordian
worms’ observed swimming
about in stagnant pools or
the margins of streams and
in irrigation ditches belong
to the genus Gordius.

The worms of this group
are parasitic within insects.
The eggs are laid in water,
usually in the spring, and in
the course of a week or ten
days the young worms
emerge. They are armed

Fig. 17. Hair njorms ceeaping rom a parasitized with piercing mouth parts

with which they force their
way into the body of some insect where they become encysted in its
muscles. This insect is in turn eaten by some other within which the
encysted hair worm completes its development. Many Rocky Mountain
locusts were destroyed by these worms during the outbreak of this insect

107

Grasshoppers

in the seventies. Infested grasshoppers have a pale, sickly appearance
and are more or less sluggish in their movements.

Ground beetles are also often infested. Figure 17, Page 107 shows
a common species just as the hair worm is emerging. Figure 18, Page
108 shows the worm after freeing itself from the beetle. Figure 16,
Plate IV, Page 17 repre-
sents a mature male hair
worm taken from a ground
beetle.

Birds

A discussion of the natural
enemies of the grasshopper
would not be complete with-
out mention of some of the
many birds which assist in
holding this pest in check.

The list of birds which
render a real service to agri-
culture by destroying grass-
hoppers includes some which
are not in very good stand-
ing because of occasional
damage to crops or raids
upon the poultry yard or
orchard, and because of a
lack of knowledge of their

Fig. 18. The Hair Worm shown in Figure 17, a 7
after it had escaped from the Becile feeding habits throughout
the entire year.

Generally speaking, all owls are looked upon as undesirables and
as the legitimate prey of the hunter. As a matter of fact, with the
exception of the great horned owl, these birds do far more good than
harm. The occasional young chicken or turkey which they steal is small
pay for the many mice, ground squirrels and other injurious rodents
which they kill, to say nothing of the grasshoppers which some destroy.

The long-legged burrowing-owl, which inhabits deserted prairie dog
burrows, feeds very largely upon grasshoppers during those months when
these insects are plentiful. As individuals they are among the most
effective feathered grasshopper destroyers.

While blackbirds are not so effective as individuals, their great
numbers make them of even greater value than the burrowing-owls.

The red-headed woodpecker is quite generally condemned for peck-
ing holes in buildings, eating fruit and occasionally damaging other crops.
Despite his bad habits, this bird is not without good points. Over
seventy different kinds of insects enter into this bird's bill-of-fare, which
includes many crop pests, among them large numbers of grasshoppers.

Together with the owls, hawks enjoy a bad reputation among rural
communities. It has been stated that of over seventy species of hawks

108

Grasshoppers Field Crickets

and owls found in the United States but six are considered really injurious.
These are the gyrfalcon, duck hawk, sharp-shinned hawk, Cooper's hawk,
goshawk and great horned owl.

The little sparrow hawk and the large, dark brown Swainson’s hawk
are noted insect eaters. Both of these feed freely upon grasshoppers.

Fungous Diseases

During late sum-
mer numbers: of
dead grasshoppers
arealways observed
clinging to weeds
and other plants
along the roadside
or mele! loorel ies
These have been
killed by a fungous
disease (Empusa
grylliFres.). Grass-
hoppers attacked
by this disease
climb to the top of
some plant when
about to die and
clasp it with their
fore legs. (Fig. !9,
Page 109). In this
position they die
and remain clinging
until their bodies
become so decom-
posed that they
fall to the ground.

This seems to be
the most common
disease attacking
grasshoppers.

Fig. 19. Grasshoppers killed by the Fungous Disease,
Empusa grylli However, there are

several other fun-
gous as well as bacterial diseases which destroy some grasshoppers
nearly every year.

4. FIELD CRICKETS
(Fig. 7, Plate IV, Page 17)

Crickets are familiar objects during late summer and early fall.
Their lively chirping during mild fall evenings seems to add to the general
spirit of harvest cheer. Yet these dusky cousins of the grasshopper are
not without their bad habits. In fact, they are noted for their appetites
and their liking for such articles as binder twine, clothes, carpets and

109

Field Crickets
Leaf-miners Beet or Spinach Leaf-miner

rugs. Sugar beets are also sometimes attacked. The leaf stems are
often eaten and deep pits are eaten in the crowns of the beets. Figure 7,
Plate IV, Page 17 represents an immature female field cricket.

5. LEAF-MINERS

Thus far in our discussion of leaf feeding insects only those which
feed exposed on the surface of the leaves have been considered. There is
another group of leaf feeders, however, which live protected within gal-
leries, or “mines,” as they are popularly called, which result from the
eating away of the pulp of the leaves while the outer portion or epidermis
is left untouched. Some of these mines are serpentine in form, while
others are irregular in shape, becoming unsightly and discolored as the
season advances.

Several species of leaf-miners are known to attack sugar and garden
beets and mangels. However, only the following species appears to do
any considerable damage to the sugar beet crop.

(a) BEET OR SPINACH LEAF-MINER
(Figs. 1, 2, 3, 4 and 5, Plate III, Page 15)

NATURE OF INJURY

The beet leaf-miners burrow into leaves and feed upon the pulp.
At first the mines appear as tortuous whitish or brownish lines on the
blade of the leaf. As the miners increase in size the mines become large,
irregular areas, as shown in Figure 1, Plate III, Page 15.

While still inhabited the mines may have a watery appearance,
and in case the greater part of a small leaf is mined out the leaf droops
and appears to be decaying. If such leaves are held between the ob-
server and a strong light the miner can be seen within, usually near the
side of the mine.

If the weather is very warm, dry beet leaves may wilt and lie on the
hot soil during very warm days. Sometimes portions of these leaves are
killed by the heat. These dead areas often appear very similar to the
deserted mines of leaf-miners. They can be distinguished from them
very easily, however, by the fact that the pulp still remains, there being
no cavity between the upper and lower surfaces of the leaves.

Ordinarily the damage to sugar beets is so slight that no account
need be made of it. Occasionally, however, the miners are so numerous
that they materially injure a crop. The destruction of the inner portion
of the leaves has the same effect as though the entire leaf were destroyed.

METHODS OF CONTROL

It is doubly fortunate that the injury is usually so slight that reme-
dial measures are not required, as there is no known remedy practical
for field use. Several poisons have been tried, but all have proved un-
satisfactory.

Picking Infested Leaves

In the case of small gardens the infested leaves can be picked off
and destroyed. This will prevent the rapid multiplication of the miners.

110

Beet or Spinach Leaf-miner Aphids or Plant-lice

Clean Culture

As in the case of many other insect pests, preventive measures are
of more value than curative ones. The beet leaf-miner feeds in the leaves
of lamb’s-quarters, or white pigweed, as it is sometimes called. The
destruction of this weed will do much to reduce the number of miners
in a vicinity.

DESCRIPTION AND LIFE HISTORY

The Egg

The eggs, which are placed on the under side of the leaves of the
host plants, are shown natural size in Figure 1 “A,” Plate III, Page 1.
Usually they are laid side by side in groups of from two to five or six.
Their surfaces are finely reticulated. Figure 2, Plate III, Page 15 repre-
sents three eggs much enlarged, showing this reticulation of the surface.

The Miner

The miner (Fig. 3, Plate III, Page 15) hatches in about four days.
It is a whitish maggot, pointed at the head and broadening toward the
opposite end. When fully grown it is about one-fourth of an inch long.
As soon as hatched it burrows into a leaf and begins to feed upon the

pulp.

The Pupa

At the end of seven or eight days the fully grown miners drop to the
ground and after burying themselves just below the surface or beneath
trash lying on it, they pass into the pupal stage within the puparium
(Fig. 4, Plate III, Page 15). The pupal state lasts from ten to twenty
days during warm seasons of the year. The last generation of miners in
the fall is thought to pass the winter in the pupal stage, the flies emerging
the next spring.

The Adult

The adult miner (Fig. 5, Plate III, Page 15) is a two-winged fly
belonging to the same order as the common house fly. This fly has no
very distinctive markings. The face is silvery white between the eyes,
which are brownish. The body, which is dull grey, is sparsely covered
with quite long stiff hairs.

B. SUCKING LEAF FEEDERS

(Aphids or Plant-lice, True Bugs, Leaf-hoppers)
1. APHIDS OR PLANT-LICE

Aphids, or plant-lice, as they are commonly called, are small, soft-
bodied creatures which usually feed in compact masses on the stems,
leaves or roots of plants. Some feed exposed upon the plant (Fig. 20,
Page 112), others cause the leaves upon which they feed to curl over them
(Fig. 21, Page 112), and still others, like the sugar beet root-louse, spend
a part of the season, at least, within galls produced by their feeding upon
the host plant (Fig. 22, Page 113).

Aphids or Plant-lice

Fig. 20. An exposed Colony of Plant-lice on a common roadside Weed

Fig. 21. Leaves of White Ash curled by a Plant-louse
112

Aphids or Plant-lice

Fig. 22. Gall of Sugar Beet Root-louse on Leaves of Narrow-leaf Cottonwood

A common Wingless Aphid; Honey Tubes at ‘A’’
113

Fig. 23.

Aphids or Plant-lice

NATURE OF INJURY

The indications of aphid infestation are varied, the different plant-
lice affecting their hosts differently. A slow growth associated with
wilting of the leaves, which are apt to be a pale yellowish green, is char-
acteristic of root-louse attack.

Most lice which feed above ground prefer the new, soft growth of
plants. If the leaves and new growth wilt, if the leaves are covered with
a sticky, sweetish substance called ‘honey dew,” or if they become curled
and distorted, plant-lice are very likely present.

Ants are very fond of honey dew and in order to secure it are known
to care for aphids and their eggs, exhibiting in this an instinct which
amounts almost to reasoning. Ants and aphids are so closely associated
that the presence of the former on a plant is a very good indication that
the latter are present also.

METHODS OF CONTROL

The stomach poisons used in the control of biting insects
will not kill plant-lice. Contact poisons must be used. Even
then, the control of those aphids which live within galls or curled leaves
is very difficult unless the remedy is applied during the season when the
lice are in the egg stage or just as the eggs begin to hatch in the spring.
After these lice once become inclosed within the galls or leaves it is impos-
sible to reach them with any contact spray. Several species are so cov-
ered with a flocculent secretion that a spray must be very thoroughly
applied and with considerable force to be effective.

Kerosene Emulsion

Where only a few plants in the garden or a small number of orna-
mental shrubs are to be treated, kerosene emulsion has long been a stand-
ard remedy because of its simplicity and the fact that all the ingredients
required in its making are always at hand.

This contact poison is usually made in the form of a stock solution,
in which form it can be kept for several weeks. When used it is diluted
by adding water. The stock solution is made as follows:

Mix one-half pound of common laundry soap or whale oil soap in
one gallon of water by boiling over a slow fire until the soap is completely
dissolved. After removing from the fire add two gallons of kerosene and
beat until the oil is thoroughly mixed with the soap and water.

This stock solution is too strong for any plant and will kill the leaves
and tender parts if applied to them. Before using thoroughly mix one
part of the stock solution with ten to fifteen parts of water. Apply a
little to the plants to be treated and watch the results. If the leaves
are burned dilute the solution still more.

Black Leaf 40

This is a tobacco preparation containing 40 per cent nicotine, or the
active poison in tobacco. As a remedy for plant-lice one part of ~ black
leaf 40°’ is mixed with 600 to 800 parts of water and sprayed on the in-
fested plants, care being taken to spray the aphids thoroughly. As the
black leaf is very poisonous great care should be taken in handling it.

114

Aphids or Plant-lice

Lime-sulphur Mixture

In the case of those aphids which cause the leaves to curl, spraying in
winter or early spring to kill the eggs and newly hatched lice is most
effective. For this purpose the lime-sulphur mixture has proved satis-
factory. This mixture may be made on the farm, but it can be pur-
chased in a concentrated form from insecticide dealers at a cost not
exceeding that of making it. The trees or shrubs to be treated should
be thoroughly sprayed before the buds begin to open.

Tobacco Decoction

This is made by boiling tobacco stems or powder in water. Two
pounds of the former to four gallons of the latter make a mixture suffi-
ciently strong for general use. Do not let the mixture boil violently as
this drives off some of the nicotine, thus reducing its strength.

DESCRIPTION AND LIFE HISTORY

In size and color the plant-lice vary greatly. Among the larger
species the bright red Macrosiphum so common on the stems of golden-
glow in late summer is very conspicuous. Contrasted with this is the
small green species commonly found on the under side of rose leaves and
clustered about the unopened buds.

Many aphids have two tubes near the tip of the abdomen (Fig. 23,
Page 113). These are called honey tubes, and it was originally supposed
that the sweetish liquid or honey dew which is discharged from the ali-
mentary canal was discharged through them.

The mode of reproduction of plant-lice differs from that of other
insects. The louse hatching from the over-winter egg and all of the
individuals of several subsequent generations produce living young with-
out the aid of the male element. This “asexual” reproduction, as it is
called, usually continues until cold weather approaches. In the fall
true males and females are produced. These mate and the females
produce the eggs which carry the species over winter.

In some species the young of a single individual consist of both males
and females, while in the case of others one set of females bear all female
and another all male young.

The rate of reproduction is exceedingly rapid, a generation being
produced every few days during warm weather. This rapid multiplica-
tion results in widespread damage, many times, before the presence of
the lice becomes known.

NATURAL ENEMIES

Were it not for the natural enemies of plant-lice in the form of pre-
dacious and parasitic insects, fields, orchards and gardens would soon be
overrun by them.

Chief among these natural enemies are the lady-beetles, two of which
are shown in Figure 10, Plate II, Page 13, and Figure 15, Plate IX, Page
27, and their larvae in Figure 15, Plate II, Page 13, and Figure 23, Plate
De Pace 27.

115

Aphids or Plant-lice Green Peach-aphis

The aphis-lion (Fig. 18, Plate [X) and its parent (Fig. 19, Plate 1X),
the lace-winged fly, are persistent aphid destroyers. (See pages 133
and 134.)

The larvae of many Syrphus-flies, one of which is shown in Figure 13, - -

Plate VI, Page 21, devour large numbers of plant-lice.

(a) GREEN PEACH-APHIS
(Figs. 2, 9 and 10, Plate VIII, Page 25)

As a sugar beet pest the green peach-aphis is of little importance.
However, under favorable conditions for its multiplication, it often
occurs in considerable numbers on the under side of beet leaves.

NATURE OF INJURY

Injury to sugar beets is due to the withdrawing of the sap from the
leaves by the aphids in feeding. This retards the growth of the plants.
The presence of lice is sometimes indicated by pale green or whitish
blotches on the upper side of the leaves.

As its name indicates, the green peach-aphis is found on the peach
tree. It also feeds upon the plum tree. Its greatest damage is done to
these trees during early summer.

