Papers on deciduous fruit insects and insecticides

Historic, archived document

Do not assume content reflects current
scientific knowledge, policies, or practices.

SN he ay

“AND INSECTICIDES,

L. THE PEAR THRIPS.

oe ‘By DUDLEY MOULTON, Engaged in Deciduous Fruit Insect Investigations.

Il. THE SPRING CANKER-WORM.

By A. L. QUAINTANCE, In Charge of Deciduous Fruit Insect Investigations.

Il. THE TRUMPET LEAF-MINER OF THE APPLE.

_ By A. L. QUAINTANCE, In Charge of Deciduous Fruit Insect Investigations.

IVY. THE LESSER PEACH BORER.

By A. A. GIRAULT, Engaged in Deciduous Fruit Insect Investigations.

V. THE LESSER APPLE WORM.

> ‘By A? L. QUAINTANCE, In Charge of Deciduous Fruit Insect Invescigations.

YL. GRAPE ROOT-WORM INVESTIGATIONS IN 1907.

Be FRED JOHNSON , Engaged in Deciduous Fruit Insect Investigations.

we eealpcs are, ea FOR THE CODLING tie

4

ae —— 24 VII. THE GRAPE. LEAR SKELETONIZER,

_ ~By P.R. JONES, Engaged in Deciduous Fruit Insect Investigations.

1X. THE PEACH-TREE BARKBEETLE.

o By: H. F. WILSON, Engaged in Deciduous Fruit Insect Envestigations,

ina =<
MINS

WASHINGTON:
2 GOVERNMENT PRINTING OFFIOR.
1909.

«oe

U. S. DEPARTMENT OF AGRICULTURE,

BUREAU OF ENTOMOLOGY— BULLETIN No. 68.
L. O. HOWARD, Entomologist and Chief of Bureau.

PAPERS ON DECIDUOUS FRUIT INSECTS
AND INSECTICIDES.

I. THE PEAR THRIPS.

By DUDLEY MOULTON, Engaged in Deciduous Fruit Insect Investigations.

I. THE SPRING CANKER-WORM.

By A. L. QUAINTANCE, In Charge of Deciduous Fruit Insect Investigations.

Hl. THE TRUMPET LEAF-MINER OF THE APPLE.

By A. L. QUAINTANCE, In Charge of Deciduous Fruit Insect Investigations.

IV. THE LESSER PEACH BORER.

By A. A. GIRAULT, Engaged in Deciduous Fruit Insect Investigations.

V. THE LESSER APPLE WORM.

By A. L. QUAINTANCE, In Charge of Deciduous Fruit Insect Invesiigations.

VI. GRAPE ROOT-WORM INVESTIGATIONS IN 1907.

By FRED JOHNSON, Engaged in Deciduous Fruit Insect Investigations.

VIL. DEMONSTRATION SPRAYING FOR THE CODLING MOTH.

By A. L. QUAINTANCE, S. W. FOSTER, FRED JOHNSON, and A. A. GIRAULT.

Vl. THE GRAPE-LEAF SKELETONIZER.

By P.R. JONES, Engaged in Deciduous Fruit Insect Investigations.

IX. THE PEACH-TREE BARKBEETLE.

By H. F. WILSON, Engaged in Deciduous Fruit Insect Investigations.

& wv
pm SH =
evs ae Sete
as SN We: =

sas BA ies
ae eV qe
SS SS SS
+ ——— 1 NAS BEB
Sn Se A BE
CSA ere << =e,
os, ~ Tian <P S)
yi =\ 4 1’ NV ba ek
SS aT in}! / ») =
Nt iy J,
= Nunn \ a

WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1909.

ta i i

BUREAU OF ENTOMOLOGY.

L. O. Howarp, Entomologist and Chief of Bureau.
C. L. Maruatt, Entomologist and Acting Chief in Absence of Chief.
R. 8. Currron, Executive Assistant.
C. J. Giuuiss, Chief Clerk.

. CHITTENDEN, 1 charge of truck crop and stored product insect investigations.
. Hopkins, in charge of forest insect investigations.
. Hunter, in charge of southern field crop insect investigations.
. WEBSTER, %n charge of cereal and forage insect investigations.
. QUAINTANCE, 1n charge of deciduous fruit insect investigations.
. Pures, in charge of bee culture.
. RoceErs, in charge of gipsy moth field work.
. Fiske, in charge of gipsy moth laboratory.
ISHOPP, 7n charge of cattle tick life history investigations.
ORGAN, in charge of tobacco insect investigations.
Joaium, in charge of hydrocyanic-acid gas investigations.
R: P. CuRRIE, in charge of editorial work.
MABEL Garcoen librarian.

PPS a Unb tab
oS

WeROOm EEE Ey Ur

=

Decipuous Fruir INSEctT INVESTIGATIONS.

A. L. QUAINTANCE, 7n charge.

FRED JOHNSON, DupLEY MoutrTon, S. W. Foster, E. L. JENNE, C. B. HARDENBERG,
P. R. Jones, A. G. Hammar, R. W. Braucuer, F. W. Fauror, E. W. Scort, §
C. W. Hooker, J. R. Horton, WAttER Postirr, E. J. Hoppy, H. F. Witson,4
agents and experts.

2 Transferred to another branch in the Bureau.
II

LETTER OF TRANSMITTAL.

U. S. DEPARTMENT OF AGRICULTURE,
BurEAU OF ENTOMOLOGY,
Washington, D. C., July 20, 1909.

Smr: I have the honor to transmit herewith, for publication as
Bulletin No. 68, nine papers dealing with deciduous fruit insects and
insecticides. These papers, which were issued separately during the
years 1907-1909, are as follows: The Pear Thrips, by Dudley Moulton;
The Spring Canker-Worm and The Trumpet Leaf-Miner of the Apple,
by A. L. Quaintance; The Lesser Peach Borer, by A. A. Girault; The
_ Lesser Apple Worm, by A. L. Quaintance ; Grape Root-Worm Investi-
gations in 1907, by Fred Johnson; Demonstration Spraying for the
_ Codling Moth, by A. L. Quaintance, S. W. Foster, Fred Johnson, and
A. A. Girault; The Grape-Leaf Skeletonizer, by P. R. Jones; The
Peach-Tree Barkbeetle, by H. F. Wilson.

Respectfully, L. O. Howarp,
Chief of Bureau.

Hon. JAMEs WILSON,
Secretary of Agriculture.

iit

CONTENTS

!
‘
'
f
y

Page

The pear thrips (Huthrips pyrt Daniel)...........--..-.-.--- Dudley Moulton. - 1
ENNNIEE See ee ree ie ee ee ee cw ec ho ee 1
rr Mn MNGIPiTiiGi 2-2. oa SL Le 2 a 2 ee 1

0 EES EO RV El a ears san pe 2
ENUM ANON es Pe 2 ian ie 2 wis 2 ox Se 7
menos and natural factors in Control.................-.--2.--22--2---ne 12

_ The spring canker-worm (Paleacrita vernata Peck)......-.--- A. L. Quaintance. . 17
IRIE EMRIN et es Se er SS re ale Lc iera swe bo oe ee 17
PREMIERE INE AISA 2 ee nD 2 et ei. 8 ee 18
emonstration work in canker-worm control.............-.......-.------- 20
MS RaMaSi Te eves We SO et ee ee ee eee 21

The trumpet leaf-miner of the apple ( Tischeria malifoliella Clemens).
A. L. Quaintance. . 23

wr SSR NE ER, aR Oa Sl ne eee a PE 23
NINE ee Liter or ted Bs oes «Pater ek te ani an = Boe ee 24
EI Pert Ste cy ee a Soe re Pee 2 ts Sp, ew ewes - Sece 26
a ENIPIREMIN etrte? gee Nis 8 Se ee Se Os ee 27
NRMP ENS Ae he nt ete de ee eS ee oe cle he ok errr 29
Ts ia soe ee Se eke = oe pee ence 29

| nti gE nee SS alae Sein ped Ges beds liege haan ose 30
The lesser peach borer (Synanthedon pictipes G. & R.).........A. A. Girault.. 31
erat sad eet IP see 31
ES gel aS OE ee ea ee ee 31
San CedCrinien Sciontilac WAMG._...............-.-----:-....---<--- 32
SESE ale ee RS SS ee A nel ee 32
ammanis: chatacter and extent of injury .......-.....-.-.....-------+- 33
EES eager 34
as na yer Se Re FE PO a 34
MIEN REMEDY Sah oon ns ot oe ee Sc oa aden 35
re a a a OO Renee 42
ee Bre ar fo Sa oe a wa swe Sac ea ces usescencase 44
EERO Sod ho di Gane cee ka nw win ee hava enc am cede oe 45
ncn aS pan oe umn vk cee winin o ese Aang 46
The lesser apple worm (Enarmonia prunivora Walsh)........ 4. L. Quaintance. . 49
Eo he i aan kn ean u sas nas cancecdcine tases 49
oe ee ee ie Webwat imme duel asdcnemee 49
EES 2 eS 52
= Food plants and destructiveness.....................-- LEN ena Re eS, 5 53
me Onaracter of injury............ ep A SE Pe in Ra OM tet Perk ce ene, Roe 54

_ @ The nine papers constituting this bulletin were issued in separate form on June 10,
July 6, October 15, and October 17, 1907; January 8, April 24, and April 29, 1908; and
January 20 and February 11, 1909, respectively.

7 v

VI DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

The lesser apple worm—Continued.
Description ose cs ees eee ee ee ee ee eee ee
seasonal history-andhabitess aie ee es eee ee
Identity 222.2 sas shee b ese Roe eee Ore | SE ae
Parasites: 2.505 feted an co. met Sore ec Sena Ne nee

Grape Toot-wornl In vestigations tn S072 ..242--. 6 ee Fred Johnson. .
Introduction: 3: se:5 25s We ee ee ee eee ee
A (briet-consideration of vineyard conditions..2 5-5. = ee eee
Work undertaken at North HastoPa. soe er ee see ae
Extent,of injury to newly bearing vineyards. 222-242 .9o5 eee
Renovation experiment on an old, run-down vineyard..................-
Spraying experiment on a newly infested vineyard..........-------..----
Methods of recording, results: e925 25 See eae ee eee ee ae
Recommendations based on observations and results of season’s work... -
Demonstration sprayine for the codling moth: ===) 2 son Season ee ee
introdaetvomne ja: Ao ees as a eee erp ee eee ese A. L. Quaintance. .
Demonstration spraying in Virginia in 1907..........-...--- 1S Aue Oster =e
Demonstration spraying in Pennsylvania in 1907.......... Fred Johnson. -
Demonstration spraying in Ohio in 1907_--------..-.-- 22. AwA, Giraulte.
The grape-leaf skeletonizer (Harrisina americana Guérin-Méneville).
Py Ee. JOnese.
Tinteod ction... 2.5. he tects cece ee ee
ISCOPY = 2325 <P Seice nike ale LS SEN eee Ss ec ee oh
Origin and distribution. 22s. o< Se hes Bae ee Sa ee
Food: plants and destructiveness... -2-- 2 sea322 ee ee ee eee
Character of injury 5.22.42. (52 beck sank ea ee oe eee
Description... x. sos ae. S86 oe Ses Soe, RON oe ets ee ae
Seasonal Instory: i--6. 5-252 ee ole ee i ee ee ee
TAU oo ios naeis dna eee Sd seen ees pe ee ir ee ae a
identity.-. .ei 202 so aoSS ee eee Sa oe eae
Natural enemies. c22 2 oot akc, Jad ae er eet es eine eee ete
Remedies os) cto) oo i eae a ae le Rel Se
Bibliography 2-54.52 eek Ao ah ets Be Ye ae Dean ae ee
The peach-tree barkbeetle (Phleotribus liminaris Harr.)........H. F. Wilson. -
Tnttoductiones ss. «eae Dec ae ae Se 9 ail ee
ERS GODS sd =o sje wee a a0 Se eS Oe en eres ne en
Distri bition: :3...ac Sesh eeae seen oe ae Se ees eee ee ee

Extent and: character ‘omy tity 22.22 oes ee oe eee
ite ihistony. o-oo 2 wi Bcd ee AS cas. Sian ol Sin 2k Neg aye ai ee et os A eae
Parasltes.dcccccc.cn ni. Sos cc a ef a ae a ae ee
Experiments with remedies: wi 2) 7.7208) (ee ee
Methods of control jo. Jo225 ee sekecee ee ee Ste ee
Brbliography ssc hc 2e shee ee oe ee Se te ee ae

PuaTE I.

FE;

TL.

ry.

WIT.

VIII.

IX.

ILLUSTRATIONS.

PLATES.

Work of the pear thrips (Euthrips pyri Daniel). Fig. 1.—Imperial
prune, showing buds and blossoms injured by feeding of adult
thrips. Fig.2.—Unfolding leaves of Hemskirk apricot injured
by young thrips. Fig. 3.—Madeline pear, showing cup-shaped
deformities of the larger and rolling of the smaller leaves, the injury
Remi a MOUR THTIMR ES oe eS ik Soo sco Ja enoe She ee

Work of the pear thrips. Fig. 1.—Black Tartarian cherry blossoms
killed by adult thrips and leaves injured by young thrips. Fig.
2.—Bartlett pear, showing all except very late blossoms dead from
thrips and leaves injured by feeding of young thrips...........-.--

Stages and work of spring canker-worm (Paleacrita vernata Peck).
Fig. 1.—Egg mass on bark scale. Fig. 2.—The larve or canker-
worms. Fig. 3.—Pupe. Fig. 4.—Female moths. Fig. 5.—Male
moth. Fig. 6.—Work of canker-worms on apple leaves when small.
Fig. 7.—Later work of the larve, only the midribs of leaves being

Trees defoliated by spring canker-worms and effects of treatments.
Fig. 1.—Defoliated trees in Lupton orchard. Fig. 2.—The same
trees a year later. Fig. 3.—Defoliated trees in the Purcell orchard.
Fig. 4.—An adjacent row of trees protected by applications of
Sr MAUR See ieee Sob oe eis cto a Peco ween bed, e

. Work of the trumpet leaf-miner of the apple (Tischeria malifoliella):

ary eipmes eas lS feel... 2c 2k we en ee ee cone os

. The lesser peach borer (Synanthedon pictipes). Fig. 1.—Male and

female moths. Fig. 2.—Cocoons as exposed by removing bark
from trunk of peach tree. Fig. 3.—Trunk of 10-year-old peach
tree badly infested with the larvee..............22.--2-..-0-05ee
Work of the lesser apple worm (Enarmonia prunivora). Fig. 1.—
Apples showing surface injury by lesser apple worm. Fig. 2.—
Portions of apples showing, in lower figures, injury at calyx and
stem ends; in upper figures, injury to flesh under blotch mines. -
Vines injured by grape root-worm compared with uninjured vines.
Fig. 1.—Six-year planted vines making but a weak growth, because
of injury to roots by grape root-worm. Fig. 2.—Two-year planted
vines not yet attacked by grape root-worm...............-...---
Vines injured by grape root-worm compared with uninjured vines.
Fig. 1.—Young vines almost ruined by feeding of grape root-worm
upon their roots. Fig. 2.—A normally thrifty vineyard at North
East, Pa., uninfested by grape root-worm.........................

. Work of the peach-tree barkbeetle (Phlwotribus liminaris). Fig. 1.—

Gum exuding through burrows made in bark of peach tree.
Fig. 2.—Exit holes in bark of peach tree........................

Vil

Page.

18

20

34

54

64

64

Vill

PLATE

Ere 1.

. Resting spores of a fungus found within dead thrips larva
. Trumpet leaf-miner of the apple ( Tvscheria malifoliella): Adult, larva,

DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

XI. Work of the peach-tree barkbeetle. Fig. 1.—Orchard severely
pruned April 19, 1908. Fig. 2.—Gum exuding through burrows
made in bark of cherry tree. Fig. 3—Removing stumps of trees
supposed to have been killed by the barkbeetle

TEXT FIGURES.