METHODS OF CONTROL

Spray infested peach and plum trees with lime-sulphur mixture
(See page 115) before the buds open in the spring to kill eggs and newly
hatched stem-mothers. After the buds open use black leaf 40. (See
page 114).

The lice should be killed on the fruit trees. After they have mi-
grated to the beets it is practically impossible to kill them.

DESCRIPTION

The apterous or wingless lice (Fig. 9, Plate VIII, Page 25) are most
plentiful. A few winged lice (Fig. 10, Plate VIII, Page 25) may be found
among the wingless ones, especially during the latter part of the sum-
mer. These differ from the wingless individuals in coloring as well as
form. The most distinguishing mark is the dark patch on the abdomen.

LIFE HISTORY

In early spring the eggs, which are deposited on peach or plum
trees, hatch. In a few days the pinkish stem-mother, as the louse from
the egg is called, becomes mature and begins depositing her young on the
leaves. These young are not pink like their mother, but green, as shown
in Figure 9, Plate VIII, Page 25. In due time these green lice begin
giving birth to young.

The lice of this third generation very largely become winged (Fig.10,
Plate VIII, Page 25). These winged lice migrate to a number of annual
plants where the summer generations are produced. The list of about
eighty plants upon which this louse spends the summer includes nearly
every vegetable grown in the garden.

116

Green Peach-aphis Black Beet-seed Louse

With the approach of fall the winged lice of the late summer gen-
erations return to the peach and plum trees. The first lice to return to
these trees give birth to wingless females which lay eggs instead of giving
birth to young. About the time these females are mature the winged
males begin to arrive from the summer hosts.

After mating the females deposit several greenish eggs, which later
become shining black. These eggs (Fig. 2, Plate VIII, Page 25) serve
to carry the species through the winter.

(b) BLACK BEET-SEED LOUSE*
(Figs. 6 and 7, Plate III, Page 15)

The black beet-seed louse is notorious because of its injury to sugar
beet seed, both in Europe and America. In this country it has been par-
ticularly destructive in some of the western states where beet seed is being
grown on a commercial scale.

NATURE OF INJURY

In feeding upon beet seed plants the lice congregate in compact masses
at the tip of the growing seed branches. Their feeding so exhausts the
sap that the plants make very slow growth and in severe cases the infested
branches die. The yield of seed is very materially reduced as a result of
attack by this louse.

METHODS OF CONTROL

Hand Picking

In Europe all infested branches are collected and carried from the
field, together with the lice, and destroyed. This method is hardly prac-
ticable except in the case of cheap labor and selected breeding plants.

Black Leaf 40

Spraying infested plants with black leaf 40 (See page 114), one part
to 600 to 800 parts of water, will destroy the lice and not affect the quality
of the seed.

Winter Spraying
Spraying the winter host with lime-sulphur mixture (See page 115)
to destroy the eggs before the buds open or with black leaf 40 (See page
114) as the lice are hatching in spring is undoubtedly the most effective
means of controlling this pest.

Destruction of Summer Hosts

When lice occur on wild plants during the summer these should be
destroyed, together with the lice on them. The destruction of all wild
host plants in the vicinity of beet seed fields, before they become infested,
is to be recommended.

*There is some evidence that there may be more than one species of black louse attacking beet
ee ae United States. This Bulletin discusses but one, the species damaging beet seed in Northern
colorado.

117

Black Beet-seed Louse

DESCRIPTION
The black beet-seed louse occurs in three forms.

1. Wingless Lice

The majority of the
lice during the warmer
months are wingless.
These wingless lice (Fig.
6, Plate III, Page 15)
are a very dark, dull
green. As the name
implies, they are so
dark as to appear black,
with the exception of
the legs, which are
yellowish. Some of the
older individuals have
several white tufts on
the abdomen.

2. Pupae

As the season ad-
vances many of the lice
develop wing pads.
These are the imma-
ture alate’ or winged
lice. These pupae, as
they are sometimes
called, also have the
white tufts on the ab-
domen.

3. Winged Lice

The colomrotestehie
winged) licem(igam7.
Plate III, Page 15) is
similar to that of the
wingless individuals

Fig. 24. A Branch of Euonymus Species, showing
Star-shaped Fruit except that the head

and thorax (that part
of the body just back of the head) are a shining black. The wings show
rainbow colors when the light strikes them at the proper angle.

LIFE HISTORY

The life history of this louse is very similar to that of the green peach-

aphis.

The winter is spent in the egg stage on the twigs of a shrub variously
~known in different parts of the country as spindle tree, burning bush,
Ewaahoo, and strawberry bush (Fig. 24, Page 118).

The first winged lice in the summer migrate to the summer hosts,

which include beet seed and a variety of weeds and wild plants, poppies,

118

Black Beet-seed Louse
True Bugs False Chinch Bug

and several varieties of beans, especially the horse bean of Europe. In
the fall the migrants return to the winter host, where the sexual forms
mate and the eggs are produced.

2. THE TRUE BUGS

People who are not familiar with their classifications are apt to apply
the word “bug” to all insects. However, strictly speaking, this name
is only properly applied to those sucking insects belonging to the order
Hemiptera. Many authors confine the term to individuals of the
sub-order Heteroptera. Like most of the scientific names of insects,
this one seems unnecessarily long and meaningless to the average reader.
It is taken from two Greek words, “heteros, meaning diverse, and
“petron,’ a wing, and was suggested by the peculiar form of the wing of
these bugs.

The common stink-bug so frequently encountered on raspberries
and other small fruits and the notorious chinch bug of the grain fields of
the Mississippi Valley are familiar representatives of this group.

Several species attack the sugar beet, of which the false chinch bug
is the most important in the arid West.

(a) FALSE CHINCH BUG
(Figs. 11 and 12, Plate VIII, Page 25)

This insect has attracted quite widespread attention because of its
damage to sugar beet seed. When very numerous it has been known
seriously to injure commercial sugar beets also.

NATURE OF INJURY

In feeding, the false chinch bug congregates in compact masses upon
afew plants. The juice of these plants is so rapidly exhausted that they
wilt and become lifeless in a very short time.

When attacking commercial beets the bugs congregate about the
crowns of small plants, or on the leaves, which soon become wilted and
dead. The growth of commercial beets is very much retarded and in
extreme cases small beets are killed.

The growing tips of the branches of seed beets are attacked. The
sap of these is soon so exhausted that they droop and die. The yield of
seed is very much reduced by the feeding of this pest.

When the sap of one plant is exhausted the bugs move to others,
and as they are strong fliers and voracious feeders they affect large areas
in a short time.

Fields of commercial beets near waste land overgrown with pepper-
grass or shepherd’s-purse and other plants of the mustard family are
quite apt to be attacked.

The odor of the blossoms of seed beets seems to attract the false
chinch bug, which usually appears in seed fields about the time the plants
begin to bloom. Of course the proximity of infested land to seed fields
increases the infestation, at least early in the season.

119

False Chinch Bug
METHODS OF CONTROL

Clean Culture

In the control of the false chinch bug preventive measures give more
satisfactory results than the application of any remedy yet devised. As
has already been intimated, this insect breeds upon various wild plants,
especially shepherd’s-purse and other closely related plants of the mus-
tard family. By preventing these weeds from growing about fields,
ditch banks and roadsides the multiplication of the false chinch bug in
a vicinity will be materially checked.

Burning

The bugs probably spend the winter in hibernation beneath dead
weeds and about the roots of grasses growing on waste land. If all un-
plowed land is cleaned up during the winter and early spring by burning
all dead vegetation the hibernating bugs will be destroyed. If straw
is spread over the ground and burned the treatment is often more effec-
tive. Many other injurious insects which spend the winter in hiberna-
tion in the same locations as the false chinch bug will be destroyed at
the same time.

Hand Picking

Hand picking under certain conditions will serve to prevent the
insect from injuring a crop. In catching the bugs a wide-mouthed dish
of some kind should be used. Place a small quantity of water in this to
which a little kerosene has been added. By suddenly slapping the
infested plants the bugs can be knocked into the water and kerosene.
The latter soon kills them. When the dead bugs cover the surface of
the liquid skim them off. Whether or not this method of control is
practicable will depend upon the value of the crop and the labor required.
It is doubtful if it will pay in the case of large fields. In order that it be
most effective the work must be done during the early morning or
cool days, as in bright sunny weather the bugs are so active that they
scatter upon the approach of the worker, so that but a small proportion
are caught.

Sticky Shields
Sticky shields* carried through the fields have been used with some
success. [he same question of crop and labor values makes this a doubt-
ful method except for small plots of very valuable crops and crops grown
for experimental purposes.

Spraying
Various sprays have been employed, with rather indifferent results.
Mr. F. B. Milliken* reports the killing of this pest by spraying with
whale oil soap, one pound of soap to five gallons of water. According to

*F. B. M1 “ken, “The False Chinch Bug and Measures for Controlling It,” Farmers’ Bulletin No.
762, U. S. Department of Agriculture (1916).

-120

False Chinch Bug

this author the above is too strong for turnips and radishes, for which
one pound of soap to ten gallons water should be used, adding one part.
of nicotine sulphate to 1000 parts of water.

DESCRIPTION
The Eg¢
The eggs, which are deposited in crevices of the ground and upon
certain plants, are very small, being about ,); of an inch long by about
one-fourth as wide at the greatest diameter. They are finely ribbed
lengthwise. The color is pale yellowish white, taking on an orange tinge
as the young bug develops within.

The Nymph
The nymphs are slightly reddish when first hatched, becoming grayer
with age. When about half grown they appear as shown in Figure 11,
Plate VIII, Page 25.

The Adult
The adult (Fig. 12, Plate VIII, Page 25) is about 3; of an inch long.
The color of the head, body and legs is brownish gray, with fine dark
spots over the surface. These spots are especially prominent on the legs.
The wings are whitish. The color of the body showing through them
gives them a grayish appearance.

LIFE HISTORY

The number of broods produced annually will depend upon the
latitude and general weather conditions prevailing. There are probably
four or five in the latitude of Denver.

.According to the author already quoted,* the late fall and early
spring broods deposit their eggs in cracks in the soil surface or in pul-
verized soil. During the warmer months the eggs are thrust among
the clustered parts of plants such as the flower heads of some weeds**
and the glumes of the strong scented stink-grass or love-grass.

When first hatched the young feed upon weeds almost exclusively,
especially the shepherd’s-purse, peppergrass and pennycress.

At maturity the adults scatter to other plants. It is at this time
that beet seed fields become infested.

The adults of the last generation in the fall spend the winter in
hibernation.

NATURAL ENEMIES

Very little seems to be known of the natural enemies of this bug.
The writer has observed many adults containing the maggots of a small
two-winged fly.

Many bugs were killed by a fungous disease in breeding cages, but
no noticeable effect of this malady was observed in the field.

*F. B. Milliken. *‘The False Chinch Bug and Measures for Controlling It..‘ Farmers’ Bulletin No,

762, U. S. Department of Agriculture (1916).
**Gaillardia pulchella Foug. Mollugo verticillata L.

121

Tarnished Plant-bug

(b) TARNISHED PLANT-BUG

The tarnished plant-bug is one of the most common of the true
bugs. It is found everywhere in North America from Mexico to Canada
and feeds upon almost any plant, either cultivated or wild. This bug
often attacks sugar beets.

NATURE OF INJURY

Only when tarnished plant bugs are abundant are there any visible
effects of their feeding. During the latter part of the season, however,
they often attack the young leaves at the center of the beet crown in
such numbers that the tips of these leaves wilt and finally become brown
and dry. Frequently the injured beets begin to make growth in the
axil of the outer leaves. This gives the beet top a bushy appearance.

METHODS OF CONTROL

Sugar beets are rarely injured to the extent where remedial measures
are profitably applied.

Clean Culture

Since the tarnished plant-bug spends the winter in hibernation
under the trash about fields, ditch banks and fence rows and breeds on
the weeds growing in these places during the early part of the season,
cleaning up all waste land by burning during winter or early spring will
destroy many of them. By preventing the weeds from growing about
fields the bugs are not so apt to be attracted to them as when these wild
plants are plentiful in and about them.

Kerosene Emulsion
In the case of small garden plots kerosene emulsion (Page 114) is
probably the best remedy where the nature of the crop attacked is such
that it can be used.
Dr. F. H. Chittenden* states that where insecticides are used they
should be applied early in the morning while the dew is still on the plants
and the bugs are not very active.

Hand Picking

Hand picking may be resorted to where the areas covered by the
attack are small. It is obvious that this method is not suited to large
fields.

DESCRIPTION
The Egg

The eggs, which are about ;'; of an inch long, are oval, several times
as long as thick and flared at one end so as to be somewhat bottle-shaped.
The color is a pale yellow.

The Nymph

The nymphs pass through four stages in the course of their devel-
opment. In the first stage they are about s of an inch in length and
of a yellowish or yellowish green color.

** A Brief Account of the Principal Insect Enemies of the Sugar Beet,” Bulletin No. 43, Division
of Entomology, U. S. Department of Agriculture (1903).

122

Tarnished Plant-bug
Leaf-hoppers Sugar Beet Leaf-hopper

The second stage differs from the first in that the nymphs are about
twice as large and have two pairs of dark spots on the thorax.

These spots become more distinct in the third stage and the wings
are represented by two small pads on the back margin of the thorax.

In the fourth stage the wing pads reach nearly half way down the
back and the four dark spots become quite prominent.

The Adult
The adults are nearly one quarter of an inch in length. The color
ranges from a greenish to a brassy brown. The markings are quite
variable. Some individuals are quite prominently marked with black,
yellow and red, while others are much more modestly colored, greenish
brown predominating.

LIFE HISTORY

The adults, as already mentioned, as well as some nymphs in the
third and fourth stages, hibernate under any convenient trash or under
stones, boards and leaves about fields and waste land.

The adults emerge during the first warm days of spring, and egg-
laying begins soon after emergence. Little seems to be known about
the place where the eggs are deposited. In all probability, they are
placed within the stems of the plants upon which the adults feed. In
_ the latitude of Northern Colorado the eggs of the first generation are
deposited about the last of April and early May.

About a month is required for the development of a single generation.
Therefore, there are probably two or three generations each season.

The generations overlap to such an extent that nymphs of all stages
and adults can be found feeding together during the entire summer.

NATURAL ENEMIES

Very little is known regarding the natural enemies of this insect. In
all probability it is held in check by predacious and parasitic insects
and fungous diseases similar to those attacking the false chinch bug.

3. LEAF-HOPPERS

With the exception of the aphids, leaf-hoppers probably exceed in
number of individuals all other families of sucking insects attacking
cultivated crops.

Although most leaf-hoppers feed upon grasses, often occurring in
meadows in such numbers that it has been estimated that from one-
fourth to one-half of all the grass growing annually is destroyed by them,
several species seriously damage field crops, vegetables, fruits and shrubs.

The small cream colored rose leaf-hopper which causes the whitish
blotches on the leaves of cultivated and wild roses is familiar to nearly
every one and will serve as a typical example of this group of insects,
several species of which attack the sugar beet.

(a) SUGAR BEET LEAF-HOPPER
(Figs. 5, 6 and 7, Plate VIII, Page 25)

Few insects attacking the sugar beet cause as large annual losses as
this minute leaf-hopper. Fortunately this pest has not appeared to any

123

Sugar Beet Leaf-hopper

damaging extent in the territory in which The Great Western Sugar
Company operates.

Its association with the disease known as “‘curly-top,”’ (Fig. 5, Plate
VIII, Page 25), or more locally as “blight,” “western blight’ or ~ whis-
kered beets” (Fig. 7, Page 60), has long been known, but just how its
feeding produces the malady is not so well known.

Fig. 25. Sugar Beet showing characteristic Curling of Leaves caused by Curly-top
(After Harry B. Shaw, Bulletin No. 181. U. S. Bureau of Plant Industry)

NATURE OF INJURY
Indications of Injury

The symptoms of injury by this leaf-hopper are to be found upon all
parts of the plant. The first to appear is usually an inward curling of the
inner leaves. ‘This is associated with a distortion and enlargement of the
veins of the leaf (Fig. 5, Plate VIII, Page 25). In severe cases the veins
are covered with nipple-like protuberances. As the disease advances
the whole plant becomes affected. The leaves become badly crumpled
(Fig. 25, Page 124), the stunted roots develop an abnormally large num-
ber of fibrous rootlets from the root seams (Fig. 7, Page 60), and the
root itself becomes darkened, especially where the rings of fibrovascular
bundles show in cross sections (Fig. 26, Page 125). The crown of the
beet will often be covered with a sweet gummy substance which exudes
from the beet.

How the Disease is Transmitted

In some way not at present thoroughly understood, certain so called
virulent leaf-hoppers have the power of producing curly-top in healthy
beets. A single individual which possesses this power will infect a
healthy plant if confined upon it for five minutes.*

*E. D. Ball, “The Beet Leafhopper and the Curly-leaf Disease That It Transmits,”* Bulletin No. 155,
Utah Agricultural College (1917).

124

Sugar Beet Leaf-hopper

Normal individuals do not have the power to cause the disease. It
has been demonstrated quite recently that before a sugar beet leaf-hopper
can transmit curly-top it must itself become inoculated by feeding upon
a diseased plant.

There seem to be many points in common between the carrying of
curly-top by these leaf-hoppers and the relation existing between certain
mosquitoes and malaria fever transmission. The micro-organism which
is now supposed to be the real cause of the disease must be taken up by
the leaf-hoppers while feeding on a diseased plant and then transmitted
to healthy plants during the process of feeding upon them.

Fig. 26. Cross Section of Sugar Beet, showing Darkening of Rings caused by Curly-top
(After C. O. Townsend, Bulletin No. 122, U. S. Bureau of Plant Industry)

Investigations, the results of which have just been published,*
emphasize the importance of clean culture as a possible means of con-
trolling this insect.

These investigations show that without a doubt the wild host plants
of the beet leaf-hopper become diseased and that when fed upon by non-
virulent leaf-hoppers, these insects become inoculated and can and do
transmit the disease to healthy sugar beets. The plant experimented
with was a common mallow.

METHODS OF CONTROL

There is very little to be said regarding the control of this insect.
In fact there is no known method by which curly-top can be prevented.

The practicing of clean culture and the working and burning over of
all possible hibernating places is always to be recommended, but even
this is not sufficient. Until more is known of the insect and its associa-
tion with curly-top we cannot hope to be able satisfactorily to prevent
the damage it causes. There are cases on record where early planting
prevented injury. This does not seem to be a sure remedy in all locali-
ties, however.

*” Wild Vegetation as a Source of Curly-top Infections of Sugar Beets,’ Boniquit and Slake, Journal
of Economic Entomology, Vol. 10, No. 4 (1917).

125

Sugar Beet Leaf-hopper Clover Leaf-hopper

DESCRIPTION
The Egg

The eggs, which are pearly white, are deposited in the tender stems
of beet leaves. Late in the season the elliptical scars caused by the
punctures made in depositing the eggs are sometimes very numerous.

The Nymph
The young leaf-hoppers or nymphs (Fig. 6, Plate VIII, Page 25) are
very minute, active little fellows of a creamy white color. They are so

small and so easily disturbed that they are found only by making very
careful search for them.

The Adult

The fully matured sugar beet leaf-hopper (Fig. 7, Plate VIII, Page
25) is about one-eighth of an inch long, and with the exception of the eyes,
is of a light creamy white color. They are so exceedingly small and active
that they are very difficult to observe in the field except as they fly from
plant to plant.

LIFE HISTORY

The following summary of the life history and habits is taken from
U. S. Department of Agriculture Bulletin No. 181, by Harry B. Shaw:

The beet leaf-hopper is single brooded and begins to deposit its
tiny, white eggs in the stems and midribs of beet leaves from about the
end of June—the time doubtless varying somewhat with the locality and
local climatic conditions—until the end of August. Probably the major-
ity of the eggs are deposited by the middle of July. The nymphs begin
to appear about the second week in July, and the writer has observed
their appearance in considerable numbers in Idaho as late as the end of
August. Slit-like scars are produced on the beet stems where the eggs
have been deposited; sometimes these ovipository scars are very numer-
ous and conspicuous. The egg stage appears to last about fifteen days,
and the young insects reach the adult stage in about twenty days more.
These adults hibernate and resume their activity the following spring.
In Utah and Idaho they have been seen on weeds in May and on beets
near the end of May or early in June. The greater portion of the nymph
stage appears to be spent among the inner leaves and petioles of the plant,
where the egg is hatched, and as the insect approaches the adult stage it
gradually works outward.

“The beet leaf-hopper is an exceedingly active insect; its favorite
mode of locomotion is by hops of lightning-like rapidity. The range of
its leaps seems to be about 18 inches. The adult while on beets uses its
wings but little. In common with several closely related species it is a
true sucking insect; it is provided with powerful head parts and a stout
bill. The latter when not in use is tucked snugly against the under side
of the body.”

(b) CLOVER LEAF-HOPPER

(Fig. 8, Plate VIII, Page 25)

The clover leaf-hopper is frequently encountered in quite large num-
bers in beet fields and is often mistaken for the sugar beet leaf-hopper
just discussed. It can be easily distinguished from it, however, by its

126

Clover Leaf-hopper

more robust form, slightly larger size and darker color. The two dark
spots on the head between the eyes serve to distinguish it from many
other small, grayish species with which it is often associated in clover
and alfalfa fields, where its greatest damage is done.

NATURE OF INJURY

Fields of sugar beets where this crop has followed alfalfa have been
seriously damaged in the early part of the season while the beets were
still small. The injury is most severe during dry, hot weather.

The leaves of sugar beets attacked by this insect are covered with
light, grayish areas as a result of the punctures and irritation caused in
feeding. If the weather is dry and warm the plants show a very striking
lack of thrift and make very slow growth. An examination of such beets
will reveal the leaf-hoppers on the under side of the leaves, or during
piel oes days they will be seen flying ahead of one walking through
the field.

METHODS OF CONTROL
Clean Culture

Keeping waste land free of rubbish by burning all dead vegetation
during the fall will prevent the adults from hibernating about fields.
Burning during the winter or early spring will destroy the hibernating
adults.

DESCRIPTION
The Egg

The eggs, which are white and very small, are placed in slits in the
host plants. These slits are made with the saw-like ovipositor of the
female.

The Nymph

The young or nymphs resemble the adults in form but lack the wings
of the latter. ‘Their color is a creamy white with darker spots and bands.

The Adult

The adult leaf-hopper (Fig. 8, Plate VIII, Page 25) is of a light gray-
ish color with dark markings. The face is marked with short, dark
stripes and just between the eyes on the top of the head are two dark
spots.

LIFE HISTORY

The hibernating female places her eggs in the stems of plants in early
spring. These hatch in from five to twelve days during the warmer
months.

The number of generations varies with the latitude and general
weather conditions. In the latitude of Denver there are at least two
and probably three each year.

The nymph stage lasts from 20 to 30 days, with an average of about
25 days. The last generation hibernates during the winter at the base
of clumps of grass and about the roots of weeds or under rubbish lying
about fields and waste lands.

127

Clover Leaf-hopper Eutettiz Strobi

In the warmer sections of the Southern states the adults are more or
less active during the entire year, and in the extreme South they do not
hibernate at all.

This bright colored leaf-hopper (Fig. 4, Plate VIII, Page 25) is the
cause of the deep purple blotches (Fig. 1, Plate VIII, Page 25) so often
seen on the leaves of lamb’s-quarters and sugar beets during spring and
summer.

It is not of interest to beet growers because of any damage it does
to the crop but because of the widespread attention which the discolora-
tion of the leaves, caused by its feeding, attracts.

During late spring and early summer and again during late summer
the nymphs (Fig. 3, Plate VIII, Page 25) may be found on the under
side of the leaves, resting on the colored spots. Their color harmonizes
so completely with these spots that they are easily overlooked.

The adults (Fig. 4, Plate VIII, Page 25) are very prettily marked
with shades of tan and brown, and measure about one-fourth of an inch
in length. The dark saddle across the center of the wings is especially
prominent. This is one of our most brightly colored and attractive
leaf-hoppers. There appear to be two broods of this insect annually,
the adults appearing in June and August.

128

Beneficial Insects
CHAPTER IV

BENEFICIAL INSECTS

So much is written about the injurious insects in bulletins and farm
papers that we are apt to look upon all insects as the arch-enemies of
mankind. However, if we study those about us carefully we are soon
astonished at the number of friends we have among them, friends whose
whole existence is one constant warfare against our enemies. It is not
enough that we learn to recognize enemies alone; we should know our
friends as well and do all we can to encourage and protect them.

In the preceding pages frequent mention has been made of beneficial
insects in connection with the particular injurious species which they
help to control. However, out of justice to our insect friends and our-
selves it is only right that we devote a few pages to a general discussion
of this large but little appreciated group.

Every order of insects contains forms which feed upon other forms
of insect life. However, these friendly species are in some cases so
minute that they are overlooked, or their work of ridding our fields of
noxious insects is carried on so quietly that their presence is not apparent.
Still others so resemble some of the injurious species that their real mis-
sion is not suspected. Instead they are blamed for the damage they are
really helping to prevent. Many times friends are taken for foes because
in searching for the real culprits they are forced to frequent the damaged
crop. Unless we are familiar with these insects they often share the fate
of the spy who, in order to hide his identity more completely, appears in
the role of an enemy.

Beneficial insects are spoken of as either predacious or parasitic.
Owing to the fact that, in habits, these two groups are not clearly defined,
but merge one into the other, it is very difficult to give a definition of
the terms predacious and parasitic which is wholly satisfactory.

In a general way insects which wander about in search of the insects
upon which they feed are spoken of as being predacious. Insects of this
class require many hosts or victims for their maintenance.

Insects which pass the entire larval stage within the body of a single
host, or attached to a single host from which they draw their nourish-
ment, are said to be parasitic.

Parasites gain entrance to the host in many ways. The adult para-
site of some species stings its eggs into the body of the host, using for this
purpose a sharp organ called the ovipositor. This is usually located at
the tip of the abdomen or near it on the underside of the body. Other
parasites fasten their eggs onto the surface of the host’s body. When
the young parasite emerges from the egg it burrows into the host. In
other cases the young parasite remains on the outside with only a small
portion of its body, including the head, buried in the host.

The larvae of certain flies are deposited upon the host and immedi-
ately proceed to enter its body through natural openings or by burrowing
through some tender tissue.

129

Beneficial Insects

These parasitic larvae feed upon the blood of the host insect. The
host in many cases remains alive and functions naturally until the para-
site is fully mature. In the case of some caterpillars the parasite does
not emerge until after the change to the pupa has taken place.

Some parasites live only within closely related insects. Thus certain
kinds are parasitic upon cutworms only, others upon grasshoppers and
related insects, and still others upon the eggs of certain insects.

Since these parasites are dependent upon certain hosts for their
existence their numbers rise and fall with the increase and decrease of
their hosts. This is why some noxious insects become so numerous at
times. A scarcity of these insects is followed by a scarcity of their para-
sites. When the parasites become very few and favorable conditions
exist for the multiplication of a particular insect it often increases so
ray as to do much damage before the parasites again get the upper

and. i

A. PREDACIOUS INSECTS

1. GROUND BEETLES
(Figs. 1, 2, 3, 20, 21 and 22, Plate IX, Page 27)

The popular name, “ground beetle,’ has been applied to these
beetles because they are most frequently encountered running rapidly
over the ground or lurking under stones or other objects lying on its surface.

The majority of these beetles are shining black. However, some are
bright metallic green, dark blue, brown or even spotted. Their legs are
long and slender and their movements rapid.

Most of the species are predacious, feeding upon other insects which
they capture either by pouncing upon them or by chase. Several species
feed upon vegetable matter, but their depredations are rarely, if ever, of
great economic importance.

The larvae of ground beetles frequent the same places as the adults,
and, like them, are predacious. Figure 1, Plate IX, Page 27 will serve
as a typical example of ground beetle larvae. Figure 3, Plate IX, Page
27 represents a very common, black ground beetle, while Figures 20, 21
and 22, Plate IX, Page 27 represent the larva, pupa and adult of a
species already mentioned in connection with the natural control of

grasshoppers.
(a) FIERY HUNTER

(Figs. 1 and 2, Plate IX, Page 27)

The fiery hunter is one of our largest ground beetles and can be
recognized by the copper colored or golden spots on the wing covers.
This beetle (Fig. 2, Plate IX, Page 27) and its larva (Fig. 1, Plate IX,
Page 27) are particularly fond of caterpillars. sy some authors it is
known as the “caterpillar killer.’ Many a cutworm has fallen a prey to
these beetles.

(b) BOMBARDIER-BEETLES

The members of one group of ground beetles are provided with a
sack of very volatile fluid at the tip of the abdomen. When pursued,
this fluid is ejected with a loud popping sound and as it comes in contact
with the air it is reduced to a gas which appears like a tiny puff of smoke.
The sharp report accompanied by the puff of smoke-like gas suggested
the name “ bombardier-beetles, by which these beetles are known.

130

Beneficial Insects

2. TIGER-BEETLES
(Figs. 5, 6 and 7, Plate IX, Page 27)

The tiger-beetles
are common objects
about the borders of
fields or on beaten
pathways and road-
sides. They are lov-
ers of sunshine and
frequent exposed po-
sitions.