The pear thrips (Euthrips pyri): Head and prothorax from side, show-
ing mouth “parts <2 22 es eas yen Sc ee ete eee ee

.. The pear thrips: (Mepsee feo cc ote ee oe ie eee
. The pear thrips: Ovipositor and end of abdomen from side
. The pear thrips: Larva
. The,pear thrips: Niyniphi or pupasesetsss2s- sees soa eee aoe cern
. The pear thrips: :Adullt2 so.ce 3. Geen ee eee ee ee
. A fungus which attacks the pear thrips: Active fruiting stage on adult

thrips, branching mycelia, forming Spores2- 2 noe - ee eo ee ee

pupa, detatle. 22 sot uckue cases ae See ale ee ee

. The lesser peach borer (Synanthedon pictipes): Adult, eggs, larva, pupa,

cocoon, and pupal sisim. 205224 sae, ois eee Se ae ees

. The lesser apple worm (Enarmonia prunivora): Moth, larva, cocoon,

. The grape-leaf skeletonizer: Eggs on leaf, egg enlarged........-..--...-
. The grape-leaf skeletonizer: Larva and details............-....--.---
~». Lhe grape-leai:skeletonizer: ‘Gocoen- 22. ihe ess ee
: 7Ehe grape-leaf skeletonizer:,Pupa.2. =. 2.222) 259328459 eee
. The: grape-leaf'skeletonizer: Moth: 2 2 32 a eee ee
. Work of the peach-tree barkbeetle (Phleotribus liminaris): Galleries in

lamb of peach tre@sz sic 5504. 25 Le oe sa BOs ce nae, eee

. Work of the peach-tree barkbeetle: Galleries in wood of peach tree. .- -
. The peach-tree barkbeetle: Adult, egg, larva, pupa............-....-

Page. |

94

U.S. D. A., B. E. Bul. 68, Part I (Revised). D. F. I. I. September 20, 1909.

PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

THE PEAR THRIPS.
(Euthrips pyri Daniel.)
By Duptry Moutron.

Engaged in Deciduous Fruit Insect Investigations.
INTRODUCTION.

This paper brings together the results of an investigation of the
life history, habits, natural enemies, and methods of control of the
pear thrips (Huthrips pyri Daniel), a pest of deciduous fruit trees in the
San Francisco Bay region of California. The investigation was under-
taken at the request of the Santa Clara County board of supervisors,
who furnished the funds and liberally granted necessary facilities
for a thorough and scientific study, and was carried out in the Santa
Clara Valley, where the thrips seemed to be at its worst. The investi- -
gation extended through a period of fifteen months, from February,
1904, to April, 1905.4

The writer offers this paper rather as an introduction for future work
than as a completed account, and it is intended especially for the fruit
grower, that he may understand the nature of the insect and its injury.
The alarm felt for the safety of the deciduous fruit industry, which
the pear thrips caused during 1904 and 1905, in the light of our pres-
ent knowledge need not again be experienced, and, although no effect-
ive means of control are yet offered, a knowledge of the life habits
should do much to clear away the uncertainty usually following the
first appearance of a destructive pest in any locality.

OCCURRENCE AND DISTRIBUTION.

The pear thrips is known to exist in the San Francisco Bay counties
and along the Sierra Nevada foothills, but it is not known how widely
the pest is distributed outside of these localities. It is still a question
whether the insect is a native of California or an introduced form.
The pear thrips may have had some indigenous plant, such as the

aThe writer wishes to acknowledge the work of Mr. Earl L. Morris and Mr. ©. T,
Paine. He is indebted also to Prof. W. R. Dudley, head cf the department of sys-
tematic botany, and to Dr. G. H. Pierce, of the Leland Stanford Junior University,
for literature and helpful suggestions, and finally to Prof. Vernon L. Kellogg for his
ever helpful suggestions and encouragement.

2 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

wild plum or cherry, for its original food plant, and later, as large
fruit-growing districts were developed and as the insect found more
and better food, it may have changed its feeding habits from the wild
to the cultivated plants. This would be a not unusual change. On
the other hand, it may have been imported and, finding conditions
favorable here and no effective natural enemies present, may have
increased and spread rapidly.

In 1904 the pest was thought to be strictly local in the Santa Clara
Valley, but in 1905, when the insect had become better known, it was
found to be widespread in the San Francisco Bay regions and its
ravages were being felt in fruit sections in other than this one valley.
A peculiar blighting of blossoms had been commonly observed in
several localities in the Santa Clara Valley previous to 1904, and this
blighting was invariably followed by an almost complete failure of
crop. Its cause was not at first explained, for trees were injured
within a very few days and the insects, as it happened, were gone
before the owner was aware of the infury.

The pear thrips seems to have reached a maximum in numbers
during the season of 1905. Large orchard sections, often miles in
length, suffered an almost complete failure of crops and these worst
infested areas were in the heart of the best fruit sections of the valley.
All of this loss, however, can not be.charged to the thrips, for there
occurred unusually heavy and driving rains during the blossoming
season of this year, and it was often impossible to determine the
relative amount of injury caused. by the thrips and that caused by
rain, except where thrips were found feeding before the storms came
on. The season of 1906 proved to be a more hopeful one. Thrips,
fewer in numbers, were late to appear, and the early injury to buds
was not so apparent. The trees blossomed almost in the normal
way. The later injury to fruits, however, was quite as noticeable.
The scab on mature prunes—the never-failing evidence that thrips
have been feeding in the spring—depreciated the value of the fruit in
all of the thrips-infested regions.

NATURE AND EXTENT OF INJURY.
Injury to plants is the direct result of the feeding and ovipositing
of the thrips.
DESCRIPTION OF THE MOUTH PARTS.

The mouth parts of thrips project from the lower posterior side of
the head and have the appearance of an inverted cone (fig. 1). The

ee a

Pied

mouth opening is in the small distal end, and through it the stylets or ;

piercing organs are projected when the insect is feeding. The rim at
the tip is armed with several strong, chitinous points, which figure

prominently in tearing open the plant tissues. The insect first pierces

a
a
® |
" |

|

4
ae

THE PEAR THRIPS. 3

the plant epidermis with the stylets, then, moving the cone tip back-
ward and forward, it enlarges the opening and lacerates the plant
tissue by means of the barbed snout. It then pushes the tip of the
mouth cone into the puncture thus made and sucks in the plant
juices. Larve feed in a similar way, having similarly constructed
mouth-parts.

RELATION OF THE BUDDING AND BLOSSOMING OF TREES TO THE FEED-
ING HABITS OF THRIPS.

The dark-brown adult thrips arrive on the trees in late February
and early March, the period of early opening buds and first blossoms;
they are common in March and April, the two months of bloom and
early leaf, and all are gone from the trees
by the middle of May. Only a few adults
can be found after the 1st of May, and most
larve have reached full growth, by this time
and have gone into the ground. Thus it is
that the active feeding stages of the thrips
coincide with the budding, blooming, and
early leaf periods of the host trees.

The difference in bud formation and pro-
gress of development of various deciduous
trees influence to a large extent the man-
ner of injury which thrips inflict. Trees may
be divided for the sake of convenience, in re-
gard to the bud structure, into two groups, ee ee sea kc
namely: (1) Those in which asingle fruit bud _ side, to show mouth-parts.
produces one blossom, such as the almond, “°° °™2rFed (original).
apricot, and peach; and (2) those in which a single fruit bud opens
out to form a cluster of blossoms which later produces a cluster of
fruits, as the prune, cherry, pear, and apple.

The relative blooming periods of the several varieties of fruit on
which thrips inflict injury, as found in the Santa Clara Valley, may
be noted as follows:

Group 1: Almonds, late in February; apricots and peaches, early in March.
Group 2: Prunes, middle and last of March; cherries and pears, early in April.
These periods vary from year to year and the varieties of each
fruit also vary to a large degree, but the general order of blooming is
suggestive. Opening buds precede full bloom by eight or ten days.
The almond, of the first group, presents an interesting study of
the feeding habits of thrips. The bud development occurs dur-
ing early February, early blossoms from February 5 to 16, and
full bloom from February 9 to 20 and later. Thrips appear about
February 25 or March 1, and it is evident that almond blossoms are

4 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

well along before enough thrips have appeared to become especially
injurious. Many instances can be cited where thrips were especially
numerous on almond trees, often as many as 25 or 50 inhabiting a
single blossom, and yet the trees set and matured a full crop of nuts.
The insects did not have an opportunity to attack the opening buds,
and after blossoms were open they preferred the nectary glands on
the inside of the calyx cups. They did not, apparently, relish any
other parts of these particular blossoms, and the pistil, stigma, and
young fruits were not attacked. Stamens were weakened, for they
arise from the rim of the calyx just above the place where the insects
find their enticing food, but the pollen had already ripened and had
been shed. Thrips can be found as numerously on almonds as on any
other variety of affected trees, but there is a large, newly exposed leaf
and blossom surface, and the greatest danger period is passed before
the insects arrive. For these reasons the trees are able to support
many thrips without the amount or the quality of their fruit being
appreciably affected.

The peach, especially the Muir and the Nicols’ cling varieties,
suffers as much as other fruits, but the acreage in the Santa Clara
Valley is not large as compared with that of the prune, for instance;
consequently the damage has not been so marked. The period of
opening buds and blossoms occurs just at a time to permit of thrips
entering them from their earliest development. The swelling bud
pushes apart its outer winter protecting scales and thrips immediately
force a way in. The insects feed on the tender, closely plaited tips
of petals, which are readily killed. They force an entrance between
calyx lobes and petals, feeding as they go, and soon reach and attack
the very small and fragile blossom stem. This is soon destroyed.
Later the blossoms which may have escaped the early injury are
attacked from within, the thrips feeding on the inner flower parts.
The piercing and rasping manner of feeding is very disastrous to ten-
der plant tissue, and fatal injury can be effected by a very few move-
ments of the powerful mouth cone with its armed tip. The writer
has often examined peach trees which had but recently been attacked
by thrips and found that almost every blossom would fall out from
its cluster of scales when the limbs were gently tapped. Badly
infested peach trees do not bloom at all.

Apricot blossoms are similar to those of the peach and are injured
in the same way. |

The thrips is at its worst on trees of the second group, which
includes the pear, prune, cherry, and apple. These fruits bloom
later, which permits the gathering of thrips in numbers before
buds are at all advanced. The writer has found thrips on cherry and
prune trees waiting, as it were, for the buds to open, and he has found
as many as 75 individuals in a single blossom which opened prema-
turely early. A thrips enters a prune bud through the tip and forces —

THE PEAR THRIPS. 5

a way down the center of the cluster, feeding as it goes on the con-
tiguous sides of the several blossom buds. Normal growth ceases
immediately. The untouched outer side of each blossom bud
develops for a time, but the injured inner part becomes brown and
dies. This causes each flower bud to turn in toward the center, and
the whole cluster eventually falls. (See Pl. I, fig. 1.) When thus
injured, most blossoms do not open at all, but if they do thrips are
able to enter and feed in the more vital flower parts. Only a few
blossoms survive both periods of injury when thrips are very numer-
ous. The insects attack blossom and leaf buds alike and, in fact,
every part that offers new and tender plant tissue.

Pears suffer mostly during early bud development, and blossoms
are nearly all dead before the clusters open.

Cherries present a more resistant growth. There is a decidedly
sticky secretion on the surface of newly exposed leaves, and often
wings of thrips stick fast and many are thus trapped. Cherries
develop so rapidly that when buds once start, blossom clusters are
able to push out, often almost unharmed, even when many thrips are
present. These clusters form ideal places for oviposition, and, as will
be seen later, cherry trees which may be able to resist the early inju-
ries of feeding will suffer from the effects of ovipositing.

Thrips have displayed very decided preferences for certain flower
parts. It has been mentioned that they choose the inner side of the
almond calyx cup. In prunes they are partial to the tiny blossom
stems and to the tips of petals and, when blossoms have opened, to
the stigma and style. This last injury is especially noticeable on
cherries, where the writer has many times found the stigmas and
styles blackened as a result of the feeding of thrips, while the rest
of the blossoms was untouched.

Injury on leaf buds and on tender foliage is almost as marked as
when blossoms alone are attacked, although there can be no closely
drawn line of distinction, because of the close interrelation of leaf and
blossom buds. Trees that have been ravaged for three or four days
can not again put forth new leaf buds and assume a natural growth
for several months, and then they appear sickly for the entire year.
Often they can not start anew until the thrips have actually left the
trees, as the insects continue to hinder each new effort which the
trees may make.

The pear thrips is known to feed on the following plants, and it is
probable that this list, extensive as it is, is not complete: Almond,
apple, apricot (several varieties), cherry, fig, grape, peach (Muir and
Nicols’ clings preferred), pear (especially Doynne du Comice and
Bartlett), plum, prune, walnut (English).

The insect shows a decided preference for certain varieties of
prunes, pears, and peaches, but of the other fruits all varieties seem
to be attacked alike. The pear thrips has been colle:ted from the

6 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

following indigenous plants: Blossoms of the madrofia (Arbutus
menzieswv) and wild California lilac (Ceanothus thyrsiflorus), and foli-
age of poison oak (Rhus diversiloba). All of these plants, however,
were near thrips-infested orchards, and, moreover, only a few indi-
viduals were taken from each of the plants.

| FEEDING HABITS OF LARVE.

1 Thrips larvee feed almost entirely on young, tender foliage and on
i the surface of fruits. They conceal themselves in terminal buds (PI.
| I, fig. 2), and often, as on the cherry, they attack the underside of
| | leaves, usually near the prominent veins. They cause the leaves to
| become much contorted, ragged, and full of holes (Pl. II, fig. 1). The
| insects seem at times to take advantage of certain tendencies in the
growth of plants on which they happen to feed. For example,
newly opening pear or apple leaves show a tendency to roll from the
sides inward and thrips find this inner protected surface a most
desirable feeding place. In such a case the upper, inner surface is
destroyed, and the leaf, instead of opening out,
becomes rolled up tight and eventually dies. The
insect thus secures the tenderest of leaf tissue for
its food, and also protection in the folded leaf.
(Pl. I, fig. 2.) Thrips often cause a deadening
of the leaf margin, and in such cases the leaf is
forced into an abnormal, often cup-shaped, growth.
ee eee Ow te De’ This is a very characteristic injury on pear trees.
thrips (Euthrips pyri). yi jury p
Se Oia corig- (Pl.1,fig.3.) The feeding injury of thrips larve
on fruits, especially prunes, is in a way superficial,
but it seriously impairs the appearance of the ripened fruits and
greatly lessens the value of the finished product. A prune grows
to be larger than a grain of wheat before the dead calyx is sloughed |
off. Larve feed under protection of this dead calyx, and asa
result an abrasion of the skin, the feeding injury, is noticeable, even
on very small fruits. The wound appears first as a small brown
spot which enlarges and produces a scab as the fruit matures. The
| seriousness of what at first might seem a small surface marking
I] is more readily appreciated when one recalls that when prunes are
| being cured the tough, scabby spot does not shrivel up during the
| | process of drying as does the flesh of the prune, nor does it assume
| a darker color as does the prune.
Thrips larve are often carried by various means from the original —
| food plant to other hosts, being blown, for example, from a tree to”
grass or weeds beneath. They have no wings and can not fly back to
the tree. A few crawl up again, but most larve adapt themselves to”
the new plant until fully grown, when they, too, go into the ground.
Many of the common weeds have thus been found supporting larve,
although no full-grown thrips have ever been seen feeding or deposit- _|

.

ovipositor can be inserted through the

THE PEAR THRIPS. 7

ing eggs on such plants. The insect has proved itself a strictly fruit-
tree pest, and it is carried to weeds and lives on them or on other
plants only by accident.

LIFE HISTORY AND HABITS.
THE EGG, THE OVIPOSITOR, AND OVIPOSITION.

The thrips egg is bean-shaped (fig. 2), light-colored, almost trans-
parent, and is very large in proportion to the size of the abdomen
when seen within the body of the adult female. Itis about 0.33 mm.
long by actual measurement.

The ovipositor (fig. 3) is made up of four distinct plates. Each
plate is pointed, has a serrate outer edge, and is operated by powerful
muscles and plates within the abdomen. The pairs on each side fit

together along the inner edges with a tongue-and-groove-like structure,

which in action renders possible a sliding back and forth, or sawing
motion. The ovipositor is protected
within a sheath in the ventral tip of
the abdomen when not used, but before
and during ovipositing it is lowered
until almost at right angles to the
body.

Oviposition accompanies feeding. It
seems necessary, indeed, that before the

plant epidermis the thrips must first ip
weaken or break an opening through Fic. 3.—The pear thrips (Euthrips pyri):
this tissue with the mouth-parts. The ovipositor and end of abdomen from
‘ 5 side. Much enlarged (original).
successive operations of lacerating the
plant tissue, lowering the ovipositor, placing an egg, and withdrawing
the ovipositor require from four to ten minutes, and may be briefly
described as follows: After making an incision with the mouth parts
the insect moves forward, lowers and inserts the ovipositor, and by
operating the tiny saws she makes a deep incision in the plant tissue.
While the ovipositor is still deeply set in the plant, an ege is con-
ducted through the cavity between the plates and deposited under-
neath the epidermis. The ovipositor is withdrawn and the egg is
thus left deeply embedded within the plant. During the oviposition
period one often finds a branch or a tree, or even many trees, on
which almost all thrips are ovipositing at the same time.

The small, fragile, just-exposed blossoms, stems, and leaf petioles,
and later the midribs and veins on the back side of the leaves, and
still later even the leaf tissue itself, are the places preferred for ovi-
positing. A thrips always places her eggs in the tenderest of the
plant’s tissue. There is danger of the ovipositor getting caught if the
tissue is hard. Also, it is necessary during ege development that the

toil DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

surrounding tissue be flexible and moist, for the egg covering is elastic
and the embryonic thrips within increases in size very noticeably
before the larva issues.

There is space within the adult insect’s body for only a few eggs at a
time—seven or eight. A thrips probably places only a few eggs dur-
ing a single day. She feeds for a time, deposits an egg, and then
moves to another place, and later to still other places, and these may
be all on one or scattered on several trees. The adult thus spreads
her progeny from tree to tree wherever she goes. Nothing seems to
hinder thrips which may be set on ovipositing. They have been ob-
served placing eggs at all hours of the day and
night and under all conditions of weather.
The period of oviposition lasts for several
weeks, or during practically all of the life of
the adult insects. Injury from oviposition
is most conspicuous on cherry trees. Oper-
ating at the base of a cluster of fruits, a few
thrips will cut several incisions and place as
many eggs in a single stem. This so weakens
the stem that it fails to perform its usual
function, and the rapidly developing cherry
soon becomes yellow, and falls. Thrips seem
to prefer the cherry to other varieties of fruits
as a place for ovipositing during the later sea-
son, and this fruit suffers severely from
ovipositing, though it may escape the first
feeding injury. The result is a heavy drop-
ping of half-grown cherries, which in badly
infested regions means almost the whole crop.

Numerous leaf and blessom stems in which
, eggs had been placed were closely watched
Fic. 4.-The pear thrips (ku. to determine the length of the egg stage. In |

thrips pyri): larva. Much en- many cases these stems became dry during 9)
larged (original).

variably from these no thrips issued. Eggs need moisture for their

confinement in the laboratory, and almost in- a

preservation and development, and young thrips must have tender

and pliable tissue through which to emerge. The egg stage lasts, 2 |
approximately, four days. |
THE LARVA.

It is interesting to watch, with the aid of a strong lens, a young
thrips issuing from the egg. The tiny incision in the stem of a
blossom or leaf shows where an egg has been placed, and the enlarging __
egg within, causing a swelling in the plant tissue at the summit of
which is the incision, indicates that the insect is about ready to
emerge. The first sign of life is the appearance, pushing out from the

a fully maturedinsect. It then ceases to feed,
falls to the ground, and enters the ground

exceedingly small natural cavity and shapes

or just a little longer than the insect itself.

THE PEAR THRIPS. 9

incision, of the head with its bright red eyes. Little by little, and
swaying backward and forward, the larva forces itself out until about
one-half of the body is exposed, when first the antenneze and then
one by one the pairs of legs are made free from their resting position
against the body. Swaying backward and forward, with legs and
antenne waving frantically about, the insect pushes out of the egg
cavity almost to its full length, whereupon, leaning forward it eagerly
takes a hold with its newly formed feet, and, with a final effort, pulls
itself free and walks rapidly away. From four to ten minutes are
required for the insect to free itself from the egg. The young insect
is almost transparent and the green chlorophyll particles taken into
the stomach can be seen through the body wall. Growth is rapid
from the beginning.

A very decided change takes place during the second larval stage
(fig. 4). In about three weeks the insect
reaches a size often larger than that of the (ii \\

_by some crack or wormhole. It goes down
- from 3 to 10 inches, according to the structure
and condition of the soil, the usual depth
being about 4 inches. Upon reaching a
secure depth, the larva hollows out for itself
a tiny spherical or oblong cell or it finds an

this for its convenience. The completed
chamber has a hard, smooth inner wall,
and it is about one-twelfth of an inch long,

The insect here spends the greater portion fig. 5.—The pear thrips (Euthrips
of its life. It remains for several months = ?¥?!): nymph or pupa. Much en-
. : larged (original).

a quiescent, non-food-taking larva. Later

the pupal changes are undergone, and lastly the adult insect appears
5 ron) ) v

before it issues forth to the tree. Larve collected from the ground

on August 28 were active, and, strange to say, green chlorophyll

matter, undigested food, which had been taken into the stomach

several months before, was still present in their bodies. The insects

are scattered through the soil from near the trunk to several feet

from the tree.

THE NYMPH OR PUPA.

The writer has not been able to determine how long the nymph
stage (fig. 5) lasts, but it evidently extends over several weeks.
Nymphs in all stages of development were collected during May and
at intervals until the following February, but they are most common
during December, January, and February. The writer has gathered

10 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

nymphs from the ground early in May, but it is difficult to explain
their presence there so early in the spring. It hardly seems possible
that these were the still immature forms of the previous year, for by
this time all adult thrips had left the trees. These nymphs were
taken along with the larve, which had just entered the ground, and
| it might seem that they were hurrying through to produce a second
1 generation; but to the writer’s certain knowledge adults of a second
| generation did not appear on the trees. The nymph is active at all
| times. Wings develop from mere buds to long sacs which project:
backward along the sides of the body, and eventually reach beyond
it the tip of the abdomen.

THE ADULT.

|

}

|

|

| The adult thrips (fig. 6) remain in the pupal chamber for days,
and it may even be weeks before they issue forth to take up active
|| life. How individual thrips force their
| way through the several inches of earth
. which lies above them is still a question. —
| They come out, it

| seems, only after
the ground has —
been thoroughly
softened by
rains, and it is
evident, too, that
they depend
largely on the
natural open-
ings. They can
not possibly use the backwardly bent mouth
cone as a means of boring or biting their way _

2 = ,
zm 4
roe evs) gic aii Been CO

: me pata corey =
Ste asia Y= :

x iam | Vaneeyy ,

) Ne
4

Sores Foe
PELISAL LL
TBE GLARE

aa ZILA

Lit ppp pp pips

Caceres Berea FAIS

Bee ee
) eet eg ©

in forcing a way through the soft soil. Th
also possess roughened, scoop-like structures—
i : parts of the chitinous, hoof-like shell of the
| Pape gecre saute wack feet—which undoubtedly are used for digging.
eulateeaiceriginal). Adult thrips appeared in alarming numbers
in many Santa Clara Valley orchards in 1904, about February 24; —
in 1905 several days later, and in 1906 about March 1. They appear
on the trees by millions and, it seems, all at about the same time.
They feed and oviposit most actively during March and April, and
by May 1 almost all have disappeared. No male individuals of the
pear thrips have ever been collected; all have been females. a

out. They have several groups of spines andy
F| certain angular edges on the sides oi the ab-4
| dominal segments, however, which might be used —

i. 68, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE I.

WORK OF THE PEAR THRIPS (EUTHRIPS PYR!I DANIEL).

Fig. 1.—Imperial prune, showing buds and blossoms injured by feeding of adult thrips.

Fig. 2.—Unfolding leaves of Hemskirk apricot injured by young thrips. Fig. 3.—Madeline

pear, showing cup-shaped deformities of the larger and rolling of the smaller leaves, the
injury caused by young thrips. (Original.)

68, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE Il.

%

WORK OF THE PEAR THRIPS (EUTHRIPS PYRI DANIEL).

Fig. 1.—Black Tartarian cherry blossoms killed by adult thrips and leaves injured by young
thrips. Fig. 2.—Bartlett pear, showing all except very late blossoms dead from thrips and
leaves injured by feeding of young thrips. (Original.)

. THE PEAR THRIPS. we

Adults may be present in an orchard for a few days and then
suddenly almost all disappear. This is explained by their habits of
migration as evidenced by the following observations: In a certain
pear orchard which had been kept under daily observation for a
week or more thrips had been abundant in blossoms and buds until
suddenly one day all seemed to have disappeared. Upon closer ex-
amination, however, they were found congregating and walking
around on the larger branches. This was about 3 o’clock in the after-
noon. On the following morning hardly an individual could be found

in the orchard. This manner of flight seems to be distinctly migra-

tory. Thrips often leave their places of feeding just before sunset
and hover around and over and later settle back on the same trees.

This mode of flight is decidedly different from the migratory one.

It occurs only at evening, and the writer has never seen the pear
thrips in flight during the morning or during the middle of the day.

DESCRIPTION.

Euthrips pyri Daniel.
Measurements: Head, length 0.13 mm., width 0.15 mm.; prothorax, length 0.13
mm., width 0.2 mm.; mesothorax, width 0.28 mm.; abdomen, width 0.31 mm.; total

length 1.26mm. Antenne: 1, 334; 2, 45u; 3, 63u; 4, 54u; 5, 33; 6, 664; 7, Iu;

8, 12”; total, 0.31 mm. Color dark brown, tarsi light brown to yellow.
Head slightly wider than long, cheeks arched, anterior margin angular, back of head
transversely striate and bearing a few minute spines and a pair of very long prominent

“spines between posterior ocelli. Eyes prominent, oval in outline, black with light

borders, coarsely faceted and pilose. Ocelli are approximate, yellow, margined
inwardly with orange-brown crescents, posterior ones approximate to but not con-
tiguous with light inner borders of eyes. Mouth-cone pointed, tipped with black;
maxillary palpi three-segmented; labial palpi two-segmented, basal segment very
short. Antennx eight-segmented, about two and one-half times as long as head,
uniform brown except segment 3, which is light brown; spines pale; a forked sense
cone on dorsal side of segment 3, with a similar one on ventral side of segment 4.
Prothorax about as long but wider than head; a weak spine at each anterior and two
large, strong ones on each posterior angle; other spines are not conspicuous. Meso-
thorax with sides evenly convex, angles rounded; metanotal plate with four spines
near front edge, inner pair largest. The mesonotal and metanotal plates are faintly
striate. Legs moderately long, uniform brown except tibize and tarsi, which are yel-
low. Spines on tip of fore and middle tibiz weak; several strong spines on hind

tibiz. Wings present, extending beyond tip of abdomen, about twelve times as long

as wide, pointed at tips; costa of fore wings thickly set with from twenty-nine to
thirty-three quite long spines; fore vein with twelve or fifteen arranged in two groups
of three and six, respectively, on basal half of wing and a few scattering ones on distal
part; hind vein with fifteen or sixteen regularly placed spines; costal fringe on fore
wing about twice as long as costal spines.

Abdomen subovate, tapering abruptly toward the tip from the eighth segment;
longest spines on segments 9 and 10; abdomen uniform brown, connective tissue
yellow.

Redescribed from many specimens, including several cotypes from Miss Daniel.

Male unknown.

Food plants: Apricots, apples, almonds, cherries, figs, grapes, pears, prunes, plums,
walnuts. The insect is found mostly on deciduous fruits.

Habitat: San Francisco Bay region, California.

12 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

METHODS AND NATURAL FACTORS IN CONTROL.

The study of the life habits of the pear thrips, as already given in
detail, explains why certain artificial remedies are not entirely effect-
ive, and it also suggests other methods. Adults appear suddenly in
late February and early March. They enter the opening buds and
feed largely in protected places, and always on newly developing plant
tissue. Destruction to buds can be accomplished in a very few days
it may be in less than a week. The fully developed wings of the
insect permit of active flight and widespread distribution. Ovipo-
sition, extending through several weeks, permits of a widespread and
a continuous feeding period for the new brood. Eggs are safely placed
within the plant tissue. Larve feed largely in protected places while
on the tree, and then seek shelter and spend many months in the
ground. An individual of the species will spend about eleven months
in the ground and one on the tree, although the whole period of infes-
tation cf trees by adults and larve may be about three months.

SPRAYS.

Exposed thrips, both adults and larve, can be killed by several of

the contact insecticides, but sprays have not proved successful, be-
cause the spray mixture can not be forced into the very tender buds |
and blossoms where the thrips are, without injuring the plants, and, —
besides, all of the thrips can not be reached by a single spraying. It)
was found in the limited experiments of 1905 that thrips could be |
killed over any given area, but that within a few days the infestation |
would be as bad as though no spraying had been done. This is —
accounted for by the presence of those thrips which escaped the spray |

and by the new individuals which had migrated into the orchard.
It would be impossible for all persons to accomplish their spraying

within the few days when the thrips are arriving on the trees. Larvae |
are more easily killed than adult thrips, but as they feed largely within —
the leaf clusters they, too, are protected. Spraying to kill larvee would —
necessarily be done after the serious injury from adults had been |
effected. It might be possible to obtain some results by applying a |

poisonous spray, but the ever newly unfolding leaf surface, upon

which the insects could feed and which would not be poisoned, would ||

render this kind of spray almost useless.

CULTIVATION.

There is some ground for believing, although the evidence is not |

conclusive, that thorough cultivation will figure largely as a means of
control for the pear thrips; but even here the treatment must cover

areas of considerable extent. Thrips larve in the ground are mostly |

within reach of the plow, being usually found within 5 inches of the -
surface, although a few may go deeper. On uncultivated areas they ,

THE PEAR THRIPS. 13

| ~ may be found within 2 or 3 inches of the surface. Thrips are entering

the ground mostly during the last two weeks of March and during April,
a period when the most active cultivation of the year is carried on.
But the insects are very active at this time, and if they are only dis-
turbed and not killed in the mechanical stirring of the soil they simply
find a new place to hide and perhaps go a little deeper into the ground.
From the following evidence, however, it is quite obvious that careful
spring cultivation is helpful. A certain row of cherry trees which was

_ badly infested with thrips during 1905 was kept under constant obser-
~ yation for several months because it represented various interesting

= 4 pele SS ereY ft

conditions. The trees bordered a roadway and were for this reason
cultivated only on one side. There was a strip of land perhaps 3 feet

_ wide extending on either side of the row, which, though uncultivated,

was not hardened like the roadway. In February and March, 1905,
the trees in question were very badly infested, were stripped of all
their fruits, and left with pale, ragged leaves. Adults were numerous.
Many eggs were deposited and larve by thousands matured, dropped
down, and entered the ground. These larve were actually seen enter-

ing the soil, mostly during the month of April. During April and

May they were readily found in the ground several feet from the tree
as well as near to its trunk. They werescattered about generally,
regardless of cultivation, except that the many individuals which were
unable to penetrate the hard gravel road crawled off to the side. They

_ did not go deeper than 3 or 4 inches in the uncultivated strip near the
_ trees, while in the well-cultivated soil they were often found 6 or 7

, - inches below the ground surface. They could be found easily any-

where, in April, just after entering the ground. After the spring and

- early summer cultivating, however, almost none could be found in

the deeply cultivated soil, but they were as common as ever in the

uncultivated ground. A dozen or more thrips were often collected

from a small clod about aninch and a half in diameter. Small uncul-

tivated areas may be found in almost any orchard, and it is a fact
that a few square yards of ground can harbor a very large number

of thrips.