The tiger-beetles
are the most agile
of all beetles, being
equally at home on
the ground, where
they run with amaz-
ing rapidity, or on
the wing. When ap-
proached they take
flight, fly a short dis-
tance, and invaria-
bly alight facing the
intruder.

Fig. 27. Entrance to Burrow of Tiger-beetle Larva. The larvae and
There is never any soil at the entrance to these bur. adults are preda-

aa cious, feeding entire-
ly upon other in-
sects. One author
states that the only
thing in common be-
tween these beetles
and their young is
their eagerness for
prey.

The larva (Fig.
5, Plate IX, Page
27) is an uncouth
creature and spends
its entire existence in
a perpendicular bur-
OWA (sl Co ace
EB) itis telayS lever
ground of some path
or roadside. During
the day it lies with
its head just at the
surface of the ground
(Pion 7S mace slab).
its jaws open like a

Fig. 28. Same Burrow as shown in Figure 27, with she
head of larva resting on level with the surface, ready Steel trap, waiting

to seize a victim.

131

Beneficial Insects

for some unfortunate insect to pass near. When one comes within reach
the jaws snap shut and the victim is drawn into the burrow and devoured.

In order to prevent some stronger insect from dragging the young
tiger-beetle from its burrow, nature has provided it with a peculiar anchor
in the form of a hump on the fifth segment of its abdomen. This hump
is armed with several curved hooks which fasten into the walls of the
burrow, thus making it possible for the larva to withstand the pull of a
powerful victim.

The adults (Figs. 6 and 7, Plate IX, Page 27) are usually a metallic
green or bronze banded with light markings, from which comes the name
“tiger-beetle."’ However, some are black, while others are light, in har-
mony with the color of the sand on which they live.

3. LADY-BEETLES OR LADY-BUGS

(Figs. 14, 15, 23 and 24, Plate IX, Page 27; Figs. 10 and 15, Plate II, Page 13;
; Fig. 14, Plate VII, Page 23)

The lady-beetles, or lady-bugs, as they are commonly called, are
among the best known and most important predacious insects.

Both the adults and larvae feed upon small, soft bodied insects and
insect eggs.

These beetles have the peculiar habit of congregating in very large
numbers in the fall of the year just before going into hibernation. At
such times they can be scooped up by thé quart as they cluster about the
bases of trees and shrubs or under stones, in layers many deep. Such a
congregation of the species discussed below occurred at the very top of
one of the highest mountain peaks near the city of Denver in 1916.

Hippodamia convergens (Fig. 15, Plate IX, Page 27) is the com-
monest of all species. This, together with several others, is especially
noted for the numbers of plant-lice which it destroys. The larva (Fig. 23,
Plate IX, Page 27) is a common object among colonies of plant-lice,
where the pupa (Fig. 24, Plate IX, Page 27) is also often encountered
fastened to a twig or leaf. Other species are especially useful for their
work in orchards, where they devour scale insects which would otherwise
injure the trees and fruit. Figure 10, Plate II, Page 13 shows a lady-
beetle which feeds upon sugar beet root-lice. Figure 15, Plate II, Page
13 shows the larva, and Figure 14, Plate VII, Page 23, the pupa, of this
same beetle.

The eggs of lady-beetles vary with the species, as does the place
selected for depositing them. Those of our common forms resemble
the eggs of the Colorado potato-beetle, but are smaller. They are de-
posited in clusters, the eggs standing on end. A cluster of the eggs of
Hippodamia convergens is shown in Figure 14, Plate IX, Page 27.

4. TRUE BUGS
(Fig. 14, Plate II, Page 13)

The majority of the true bugs are vegetable feeders, and pests of the
first magnitude. However, several families contain species which are
predacious, feeding upon the blood of other insects or the higher animals,
which is sucked up through their strong, jointed beaks.

132

Beneficial Insects

(a) ASSASSIN-BUGS

The members of this family are so pre-eminently predacious that
they are known as the assassin-bugs. Their mode of attack is truly that
of the assassin. Approaching their prey by stealth or lying in wait for it,
they pounce upon their victims and pierce them, oftentimes in the back,
with their beaks and proceed to drink up their life blood.

One noted member of this family feeds upon bedbugs and is known
as the masked bedbug hunter. This insect infests houses where its prey is
ae (b) AMBUSH-BUGS

The bugs of this family are called ambush-bugs because of their
habit of lying concealed in flowers, especially those of thistle and golden-
rod, patiently waiting for some nectar loving insect to visit their ambush.
The unlucky visitor is grasped with the much enlarged fore legs of the
ambush-bug and impaled on its strong beak.

The common species of this family are yellowish or greenish, marked
with dark bands and spots. The abdomen is broadened behind, con-
cave on top and very convex below. The forward pair of legs is very
much enlarged and armed with heavy claws with which the bug's prey

is held.
(c) STINK-BUGS

(Figs. 8 to 13, Plate IX, Page 27)

The members of the stink-bug family are furnished with glands
which secrete a very ill-smelling fluid which escapes through two open-
ings on the under side of the body.

While most of these bugs feed upon vegetables, some being noted
pests, several species are predacious.

The pictured soldier-bug (Figs. 12 and 13, Plate 1X, Page 27) is noted
as a destroyer of potato-beetles, and also feeds upon alkali-beetle larvae.
The eggs (Fig. 8, Plate IX, Page 27, natural size, and Fig. 9, Plate IX,
Page 27, enlarged) are placed on the leaves of potatoes and other plants
where the insects fed upon by the young are found.

When first hatched the young are reddish, as shown in Figure 11,
Plate IX, Page 27. The half-grown nymphs appear as in Figure 10,
Plate IX, Page 27. The adults are of two colors, as shown in the figures.

5. LACE-WINGED FLIES
(Figs. 16, 17, 18 and 19, Plate IX, Page 27)

The delicate, green, lace-winged fly or golden-eyes (Fig. 19, Plate IX,
Page 27), as it is frequently called, is a familiar object flitting about in
the cool of dense foliage, especially where aphids or other small, soft
bodied insects are numerous.

The eggs (Fig. 16, Plate IX, Page 27) are always attached to the
surface of a leaf or other object by a hair-like stalk about one-half inch
long. One author* states that this is nature's way of protecting the
unhatched eggs from the newly hatched larvae, which are so exceedingly
voracious that even their own unhatched brothers and sisters are not
safe when ‘other food is not available.

*Comstock, ‘Manual of Insects,”” page 181.

133

Beneficial Insects

The larvae (Fig. 18, Plate IX, Page 27) are common among aphid
colonies. When first hatched they devour these soft bodied insects at
the rate of four or five a day and at the rate of twenty or more a day
when fully grown. Because of the numbers of plant-lice (ney devour,
these spindle-shaped larvae are called aphis-lions.

In feeding, the aphis-lion seizes its prey in its long jaws, which are
so formed that each pair makes a tube through which the body contents
of the aphid are sucked up.

During its existence as a larva the lace-winged fly probably con-
sumes from 300 to 400 plant lice.*

Many other small insects are eaten besides aphids. In the article
referred to in the preceding paragraph, the author lists ten insects be-
sides several species of plant-lice as hosts of the green lace-wing of Cali-
fornia. Among these are mites, leaf-hoppers, scale insects, mealy-bugs
and psyllids.

When the larvae are fully grown they spin a white globular cocoon
(Fig. 17, Plate IX, Page 27), within which the pupal stage is spent. The
adult escapes by gnawing the end of the cocoon partially off and pushing
this up as shown in the figure.

As there are several generations of the lace-winged fly each season
their importance as destroyers of injurious insects is difficult to estimate.

6. WASPS

(a) DIGGER-WASPS
(Figs. 16, 17 and 18, Plate VI, Page 21)

We are so accustomed to considering wasps as creatures of quickly
aroused temper who resent any trespassing in the vicinity of their nests
by stinging the intruder, that many an innocent and beneficial member
of the wasp tribe is summarily put to death and as a result many a crop
pest continues its work of devastation.

There are fourteen families of digger-wasps in America north of
Mexico. Many of the members of these render invaluable service to the
farmer and gardener by destroying the insects feeding upon his crops.
In habits many of these represent a class intermediate between the true
predators, such as the ground beetles, and the true parasites, which will
be discussed later.

(a-1) FAMILY SCOLIIDAE

One member of this family, Tiphia inornata,; which has been pre-
viously mentioned, burrows into the ground in search of white grubs,
upon which it lays its eggs and upon which the larvae are parasitic.

These wasps are shining black and about three-fifths of an inch long.

(a-2) SPIDER-WASPS

Most of the members of this family dig burrows in the ground which
are stocked with spiders upon which the young wasps feed. A few spe-
cies, however, build cells of mud which are fastened under stones and in
other secluded places.

(a-3) THREAD-WAISTED WASPS

The wasps of this family can be distinguished from those of the pre-

sess ones by the long slender first segment of the body. The peculiar

L. Wildermuth, “California Green Lacewing Fly,” Journal offAgricultural Research, Vol. VI,
No. 14 veCyi 6).
134

Beneficial Insects

Fig. 29. Nest of a Mud-dauber taken from Rafter of an Out-building

development of this joint suggested the name “thread-waisted wasps”
by which they are commonly known.

Many of these species build large many celled nests of mud on the
beams of outbuildings and about farm machinery stored under imple-
ment sheds (Fig. 29, Page 135).

The cells of these nests are provisioned with spiders and caterpillars,
upon which the young wasps feed.

After dry spells these wasps are common objects about mud puddles
near wells or after showers, where they secure the mud required in the
construction of their nests.

(b) SOLITARY WASPS
(Fig. 15, Plate VI, Page 20)

These insects, many species of which resemble the fiery tempered
yellow jackets, are peculiarly subject to persecution because of this
resemblance.

Some of the members of this family are masons, building their nests
of mud; some are miners, digging tunnels in the earth in which their
young pass through the stages of their development; and still others are
carpenters, cutting out tubular nests in wood, and partitioning these off
into cells with mud.

One species (Fig. 15, Plate VI, Page 21) has already been mentioned
in connection with the sugar beet webworm (See page 44), and its bur-
row figured on page 78 (Fig. 14).

Another species builds a jug-shaped nest, which is attached to the
stem of some plant, and provisions it with small caterpillars.

B. PARASITIC INSECTS

While the predacious insects do much to keep down the enemies of
cultivated crops their work is not so effective as that of the true parasites,
such as the Ichneumon-flies, Braconids, and Chalcis-flies.

135

Beneficial Insects

1. ICHNEUMON-FLIES
(Fig. 5, Plate I, Page 11; Fig. 7, Plate V, Page 19; Figs. 9 and 10, Plate VI, Page 21)

Many times when our fields are overrun by a pest we wish that by
some magical power we could destroy it and save our crops. Sometimes
these pests do disappear as if by magic. Many times we little suspect
that the small to medium sized, wasp-like insects, which we observe hov-
ering over the field, are the friends that stood by us in our hour of need
and wiped out our enemies in an incredibly short time.

The Ichneumon-flies belong to the same order of insects as the digger-
wasps, already discussed.

These flies have long slender bodies. That of the female is often
armed with a long hair-like ovipositor (Fig 7, Plate V, Page 19). This
is composed of three parts. The central one is a tube through which the
eggs pass, while the two outer ones are the sheath which protects the
ovipositor proper. When the insect is alive the three parts are held close
together and appear as a single hair-like organ.

The name ‘“‘Ichneumon”’ was suggested by a fancied resemblance to
the Ichneumon of Africa, which is a mammal belonging to the same
family as the mink and weasel.

Mention has already been made of two Ichneumon-flies. Figure 5,
Plate I, Page 11 is parasitic upon caterpillars and was reared from the
western army cutworm. Figures 9 and 10, Plate VI, Page 21 represent
a species which destroys the alfalfa looper.

2. BRACONIDS
(Figs. 6 and 7, Plate ] Page 11; Fig. 14, Plate V, Page 19)

Closely related to the Ichneumon-flies is a group known as the Bra-
conids. The members of this family are small or minute insects.

Frequently dead cater-
pillars are observed coy-
ered with small silken
cocoons, or with a mass of
these cocoons fastened to
some object near them
(Fig. 30, Page 136). These
caterpillars have been
killed by the larvae of
some Braconid which
have gnawed their way
out of the worm and spun
cocoons in which to com-
plete their own develop-
ment.

One of the most inter-
esting forms of this family
belongs to the genus Aph-
idus. These minute para-
sites live within the bod-

ies of aphids. When ma-
Fig. 30. A Cabbage-worm killed by the Larvae i

of a Braconid, the Cocoons of which are fastened ture the parasite SSCBISES
to the Window-screen near it (Hnlarged) through a hole which it

1356

Beneficial Insects

gnaws in its dead host. If a colony of aphids is examined, especially in
the latter part of the season, many brown and much inflated individuals
will be observed. These are dead, and if no hole is to be seen on their
backs they harbor one of these little parasites. Whole colonies of plant
lice are often wiped out by these little insects. ;

Figure 6, Plate I, Page 11 represents a Braconid which is parasitic
upon cutworms. Figure 7, Plate II, Page 11 represents a cocoon of this
same species.

Figure 14, Plate V, Page 19 represents another Braconid which was
reared from a sugar beet webworm cocoon.

3. CHALCIS-FLIES
(Fig. 8, Plate I, Page 11; Fig. 4, Plate IX, Page 27)

The Chalcis-flies are among the smallest parasitic Hymenoptera.
Some species are not over one-hundreth of an inch long. They are
usually black with strong metallic reflections. Some appear quite green,
while others are yellow. These flies can be recognized by the lack of
veins in the wings (Fig. 8, Plate I, Page 11). This Chalcis-fly, as already
stated, is parasitic upon cutworms. (See page 44, and Figure 4, Plate
IX, Page 27). ;

The greater part of the parasites of small insects belong to this
family. Some are parasitic upon scale insects. One species is the most
effective natural check on the cabbage-worm.

Some Chalcis-flies are parasitic within the eggs of other insects.

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146

BIBLIOGRAPHY

The following is a bibliography of the references quoted in this Bulletin and a few
other publications on related subjects:

A. References Quoted:

E. H. Streckland, “Control of Cutworms in the Prairie Provinces,’ Circular No. 6,
Department of Agriculture, Dominion of Canada (1916).

Prof. R. A. Cooley, “Observations on the Life History of the Army Cutworm,
Chorizagrotis auxiliaris, Journal of Agricultural Research, Volume VI, No. 23 (1916).

G. E. Bensel, “Control of the Variegated Cutworm in Ventura County, California,”
Journal of Economic Entomology, Vol. [X, No. 2 (1916).

J. J. Davis, “Common White Grubs,’ Farmers’ Bulletin No. 543, U. S. Depart-
ment of Agriculture (1913).

John E. Graf, “A Preliminary Report on the Sugar-beet Wireworm,” Bulletin No.
123, Bureau of Entomology, U. S. Department of Agriculture (1914).