Cultivation methods, however, as a means of control, can be only
partially effective at best. One can not kill all of the thrips in the
ground even with the most careful cultivation, and there are always
men who can not or will not cultivate at the proper time. Then, too,
there are areas along fences, ditches, etc., which can be cultivated only
with great difficulty. What is even more important, certain kinds of
soils—adobe and clays—can be cultivated only under certain condi-
tions to be kept mellow and loose. The present manner of cultivation
in the Santa Clara Valley offers almost ideal conditions for the thrips,
in that the insect is left undisturbed during almost the entire period
occupied by the resting stage—from June until the following February.

14 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

Thrips are in the ground all of this time, and for the most part within |
reach of the cultivator, but they mature and arrive on the trees in
March and April, before spring cultivating is begun.

NATURAL ENEMIES.

if The pear thrips is largely protected from ordinary preaaceous and
| parasitic insects, because it spends so long a time hidden away in the
| ground. A successful parasite must in a way parallel the life of its
| host, and we have found no insect which thus follows the pear thrips.
Raphidians, or snake flies, their commonest enemies in the Santa
Clara Valley, feed rather on the younger forms than on the fully
developed insects, and they do not
appear early enough in the spring
to constitute an effective check to
the pest. To be competent thrips
killers they would have to feed on
other insects for perhaps ten months
in the year and then, when thrips
appear, suddenly change their diet
and later, after thrips have gone into
the ground, as suddenly change back
again to aphides or to something
else. Such feeding habits are not
to be expected in a vredaceous
species. |
Ants were at one time thought to
be doing much good as an enemy of —
the thrips. A certain orchardist @}
brought in an ant with a thrips
impaled in its jaws—the evidence |
: complete. After a careful investi- |

iI EES eS ee UNS 2 ees ie) nee gation, however, it was found that |
thrips: a, active fruiting stage or adult ? d > |
| thrips; 6, branching mycelia; c, forming only avery. small percentage of ants > ||
: ee Roe ee ge ® © highly were actually killing thrips. Four |
hundred ants were examined as

| they descended a thrips-infested tree. Twelve of these carried
| something in their jaws and only 4 of these objects were thrips. Thus —
I only 1 per cent of the ants on the tree were actually killing thrips —
| and carrying them down. It has been a common observation among —
orchardists, however, that thrips are not common where ants are ©
| unusually abundant.
Spiders and mites are active enemies of thrips. In some of our —
breeding cages almost all of the thrips would at times be killed by
il some small spider or mite which had gained an entrance. The writer
| has observed ared mite (Rhyncholophus sp., determined by Mr. Nathan —
| Banks) actively engaged in feeding on the onion thrips (Thrips tabaci —

THE PEAR THRIPS. 15

Lind.). Both the thrips and the mite were very common in large onion
fields, covering several hundred acres. A mite would be seen to ap-
proach and grasp a thrips with its front pair of legs and, inserting its
proboscis, suck out the body juices of its prey. A single mite was
often observed thus to kill several thrips within a very few minutes.
The writer strongly suspects that some mite preys on the younger
stages of the pear thrips while it is in the ground. This would be
entirely possible, and mites are commonly found in the grass and in
the ground.

A fungus, presumably parasitic, has been endemic among thrips
during the seasons 1905 and 1906. In its different stages it lives
on both young and mature thrips, and in a way parallels the life of its
host. During the spring of 1905 thrips larve were often observed to
be thickly infesting a tree, and after these had disappeared, presum-
ably having gone into the ground, none or but few living ones could
be found. Many larve, too, seemed to
leave the tree before they ha reached
full growth, and within breeding cages
these larve were seen to die as the
direct result of the parasite. Project-
ing from their bodies were to be seen
the tiny fruiting conidiophores of the
fungus. Adult thrips were seen to be
attacked by another form of the para-
site during the spring of 1906. The
past two seasons have offered almost
ideal conditions for the development
of the fungus, enabling it to become
quite widespread. Fic. 8.—a, Resting spores of a fungus

The life history of the fungus has found within dead thrips larva, much
been determined only in part. The at oe ae
heavy-walled resting spores, the dor-
mant stage, are found within larve and adults in the ground; never,
thus far, in pup in the ground or in individuals on the tree. Dead
larve from the ground show that the internal body organs have all
been displaced by the fungus, and in most cases the body contains
only a mass of the heavy-walled spores. The transition which takes
place in the formation of these spores is as yet not clear, but there
seems to be a general breaking up of the fungus hyphx within the
thrips’ body. In one well-prepared specimen there was an indistinct
grouping of particles around many centers. These were presumably

the forming spores, for in the next stage the formation of such spores

was complete. These heavy-walled spores may be found nearly the
whole year through, although they are especially abundant from May
until the following February.

16 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

In the conidiophore stage on the tree the fungus hyphe break forth
in groups from between the body segments and extend out as long
slender threads, which in turn branch and form numerous fruiting
organs. This stage of the fungus has been taken only from adult
thrips on the tree and not from the larve, and it has been found
present almost everywhere that the pear thrips has been collected.

There is no doubt that the fungus spends a part of its life on the tree
and a part in the ground, the rapidly fruiting stage among the active
thrips and the heavy-walled dormant stage within the hibernating
individuals in the ground; but we can only surmise how it is carried
from one to the other. The bodies of the larval thrips within the

eround are all absorbed by the fungus and naturally, therefore, the

spores must be carried to a new host before they can germinate to
any great extent. We have found adult thrips in the ground whose
dead bodies contained only a few spores and others which developed
some of the external mycelial growth within their cells. If this were
often the case, and these individuals in the ground produced fruiting
spores as they do on the trees, it would be an easy matter for healthy
individuals in coming from the ground to become accidentally infested
and to carry the parasite up to the tree where, because of the gre-
garious habits of the insect, it would spread rapidly.

The fungus grows readily in the nutrient agar under ordinary con-
ditions and seems to retain its virulence and can be transferred from
cultures to the living thrips. The fungus may prove to be a check
for the pear thrips, but its effectiveness is uncertain because it is so
subject to climatic conditions.

Wier s) >on Pres —

2 4

. —_— i
‘ A ow >

ae.

A.
Tell By

Dw agian er piak

ry

hb Oo

U.S. D. A., B. E. Bul. 68, Part IT. ‘ D. F. I. L, July 6, 1907.

PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

THE SPRING CANKER-WORM.

(Paleacrita vernata Peck.)

By A. L. QUAINTANCE,

In Charge of Deciduous Fruit Insect Investigations.
INTRODUCTION.

Two species of canker-worms in the United States, the spring
eanker-worm (Paleacrita vernata Peck) and the fall canker-worm
(Alsophila pometaria Harr.), are often very troublesome pests in
apple orchards, infesting also the elm, cherry, and, to a less degree, a
few other trees. These insects, though widely distributed, usually
occur in injurious numbers quite locally, infesting often but one or
two orchards in a neighborhood where conditions have been favorable
for their development. The females of both species are wingless,
hence their dissemination is very slow. The insects are doubtless
distributed mostly on nursery stock in the egg stage, or locally the
larve and moths may cling to clothing of persons, or may be dis-
tributed by teams visiting the infested orchards.

Old orchards which hae been in sod or have not been cultivated
for many years and which are not sprayed with arsenicals furnish

‘ideal conditions for the multiplication of canker-worms when the

latter are once established. Frequently such orchards are defoliated
each spring, with the result that the injury to the trees prevents the
formation of fruit buds, and after a few years of such injury the
trees will begin to die. While certain weather conditions and the
natural enemies of canker-worms may often greatly reduce the num-
ber of these insects, energetic steps on the part of the orchardist are
usually necessary to insure the complete destruction of the pests and
to permit the trees to resume their normal fruit production. In the
great majority of cases, if not in all, canker-worms are practically
limited to orchards which are neglected as to spraying and cultiva-
tion, either practice usually serving to keep them so reduced in num-
bers that their injuries are inconsequential.
17

18 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

Complaints of both fall and spring canker-worms are frequently
received by the Bureau of Entomology. Correspondents often report
that they are unable to protect their trees by the use of arsenicals, and
the opinion has at times been expressed that these insects can not be
destroyed by arsenical sprays. While it has often been stated in the
literature on canker-worms that they are more resistant to poisons
than many other species of insects, yet there is no doubt that they
may be readily killed by thorough use of poisons. In most cases the
poor results from spraying are evidently due to failure to make thor-
ough applications of the spray, the large size of the trees and the
unfamiliarity of the orchardist with spraying operations often con-
tributing to this end.

In the present brief article the life history and habits of the spring
canker-worm are given, together with results of practical work in its
control. The hfe history and habits of the fall canker-worm prac-
tically parallel those of the spring species, except that the great
majority of the moths of the former species emerge and oviposit in
the fall. The operations of spraying and plowing herein discussed
will be equally effective in its control.

LIFE HISTORY AND HABITS.

There is but one generation of canker-worms each year. After
obtaining their growth on the trees in the spring, the larvee enter the
soil to a depth of from 2 to 5 inches, and after making an earthen
cell transform to pupe (see Pl. III, fig. 3), in which condition they
remain until the following spring. Early in the spring, or even
during warm spells in winter, the pupe transform to moths, which
make their escape from the soil and go to the trees. The males are
winged, as shown in Plate III, figure 5, but the females are destitute
of wings, as illustrated in Plate III, figure 4. In ovipositing the
females climb the trees and place their eggs in irregular masses under
loose bark scales, in cracks in the bark, in crotches of limbs, etc., as
shown in Plate III, figure 1, which illustrates an egg mass which was
placed on the underside of a bark scale. The number of eggs in an
individual mass varies greatly. Females taken presumably before
oviposition had begun deposited eggs in confinement, the number to a
mass varying from 17 to 119, with an average for 12 masses of 47.

An individual egg is elongate-elliptical in outline, somewhat
resembling a hen’s egg in miniature. The average dimensions of ten
recently deposited eggs were found to be 0.69 by 0.42 mm. When
first deposited the surface is shining, pearly white, but in the course of
a few hours the egg takes on a yellowish-green color, in certain lights
showing a golden, greenish, or purplish iridescence. As the embryo
approaches maturity it becomes very evident and lies curled around
just within the shell, its cephalic and caudal ends together, the egg-

Bul, 68, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE Ill.

STAGES AND WoRK OF SPRING CANKER-WORM (PALEACRITA VERNATA PECK).
Fig. 2.—The larve or canker-worms. Fig. 3.—Pupe.
Fig. 6.—Work of canker-worms on apple
Fig. 7.—Later work of the larvae, only the midribs of leaves being
left. Figs. 1-5, considerably enlarged; tigs. 6, 7, reduced. (Original.)

Fig. 1.—Egg mass on bark scale.

Fig. 4.—Female moths. Fig. 5.—Male moth.
leaves when small.

’ 4 J 44 Th Re h
. J,
i
' ‘ ‘ ‘
' ABT -
. 5 ;
* Se: | ty
rims
fetus
a ‘
4 .
ss
4
.
7
ea
1
‘
*

a

”
‘
= ‘
e 4
7 \
«
i
rt '
; t
V
von}
fi

a ve LT a

8
.
fa

asad,

THE SPRING CANKER-WORM. 19

shell becoming more or less concave centrally. Shortly before hatch--
ing the eggs become quite dark, due to the color of the larva within.
Eggs secured from females in confinement on the nights of March
8, 10, and 12, and kept under out-of-door conditions in the insec-
tary yard at the Department of Agriculture, Washington, D. C..
were hatching April 10, 11, and 14, respectively, giving for this stage
a fairly uniform period of thirty-two to thirty-three days. The
effect of warm weather upon the development of the embryo may be
judged from the fact that eggs kept in the insectary at a temperature
of 65 to 70° F. hatched in about eleven and one-half days.

When just hatched the spring canker-worm is quite small, measur-
ing but 1.25 to 1.5 mm. in length, varying with the extension of the
body. The head is about 0.25 mm. wide, which slightly exceeds the
width of body across thoracic segments. The head and shield are
shining black, and the body above dark olive-green, with a distinct
central longitudinal white stripe centered with narrow interrupted
lines of the same color as the body. Along each side is a wide irregu-
lar white stripe, including the spiracles and adjacent tubercles.
Below, the body is dark yellowish or brownish in color. The thoracic
legs are stout and dusky exteriorly. There is a single pair of pro-
legs on the sixth abdominal segment and a pair of anal prolegs.

The larve come from the eggs about the time the leaves of the
apple are pushing out, and the latter are at once attacked. At first
only small holes are eaten through the leaves, but later, as the larve
grow, the entire leaf substance save the midrib is devoured. (See
ma. AIT, fios. 6, 7.)

After three or four weeks of feeding, the time varying much with
the temperature, the larve have become full grown. They then meas-
ure from 18 to 23 mm. (0.7 to 0.9 inch) in length. Considerable
color variation is likely to occur, some specimens being ash-gray,
green, or yellow, but the predominating color is dark greenish olive
or blackish. There are two pale narrow lines down the back, centered
with a broader dark stripe and a whitish stripe along each side.
(See Pl. III, fig. 2.) The larva of this species is readily distin-
guished from that of the fall canker-worm by the fact that the former
has but two pairs of prolegs, while the latter has three, the first pair,
however, on the fifth abdominal segment, being more or less reduced.

Newly hatched larve placed on apple trees under a large wire
cage in the insectary yard April 12, 1905, had matured and were
entering the ground for pupation by May &, and by May 11 all had
disappeared from the trees. This gives twenty-seven to thirty days
for the larval existence. The egg and larval stages together require
some two months, and the remainder of the year, except the time
spent in the adult condition before ovipositing, is passed in the pupal
stage in the soil. As has been stated, the insect pupates from about

20 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

2 to 5 inches below the surface of the ground and may be readily
destroyed by thorough plowing and cultivation during the summer
and fall.

DEMONSTRATION WORK IN CANKER-WORM CONTROL.

For several years the spring canker-worm has been quite trouble-
some in a few old orchards in northern Virginia and very little head-
way had been made by the owners of the orchards in its control. In
the spring of 1905 Dr. John S. Lupton, of Winchester, Va., desired
the assistance of the Bureau of Entomology in freeing from this pest
his large orchard of 30-year-old Newton pippin trees, which had been
defoliated to a greater or less extent for three or four seasons. The
orchard had been in sod for years and no recent spraying had
been done for the coding moth. Under these conditions the canker-
worms had been able to multiply with practically no interfer-
ence and had become exceedingly abundant, 50 per cent of the trees
being practically defoliated and the others more or less so. A plan
of treatment was submitted to Doctor Lupton, which was carried out
by him under the writer’s supervision. This treatment consisted in
a thorough spraying of the orchard with Paris green at the rate of
1 pound to 75 gallons of water (plenty of lime being added to lessen
danger of injury to the foliage), the thorough plowing of the orchard
during the early summer, and its subsequent cultivation during that
season. Only one application of poison was made, and not until ~
much later than was desirable, the larve being already from one-half —
to three-fourths grown, many trees having been practically defoliated. —
Nevertheless, the treatment checked further defoliation and within two
to three days the larve had largely disappeared. That the majority
were poisoned was evident, since upon later examinations pup were —
exceedingly scarce, even under trees from which the leaves had been
i almost stripped. During early August the orchard was thoroughly
plowed, special: pains being taken to break up the soil under the
ih trees. Late in the fall the worst infested portion of the orchard was |
iF again plowed, and at right angles to the direction followed in the
iit first plowing. The rest was plowed early the following spring, the
HII whole being prepared for corn, which later was planted, receiving
necessary cultivation during 1906. As was quite evident in the spring —
| of 1906, the thorough spraying with Paris green and plowing of the
i orchard had destroyed the great majority of the insects. In the early
Hi spring of 1906 bands of a sticky preparation placed around the —
iH trunks of trees which had been practically defoliated in 1905 caught —
\ - not more than two dozen specimens of adults in all, and larvee were —
very difficult to find later. That the absence of the insects in this
Mi orchard is to be attributed solely to the spraying and plowing and —
| not to unfavorable weather conditions or the influence of parasitic

Bul. 68, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE IV.

TREES DEFOLIATED BY SPRING CANKER-WORMS AND EFFECTS OF TREATMENTS.

Fig. 1.—Defoliated trees in Lupton orchard. Fig. 2.—The same treesa year later. Fig. 3.—Defo-
liated trees in the Purcell orchard. Fig. 4.—An adjacent row of trees protected by two appli-
cations of arsenate of lead. (Original.

eT ree ee ee SS — OOO e™

9

THE SPRING CANKER-WORM. 91

and predaceous enemies is evident from the fact that in a near-by
orchard, untreated, the insects were excessively numerous, completely
defoliating the trees during the spring of 1906. Figure 1, Plate IV,
is from a photograph of trees in the worst infested portion of the
Lupton orchard in 1905, and shows the injury that had been done
before the application of the Paris green spray. The condition of
these same trees, but looking in another direction, on June 9, 1906, is
shown in figure 2.

During the spring of 1906 spraying work against canker-worms
was also carried out in another orchard near Winchester consisting
of 30 acres of 35-year-old Baldwin trees. This orchard also had been
entirely neglected as to plowing and spraying for many years past,
and for some years most of the trees had been completely defoliated
by the spring canker-worm, some of them and portions of others
being dead. Arrangements were made to spray a portion of the
orchard, though it was not considered practicable by the owner to
have the ground plowed. Arsenate of lead was used as a poison and
applied at the rate of 3 and 5 pounds per 50 gallons of water for the
first and second applications, respectively. At the time of the first
application the leaves were well out, being from three-fourths of an
inch to an inch in diameter. The canker-worms had almost all
hatched, very many being in the second stage, and were literally
swarming over the trees. The second application was made May 5,
most of the larve at this time being from’one-half to three-fourths
grown, the untreated trees being already nearly bare of leaves. The
treated trees, while showing some injury from the larvee, especially
in the higher parts, were in almost full foliage, though subject to
infestation from adjacent trees. The second application largely pro-
tected the trees from further injury, and there is no doubt that if the
entire orchard had been treated the insects would have been practi-
cally exterminated. Figure 3, Plate IV, shows the defoliated condi-
tion of untreated trees June 9, after the larve had all disappeared,
and the condition of sprayed trees in an adjacent row is shown in
figure 4 on the same plate.

RECOMMENDATIONS.

Orchardists having canker-worms to contend with may confidently
expect to practically eradicate them in the course of one or two sea-
sons by following the methods above described, namely, thoroughly
spraying the trees with a strong arsenical and thoroughly plowing
the ground during the summer. If Paris green is used, this should
be applied at the rate of 1 pound for each 100 gallons of water, and
unless used in Bordeaux mixture there should always be added the
milk of lime made from slaking 4 or 5 pounds of good stone lime.
Arsenate of lead may be used at the rate of 6 to 10 pounds to 100

72 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

gallons of water or Bordeaux mixture, and because of the strength
at which it may be used without injury to foliage and its excellent
sticking qualities it is to be preferred to other arsenicals for canker-
worms. At least two applications of the poisoned spray should be
made; the first as the fruit buds are exposed, or just as the foliage is
pushing out, but before the blossoms open, and the second in eight to
ten days, or at once after the blossoms have fallen. In bearing
orchards the second treatment is the principal one for the codling
moth, and if the poison be used in Bordeaux mixture the two applica-
tions of this combined insecticide and fungicide will largely protect
the trees and fruit from canker-worms, the codling moth, and other
leaf-feeding insects, and will lessen apple scab.

While it may often appear impracticable to spray some oreharee on
account of the height of the trees, most orchards may be plowed and
cultivated, and this work should certainly form a part of the plan of
canker-worm eradication.

Another important method of protecting high orchard and other
trees which it is impracticable to spray is the employment of special
protectors, such as bands of cotton, or sticky substances. These are
placed around the trunk of the tree near the base, and are used to pre-
vent the ascent of the wingless females to deposit their eggs, or the
ascent of any larve from eggs deposited below the bands or which
have fallen from the trees. Sticky substances, such as printer’s ink, -
tar, bird lime, and certain proprietary preparations, are best. On
account of the danger of injury to the trees, these are best applied on
strips of paper 5 or 6 inches wide and of sufficient length to go around
the tree. The loose bark should first be scraped from the trunk where

the band is to be applied, and if a light band of cotton batting be

first fastened where the paper band is to be placed this. will effectu-
ally prevent the insects working up beneath the sticky paper band.
Cotton batting may also be used, the trunk being encircled with a
strip 4 or 5 inches wide. This is tied with a string at the lower edge
and the band then turned downward. This will be effective so long —
as it remains fluffy, but usually requires renewal after heavy rains.
Whatever form of protector is used must be applied quite early in the ©
spring, at least six or eight weeks before the apple buds are due to —
burst, as the moths come out very early, sometimes even during ©
warm spells in the winter.
The methods of control given above are equally applicable to thea %
fall canker-worm, except that in the use of bands to prevent ie
ascent of moths these must be applied in early fall, since the moths om”
this species oviposit mostly during that season.

mes. . AL, B: b Bul..68, Part. ITT. D. F. I. I., October 15, 1907.

PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

THE TRUMPET LEAF-MINER OF THE APPLE.

(Tischeria malifoliella Clemens. )

By A. L. QUAINTANCE,

In Charge of Deciduous Fruit Insect Investigations.

During 1905 this species became unusually abundant in the Dis-
trict of Columbia and in localities in adjacent States. Specimens
of mined apple leaves were received from Afton, Va., Newark and
~ Woodside, Del., Cheltenham, Pa., and Vermont. Judging from the
- condition of the leaves sent, the insect in these several places was
much less abundant, however, than in the immediate vicinity of
~ Washington. During 1906 the insect was again exceedingly abun-
|
:

en ee ee eee

— dant in the environs of Washington, was the subject of further com-
plaint from Delaware, and was received from Connecticut.

HISTORY.

This species was described in 1860 by Clemens in the Proceedings
of the Philadelphia Academy of Sciences, Volume XII, page 208.
_ from material presumably from Pennsylvania. Interesting observa-
_ tions concerning its food plants are presented by Chambers in the
— Canadian Entomologist, Volume III (1871), page 208; Volume V
(1878), page 50, and Volume VI (1874), page 150. Additional notes
are given by him in the Cincinnati Quarterly Journal of Science,
~ Volume IT (1875), page 3; in Bulletin U. S. Geological and Geo-
) graphical Survey, Volume IV (1878), page 107, “ Tineina and their
~ Food Plants,” and in Psyche, Volume IIT (1889), page 68. Messrs.
Frey and Boll, in Stettiner Entomologische Zeitung, Volume

XXXIV, page 222, note its occurrence in Germany on apple im-

ported from this country. The insect has been occasionally men-
tioned by Lintner in the reports of the New York State Entomolo-
gist and elsewhere, and is the subject of an article with bibliography
in his Eleventh Report. Dr. E. A. Brunn, in the Second Report of
the Entomological Department of Cornell University (1882), in a

.“
-o

24 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

paper on the Tineide infesting the apple trees at Ithaca, N. Y.,
gives an account of the insect with figures of moth, larva, and mines
in apple leaf. A more extended account is given by Dr. C. M. Weed
in the Fifteenth Report of the Illinois State Entomologist (1889),
pages 45-50; and it is mentioned by Lugger in Minnesota Experiment —
Station Bulletin 61 (1898), page 316, and later (1903), by Wash-
burn, in Minnesota Bulletin 84, page 66. In Bulletin 180 of the ~
Michigan Experiment Station (1900), ee 125, and Special Bulletin |
24 of the same institution (1904), page 22, the species is the subject —
of short illustrated articles by Pettit; and it is also discussed by ©
Lowe in Bulletin No. 180 of the New York Agricultural Experiment |
Station (1900), page 134. In 1906 brief mention is made by C. P. ©
Close of the occurrence of this species in central Delaware (Bul. 73, ©
Delaware College Agric. Exp. Station, p. 18), where it is said to have ©
been increasing for several years past.

The above includes the important references to this species so far —
as the writer has been able to determine.*

DESCRIPTIVE.

The mine.—The mines occur exclusively on the upper surface of |
leaves, beginning at the point of deposition of the egg as a narrow, —
often curved line, gradually or suddenly enlarging in isolated and |
typical examples, and finally having the outline of a trumpet or
mussel shell (see Pl. V). Completed mines vary much in shape and —
size, but will average, perhaps, in the more typical examples one-half _
inch long by one-fourth inch wide. There is considerable irregu-
larity in the feeding habits of the larve, and blotch mines are often —
produced, the narrow linear portion being frequently more or less—
obliterated. In many mines crescent-shaped patches of white cross
the linear portion, extending often well into the body of the mine. 2 |
Unless held to the light the mine is scarcely noticeable from the lower 2 |
surface of apple leaf, but above the blistered epidermis varies in _
color from whitish to dark brown, and the spotted appearance of
badly infested leaves is noticeable some distance from the trees. _
Injury is confined principally to the palisade layer of cells immedi- _
ately below the epidermis of the upper surface of the leaf. The posi- _
tion of the mine on the leaf is quite variable, but it does not usually |
cross the larger veinlets, extending more or GS parallel with them. ie

The egg—The eggs of Tischeria malifoliella are regularly ellip- _
{ical in outline, somewhat convex centrally, but flattened around the —
mar rgin, which area is more or less wrinkled. When first laid they

«Since this article was prepared this species has been well treated by Mr
C. D. Jarvis, in Bulletin 45 of the Storrs, Connecticut, agricultural experiment
station. an |

.
!

- flat, with the segments

ts

ond or third segment,
the last three segments
rounder and narrower
‘than the preceding.

THE TRUMPET LEAF-MINER OF THE APPLE. 25

are greenish yellow in color and somewhat translucent. In some
lights they are irridescent, as are the empty egg shells. One or two
days previous to hatching they become comparatively conspicuous,
the embryo being central and the whitish margin showing plainly
against the dark color of the leaf. The empty shells are white and
mark the beginning of the mine. The average size (based on meas-
urements of five eggs) is 0.34 mm. by 0.54 mm. The eggs are at-
tached closely to the leaf, usually in furrows along a veinlet, but
occur more or less promiscuously. This stage has not previously been.
described.

The larva—tThe larva (fig. 9, ¢) upon hatcning measures about
0.7 mm. in length. The head is brownish, the rest of the body whit-

ish, except cervical and anal shields, which are dusky. Full-grown
—larve will average 5 mm. in length by 1 mm. in width across the

third thoracic segment. The head is about 0.5 mm. wide, retractile,'

bilobed, brownish or even black in color. The general color of the

body is light green, ex-
cept cervical and anal
shields, which are
brownish. The body is

Yi
Ny Yj
i
fi)
Mes

: Ih
My ite
} ?
Wr
7

very distinct, and taper-
ing caudad from the sec-

Fic. 9.—Trumpet leaf-miner of the apple (Tischeria malifo-
é : liella): Adult, larva, pupa, details.
Thoracic segments with

three long sete on each side; succeeding segments with two setz on
each side varying considerably in length; at caudal end there are

humerous shorter curved setw. Thoracic legs absent. Abdominal

and anal legs marked by five pairs of crochets (see fig. 9, c, d).

The pupa.—The pupa is rather variable in size, the average of five
being 3.35 mm. by 0.95 mm. The color when first formed is rather
uniformly pea green, later becoming much darker, varying with age.
The general color of the thoracic region and head is dark brown to
blackish. The abdomen is dark green, yellowish caudad; the caudal

margin of the rather distinct segments is brown. Leg and wing

sheaths free; tip of third pair of legs reaching to cephalic border of
third segment from last. The antennal sheaths reach the cephalic
margin of the fifth segment from last. The spiracles are on slight
conical elevations, and on each side of abdomen, ventrad of spiracles,

isa row of long slender seta, a pair to each segment. Cremaster of

two stout short projections, slightly curved at tip. Head obtusely
si 10090—Bull. 68—09——3

26 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

rounded, without horn-lke processes, but with a pair of slender
sete. This stage has not hitherto been described, the description _
given by Weed being evidently that of the pupa of some other
species. (See fig. 9, e, 7.) |

The adult or moth—The description given by Clemens is as fol-
lows: “ The head and antenne shining, dark brown, face ocherous.
Fore wings uniform, shining, dark brown with a purplish tinge, —
slightly dusted with pale ocherous; cilia of the general hue. Hind ©
wings dark gray; cilia with a rufous tinge.” (See fig. 9, a, 0.)

FOOD PLANTS.

In his original description Clemens gives the food plant as apple. -
Chambers states that he bred it from ie es of different species of —
haw (Crategus), sweet-scented crab (Pyrus coronaria), blackberry il
(Rubus villosus) , and raspberry (Rubus occidentalis), and adds that
it probably mines other species of Rosaceee. Later Clemens saya |
that this species, as well as certain others, feeds indifferently on
leaves of Crateegus, Prunus, and Malus. {

In 1873 Messrs. Frey and Boll described 7%scheria enea, bred from | |
Rubus villosus, and Tischeria roseticola from Rosa carolina. Tn the ~
Cincinnati Quarterly Journal of Science Chambers adds tl: a
berry (ubus canadensis) to the food plants of Tischerta mali
and does not consider 7’. enea of Frey and Boll, from blackbe ~§
tinct from 7. malifoliella; he regards as belewenne to this species '
the specimens bred from all the species of abuse Crategus, and —
Pyrus. He also doubts the distinctness of 7’. roseticola. However,
in a later publication, “ Tineina and Their Food Plants,” Mr. Clemens
recognizes the two species of Frey and Boll above Shea, and as food —
lente of 7. malifoliella gives Crategus, Pyrus coronaria, and Pyrus —
malus, omitting as food plants species of Prunus, Rubus, and Rosa,
assigning the two latter as food plants of wnea and roseticola, re- .
spectively. The distinctness of the three species was again recog- 1
nized by Chambers in his Index to the Tineina of the United States
and Canada, ae more recently by Doctor Dyar in his “ List of N. A.
Lepidoptera.” x

Finally Mr. Pettit notes serious damage to blackberries from
T. malifoliella at the South Haven substation in Michigan, and —
states that the insects seem to breed in the neighboring apple trees
and come to the blackberries from them. However, in the absence
of definite breeding work and the critical comparison of adults thus
secured, it will be best to follow the evident conclusions of Chambers
and Dyar, and limit the food plants of 7. malifoliella to species of
Crategus and Pyrus. During the present season (1907) the insect

}

a Bul. 52, U. S. Nat. Museum, 1902.

Bul. 68, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE V.

;
“y
s\*
PA
an
a
¥
5
‘

s

Oe a

WORK OF THE TRUMPET LEAF-MINER OF THE APPLE (TISCHERIA MALIFOLIELLA): LARVAL
MINES IN APPLE LEAF.

b

THE TRUMPET LEAF-MINER OF THE APPLE. 27

was never found on blackberry, though growing in abundance near
infested apple trees.