J. R. Parker, “Life History of the Sugar-beet Root-louse, Pemphigus betae,’ Journal
of Economic Entomology, Vol. VII, No. 1 (1914).

J. R. Parker, “Sugar Beet Root Louse Controlled by Irrigation—Four Years
Summary.”

J. R. Parker, “Life History and Habits of Chloropisca glabra Meign.,” Journal of
Economic Entomology, Vol. XI, No. 4 (1918).

Harry B. Shaw, “Control of the Sugar-beet Nematode,” Farmers’ Bulletin No. 772,
U. S. Department of Agriculture (1916).

C. S. Scofield, “The Nematode Gallworm on Potatoes and Other Crop Plants in
Nevada,” Circular No. 91, Bureau of Plant Industry, U. S. Department of Agricul-
ture (1912).

Davis and Satterthwait, “Life-history Studies of Cirphis unipuncta, the True Army
Worm,” Journal of Agricultural Research, Vol. VI, No. 21 (1916).

J. A. Hyslop, “The Alfalfa Looper,” Bulletin No. 95, Part VII, Bureau of Ento-
mology, U. S. Department of Agriculture (1912).

Mr. Koebels, Bureau of Entomology Notes, No. 95-K.

H. O. Marsh, “Biologic and Economic Notes on the Yellow-bear Caterpillar,”
Bulletin No. 82, Part V, Bureau of Entomology, U. S. Department of Agriculture (1910).

Dr. F. H. Chittenden, “A Brief Account of the Principal Insect Enemies of the
Sugar Beet,” Bulletin No. 43, Division of Entomology, U. S. Department of Agricul-
ture (1903).

Prof. R. A. Cooley, “Spinach Carrion Beetle,” Journal of Economic Entomology,
Vol. X, No. 1 (1917).

E. O. G. Kelly, “A New Sarcophagid Parasite of Grasshoppers, Journal of Agri-
cultural Research, Vol. II, No. 6 (1914).

F. B. Milliken, ~ The False Chinch Bug and Measures for Controlling It,’ Farmers’
Bulletin No. 762, U. S. Department of Agriculture (1916).

Boniquit and Slake, “Wild Vegetation as a Source of Curly-top Infections of Sugar
Beets,” Journal of Economic Entomology, Vol. X, No. 4 (1917).

J. H. and A. B. Comstock, “Manual for the Study of Insects” (1909).

V. L. Wildermuth, “California Green Lacewing Fly,” Journal of Agricultural
Research, Vol. VI, No. 14 (1916).

B. Other Publications on Related Subjects:

H. T. French, “The Beet Army Worm,” Information Circular of the Colorado
Agricultural College.

E. D. Ball, “The Beet Leafhopper and the Curly-Leaf Disease That It Transmits,”
Bulletin No. 155, Utah Agricultural College Experiment Station (1917).

Herbert H. Bunzel, “A Biochemical Study of the Curly-top of Sugar Beets,” Bulle-
tin No. 277, Bureau of Plant Industry, U. S. Department of Agriculture (1913).

147

E. O. G. Kelly and T. S. Wilson, “Controlling the Garden Webworm in Alfalfa
Fields,’ Farmers’ Bulletin No. 944, U. S. Department of Agriculture (1918).

Ernst A. Bessey and L. P. Byars, © The Control of Root-knot,”’ Farmers’ Bulletin
No. 648, U. S. Department of Agriculture (1915).

C. O. Townsend, ~Curly-top, A Disease of the Sugar Beet,” Bulletin No. 122,
Bureau of Plant Industry, U. S. Department of Agriculture (1908).

Harry B. Shaw, * The Curly-top of Beets,” Bulletin No. 181, Bureau of Plant Indus-
try, U. S. Department of Agriculture (1910).

C. O. Townsend, *’ Field Studies of the Crown-gall of Sugar Beets,’ Bulletin No. 203,
U. S. Department of Agriculture (1915).

F. B. Milliken, “Grasshoppers and Their Control on Sugar Beets and Truck Crops,”
Farmers’ Bulletin No. 691, U. S. Department of Agriculture (1915).

Charles R. Jones, “Grasshopper Control,” Bulletin No. 233, The Agricultural
Experiment Station of the Colorado Agricultural College (1917).

W.R. Walton, “Grasshopper Control in Relation to Cereal and Forage Crops,”
Farmers’ Bulletin No. 747, U. S. Department of Agriculture (1916).

E. D. Ball, “How to Control the Grasshoppers,’ Bulletin No. 138, Utah Agricultural
College Experiment Station (1915).

Leland O. Howard, “Insect Book” of the “New Nature Library” (1914).

F. H. Chittenden, “Insects Injurious to Vegetables” (1907).

E. D. Sanderson, * Insect Pests of Farm, Garden and Orchard.”

J. R. Parker, “Influence of Soil Moisture upon the Rate of Increase in SU
Root-louse Colonies,’ Journal of Agricultural Research, Vol. IV, No. 3 (1915).

C. P. Gillette and Geo. M. List, “Insects and Insecticides,’ Bulletin No. 210 of ane
Agricultural Experiment Station of the Colorado Agricultural College (1915).

Singerland and Crosby, “Manual of Fruit Insects.”

E. W. Scott, W. S. Abbott and J. E. Dudley, Jr., “Results of Experiments with

Miscellaneous Substances Against Bedbugs, Cockroaches, Clothes Moths, and Carpet
Beetles, Bulletin No. 707, U. S. Department of Agriculture (1918).
Ae Harry B. Shaw, “The Sugar Beet Nematode and Its Control,” Reprint from
ugar.
Wm. H. White, “The Sugar-beet Thrips,” Bulletin No. 421, U. S. Department of
Agriculture (1916).
H. O. Marsh, “The Sugar-beet Webworm,” Bulletin No. 109, Part VI, Bureau of
Entomology, U. S. Department of Agriculture (1912).

H. R. Cox, “Weeds: How to Control Them,” Farmers’ Bulletin No. 660, U. S.
Department of Agriculture (1915).

A448

INDEX

A
Abdomen of Insects. ..29, 30, 43, 46, 104
INGIGRVATSENOUS. ccf eo ee 33
ANGUGBIMSECES ein secs eee ees 29, 30
FNPeMESMCOUNEV Ric tadcnisciemencs 234
Agricultural College.............. 2,4
Aureslakedbimey ss o.2 0.00.6 0d 32, 89
PN GUSOCUIOLUS: cisco cals lea seas Dy)

Alfalfa, 5, 6, 8, 39, 40, 41, 45, 47,
50; Dil, D3, CB, Co, Hil Hs Ws

76, 81, 82, 84, 85, 86, 94, 98,
101, 104, 127
Alfalfa Cutworm...... 4l
Alfalfa Looper......... 8 20, 81-84, 136
INatureof injury. cs 265-22 sas: 82
Methods of Control............ 82
me ob18 6 tegen te Ree Pe eae 82, 83
5 5 OOD tr Oe One Ce CoRR 82, 83
Ce ilar SI IS ab SR te eM 83
COON» Jet eee oe 83
|PRS(S. o.oo.) 6 SOR O REO RoR oe 83
IMLOLELS oo cle Bio Oe ON Cea 83
[Bi CMeLISEOGYieiaass 5 <auciers ss ds 83
INatunaleenemies. 46 yo eaescn es. 83, 84
Alfalfa Webworm........... 7, 20, 84, 85
INatunelollnyunya-,6- 4-25-46 84
Methods of Control............ 84
IDESCHIPBIOMN. «646. ae sce dates are 84, 85
\WORS So cihe oo Ao RI roe eee 84, 85
IPWTSR Le obo on ee ene eee 85
INACIE SN. doe ate GR SIE ene 85
TBM SONY es, os secsis co ooacvouons nists 85
INaturalllnemiess. 9. )5 64625 85
Niall, «0:66 Bb Seen en eee 89, 90
Alkali-beetle or
Alkali-bug....7, 8, 22, 29, 89, 90, 92, V4
INISZOS|; oc bce SbORNe Ee a On ae
Amara, Egg-eating. . more 106
(NiRCTO OUAn on 6 de enone obo osc 106
NIA AM EMUSH aie: otis oc nd aeisie 86
LNGOLOIRORSTE 3 Uae Seat pnona anette eR phone 86
/NmiSUS IOUS Jo mene doen eels Gorm 133
Annual Meadow-grass............ 63
joe Of MESHES; ooacoooonooac 29
05:6) eo OE ee ee eae 114
Reesor Piert Like. 3,111-116,123, 134,137
INatunelon Injury. an sseeeeee ee 114
Methods of Control...........114, 115
IDESCrIpPtionss..o sneer us 115
ILS Ist toraiaem onan ceere ome cease 115
INaturalelenemiesee eee 115, 1lo
(See also Plant-lice)
/Nolonewis, (GSW, a naboconnedeegoc 136
Ap IS-lOM ca. ch se sae 26, 116, 133, 134
Appendix....... Sede okceean 2, 3, 138-146
ZATCHYLUSTAPICLChem nae eae

81
Arsenate of Lead, 32, 73, 79, 82, 86, 88, 96

Arsenical Poisons................ 33, 86
ArsenousyAcidl eek oe eet ene 33
ear a ccenods of Insect Control 31, 32
NSW ili tena iier cece erat ey count ot 112
ee Bien Deetlea aera 22, 98
Asparagus. . ; .63, 65, 66, 86
Assassin-bug. . Atos aaa cceeReo ee meni 133
Authocoris melanocerus............ 59
B

IBACtenian anit ictae Ss tana ee
pacterialllDiseases-a 45 eee ee 83, 109

Bait, Poisoned, 32, 39, 40, 47, 53,
79, 94, 95
Banded Flea-beetle............ 16, 92, 93
IDESCHIPtiOn seen eerie 92
ae ee A Ice ore rete eR EN 92
IDET aa eioeteictars cae eee 92
PAGES eeepc ci Aa he en 92
IBifciilistonyancr eae eee 93
a nleyR es enone one eee 63, 65, 66

Beak, of Sucking Insects..........
ETS rae ees sie Pia eee ee a Ss Ber fe hy ape 53, 119
IDMiegt IR ela oe padoloe one 3
era RET atriren py tey Mle nRa I Dberee tte 63, 66, 86
SOW Sees forrest si oes eB tah 63, 66
SLGIUGTER Selon oie GRICE ae ORR Ee 86
mEcarcedsNootsiaee een 6l
ISCO ES aepy mnths cotati ecees 133
CES eee Pete nace ney rte 29, 30, 78
Beet or Spinach Leaf-miner...14, 110, 111
INaturclofslnjunyaenem een eer 110
Methods of Control...........110, 111
IDESChIPtionneeae nen eerie 111
| BA, Seria sy Ciena CMO Cero 111
IMLime reer este rn tats read 111
FRUpoalie errs nie cio ours Sion 111
INGTON Ga, ck se eee ao TS 111
CifetislistonyA ere ieee 111
mEccEAVeaniness meee ee eae 59

Beetles, 1, 3, 29, 30, 48, 50, 51, 67,
78, 88, 105
See also:

Black Carrion-beetle
Blister-beetle
Bombardier-beetle
Click-beetle
Colorado Potato-beetle
Egg-eating Amara
Fiery Hunter
Flea-beetles
Banded Flea-beetle
Potato Flea-beetle °
Three-spotted Flea-beetle
Ground Beetles
Lady-beetle or Lady-bug
Larger Sugar Beet ee beetle
or Alkali-beetle

149

INDEX—Continued

Beet!es—Continued

Leaf Beetles

Leaf-eating Beetles

Sacred Beetle of Egypt

Snapping-beetle

Tiger-beetle

Western Beet Leaf-beetle
Beets, Garden... .63, 66, 86, 88, 99, 110
1Byxees, Sore, vocociosouncccn0eno 86
Beets, Sugar

(See Sugar Beets)

Beet-seed Louse, Black...... 14, 117-119
Beneficial Insects. . ...3, 26, 129-137
PAAGIEIC, oo obo ocado 3. 43, 52) 135-137
Predacious...-...-. 3, 43, 52, 130-135
Bibliographyaerc ceo. 2, 3, 147, 148
Birds, 43, 45, 46, 51, 54, 57, 81, 85,
87, 88, 108
Biting winsectsmare cr racer il, 2D, Dil, Ba
Mouth Parts of.. ns
(Coyatgre! Oia sacacocacavaccccs0¢ DS
Biting yleeat meederss en meaeeee 3, OY
Biting Root Feeders. . “5 3), XS)
Black Beet-seed Louse. Segchot ee 14, 117-119
Naturelof imnjunyane rece eceenee 117
Methods of Control............ 117
DeScriptiony oe oo cea 118
Witaelless IDS, 4 oo cc on sn occcs 118
IPWSEsosonoasocebooovcH Eade 118
Wiitaysgel ILS5.6 oda cc occcs00s 118
BifedglistonyAeree eer 118, 119
Blackbernyane eae cee 86
Blackbird see eee 45, 81, 108
Blackbird CrowAeeenee eee 51
Blaclaislister-beet leaner 2298
Black Car a Teun Sil Glas eae as 94
Black Leaf 40...... 33, 114, 117
[EAE coon ocoaoauoooesccococuve 124
BlishtaWesterneeene mone eric 124
Blister-beetle..............22, 96-98, 106
INE VebIRS Ge ITMICIAYs o.0nccc0s00006 96
Methods of Control............ 96
Descriptions oreo: 97, 98
lDeisva ear wana nto cg ee .c US Bc 97
Fit [eanvaluStageanoneneeene 97
Second Larval Stage..... Say oe 97
AWovigel Lawyelll SARS, ogo oasc0e 98
PUPA actierrsate cimecie hare se 98
PNG (bane oxen cao olcara a aia bo 98
Life History. . Bes 97, 98
Blister-beetle, Nene “pray Ree re 2298
Plister-beetle, Black... Pete 22, 98
Bombardier-beetle BR RA ats Barty 130

Bordeauxe VMitxtuncenee reer 92
Botrytis bassiana. . 87
Braconids, 3, 10, 18, ‘43, Wi. 135, 136, BA
Breathing of Insects. . <6