SEASONAL HISTORY.

But little of a definite character has been recorded concerning the
seasonal history of this species. Clemens states that “ when pupation
begins the leaf is thrown into a fold, which is carpeted with silk, and
_ the pupa les within it. This state begins about the latter part of
September, and the imago appears early in May.” Brunn, who
studied the species at Ithaca, N. Y., says, referring to the mines,
“ Within these clean and comfortable quarters the larva passes the
winter.” The observations of Weed, reported in “Injurious and
Other Insects of Illinois” (1886), agree entirely with those of
Brunn; and Lintner, writing in 1895, says it hibernates within the
leaf in its larval stage. Pettit, in 1900, states that “ The larve are
said to change to the pupal condition during September, and to re-

-mmain in that condition until the following May,” and again, in 1904,
he says, “ The pupal stage is passed in the mines of the leaves, neces-
sarily on the ground in the winter time.” Observations of Lowe in

1900 at Geneva, N. Y., agree with those of Brunn and Weed, though
on October 29 a larva was found evidently about to pupate.

Until 1900 this species was evidently considered single brooded,
_ though no definite observations seem to have been made on this point.
_ During that year Pettit reported for Michigan that full-grown larve
were found about the middle of July and again September 16, indi-
cating at least two generations of larve. August 16, 1905, in Niagara

County, N. Y., the writer found numerous empty mines with pro-

truded pupa cases, and a single live pupa in a mine. Young larve

from eight to ten days old were fairly common, indicating a seeond
generation for that section.

The abundance of the insects in the vicinity of Washington during
the past two years has permitted some observations on this point.
In 1905 the insect was first noticed, May 30, on an isolated apple
tree near the writer’s home in Kalorama Heights, D. C., and this
tree has been kept under observation during the seasons of 1905 and
1906. On May 30, 1905, when first seen, the first generation of
larve was maturing, one pupa being found, and by June 18 the
great majority of larve had pupated, and quite 25 per cent of the
moths had already emerged. ‘The first generation of larve was quite
abundant, almost every leaf having 8 to 10 mines. Practically all

upe had yielded moths by June 30, and the leaves were peppered

ith eggs, many of which had already hatched, the larve being yet
aite small, in linear mines. By July 27 the second generation of
larve had mostly pupated and many moths were out and ovipositing.

’

28 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

The number of mines per leaf at this time averaged from 15 to 18. |
By August 4 pup had largely yielded moths, and eggs were
again very abundant, a few having already hatched. By August 26 —
another generation of moths had developed and their eggs were in ;
an advanced condition of development and many had already hatched. 4
September 10 larve of this, the fourth generation, were of various —
sizes, from quite small to full-grown, but no pup could be found. —
The leaves, although practically covered with the mines on their
upper surfaces, were still hanging on the trees, and there was but
little evidence of serious injury having been done. By October 30
quite 50 per cent of the foliage was on the ground and those leaves
remaining on the trees were more or less rolled in from the edges.
This premature falling of the foliage was undoubtedly due to the
work of the leaf-miner, and this seems to have been its principal
injury. At this time the larve were full-grown and had lined their —
mines with a dense lining of silvery-white silk preparatory to hiber-
nation. Leaves picked from the ground contained from 6 to 15_
larve per leaf. Leaves examined December 6 showed no change of —
condition, no pupe whatever being found, and this condition was also —
found to obtain on January 21. March 12 a quantity of leaves were
collected from the ground, and at this time fully 90 per cent of the ~
larve had transformed to pupeze, though this stage had but recently
been entered, as indicated by the bright-green color. On April 22, —
at which time the fohage of the apple was just pushing out, only
pupz could be found, and some of these were quite dark in color, the ©
inclosed moth evidently being nearly developed and ready to escape.
The formation of pup as just mentioned is perhaps to be regarded
as abnormally early, since the weather about this time was unusually
warm. This belief is strengthened by the fact that in infested apple ©
leaves kept in a breeding cage out of doors in the insectary yard the ©
insects were all in the larval condition, except one pupa, on April
5, the moths mostly emerging the latter part of that month. By May
7 eggs were very abundant on the foliage of the apple tree under
observation, as many as 12 being counted on a single leaf, but on
some leaves none at all were to be seen. At this date no larvee had yet
hatched, though many eggs were in an advanced stage of development,
the embryo being readily seen within the delicate shell when examined |
with a hand lens. By June 24 larve from these eggs had mostly _
matured and had entered the pupal stage, though a few full-grown |
larve were still to be found. The time of maturing of the first —
generation in 1906, therefore, agrees closely with this period in 1905. —
Length of life cycle.-—Eggs deposited during the night of July 31 |
were very generally hatching on the morning of August 8. The-
larva leaves the egg by eating directly through the lower surface at
one end into the leaf beneath, at once beginning its mine, and is thus »

THE TRUMPET LEAF-MINER OF THE APPLE. 29

at no time exposed. The act of leaving the egg is very deliberate,
and may occupy ten or twelve hours before the body is completely
out of the shell and into the mine. Feeding alternates with resting,
the larva often working backwards out of the mine into the egg-
shell, where it may rest for half an hour or more. The mines are
at first but little wider than the width of the insect and are lined with
silk from the start. Progress at first is slow, the larva proceeding
about twice its length during the twenty-four hours following the
breaking of the eggshell. After a few days, however, it feeds much

- more vigorously and soon widens the mine in the course of its feeding.

Of the larve which hatched the morning of August 8, 12 out of the
15 under observation pupated during the night of August 25, this
stage therefore lasting approximately eighteen days; and the moths
from these pupez mostly emerged by the morning of September 2,
one emerging the morning of August 30, making for the life cycle
about thirty-three days. Moths kept in confinement without food
lived for about two days. According to Chambers, the larve molt
five times, and there are no marked differences either in color or
structure between the larve at different stages of growth.

DISTRIBUTION.

The trumpet leaf-miner is evidently a native species, its original
food plants probably being species of Crategus and wild Pyrus. It
has been recorded from New York, Texas, Illinois, and Michigan.
The material on. which Clemens based his description was probably
from Pennsylvania, and the observations of Chambers made in Ken-
tucky indicate its occurrence in that State. Records of this Bureau
show it to occur in South Carolina, Virginia, Delaware, Pennsy!]-
vania, Connecticut, Rhode Island, Vermont, Massachusetts, Missouri,
Arkansas, and Nebraska. and at Ottawa, Canada.

PARASITES.

This miner is freely parasitized. At Ithaca, Dr. Brunn bred from
it Sympiesis lithocolletidis How. and Astichus tischerie How. The
former species has been bred from this insect at Champaign, IIl., by
Weed, and ELlasmus pullatus Howard is doubtfully recorded from
this species from Missouri. At different times during the season of
1905, at Washington, D. C., infested apple leaves were placed in jars,
and the following species were secured, some of which probably are
secondary parasites: Urogaster tischerie Ashm., Sympiesis nigro-
femora Ashm., Horismenus popenoct Ashin., Closterocerus trifasciatus
Westw., Hulophus n. sp., Zagrammosoma multilineata Ashm., and a
variety of this species. A species near Phygadeuon was reared, and
one near, if not identical with, C?rrospilus flavicinctus Riley.

30 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

TREATMENT.

When excessively abundant, as has been the case in several localities -
during the past two or three years, the injury done by the larve in |
the leaves will cause many of these to fall prematurely, interfering —
with the proper development of the fruit and the health of the tree,
and its control, therefore, becomes a matter of importance. This
can perhaps best be accomplished by plowing the orchard in the ~
spring, covering as much as possible all fallen leaves and trash, as in —
the former the larvee pass the winter, and it is practically certain that
the moths will not be able to make their escape from the soil. This
work should be done not later than the blooming period of the trees,
to insure covering up the infested leaves before any early-emerging
moths escape. As this method of control involves no extra labor. —
not requisite in proper orchard treatment, this species, which has but
recently attracted attention as a pest of the apple orchards, is not to
be regarded as a serious pest of the apple in the sense that it will
require independent treatment.

After the insect has become established in orchards, and its im-
mediate control appears necessary, a thorough spraying of infested
trees with 12 or 15 per cent kerosene emulsion made in the usual way
would no doubt result in the destruction of the larvee and pupe in the
mines in the leaves, and possibly also of the eggs scattered over the
foliage. Such work, however, should be done on clear, bright days,
to lessen as much as possible danger of injury to the foliage from the
spray. Tests of a kerosene lime emulsion alone, and with Bordeaux
mixture and Paris green, have been reported by Prof. C. P. Close,
formerly of the Delaware College Agricultural Experiment Station,
in Bulletin 73 of that institution. In the experience of Professor
Close, applications in early August of 10 and 15 per cent kerosene
lime emulsions, with Bordeaux mixture and Paris green, were quite
effective in killing larve and pupe in the leaves. Applications of |
kerosene lime emulsions in September on the succeeding brood were |
not so successful in killing the insects, and the apple foliage was
injured, possibly on account of its weakened condition following the |
work of the miners.

as. AL. Bb. HW: Bul. 68, Part Iv. D. F. I. I., October 17, 1907.

PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

THE LESSER PEACH BORER.
(Synanthedon pictipes G. & R.)

By A. A. GIRAULT.
Engaged in Deciduous Fruit Insect Investigations.

INTRODUCTION.

Until recently the only lepidopterous porer of the peach known to
be common and injurious in the East was the peach borer (Sanni-
noidea exitiosa Say), an insect well known to entomologists and fruit
growers alike. About ten years ago—in 1896—however, another
somewhat similar borer, the subject of this paper, now called the
lesser peach borer, was mentioned by Webster as “ thé peach borer,”
and again, four years later, Smith recorded it as being sometimes
found on the peach in New Jersey, though apparently it was not con-
sidered a pest of any importance. It was with some surprise that,
in the investigation of the peach borer by this Bureau during the past
two years, this insect was discovered to be very abundant on peach in
Maryland and Georgia, and also to a less extent in western New York
and adjacent portions of Canada, occurring especially in the trunks
-of old or diseased trees. At first the larva was confused with that
of the peach borer, but dissimilarities in its habits soon led to its
recognition, which was confirmed upon rearing adults. Aside from
its being a practically unrecognized enemy of the peach, the insect is
of interest from the fact that it has heretofore evidently been more or
less confused with the true peach borer, to which the larva bears great
resemblance in general appearance. In subsequent pages there is
given as complete an account of the species as is possible at this date.

HISTORY.

Up to the year 1906 the species under consideration had not been
treated as an insect of special economic importance. Previous to
this time it had been known mostly as occurring on the plum and

3l

4

32 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

cherry, and it had not been sufficiently abundant to cause more than

occasional record of the fact in the literature of economic entomology.
For instance, it is not mentioned in the Catalogue of the Exhibit of
Economic Entomology at the Lewis and Clark Centennial Exposition,
Portland, Oreg., 1905, given in Bulletin No. 53 of this Bureau. It
has been listed several times, however, as occurring: on plums and
cherries, and in the following cases had been mentioned especially in
respect to its injury to these plants: Kellicott reported serious injury,
in some instances, to plums in New York State in 1881, but Smith,
nine years later (1890) ,* stated that it was rare in New Jersey. In
1892 Kellicott reported serious injury to cherries in Ohio. In 1899
Lugger thought the insect was increasing in Minnesota. Finally, in — |
1906, Quaintance reported it as very abundant in Georgia, causing
material injury to peach trees.

ORIGINAL DESCRIPTION; SCIENTIFIC NAME.

The insect was first described as new to science in 1868 by Grote
and Robinson, from adults captured in the “Atlantic district
(Penna.).” It was given the specific name pictipes and placed in
the genus Ageria of Fabricius. In 1881 it was redescribed as new
by Henry Edwards under the name of 4 geria inusitata, from speci-
mens obtained in the White Mountains, New Hampshire, and at
Andover, Mass. Twelve years later Beutenmiiller (1893) established
inusitata Hy. Edwards, as a synonym of pictipes. In the meantime
Smith (1890) had removed the species pictipes to the genus Sesia of
Fabricius, which removal was accepted later by Beutenmiiller (1896,
1897) and Dyar (1902). Soon afterwards Holland (1903), finding
that the name Sesia had been restricted to a genus of the Sphingide
by Fabricius, applied to the genus Hiibner’s proposed name, Synanthe-
don, which seems to be the proper course in this case (p. 385). The
insect’s scientific name, therefore, is Synanthedon pictipes (Grote and
Robinson ).

COMMON NAMES.

Owing to the fact that the lesser peach borer feeds in the larval
stage on a variety of trees it has become known by local or common ~
names, depending on its most common or most important food plant
in particular localities. It was first found on plum, and hence was
first called, by Bailey in 1879, the plum-tree borer, which has since
been the name oftenest applied to it. In 1896, as previously men-
tioned, Webster referred to it incidentally as “the peach borer; ”
and in 1906 it was designated by Starnes as “ the wild-cherry borer.”
In the same year, however, because of its increasing abundance on the

a@ Dates in parentheses refer to the bibliography at the end of this paper.

THE LESSER PEACH BORER. 33

peach and apparent preference for this tree over others hitherto
chosen, Quintance proposed for it the name of the lesser peach borer,
in distinction from. the better known peach borer Sanninoidea
exitiosa Say. This name seems preferable to any of the others, and
more logical, because the peach is the most important food plant
which it attacks at the present time.

FOOD PLANTS; CHARACTER AND EXTENT OF INJURY.

It has already been indicated that the lesser peach borer has more
than one food plant, a habit usual with the members of the family
to which it belongs. Bailey, in 1879, first found it on the cultivated
plum. Two years later, in 1881, Kellicott found it attacking old plum
trees at Buffalo, N. Y., and also wild cherries (Prunus serotinus and
P. pennsylvanicus). In 1891 the same author stated that, in addi-
tion to its favorite food plant, it also attacked wild black and red
cherries at Columbus, Ohio, and very probably would be found on
the cultivated cherry. Again the following year (1892) he briefly
states that it attacks both cultivated and wild cherry in the same
locality of Ohio. In 1893 Webster reared the insect from the
black-knot fungus, Plowrightia morbosa, on cherry and plum.
Beutenmiilier (1896), three years later, gave two additional food
plants, juneberry (Amelanchier canadensis) and the beach plum

- (Prunus maritima). During the same year Webster (1896) recorded

it on peach. Beutenmiiller (1897) then added chestnut, and in
1899 Lugger added wild plum, making the following known food
plants to date: Cultivated and wild plums and cherries, black-knot
fungus on plum and cherry, juneberry, beach plum, chestnut, and
peach.

Recent records of this Bureau show that this borer has a decided
preference for peach. For instance, in Georgia where large plum
and: peach orchards are grown side by side, an examination of each
kind of tree showed that it was common on the latter and scarce on
the former. We have been unable to find it numerous on wild plum
and cherry in that State, nor have additional food plants been found.
In Maryland we have found the larva in a knotty growth on peach
some 5 feet above the ground. Mr. W. F. Fiske, of this Bureau,
reared adults from girdled chestnut trees (Castanea dentauta), at
Tryon, N. C., May 28, 1904.

The insect is evidently increasing on peach, and at present in cer-
tain localities causes costly and, in the case of individual trees, fatal
injury. Bailey (1879) records a fatal attack on a plum tree in New
York; and as an example of such concentrated attacks on individ-
ual trees in orchards mention may be made of the case of a nearly
girdled 3-year-old Greensboro peach tree in Georgia, from the slender

34 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

trunk of which were taken 14 pupa, 1 larva in cocoon, and 28 larvee

-of various sizes.

The attack of this insect is somewhat similar to that of the peach
borer, but differs in many respects. Apparently it attacks none but
injured trees, where the bark has been injured in various ways, and
it is therefore usually found in old trees where this condition is more
likely to occur (see Pl. VI, fig. 3). Further, the larve occur upon
the trunk as a rule, make more irregular and longer burrows, and
generally follow the outlines of wounds or along the edges of the
cracked bark. They may be found, however, at or slightly below
the surface of the soil and above the crotch or fork of the tree in the
larger branches. The larvee feed on the soft tissues of the hving
bark, and an infested tree exudes a considerable amount of gum from
the area in which they are working. In some of the Georgia and
Maryland peach orchards groups of old, scarred trees have been
found with their trunks literally honeycombed by the channels of
these larvee, and this is hkely to be the condition in any neglected
orchard in which the trees have reached some size. An average of
two larve to the tree was found in 14-year-old trees in Georgia in
1906, but occasionally individual trees were discovered harboring as
many as 40 or 50 specimens of the insect in various stages.

DISTRIBUTION.

The lesser peach borer is rather widely distributed in the United
States, to which it is native. In his List of North American Lepi-
doptera, Dyar (1902) simply gives “ U. S.,” denoting general dis-
tribution. Beutenmiiller (1901), in his monograph of the Sesiide
of America North of Mexico, gives from Canada to Florida and
Texas, westward to the Pacific. It has been recorded from the
following States: New York and adjacent portions of Canada, Penn-
sylvania, New Hampshire, Massachusetts, Illinois, New Jersey, Ohio,
California, North Carolina, Minnesota, Maryland, District of Colum-
bia, Virginia, and Georgia. It has been recorded as common and
locally injurious in New York State and Ohio. The records of this
Bureau (Quaintance, 1906) report 1t common in Maryland, western
New York and circumjacent territory, and in Georgia, where it is
especially abundant. It is known to occur on peach in New Jersey,
Ohio, New York, Virginia, Georgia, District of Columbia, and
Maryland.

LITERATURE.

The literature of this insect is not extensive. Bailey (1879) gives
the only account of its life history yet published, and his description

Bul. 68, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE VI.

LESSER PEACH BORER (SYNANTHEDON PICTIPES).

Fig. 1, Male and female moths (male above); fig. 2, cocoons as exposed by removing bark from
trunk of peach tree; fig. 8, trunk of 10-vear-old peach tree badly infested with the larve.
Figs. 1 and 2, enlarged twice; fig. 8, much reduced. (Figs. 2 and 3, original; fig. 1, from
Quaintance. )

quent emergence of

THE LESSER PEACH BORER. BD
of the character of injury is especially good. From time to time it
has been treated systematically and figured, or listed, and for such
treatment reference should be made to the bibliography given at the
close of this article.

LIFE HISTORY AND HABITS.

The winter is passed in various stages of larval development under
the bark of the trunks of the trees. Upon the approach of warm
weather, and during warm spells in the winter in the South, the
larve feed, and as they reach full growth construct cocoons and
pupate (in March and April in Georgia and Maryland, respectively).
About a month afterwards the moths begin to emerge and mate, and
the females. at once commence to deposit their eggs along the tree
trunks. On account of the unequal development of the hibernating
larve, the period of
pupation and _ subse-

the adults lasts for
several months. The
eggs hatch after
about ten days, and
the young larve en-
ter the bark through
crevices and begin to
feed. In Georgia, in
the course of several

months, these larvee pre. 10—The lesser peach borer (Synanthedon pictipes): a, Adult;
reach full orowth and b, outline of eggs; c, larva; d, pupa; e, cocoon and pupal skin,
= (Original. )
pupate, and the re-
sulting moths establish another generation in the early fall,
‘) => .

which hibernates as larve. The two generations are considerably
mixed.

The seasonal history of this borer is therefore very unlike that of
the peach borer. It differs markedly in the fact of a partial second
generation, and the further fact of early spring pupation.

The egg—The egg (fig. 10, 6) is a small, compressed, elliptical!-
oval, reddish-brown object, similar in general to the eggs of the
peach borer and other members of the family .geriide. It har-
monizes in color with the bark of the trees upon which it is deposited,
and on this account is difficult to find. Seen from the side the ante-
rior end is truncate, but viewed from in front it is found to be con-
cave, the micropyle situated in the center of the concavity. The
upper side of the egg, as seen when in position on a tree, is com-

36 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

pressed and concave, the hollow being oval and following the out-
line of the margins; the bottom side or base is flat. The surface is
rough and sculptured into irregular polygons with from three to six
sides. The eggs are adhesive, hard, visible to the naked eye, but
minute, measuring 0.63 by 0.38 mm., and are deposited singly. They
differ in aspect from those of the peach borer, and also are usually
lighter in color and not as large and stout. They are rather more
difficult to find in nature.

At present the length of the period of incubation is not well known.
Mr. Quaintance records it as 74 days in the month of September,
latitude of Washington, D. C. Upon hatching, the little larva
cuts its way through the anterior end of the egg, leaving quite a
large exit hole in the egg shell, which retains its shape and place
until it weathers off.

The eggs were first observed in nature by Bailey (1879); he found
a cluster of them on the under surface of loosened plum bark, about
6 inches above the roots. Usually, however, they are deposited
singly along the trunk of the tree, being placed in crevices, openings.
or roughened places. Sometimes a few are placed on the ground or
high up in the tree on twigs or leaves, but the majority are de-
posited on the main trunk of the trees. The number deposited by
a single female is unknown. Moths kept in confinement refuse to
mate, and the female deposits few eggs or none at all. To determine
the number resort is therefore made to dissection. Mr. Quaintance
dissected two fertile females after death, and found 305 perfect eggs

in one and 296 in the other, in addition to numbers of small unde-~

veloped ones. Each moth had deposited a few eggs before dying,

which were included in the count.’ Dissection of the ovaries of a
sterile moth yielded but 58 perfect eggs, but there were present —

many undeveloped ones. Until more dissections are made the evi-
dence on this point remains inconclusive.

The larva.—When the larva hatches it is very small, and especially |
hard to detect with the naked eye because of its dull white color. It |
is an ordinary caterpillar, bearing the usual setsze and number of pro- |

legs, and in its earlier stages is almost indistinguishable from the

young larve of the peach borer. However, after molting once or |
twice it acquires a different aspect, which together with a more? |

pinkish and translucent color makes it somewhat more distinct.

Throughout all its life it remains about the same color—various |
shades of creamy white—and lives concealed under the bark. The

following is a description of a full-grown larva, or instar VI:

Length, 20.5 mm., average. Greatest width, 3.4 mm. Width of head, 1.94
mm., average. Normal for the family: Body soiled cream color, immaculate,
with the usual more or less generalized characters. Head yellowish brown,

|

THE LESSER PEACH BORER. o7

darker at base of clypeus and on labrum and mandibles, and blackish at the
lower outer angles of the paraclypeal pieces, edges of clypeus, and tips of the
mandibles; pale at vertical triangle, outer edges of paraclypeal pieces, gular
surfaces, epistoma, palpi, and antennze, the last two somewhat darkened;
mandibles broad and short, indistinctly five-toothed, the two inner teeth mere
serrations, the third tooth short, truncate, and broad, one-half shorter than the
second, which is shorter and broader than the first, which is also obtuse; cut-
ting edge of mandible oblique; two setze present, arising together from middle
of inner edge. Clypeus long, acutely triangular, its lateral margins sinuate, not
distinctly truncate at basal corners, which are impressed and bear two setz,
one caudad of the other; paraclypeal pieces long, narrowed centrally, including
the clypeus; on the inner side of each paraclypeal piece near the posterior end
is a slight depression from which arises a small seta, near the apex of the
clypeus. Ocelli 6, weak, pale, the first four in a quadrangle, each with a dis-
tinct lateral pigment spot; the fifth more cephalad, ventro-laterad of antenna,
also with pigmentation; the sixth smaller, caudo-laterad of the fifth, and with-
out pigmentation; the group protected by sete.

Cervical shield pale yellow, bearing twelve setz, in two groups of three each on
each side of meson, all separated, and the caudal one of the first group separated
by a suture; laterad of the shield, cephalad of spiracle, a group of three from a
ealloused tubercle, of which the cephalic two are much the longer; directly
laterad a group of two from a fleshy elongate tubercle, the caudal seta the
larger ; between these setigerous tubercles, caudad and opposite the spiracle, is a
narrow nonsetigerous tubercle, much narrower than the second setigerous one
(one next to the fore leg); spiracle oval, brownish; “ vii” and “ viii” small,
on the venter (7?) and base of fore leg. On segments II and III, i in the dorsal
region consisting of two sete, the laterad larger; ii the same, slightly advanced,
dorso-lateral aspect; iii single, minute, caudad between ii and iv, nearer the
latter; iv single, large, in a line laterad with iii, advanced slightly beyond i,
and in the stigmatal line; v small, its setz larger than iii, single, much advanced,
cephalo-laterad of iv; vi some distance caudo-laterad of v, about in a line trans-
versely with i, single, equal to iv, above base of leg; all in the second annulet.
A calloused spot behind iii, and a smaller one above vi, some distance caudad of
y. Segment IV, single, i cephalad, small, in first annulet; ii larger, caudo-
laterad of i; i and ii from dorsal aspect, forming a trapezoid; iii some distance
from i in a transverse line, equal to ii, apparently in the first annulet, just
above spiracle; iv and v combined just below the spiracle, the seta of v larger;
vi caudad, nearer to vii than to iv and v; vii consisting of two setz# in the
ventro-lateral line, and viii of one seta in the ventral region, minute; a minute
calloused spot behind iv and vy. Segment VY, the same, vii consisting of three
sete, one of which may be obsolete. Segments VI, VII, VIII, and IX, the
same; vii, three setze on cephalo-lateral aspect at the base of proleg: viii, minute
and single, inner side base of proleg; the intermediate seta of vii longest. On
segment X, ii caudad of i, vii consisting of two set, the inner the larger, vi
nearer to vii. Segment XI, i and ii closer, the latter also closer together trans-
versely, iii cephalo-mesad of the spiracle; iv small, against, and cephalad of
the spiracle; vii a single seta. Segment XII, i apparently absent; ii, iii, and
iv in a transverse line, iii and iv combined; v minute, between iv and vi,
slightly cephalo-laterad of iv; vi large, cephalad; vii and viii single. Anal
shield subobsolete, pale, bearing four large setz on each side, minutely maculate.
Segment XIII, four minute tubercles across the venter (vii and viii ?), in
front of each proleg, and just below the shield, a line of five on each side of the
segment, of unequal size.

38 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

Spiracle oval, inconspicuous, brown; that of segment XI larger, somewhat
obliqued, and farther dorsad. The crotchets of the legs are variable in number,
often unsymmetrical, and generally arranged as follows:

rroleg. Anterior row. Posterior row.
il 14-18 12-14
ye 14-17 12-15
ay 14 a
4, 12 all
Anal. 8 0

For the first four prolegs, the crotchets vary from 11 to 18 in number; for the
anal proleg they vary from 8 to 9. There are generally more present than in
Sanninoidea exritiosa (see fig. 10, ¢).

As compared technically with the full-grown larva of the peach borer, the
latter is 34 mm. long, 6 mm. in greatest width, with the width of the head
at least 83 mm. The head of NS. exitiosa is slightky darker in color, with a dis-
tinct, though variable, subtriangular pale area on each epicranial lobe, where
they join below the vertical triangle; the mandible is relatively more robust,
darker at the teeth, four of the latter distinct, the second tooth longest and more
slender, the outer next in length, the third one-third shorter than the second,
and obtusely rounded, the fourth a distinct tooth, but abruptly shorter, approach-
ing the fifth, which is a mere serration; the two mandibular sete are larger.
The lateral margins of the clypeus are straight, each one changing angle at its
basal third, making the clypeus shaped like (4, instead of triangular; the basal
corners of it are truncate. The parclypeal pieces are generally straight, but
curving basally to follow the margins of the clypeus; they are uniform in width.
The first two ocelli and the sixth are practically pigmentiess. The shields are
darker yellowish. The arrangement of the tubercles is the same, but they are
relatively larger, as are also the accessory warts and the setz. There is a less
number of crotchets in the prolegs, ranging from 8 to 16, and in the anal proleg
from 5 to 8.

Though these technical differences exist, they can not be recognized
in all points without considerable study, and an examination of a
series of larvee. The most conspicuous difference is the greater size
of the larva of Sanninoidea exitiosa and its different aspect.

During the course of its growth the larva molts several times, each
casting of the skin marking the end of a separate period of larval
development called an instar. There is no direct evidence by rearing
to show how many of these instars there are, but it has been shown
that the heads of lepidopterous larve are of certain limited sizes in
each instar, and therefore by measurements of a large series of the
heads of these larve, the conclusion is reached that there are six, as
shown in Table I. The larva molts five times. The length of the
separate instars has not been determined, but Mr. Quaintance records
a little over seven months as the length of the larval stage for an
individual reared on peach out of doors, from September to the fol-
lowing April, in the latitude of Washington, D. C.

ENR Se:

' THE LESSER PEACH BORER. 39

TABLE I.—Measurements of the head of the larva of Synanthedon pictipes in
each of the six instars.

FE. II. Iil. EVs Vi 88

mm. mim. mm. mm, mm. mm.
LGN e A a ee 0. 27 0. 55 0. 86 1.18 1.53 1.94
0 EE nea APS OB SASS peas areneae (a) (b) 0.72-0.95 | 1.02-1.25 | 1.36-1.70 | 1. 84-2. 64
BMOTOMCO’. ooo. 3 anise oe pe Lh Sg ee ee sed RE ee en ee Ae 0. 23 0. 23 0.34 0. 80
« Constant. ’Not obtained.

After hatching the young larva enters the tree by the way of a
crevice and soon begins to feed on the soft living tissues. It grows
rather rapidly and makes an irregular burrow between the living bark
and wood of the tree. This channel, in time, becomes filled with

— semiliquid gummy exudations and the reddish frass of the larva.

Where the larva enters there is left a small pile of fine reddish wood
dust. It is partial to wounds or diseased areas on the trunk, but, as
formerly stated, may occur anywhere on the tree, from the crown of
the root to the larger branches, and thus may be found feeding side by
side with the peach borer.

In confinement the larve will feed readily and grow on fresh
pieces of peach bark; Mr. Quaintance has fed one for several days
on peach leaves. When young, they are able to suspend themselves
with silk, and Bailey (1879) has observed them “ drinking ” moisture.

After the larva attains full growth and is ready to pupate, if some
distance from the edge of a wound or crack, it cuts a hole through,

or nearly through, the outer bark, and constructs a cocoon under this

in a suitable cavity, so that its anterior end is against the opening.
If it is near the edge of ruptured bark, which is more commonly the
case, the cocoon is made just within the boundary of the wounded
area, so that the pupa easily pushes out when ready to issue as an
adult. In old peach trees with cracked bark the cocoons are usually
found in this position.

The cocoon is constructed of pieces of bark chewed into fine bits,
frass, and silk secreted by the larva, and is light yellowish brown in
color and soft to the touch. An old cocoon, however, is dark in color,
and hard and brittle. The size of the cocoon varies, but it is always
several millimeters longer than the pupa which it incloses.

The pupa—tvThe larva, having formed a cocoon and inclosed itself
within, waits several days and then pupates. The pupa (fig. 10, @)
is brownish yellow in color, darker at the edges of the segments,
sutures, head and wing covers, spindle-shaped, and is’ broadest at
the first abdominal segment. It has all the characters normal to its
family. The sete are sparse and minute. The spines on the first
abdominal segment are very weak; in the female there is but a single

40 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

row of these spines after the fifth abdominal segment, and in the male
after the 6th abdominal segment. The secondary sexual characters
are therefore distinct (Beutenmiiller, 1901, p. 231). The cremaster
consists of eight stout spines surrounding the anal end. Structurally
the pupa is similar to that of the peach borer, but easily distinguished
from it by its much smaller size and lighter color, by the smaller and
lighter cocoons, and by the more finely granulated structure of the
latter. The pupa varies considerably in length, being from 10-17
mm., averaging about 14 mm.