BrOWn-CyStaa eer eee ah
Buckwheat. . 50
Bugs, True, 3, 2, 29, 30, 111, 119,

122, 132, 133
Burningaeeeeeee 32, 63, 89, 120, 125, ie
JRwGOIAG BUSI cogoacocsdoces cos 118

iBturaronminye Oo cacccccsc000ssa00 108
Bttcher-birdseeee eee ce ceeee 54
IBuHeeAONES, choos asccs0scc0ae) HO), G7
€
Eabbagereee seen O5h OD PROOMOOMOS
Cabbage-worm.............---.- 136, 137
California Devastating Locust..... 100
Callitosaia Sarslke, oocgonaccscceac 54
Gannaen: Seye est oe eee 86
Gantaloupesaeeeee or ooo oe eerce 63, 86
(Care Gi SOBWER: coococsocconscce 34, 35
Carrion-beetle, Black....... 94
Carrion-beetle, Spinach. . eee ag yh 94, 95
ATROUS hace See Cee 66, 86
Catalpates Son W Ee ic etait eee 66
@aterpillariallen yee ene eee 130
Caterpillars, 1, 3, 29, 30, 38, 67, 7
Ril, 120) 135, 136
Caterpillars, Leaf-eating.......... 67
Caterpillar, Yellow-bear...... 8, 18, 86, 87
GaterpillaryZebrakee eee 8, 14, 87, 88
Gauliflowersee eee re reerrree 63, 66, 86
Gelery oa ei eee 63, 66, 86
Chalcis-fly...... 3, 10, 26, 43, 44, 135, 137
Chloropisca glabra................ 59
Ghenopoditimepean a aneeeeaeneane 86
Ghierryist jhe Seiten Seen 66, 86
Ghiggerssoi aes a eee eee 106
ChinchiBugaseeren eee bee cae 119

Ghiting aie oe ee
Ghinysalis: oi seyco an ese eee 30
Classification of Insects...........
Clean Culture, 1, 32, 91, 94, 104,
LL, WO, WD, WAS. W27

Glick=bectle=a eee neee eee 52, 53, 54
CGlovernn0u a Bia eee 40, 50, 66
Crimsontecco. sane nee

WEE bee ayy Rea ees a a 63, 66, 82
Wihite yee ree aaa

Clover Leaf-hopper.. 5 ance eeere 24, 126-128
INEVEUIRS Gi Way UTAo os acccvocccns 127
Methods of Control............ a7
IDEScrIDtION: ERA nee 127
Bait eae ine a Heong ROE lay
Nymph 127
Adult Aik Ga eeke eee 127
[iferislistonvan on eee oes 127, 128
Cocconweaeeeer 44, 45, 76, 83, 85, 87, 136
Colorado Potato-beetle. . 89, Ie

College, Agricultural............. 2, 4
GolorediPlatestasee ae Mp Ay 3, 2h, ile 27
Common MallowAneeeeereoe eee 125
Compound Eye oe eee BEI ico 76
Contact Poisons. . Pen ols A
Control of Insects..........--+--- 31-33
Natural Methods.............- 31, 32
@ulttralMethodsseeeee eer eee eee
Artificial Methods........... Bi, 92, 33
Control of Biting Insects......... 39, 33
Control of Sucking Insects........ 33
Cogser's IRE. ocanceocgeceacans 109
Gornth eee ee: 50, 53, 63, 65, 66, 86, 99

150

INDEX—Continued

(Covi ROCA copa cosuee Cou E OS 38
(Comm IROGENKOGIN. con ooscseennece 31, 38
Cost of Spraying. . Se aro ee
(Celiticranuciye ie BAe Re aan cis Serene 56, 58
Cottonwood, Narrow-leaf...... VM, No, 3}
County Agents =e aciteics Chea Ra eS 2,4
@owalbeates menses - 2 den c: 63, 66
(CHESS. 0.6 deka oR 63
Crickets, Field......... 3, 16, 67, 109, 1 ie

Crimson Clover. .
Crop Rotation, 1, 31, 50, 53, 57, 62, 63, 65

(CROW. o no. d.0 6k AOR CRO CROs 51, 54
Growablaciibindien.s4.6.s05 5006. - 51
(CuctinlsoGssss se eneeeeeeeeaas 63, 66, 93
Cultural Methods of Insect Control 31
Curly-top.. .8, 24, 60; of, 124, 125
Currants. . 86
Cutwerms, Bi) ‘4, 5. 20, 26, 38- 48, 87,
130), WBA
INgieune OF IibIAys oogueeseoocbe 38, 39
Where to Look for the Worms. . . 39
Methods of Control............ 39, 47
(Cutswodin, ANNs suo oueeacaspees 4]

Cutworm, Pale Western, 10, 41, 45, 46, 47

Cutworm, Variegated. . .8, 22, 47, 48

Cutworm, Western Army, “8, 10,
41-45, 46, 47, 88, 136

D
Dalida. o6 cos decent te ae 86
Dera Clitoris. 6 a cae eee One cee ner 63
Destruction of Summer Hosts..... 117
Destruction of Weeds............ TiN, LZ
Development of Insects......... 3, 29, 30
Differential Hopper. . 16, 100
Digger-wasp...... 20, 4B, ‘AA, AS, 134, 136
Digger-wasp enemy of Cutworms. . 44, 45
IDSC.5 aie 80.00 Grd Oa ae eee ee 50, 53
IDIECINGs ogcougeee 31, 40, 50, 53, 103, 104
Diseases of Insects....59, 83, 88, 109, 121
DOC LA (RUIMMESS) os oes ace ae os eran tgene on 86
Duck Hawk... siepceelacnicerentn aan hn Ole)
Dwarf Pea Bean. . ee lo ei tire 63
=
eIWOntnstenies sea he ae: 38, 59, 64
ieezeatinesAmaray sane sey. a: ie
[Bayes IP evant (ae aie ane eee ieee 66
Eggs, Grasshopper....... 96, 97, 104, 108
IE GSS Of WHSISHSsocogcobnaacasnsoon 30, 31
JEJiS SGECUACK a doe pec setae aod 52
[BK 6 cane a olne a ele ores Seeder nance 66
EnaswsG, CNIS. cs o0dc0004000000C 59
ET USCoTAV LLU eee an one = 109
Emulsion, Kerosene......... 33, 114, 122
[EUG ABTIUS S0sa 500000 000000066006 118
[Evigiiiee SH7OMecosacceopoecss000+ 24, 128
See note opposite Clover Leaf-
Hopper in Appendix
BYES OF IlMSSCS. cooacccoooccde006 76
ip
Fall Plowing.... .31, 40, 50, 53
False Chinch Bug. . 6, 24, 29, 119- om 123
Nature of Injury Shorey nee eS 119
Methods of Control........... 120, 121

IDI NOM sodaaovsodceoodues 121
CO Meee ace tes ape rel evecaherewnke mavens 121
Nymph. 121
JANG LBNL: wich) Ree BIE Leah oon clare 121
BifeMilistonyMesercmien co aoe 121
INE eel IBIAS, cocoaoccvgcce 121
Fanweed.. raat fe eon At Ne 6
Feelers of Insects 5 ta RRA Re aE 29
FieldiGricketssen nee 3, 16, 67, 109, 110
Fel elrmerieprcy oataws iene ayaa cieree a Be 4
IRIGY ISUTND?. sono coo uoacaebasee 130
aoe... oancoaane I, \S, BY), Sh, 96
INgieUIRS OF WAYLIAY. oon cccocasoce 91
IMiethodsiom @ontroly-e seer 91, 92
Flea-beetle, Banded........... 16, 92, 93 ~
Flea-beetle, Potato. . Re PLONO3
Flea-beetle, Three- -spotted. . MR cetcay 16, 93

Fle SInehltes yates th ete G ve Rois Fy amie 105
Flesh-fly parasite of Grasshoppers 16, 105
Fllesmae ets nis SW tae Sr ugenlal | 30
Flies, Chalcis. ..3, 10, 26, 43, 44, 135, 137
Flies, IL eShisis Ate O ATMS ae Wi ce 105
Flies, Ichneumon 3, 10, 20, 43, 83, 135, 136
Flies, Lace-winged. roe dy AO, 116, 133, 134

INOS, IPBVRASIBIC. 6occcccs0ccaccus 52, 81
Flies, Robber. . EIA as 20, 78
Flies, Syrphus. . sree teed thc Oe poe a m0) 59, 116
IEINes, Ta@MiMA, coooccos IS, 20), “7, 85, 87
Flies, Two-winged....20, 29, 30, iii, 121
Flour, Low Grade.. : 532 oS
Food Plants of Insects. aes ee ena

ROSSORESAP Eee Ctr SAT ates ih
oxasliailinGreenneeeneyee rnee eee 63
ISAS ISWE, soo ncccvccecceca00b6 ~
Fupsiearatts. Soil, ocoooncacsvoncsec 65
Fegtin GIR recy een eae ean. 94

Fungous Diseases of Insects, 59, 88,
109, 121, 123
IFUIRONY WYO). soo cocoocoaconuc 72, 79, 82

Gaillardia pulchella. . 121
Gallwerm (See Root-knot Nema-
tode or Gallworm)

Galen IBSSiS.. n0c0cnevcvssoves 63, 110
(Carclenal2easae eee 63
GES Weleda. sede Ae ee 53

Giant Thorn-headed Worm....... 50
Golden-eye (See Lace-winged Fly)26, 133
Golden-glow 115

Goldenrod se saci eee 98, 133
Gooscbemyayc eraser: 86
Gowler WOR, o.cccnccncscccoe 107
Goshawileaee te epak ep heet ne ee tie 109

Grain, 5, 8, 38, 39, 45, 50, 53, 79,

80, 94, 101, 119
Grapesmenmniy eta el hen Usa dente L 86
Grass. . .49, 54, 80, 99, 123
Grasshopper Eggs. 16, 26, 96, 97, 104, 105

Grasshoppers, I, 3, 8, 16, 18, 29, 30,
31, 98-109, 130
INBiewIRe. OF IATBIAV. occ osaeeceor 101
Methods of Control........... 101-104

151

{I NDEX—Continued

Grasshoppers—Continued
Eigosna te ames 16, 96, 97, 104, 105
Life FiStOnyAee eee eee 104, 105
Natural Enemies... 4.25.2. -54. 103-109

IDISE2EES Giscscoccvocoooosboace 109
Great Homed Owl..............108, 109
Green-berried Nightshade......... 94
Greenvkoxiiliail aera eee 63
Green Peach-aphis...... 24, 116, 117, 118

INatureoh Initinyermans ee ee 116

MethodsjofiGontrolha 5 eee. 116

IDEScriptionsaeene eee 116

Stem-mothers eer ere 116
Winged iibicesa aren ieee 116, 117
Wainelessilbiceter ere eres Woy, LU
IRermales nn earn cner 117
Mae JES O MG Oe hon Moco on oni ac 117
Egos SA aaienr ieee See ee 117

Life SERioe Aarons eored EN RENE SG 116, 117
Ground Beetles, 26, 43, 54, 81, 105,

, 130

See: Bombardier-beetle

Egg-eating Amara

Fiery Hunter
GroundiScquinellaee aero 108

WWISS.cocoocs 30, 31, 38, 43, 45, 48, 50, 97

Grubs, White, 3, 5, 10, 31, 38, 48-52,
53, 54, 97, 134
Gyrialconteee sen eee 109

el
Isbin STAKE. coococcooopapas ances 107
lSbeive Wors00 ssocapcoddccoos cl, IM/, 1108
Idandiicking saree nme: 117, 120, 122
Hand Seaver pb lie ca ae oe 2 a 36
Harrow. . i eye aarti 53
Harrowing. . : nae Bil, ‘ios, 104
Biarvestmens 0: (eto ae a 106
Fai acts wna wats Nr wne chic snes 108, 109
Hawk, Sharp-shinned............ 109
SENS, SSMNGEOWocooncacddo occas 109
IREMAK, SWANITSONGS. occ0ccn0nc0ccce 109
Fleackot@linsectsnaase eee eeninee 29
IleantioimlmSeCtSeen inte eae 46
IF CUBINIOWS, oooscoccscoosooccader 86
Elemtptcr Cae eet ee 119
Fem pci rae cere re eben ae 63
Heterodera schachtii.............. 59
JARO WAC oooccasccecsan0aguaoe 119
Hibernation of Insects............ 32
Hippodamia convergens........... 132
Hogs, Pasturing with............. 50
lolly hock aan eee eee ei: 86
Home-made Sprayer...........-. 37
HioneysDewsaeer ar nore 114
lnlojoyseir IDOE, coc ononaccane 99, 102, 103
| plojos arenas dinate olin Pita nicien coir 63
IGORORCNS Ns concoocadococ00n00 65, 66
ISS IBA, 55 coop onan oo does oe 119
“twraysyse INGCES “so rcccacvnsccces 6l
Fayacinthiss.: 03 Sate sentra ieeacrces 86
iEiymenoptera=rane nee eee 37

I
Ichneumon-fly......... 3, 43, 83, 135, 136
Ichneumon-fly parasite of Alfalfa

OOP LEE Aaa oEee 20, 83, 136
Ichneumon-fly parasite of Western
Army Cutworm............ 10, 43, 136
Identification of Insects.......... il, 2
Tinclestern al ee autre mae D. x 149-157
ASE CESS rie ele ence nea ee one 3, 29-33
Abdomen of. . 29, 30, A 46, 104
ACUI eee ce oe it ec 29, 30
Antennae of. . 3 ; 29
Beneficial Insects. . 134 26, 129-137
Rarasitich eae 3. “43. 52, 135-137
Predacious......... Bh 43, 52. 130-135
Biting cern error GB, AS), Bil, B2
Biting Weat Reeders. see 3, 67
BitingsRootikeedersss pen enenne , 38
Breathinciofeee eee eerie eee 29
Glassificationlotae ener ee neee 3, 31
Gontrolioh tn eee 31-33
Control of Biting Insects....... BSB
Control of Sucking Insects...... 33
Dev clopmentiothas se eeeene 3) 9, 30
IDIGEEASES Olaccoacdons 59, 83, 88, iS 121
Egesiohie eases dee ec 30, 31
Byesioiseic., wi8c cha alee
Reelérsiofaiens sav ee ee 29
RoodtPlantsiolan ease 32
General Discussion of.......... 29-33
Flea d Of sc ics Sipser 29
FIeart Of... Benue eee 46
ISNSARMEIOIN Ola naconcvcocnerse 32
Identification ofA sees 1)
WEA AUTONSIE Ofsysccoorsosococoe 30
Jaws Ofte es sie dos cas sae 29; 31
Warvacvof. si ae 0s ee 29, 30
Weat=cating wanna See eee 79
lBcateKeedersnn een ae 3, 31, 67, 111
Bitings 2: Quasans ee eee eee f
Sueleing ei ash a Nias ates ae 3, 111
TRESS OF UUM eae wen am ene 29
Metamorphosis of.............. HS), 30)
Methods of Control of.........3, 31-33
Fe Nc Hun tolte) Wire enerelmataia reales « 31, 32, 33
@ulturall is ca eae Biles?
Naturally aoe eee eee 31
IMIGNBIHE Of cocacooccdoeoccucas 30
IWIN IPEVHES Oly oocsconcauac 29, 30, 31
Natural Enemies of, 31, 43, 44,
45, 46, 51, 52; 54; 59) 77) 78;

81, 83, 84, 85, 87, 88, 105, 106,
NO, WO, NOS), ld, Ie, WI,
123, 129-137

Parasitic Insects Bencneel 3,
5 D2, WBI=137/
Predacious Insects was
43, 52, 130-135

Proboscisiolzeereren eon nne
SProlepsioharast ten see 29
Propsmoherener rs ee meee 29

INDEX—Continued

Insects—Continued

IRootineedersian ek oe eo, Sl. 3867
FSI Disa emia sts Mi ceoreciawait ewer al 3, 38
SUCKING ee ene ainicee were irre oe 3, 55

Scales of 134, 137

STA) Ohon do. de Oe a ae ne eee 3

SIAC EST Oleg asia sie denne sete ve 29

Structure of.. 3, 29

Sucking Insects... .3, 29, 31, 32, 33, 119

Sucking Leaf Feeders........... 3, 111
Sucking Root Feeders.......... 3), 5D)
Thorax of. . ML se 29
“The nGzC Oe a 29
\NYTAERS Oikos cb deo Cannel ene ERG one ecg 29
MaSGCEICIGIESHy we Mie cn. aia eter ais 32
Insect Powders......... Biota, canted 33
Integument of Insects............ 30
Introduction to Bulletin..........
Knigationys..c:...... 1, 56, 62, 72, 84, 92
IBN NY 5.05 3.0.0 OER ROR REN meee
NGM Se ciace Scene einiew a 6 56, 5 7
SISTIAG, oo.0.00 8.0 One Ce omnes 56, 57
SawsyotmlmMsectS. s..2 nc. 66 bee cake 29; 31
) JfeiaS towers ooo Coon BeOste sa pains 48, 50
K
IK BIBI S 064.9 ales ents aoe ane 65, 66
IKGNC. 5 con 0:0 oot Bie Eat eae ae 63, 65, 66
Kansas Mixture, 39, 40, 94, 101, 102, 103
Formula for. . MESS eet oy is 39, 101
How to Make. . 2 40, 101
How to Apply. . Be 40, 102
Time to Apply. 40, 101, 102

Treating Fields Before ‘Planting 40

Whee 0 ANS Nococcessodsoooe 102
IRETOSEMC a eesti Lieve teace 96, 103, 114, 120
Kerosene Emulsion..........33, 114, 122
Key for Determining Insect Injury

to Sugar Beets...........1, 2, 3, 4, 5-8
olanatiOnuOla aay aime on 4
Iaapsackrsprayenns se. ae ose. 36, 89
IOI Era Diners SAK Sif livsiees sankey ss 63

IL
Lace-winged Fly...... 3, 26, 116, 133, 134
Wadwapcetle reac. 22, 20, 59, 115, 132
Lady-beetle enemy of Sugar Beet

IRO@OESITCE Re Ae Sete de eles cls lattregens 12, 59
LOK SUE ara cee oe Otero
Lamb’s-quarters, 69, 71, 75, 86, 93,

94, 111, es
WWamtenn Urap., : «2 cle spel Ge.

Larger Sree Beet Leaf-beetle, or
Alkali-beetle....7, 8, 22, 89, 90, 92, oe
Nature of Injury Sa We Ronse GEA Oe

Methods of Control............ 89, oo
IDESCHIPCIONS « oyecis,cacec secure 90
CLE, obo CS a er ey eae eS 90
Beira thes ches atte ee or metas Sue 90

IP Wow aiiog carotene told Glos wissen oc 90
ISCCtleNe IM ate cate re er ae 90
arnvacofilmsectsse sti aac rae 29, 30
Water Planting was ei ee 32, 41

Laundry Soap 114
Lead, Noe of, 32, 73, 79, 2, 86, 88, 96

Leaf-beetle, Western Beet..... .22, 90, 91
WeanBeetlessa ene eats ee 88, 89, 91
Weal-eatingwScetlesser anette 88, 89, 96
Leaf-eating eacpillarss: Bs late 67
Leaf-eating Insects. . “id: 67, 79
ILeait IREGCSS 5 coos coon ood Ke 2 Bil, 67, 111

JENS LOVe Sisto cle dicts ominn eo oma a iaiOn 3, 67

Sucking sei cee neha noha a Brill
Leaf-hopper, Clover. . .24, 126-128
Leaf-hopper, Rose............... 123
Leaf-hopper, Sues Beet...8, 24, 123-126
Leaf-hoppers. . We UU, 123-128
Leaf-miner, Beet or ‘Spinach. .14, 110, 111
Leaf-miners............ l, 3, 67, 110, 111
Legs OF MWOSAESS 5 coco 00 nc 000ccp oC 29
[Weratil seyseu eras ects aes clan toners alse te 63
Lesser Mere tory | Locust. . eee LOO
Lettuce. . Fav RIERA 63, 166
Lima Beans. I A en NTR ERS 63, 66, 86
[Gime mean sae n mmtar yin hati 33, 63, 89
ILirane, Ate SlEIKECl. 5 no coon ce 000aK 32, 89
Lime, Quick. . Hye oo OS
Lime-sulphur Mixture. . BD, WIS), Hie, Wi
Live Hopper Machine. . 103
LING SEWN. noc bcoceace 40, 55, 62, 74, 102

Poisoning of... ae oe 74
Locust, California Devastating. . 100
Locust, Lesser Migratory. . 100
ILOCUSE IMME, soc coon senoane 18, 106, 107
Locust, Red-legged.............. lo, 100

Locust, Rocky Mountain, 98, 100,
101, 106, 107

ILONBATEISS 3 as 5 nib ale 0 omodnlelneele 121
Lowy Greece TOU oc cccncosccobes 32, 89
Loxostege similaris............... 84
ILujoine, WMO. ccc coocccveovenge 63
M

IMESROSINMUIR oc odbodousovoKovod 115
INARI SOES WA een nts Arieeleiminteeai ons 30, 77
MallowACommonteneten eerie: 125
IMRVaeeliacau siatia att gee emery oe 110
Manuring. . Bee ners 1
Masked Bedbug Hunter.......... 133
INiavebectler meer inmranlinel as rae 48, 51
Meadow... Dy EY, Dil, 52, 53, e
Meadow-grass, yAinaualy sae sinen et
IMieaclow7 ILaidk. cn 4ccou0unaneunes 45, i
Meadow Oat-grass, Tall.......... 63
Mealy-bug. aN 134
Vee areal Methods of Insect

Gorntrol iar une meen valah nese itt 96
Metamorphosis of Insects. . 9, 30

Methods of Control of Insects. 3, 31-33
AT CII Call pear oP re iit 32, 33
Gurlttinall yas eee riy: tepan e yotpe ites Zi, BP
INA Etirall ergeen ween gee Sai ues itr ‘ 31

INI CER aris ele Nomen ated en 108

IMMETOLCMOAF S9oa000 000000086 Bpeats 10

INTIS RSa.8 eee orate ictal als mre erent 38, 67

INABTIXeo eb Scotto Gta tats Glee tha giataae 63

ISAT cea eet scatterer ne on EL 65, 66

Miners, Leaf (See Leaf-miners)

153

INDEX—Cont inued

IMGESIDIE OB, ccs cccoseascoacosos 32
Mite, Locust. . doeosncoowe LS, MGS, NOY
INJTEES Eien ci sci es en 29, 106, 134
Molhigowerticillatas neneeee reer 121
Meltingvoi nsectssee eee nee 30
Morning-glory............ 86
INIothSSe eee eee 2D, 30, 67, 78
IMGWOS, OMS. oc sccccccsasccsace 38
Mouth Parts cf Insects....... 29, 30, 31
INJO Wine Sete erences oor 82, 84
IMtid=daul bere ae ane ee 135
IMitskmelonars nee nee 66
IWiuistardis Rita seers tenho mere 63

Narrow-leaf Cottonwood......57, 58, 113
Natural Enemies of Insects, 31, 43,
A445), Ab. dill, 52) 545998 77
78, 81, 83, 84, 85, 87, 88, 105,
106, 107, 108, 109, 115, 116,

121, 123, 129-137

Natural Methods of Insect Control 31, 32

Sees Buminge 32, (63,89) 1200527
Clean Culture, 32, 91, 94,
WOE, Wil, 120), IA, WAS, 127
Crop Rotation, 31, 50, 53,
57, 62, 63, 65
Destruction of Summer
OSESISS ee eee 117
Destruction of Weeds..... AM, AB
Discing. .31, 40, 50, 53, 103, 104
Hand Picking...... 7, 120, 22
Harrowing... .31, 50, 53, 103, 104
Irrigation....... 56, 62, 72, 84, 92
ate Plantineanmea err 32, 41
Mechanical Measures..... 96
IMOMAING, coosccopoucadoae 82, 84
Picking Infested Leaves . . 110
Plowing, 31, 32, 40, 50, 53,
56, 57, 104
|SXo) Nitaveseemenia aim ston mies -cae 40
Scattenin canner 91
SuickyaS nicl Spee ere 120
INematodesy an eae ere 6, 59-66
Root-knot Nematode or Gall-
WOLKE Sushi setae aan aoe ie 3, 6, 64-66
Sugar Beet Nematode. .3, 6, 14,
31, 38, 59-64, 65
INicotine; Sulphate ase neE an ete 121
Nightshade, Green-berried........ 94
INvimphis 4 Sece7c ter eiee earar 30
Oats... Beas .63, 65, 66, oe
Oils, Miscible. PSIB) CAT IeS Nee ae iers, SE
OulshiSolublessitesit weer eerie 3
Onions asec oc Cae 66
Outline of the Bulletin........... i, 2; 3
OWSONEOP soscancccv0esacuc 43, 129, 136
O@wleGreatlsloneduaa ae eeeeerio: 108, 109
OwlemViothsaasee eee eee 38
OWwlsise nye eee, ce ee Biot 108, 109

Pale Western Cutworm..10, 41, 45, 46, 47
IDZSEHINGOM. c oooccavccoosangoe 45, 46

We nits ane a) ee en 45, 46
Pupareinncch soccer aes 46
Moth tists aug ce, moe eee 46
Biferlistonyaeae cee eee 46
INaturallle neni esa eee 46
Parasites. . .43, 44, 129, 130, 135
PardsitiolPliests 2) ae 52, 81
Parasitic Insects........ 3, 43, 52, 135-137

Paris Green, 32, 34. 35, 39, 40, 47,
53, Os, JO, 72, 73, 74, 79), 2,
86, 88, 89, 92, 96, 101

Paris Green Applied Dry......... 32, 89
Paris Green, Caution Regarding. . 37
Parsnips.. car sea eee . 63, 86
Pasture. . 4S 2 DBE 54, 80
Pasturing. with Hogs. Laat baal Ree 50
Realeanw |) wari ee 63
Redehy. eek Gee oe ee eae 66, 116
Peach-aphis, Green ..... 24, 116, 117, 118
I AStiODICCE eee hey Da oreo 6.5 86
PEAS i Ao rsniea ene es 50, 63, 06, 86, 99
COWectes <a etsilaara ae 63, 66
Garden) 25,45 ee 63
SWEEU Lagoa laid one eee 63
HAGE Sopoemoneeaesdackadcoss Wail
IPEISOOTBESS, ooccsndcomcessaos 119, 121
Pheasants. . ge sc 5
Picking Infested Leaves.......... 110
RictunedsSoldier ours =e 135)
Pigweed Wiis kets aia Seon eee itil
Pigweed, White. . ees 3% 111
Pimply ISOS. wcsaaeseceo+--- 93
Binksed ahora edo oa ee 63
Plant-bug, Tarnished......... ©, 122, U2

Plant-lice, 3, 7,29, 30, 111-116, 132, 134, 137

INattnerofeliay tavern 114
Methodsiofi @ontrolyas ses plea lal by
DescripPtionse eee eee 115
[SifeNelistonyae ee eee eee 115
INaturallenemteseas eee Md, Wile
Planting, Late. . 32, 41
Plowing, 1, 31, 32, 40, 50), 3, “56, 57, 104
Plowing, Fall ate aa bree Bile 40, 50, 53
Plurinits3 8 ee eee eee 116
Poison. ...-- 72, 79, 82, 84, 86, 92, 96, 114
Poisoned Bait, 32, 39, 40, 47, 53, 79, 94, 95
Roisonings SLOc an asa 40, 74
Poisons, Arsenical. . pee. 33, 86
IPosoras, COMACE; cccc505000c¢ BD 3B 114
Poisons, Stomach. . 40: Ee me
POppYe tee ca chen ee 118
Rotato-pect| eae eee eee 89, 133
Potato-peetlesEoloradoss ae aes 89, 132
Potatomslea=bectleass ae 16, 93
IDESOROHOM,. 5 5005cc0ucocccocs 93
IVINS Busia ie A ee 93
Adult. 23 0.036 ee eee 93
Life History. . 93
Potatoes, 45, 50, 5B 63, 65, 66, 86,
93, 96, 133
Rotatocsm 2inip lyanae eee ee 93
Rou ltmyznen ies area 40, 85, oh 1s

IPONISTEV WEEE. soc scnbocosnconene
Predacious Insects.....3, 43, 52, in Ge

154

INDEX—Continued

Proboscis of Insects....... peace se 29, 76

Prolegsiotslmsects) 4s. ..20- ea: 29

“PROS Ot Ieeeeltsycoucatoagcueds 29

NSAI Smepeeet cence ae eet es 134

[PuiaayS) ims G direeions Claro aon 66, 86, 94

Pipa Ol WASESEOssoogese owee ou Eoee 30

|PRUVDEUTTWII Os als ors Gets ORR O RRR eoCnD Ieee 30

[Pryrriyolie) Uinleleleg aod 6 oe See oe oe 52

Quiche liste ooo colo ie pene eee 33, 63

FRetoloitesntislasiie sac. css ¢ si cca ne

INACHSh eee ee er) 03.60) 86, 121

IRAYOR. «.n'o16.6:0 08d SIO; PERE RSE en eaeae 63, 6

IRAGS SBGNs 5 5. 010 CEE eon 86, 119

Red-headed plooeperier “oe eee 108

Red-legged Locust. . seactith 16, 100

Red Top. ; 65, 66

Remience, Figures, Explanation of 2

IRGDENSGES, & sic:d Shenae Nome Eee 33

IRUAWISB Sac Hb. 06'.0 Ce eReno Me atonal ars 86, 87

IRGISISEPIN 7:0 cca clo ce RCC tone Rare ones 20, 78

IRI SIGS. 5,6. 6-6 Ge One SEER RRR eae ee 45

Rocky Mountain Locust, 98-100,

101, 106, oth

FROM CRIN Seca tces Sa oe,

Room eeGenssayes ne 3, Bll, S 67
Biting Root Feeders............ 38
Sucking Root Feeders.......... . 55

Root-knot Nematode or Gallworm

3, 6, 64-
INatunerotelmyunyeaaee dese
Methods of Control............ Oo
[Et eMiStonyAe tastes. a. OD, 66

INGOESIOUSCHH ey Gs cc falas 3S, 55)
See: Corn Root-louse

Sugar Beet Root-louse

Root worm Com... 2 5.0-.-06.: Bil, BS

Rose Leaf-hopper. . ie
OSEBs cd: 0.6 dade eee ee ene

Rwimexe (Docls) tf. 44s nal. 86

Russian Thistle, 69, 71, 75, 86, 90, 93, a

INU ta aC Amey arse fs pusese cle sayarti acs

IR Ce oe Ba weg 63, 65, %

Sacred Beetle of Egypt........... 48, 49

Sal Siti Ape er Th iis orarticemasiees 66

SA Clot Slamee ace eo Gearon notes 90

Scalevinsects: 5. c 005. Seles nace 134, 137

ScatteninealmsectS. ssn scene 91

SGI. 3's ih Meee Met eae RC one 134

SCONOLOMS ess ois a seceis wey sian cicbes ates 106

Sagel Wieeaiinnsae, oobedoasoeusuccs 53

Sharp-shinned Hawk........ : 109

Sheep, Pasturing with............ - 62, 63

SIGE JE OCS aes eer oes

Sagiken Calitonmiay. nee sae ees 54

SIATRULOS, 6 5.5. Se Ee ents 88, 115, as

IMMOLMMSECESH i a. csyac Sie sine oe

Seppe 5 ease Sergiy a meen eer ; ;

IKeUTal eo OBlcikcoe MOOR Ie eiociin eae 51, 54

Skule, SooweaC lo ca coccocvassc0doe 54
SAAS. sh60000s00000090 52
SOG Dare crc ia as 33, 114, 121
Soap, Whale Oil........ 33, 114, 120, 121
SoOaj0, LAwIaGhy,occccos0cccnec0us 114
SOa bee Grolerats aay SIRE oe oH roe ENG 5
SOul EWMVIEEVNES, 5056coccngerve0cs 65
SGlanumunost.atunnirnen pee eee 86
Soldier-bug, Pictured............. 133°
Solitary WESD.occcc0cscce MO), A.) Bs, NBD
Solitary Wasp enemy of Sugar Beet
WENO. cos cseccceceucce 77,78, 135
SOWIE ON Ges as dies a alceacaue woiswse 33
SOreshumnea ween Gee 63, 65, 66
SOVA SCAMS PE Chae neha nian 63, 6
Spanish-fly. . aig shes Gia ice eye 96
Spanish Necdioee tite sc elaas BS
SJOBOTONY ISBNS o ooops bacsoueone
SGHCSBsoacososeasove 28), ICS, 135
Spider-wasp. . Seca tech ai ere Oncaea
Spinachiwee wanton wore at 63, 66, a
Spinach Carrion-beetle....... 7, 22, 94, 95
INatuKeofplnyUnyane eee ee 94
Method of Control. . 94, 95
IDESCHID LION EL er: 95
EON year aE ERR il CME 95
IEzh ieee abianeech ponte ce cre geet ree eer ae 95
PUTO er cinievarciee ets cata) Paracas cane 95
ACLU pies rise Peete ean. ie 95
Life History. . bi spent 95

Spinach Leataciine.. 110, 111
(See Beet or Spinach Leaf-miner)

Spindlemlineeh ware sieeh ie oe 118
SOUWAGES O1 WASASS, coscsoccoscnce 29
Sysotseal Skuralkes oooccoccennsvooee 54
SUAVE TSW ers) So Groh ar Generelt 33-37
Caine Ot SOWIE. sooccscvccecuc 34, 35
InByaC! SVE, con cooosococodcs 36
Home-made Sprayer........... 37
Keaalosackasprayemnn neers 36, 89
Testing of Sprayer...... 35
Traction Sprayer......... 3335 34, 47, 73

Spraying, 32, 35, 47, 73, 74, 79, 89,
91, 116, il, 120

SOmniiay, COSE Gioscancccrscocesos 47, 74
Sjoranyiias, Witter 5 ccccconoonece 117
SGMashiepenvmree mes epseaas sit 66, 86, 94
Sewisel, Growl. ooccoccncevesenc 108
SHACK IBOUHOTNS, 5 occ0nn0veedcceas 80

StaCwiays GrowinGls, .cocosocasccnce 80

StickyeSinicld staan ere eee 120
Stink-bug. . WG), 1133)
Stink-bug enemy ‘of Potato-beetle | 133
Scinkeorassa pee ned eign ee 121
StomachiPoisonss-ee eee nee 32, 114
Straw bernyeedne. =) Geek. 50, 65, 66
SWAWESTAy IBUSIN, .oncaccnccncecc 118
String Beansye sealant en aoe 86
SHAUCHUTE Of ASAHES. 54 ocnccccscc 3, 29
Sucking Insects........ DS), Bi, 2, 3B, WI

GontrOWOtA ee alienate cate 33

Mout IPBNGttS Ol, cocoon enonaaava 2S), BI
Sucking eat) Reeders), .........- 3, WIT
Sucking Root Feeders............ 3,55

155

INDEX—Continued

Sugar Beets, 1, 2, 3, 4, 5, 7, 45, 50,

On en) Dy Cy Won Cp Dy CO)

94, 96, 101, 110, 119, 122, 123,
125, 127, 128

Sugar Beet Leaf-hopper....8, 24, 123-126

INaturejofmnyunyaa aces 124, 125
Methods of Control........... 125
Description eee 126
EGG aoe adie ta encanta ews ae 126
Nymph 126
AGULE Sd ee ah ee er ore 126
Life History. . 126

Sugar Beet Nematode, 3. 6 14, 3M,
38, 59. 64, e

INaturetotsliay Unyaereeeeneeeee
How Spread. . ol, OD
Methods of Control... 62, 63
How to Prevent Spread. . sateen 62
How to Check Multiplication. 63
IDESCHIPCIONS AEE erie 64
Der nares poe eames oOU La Sade c 64
Waray Stalcestnnranr cir eee 64
ACUItE Ames mae cere rne 64
Brown-cyst Stage. . eee 64
Life History. 64

Sugar Beet Rosticuc 3 6, 12, 38,
55-59, 111, ne

INaturerofslnitnyanecen nen
Methods of Control............ 55, 57
DESCRIPTION SEE ene 57, 58
Ss cebetsha chan wise teacnyet ye eGR Cre D)
Remalesse ays Aeneas 57
Ilibernating wicca nen e mee: 58
BLES Hina ep eeger ee noree 57
Stem-motheraa.. seen ee 58
\Witayaol IUNCS, 5 a5 0ce000000000 57, 58

Winged Migrants. Mdeatali 58
Life History. . Sara:
Natural Enemies..............

5 BY
Naturelofilinitnvasase eer on eo OSe al
Methods of Control............ 71-73
IDESCHIption sehen en ere ree 74, 75
[eRe ROR ae eta ie tin aa sey Sal 74, 75
WORMS ene heey Roce 75
Rupa reo a eee 75
Cocoon ect ors 75
Moth nae chee eines cine meee 75
ILS IBURESIA. ncooado 05000009000 75-77
INaturallEmemicsaeeeeneeeeeeer 77, 78
Why Growers do not Spray..... 73, 74
Sugar Beet Wireworm............ 53
SulphateiNicotines eee 121
SUNPOWET aE eee eee 63
SWANTON IFES. 505050000000008 109
SEE CHOU so odcucocsnoes 8, 63, 66, 82
Sweet Potatoes. . 5 HOD), 66, 86
Swine y weet acter se ee ee ane 50
SWiGINESSINocooncocegsacocecuses 59, 116
Syrphus-fly enemy of Sugar Beet
IROOE-lOUSER Re net cna 20, 59

T
lachina={lieseeee eee eee 77, 85, 87
Tachina-fly parasite of Alfalfa

WEADHOEINs cdacdcoaccssccobeds 20, 85

Tachina-fly parasite of Sugar Beet
WGI oo ccoogougca00NaDS 18, 77
Tall Meadow Oat-grass........... 63
Tarnished Plant-bug.......... 6, 122, 123
Nature of Injury.............. 122
Methods of Control............ 122
IMescriptiony joer aes 122, 123
| DofeReane EO RNIN AS 0.0.0.0 122
INymphie een cne anes 122, 123
Aduilt. 2h MUG) wince sung see 123
Bifeselistonyaenee ecco ele
Natural Enemies.............. 123
dlestingiof Sprayerssa eee 35

MhoraxtofInsectsyee eae
Thread-waisted Wasp...........134, 135
Three-spotted Flea-beetle......... 16, 93
THOKS: 2 Saco ok aon ee Oe 29, 106
slhiger-beetlese ee eee 26, 76, 131, 132
Tiger-moth, Virginia............. 87
ihimothyAee see menore rane 5, 63, 65, 66
i’ phiavinornatay eee eee ene 52, 134
Mobaccos 2h. eyes ie 114
Tobacco Decoction............... 115
Tobacco Preparations............ 33
jlomatocstae eee eee ene oeene 63, 65, 66
Trachea e isy eran tora see ee 29
Traction Sprayer........... 33, 34, 47, 73
airees | yc ace ee cae ee 115
iiruesArmyaWormbep ene noee 10, 78.81
Nature of Injury.............. 79
Methods of Control............ 79, 80
IDIOTS Oa 5 sono0oe5000c90000% 80, 81
PE cas saidae sie oe ae 80
WORM isc. 21s balan cere 80
Pupaliis' ss eccccenlee eee 80
IMoGthign. veieiane as oe Oe 80, 81
Wifeiinistonyeeneeeees Meads ond e-8 0 81

INaturaliEnemicsaeenneeeeeene 8
True Bugs, 3, 12, 29, 30, 59, 111, 119,
122, 132, 133
A species of True Bug which Pies
upon Sugar Beet Root-lice.

slumble-bue isan eee eee 48
BRST g CoN Chipeta on didid 6 0dr 104
TWINS. yoe000000 63, 86, 88, 99, 101, 121
Two-lined Hopper............... 16, 100
Two-winged Flies..... 20, 29, 30, 111, 121
V
Variegated Cutworm........ 8, 22, 47, 48
INEREUIRS OF ITALIA. snob oboocuene 47
Methods of Control............ 47
Description: «2355 4-4 oe ee 47, 48
gens ca Mki ines oe eee 47
WORM ce ia.) niece cee eee 48
Mothice cain sane one 48
IDWS JENSHORY sccodn0ss00000d008 48
Werbesinasssekeaaclad satan ee 86
Vetch sijaruc taerannn os iene ect eae 63, 66
Virginia Tiger-moth..............

156

INDEX—Concluded

W
Waahoo (or Wahoo)............. 118
NWWASDSuiaives 3 ses 3, 29, 30, 44, 45, 134, 135
Digger-wasp. . ..20, 43, 44, 45, 134, 136
Solitary Wasp.......... 20, 77, 78, 135
WPIGER=WASP ner oes cele ase ose 134
Thread-waisted Wasp.. Wee 135
Watermelon. 6, 86

Webworm, Alfalfa (See Alfalfa Wee.
worm)
Webworm, Sugar Beet (See Sugar
Beet Webworm)
Weeds. . Dy ©, Hl; 72, SY, Ok
Western ‘Army Cutworm, 8, 10,
41-45, 46, 47, 88, 136

Desemptiontwnsn. |<. ks ce ee ses Al, 42
GLRA My o:0:0: 4) DIB O LOR ERO RoR Ee 4]
EAU AMEE a rien aitciis ne oye 4]
IMU Ss cco cere ee 41, 42
JEM MISLOGVAR Re iad a sis ne 42,43
INaturalienemicss sss .0e) 45. 43-45
Western Beet Leaf-beetle...... 22, 90, 91
IDESCHIPtIONG: «66 26 ee te eee 90
INatunelorslnjunye sash sess 90
_ Methods of Control............ 91
Westemlblichtyse....5.2 75.2254. 124
Wihalel@il'Soapenane sno. 33, 114, 120
WWISGEIE. 6.0 chon’ 61 Re nO aera 63, 65, 66
**Whiskered Beets”............. 6l, 124
WinitewAshiterte trea 5 cad sae 112
White Clover. . 63
White Grubs, 3, oO 10, Bite 38, “48- i,
5 3, 54, 97, 134
Nature of Injury... _ 49, 8
Methods of Control............
Iie MISCORVA Se sc hoes ese ss st
INaturalelnemieSe ances. on. Dil, 52
\Wlaites I>en@eel, ooogeepecoeeubee o 111
Why Growers do not Spray...... 73, 74
WAUIO 755 0-6 Aalb Ser Oo Eee ere eae 50
WWiitrpeclleicemny yam ica se oiec Scie: 57, 58

Wines Ot WHSBES, sccoobageavcence 29
Whitatieie Serena, osccascwooboshe 1 ue
Winthemia Sp...

Wireworm...... iB 5, ‘10, Bil, 38, 50, 52- 54
Nature of Injury bro HISceG eee AOI Rete DD, 3
Methods of Control............ 53
Descriptions een ene 53, 54

(OIdghoeA ow eleioig medics oreo ier 53
Ua None aga te aig tien iene 54
Beetle ie cuit me iMaraoiiiss 54
Life History. . Ae CaRCRSC eee 54
Natural Enemies.............. 54
Woodpecker, Red-headed. . 108
\Wormistmnn 30, 41, 43, 44, 45, 46, 47, 48
Ye

Yellow-bear Caterpillar. . .8, 18, 86, Be
INFERS OF WAUIAZ. cos beaccccces
Methods of Control............ 86
See area er lag et Uae 87

Tee clo Miceli Ga clemalcie Giasey 87
Cicitee ee le arene) che LEN te 87
WI OI peti ce cena ceaee a rieepeeret Go 87
IMothatiaes sya coaeny rica nei tsa 87
[SifesiliStonyaneeee ener 87
INaturaliEnemiesmeenene mee nce 87
Niellowalackctanee enone nner 135
YWelowy ILUWMHACscoccooodoonon0ece 63
Z

Zebra Caterpillar. . .8, 14, 87, 88
Nature of Injury... Roe 88
Methods of Control. Acs ea eee 88
DeScriptionoaeermciae ween ccs ee 88

JEG, docs colo AeA Ae oe oats 88
GCaAterpillarieies so ee oe 88
INA Ge! 5. toit Beate oes eo eco erC ote 88
Wifesislistonyeece saeco 88
Natural Enemies.....:.......- 88

157

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Full text of "Principal insect enemies of the sugar beet in the territories served by the Great western sugar company"

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