Just after scr the pupa is nearly white, gradually turning
darker and becoming its normal color after some hours. As the in-
star approaches its close, it turns darker and darker, gradually assum-
ing the color of the inclosed moth, becoming steel blue-black a day or
so before emergence. Emergence, however, may be delayed several
days after the assumption of this color. In the cocoon the pupa is
naturally covered with more or less moisture.

The duration of the pupal instar varies according to season and
latitude. At Myrtle, Ga., and vicinity records of actual instars ob-
tained during 1906, from pupe first formed, in the late winter and
early spring, showed a maximum period of 32 days, and a mini-
mum period, toward the end of April, of 20 days. In the latitude
of Washington, D. C., records obtained in 1905 for first pupee, formed
in April, the adults emerging early in May, gave the actual pupal
instar from 20 to 30 days. By the oe of May in the same lati-
tude the period had decreased to from 153 to 17 days, where it re-
mained for the rest of the month. Mr. W. F. Fiske records the
actual pupal instar at Tryon, N. C., as being about 26 days during
May, 1904. These records do not include the several days spent in
the cocoon as a larva, which must be added.

Immediately preceding the final ecdysis the pupa becomes restless
and somewhat swollen, and, by aid of the rows of spines with which
it is armed, rather quickly works its way through the anterior end of
the cocoon up to about its fourth or fifth abdominal segment. The
moth emerges while the pupa is in this position, projecting for more
than half its length from the cocoon. (See fig. 10, e.)

The adult—Moths of the lesser peach borer (fig. 10, a, and Pl. VI,
fig. 1) resemble in general others of the family AXgeriide and more
particularly the males of the peach borer. They may be distinguished
most easily from the latter by the fact of their bearing but two yellow
bands on the abdomen, on the second and fourth segments, respec-
tively, the band on the fourth segment sometimes not entirely encir-
cling it; whereas the male of the peach borer has a yellow band on the
posterior margin of each of the abdominal segments, some of which
may be more or less obsolete. The males of the latter are also larger
than the moths of the former, but again agree in having a general

| ‘ THE LESSER PEACH BORER. 4]
~hymenopteriform aspect, but flying in the bright sunlight the two
"species are easily recognized after a little practice in observing them.
The sexes of the lesser peach borer are quite similar, but may be dis-
tinguished by one or two minor secondary characters, such as the
simple antenne of the female and the more robust abdomen and
‘straight anal tuft. Probably the most available secondary character,
however, is found in the frenulum, which in the female consists of
wo closely applied, long, and slender spines, while in the male it is
single and slightly shorter. This character is concealed by the front
wings.
The adults emerge from the pupe in the morning hours, generally
between 7.30 and 9.30, the males issuing slightly earlier than the
females. They are more likely to issue on clear days, being somewhat
retarded by cloudy or inclement weather. At the time of ecdysis the
pupa, which is projecting from the cocoon as described, commences
peristalsis-like movements of the abdominal segments, which after
several seconds cause the pupal integument to part rapidly along the
meson of the thorax and the sclerites of the head and wings. Almost
simultaneously with this parting of the pupal integument, the moth
begins to move forward and glides out, the forelegs holding to the
nearest object to prevent it from falling. The actual emergence re-
ires but a few seconds. At this time the moth is perfect but -for
folded wings, and can move with a peculiar jerky, gliding motion
vhen it falls to the ground or is disturbed, but otherwise it prefers to
remain motionless or to crawl to a convenient place. During the
folding of the wings, when the moth is weak and delicate, it is
wobably in the most critical stage of its existence. If it falls, it is
likely to injure the soft wings and become crippled, in which case it
rill almost certainly die a few hours later. The slightest injury at
his period appears to be fatal directly or indirectly. The wings
egin to swell at once and slowly expand, becoming normal after
bout 8 to 10 minutes. After expansion, however, they are still
eak and unfit for use for at least another half hour.

As soon as ready for flight, the female moves to a convenient place
nd, taking position, begins to attract the males by elevating the end
f the abdomen and extending the ovipositor horizontally from it.
{o perceptible odor is present. In badly infested orchards the males
ill begin to arrive after 3 or 4 minutes, or earlier, and soon a swarm
of a dozen or more will be humming around the female. The sexes
unite suddenly; the male grasps the female with the claspers, and
hen turning assumes the position normal to the Lepidoptera. Copu-
ation may last a variable time. Mr. J. H. Beattie, then connected
with this Bureau, observed a pair remain in copula for 65 minutes
on August 16, 1905, at noon, and an observation made in the late sum-
-Iner of 1906 gave 58 minutes. In case the weather is unfavorable
10090—Bull. 68—09-——4

a

——— OO ee oe

per oe

ee

42 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

or no males appear, the females will continue to await them for
several days, during the time from about 10 a. m. to 3 p. m.
Oviposition commences soon after copulation and continues through-
out the hfe of the female. On warm sunny days it may begin as’
early as 8 o'clock in the morning, in the South, and continue at inter-
vals through the day until as late as 4.30 p.m. On very windy or
stormy days the female is inactive, hiding in the grass in the orchard
for shelter, and on cloudy days she is less active than on clear ones.
During the period of oviposition she flies very rapidly, and is hardly
discernible until she alights on the trunk of a tree; she then moves
slowly over the bark and feels with the end of the yellowish ovi-
positor for a rough place or crevice, where she usually places an egg.
Ovipositing females are exceedingly difficult to follow with the eye,
and in this respect they differ markedly from the comparatively
sluggish and more conspicuous females of the peach borer. Further,
they are apparently more careful in placing eggs, always selecting
a place which will make it easier for the larva to get into the bark,
though enough observations have not been made on this to justify a
positive statement. ;
In flight both sexes resemble wasps and make a distinct buzzing
sound. The males are seldom seen. The moths have never been ob-
served to feed, except on moisture, and in confinement show no
marked attraction to sweetened water. Meager observations made
on adults kept in confinement indicate that they probably do not live
longer than a week.

SEASONAL HISTORY.
GENERATIONS.

The number of generations occurring with an insect of this kind

>
is especially difficult to determine because of the nature of its habits.
In Georgia some attempt has been made by this Bureau during th
past two years to obtain accurate knowledge on this point by keeping

during the entire breeding season. So far, however, the data obtained
do not warrant a definite or positive statement concerning the actual

hatched and nearly full-grown specimens are present, the former
indicating late fall, the latter, late summer, oviposition. As soon as ~
spring begins to open the old larve commence to pupate, emerging a |
month later as adults; the young larve feed and grow rapidly, pupat- ~
ing in their turn, and producing a continuous supply of moths. ‘The ©
moths from the hibernating larve produce another mixed generation |

THE LESSER PEACH BORER. 43

of larvee which reach full growth and begin to pupate and emerge as
moths in the late summer and early fall. In turn these early fall
adults oviposit, producing a mixed generation of larve throughout
the fall of the year; these pass the winter and mature the following
spring. Hence two cycles of this insect are clearly indicated during a
calendar year in the latitude of Georgia. A clearer conception of
the probable occurrence of these two generations may be obtained
by consulting Table IT.

TABLE I1.—Generations of the lesser peach borer at Myrtle, Ga., 1905-6.

Generation No. | Larve. | Pupe. Moths out. ior okerele

Pe NVUMberas elas Septs LO—Miay fos...) Mar. 1-May 20 (Apr.).| Apr. 1-June 20 (May) .| 74 months.

2. Summer ...:| Apr. 10-Aug. 1 (May | July 20-Oct.15(Sept.).) Aug. 15-Nov. 20(Sept.| 4; months.
and June). | and Oct.).

In Georgia, in 1906, the first pupa of what may be called the winter
generation was found on February 27, and by the middle of March
-they were common. A month later, in April, the adults of that gen-
eration were common, continuing so throughout May and part of
June. By the latter part of May the pupe became scarce, showing
that by this date the winter generation was practically over. From
that date on we conclude that the larve then present in the trees were
practically all of the next, or summer, generation. By the last week
in July pup were again found in numbers, and continued to increase
well into September, when adults of the summer generation were ob-
served ovipositing. The winter generation, therefore, became estab-
lished mainly in the latter part of August and during the whole of
September, and the larvee from eggs deposited then had ample time to
obtain at least two months’ steady growth before being disturbed by
cold weather. The foregoing statement is based on series of ‘speci-
mens collected weekly throughout the entire season of 1906, from
February to November, at Myrtle, Ga., by Mr. A. H. Rosenfeld and
the author, combined with records obtained by Mr. James H. Beattie
during the investigations in 1905 at Fort Valley, Ga.

Observations made in the vicinity of Odenton, Md., and Washing-
ton, D. C., show that the pup were present in the spring as early
as the first week in April and that adults issued from these during
the first half of May. The pupe continued present as late as May 8,
but thereafter we have no records. Mr. Fred Johnson, of this Bu-
reau, records seeing adults at North East, Pa., on May 29; and at
Niagara, Canada, June 23, 1905, Mr. Quaintance found larve nearly
or quite full grown, and pupe and adults were present. Bailey
(1879) found the moths as early as May 25, in 1879, at Buffalo, N. Y.,
and made a general statement to the effect that they issue during
June and July. Kellicott (1881) reports the same months for New
York and Smith (1900) for New Jersey, and similar statements

|
|
|

44 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

have been made by the various authors. For northern latitudes we
are unable at present to form any definite conception as to the number
of generations.

LENGTH OF THE LIFE CYCLE.

The length of the life cycle or developmental period of a genera-
tion of the lesser peach borer, based on field observations, has already
been given in connection with Table II. The life cycle of the summer
generation was approximately 44 months, and of the winter genera-
tion 7$ months. Fortunately Mr. Quaintance has succeeded in actu-
ally rearing a single specimen of this insect through its entire cycle,
in the grounds of the Insectary of this Bureau. On September 5,
1905, he placed 8 recently hatched larvee in small artificial wounds
made 3 feet from the ground on the trunk of a peach tree. Each
larva was placed in a separate wound and the whole then protected
by a wrapping of paper. By October 1, not quite a month later, 5
of the larve were found in their respective wounds and had grown
remarkably, being from a half to five-eighths of an inch in length
(13 to 16 mm.). On the 24th of the same month, or just over a
month and a half after hatching, the five larve were still alive and
were either about to molt or had just done so; three of them measured
13 mm., one 16 mm., and the fifth, 19 mm., averaging about 15 mm.
The following spring, on April 5, 1906, another examination was
made, and it was found that 4 of the larve had perished. The re-
maining one was inactive, but began to feed voraciously five days
later, and by about April 13 had formed its cocoon and pupated.
The moth, a male, emerged on May 14, 1906.

The lengths of the respective stages: for this individual were as fol-
lows: Egg, 74 days; combined larval instars, 220 days; pupal instar,
31 days; making a total of 258 days, or 8.6 months for the cycle
(from August 28, 1905, to May 14, 1906). This agrees remarkably
well with time approximated for the winter generation in the South,
where the periods of larval inactivity during the cold months are
naturally shorter, and hence growth is more rapid. The individual
reared was a descendant of parentS from Fort Valley, Ga., mailed to
Washington.

NATURAL ENEMIES.

The lesser peach borer has a number of natural enemies, nearly all
of which are parasites belonging to the order Hymenoptera.

Elachertus n. sp., of the family Eulophide, as determined by Mr.
E. S. G. Titus, is probably the most common, and is an internal para-
site which is fatal to the host just before pupation. After the host
larva has constructed its cocoon the parasitic grubs eat their way
through its body and pupate nakedly in the host cocoon, entirely
filling it. As many as 138 of these parasites have been reared from

= = ome ~ Seeeiin Ab

THE LESSER PEACH BORER. 45
a single larva of the lesser peach borer. It has been found at Oden-
ton and Jessup, Md. (March to May, 1905), and at Fort Valley
(April, May, July, 1905), and Myrtle, Ga. (March, 1906).

Bracon mellitor Say is also a rather common parasite of the lesser
peach borer, and its method of attack is similar, being fatal to full-
grown larve in their cocoons. After leaving the body of the host
the parasite larve spin small compact cocoons side by side, which
completely fill the host cocoon. They pass the winter in this condi-
tion and emerge the following spring. Thirty-four males and 31
females of this parasite were reared from two host larve during
April, 1905. The parasite also attacks the larva of the peach borer
and has a number of other hosts. It has been found to occur in the
same localities as the eulophid parasite, but in Georgia, in 1906, 1t was
rarely met with. It was rather common in Maryland in the spring
of 1905. A species of Microbracon was also reared from the larva in
Maryland and Georgia.

During 1905, at Fort Valley, Ga., Mr. J. H. Beattie, then of this
Bureau, reared Conura n. sp. (determined by Titus), from the lesser
peach borer. The parasite emerged May 30 from the pupa. Also in
May he reared Pimpla annulipes Brullé, from the same stage of the
host. This is probably the parasite referred to by Bailey (1879).
Mr. Beattie also reared a species of Campoplex in May, 1905, and
a species of Mesostenus in May and June, at Fort Valley, from this
borer, making a total of six hymenopterous parasites, all of which
were determined by Mr. Titus.

An undescribed variety of Dorymyrmex pyramicus Roger, as deter-
mined by Mr. Theodore Pergande, has been observed to attack the
larva when exposed during “ worming.” This ant is very numerous
in the peach orchards of Georgia, in the vicinity of Fort Valley, and
will prey upon any insect which it is able to overcome. Ordinarily
it is unable to get to this borer. Occasionally, however, it will kill
recently emerged moths, and any larve which may have been over-
looked during “ worming,” but which had been exposed. Mr. Titus
reports this ant as being abundant on peach trees at Monticello, Ga.,
in August, 1905. ,

It is indicated that birds sometimes extract pup from cocoons
under loose bark, and Bailey (1879) mentions a woodpecker as ex-
tracting larve from the trunk of a plum tree.

~The value of the parasites of the lesser peach borer is greater than
that of its predaceous enemies.

PREVENTIVES AND REMEDIES.

From the fact that this insect prefers to attack trees which have
been injured or diseased, or are old, having wounded or checked bark,

46 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

it is obvious that anything which will tend to mitigate or prevent
these conditions will in turn largely prevent the borer’s presence.
Therefore proper orchard management, keeping the individual trees
in a good, clean, and vigorous condition of health, avoidance of
mechanical injury when cultivating, and prompt treatment of wounds
made about the body of the tree, are the surest ways to keep the
orchard free from this insect.

For its control in orchards already infested there is but one avail-
able remedy, namely, cutting the worms or larve out of their bur-
rows. This is best done in conjunction with the regular “ worming ”
for the peach borer, the operator taking care to examine all portions
of the trees from the roots up to the large limbs above the fork. In
doing this it will be necessary to cut away portions of the bark, and
wounds so made should be promptly cleaned and treated with some
protective antiseptic, as thick Bordeaux mixture or the hme-sulphur
wash. All rough, cracked, or diseased areas should be cleaned out
and similarly treated, whether they are infested or not, as they form
points of entrance for the borers and are in other ways a menace to
the life of the tree. The “ worming” for this insect should be ar-
ranged for the early spring, if convenient, as wounds made at that
time heal more readily, and, besides, the larvee are then pupating in
numbers and can be more easily gotten at.

So far as known, other remedial treatments in the shape of caustic
or preventive washes are practically worthless in the control of the
insect, and their application would be merely a waste of money.

BIBLIOGRAPHY.

The following bibliography contains titles of practically all of the
literature on the lesser peach borer. All of the articles have been
seen and verified, excepting that of Grote (1882).

1868. GrorE, AUGUSTUS RADCLIFFE, and COLEMAN T. ROBINSON. <Avgeria pictipes
pn. s. <Trans. Amer. Ent. Soc., Philadelphia, Vol. II (1868-1869), pp.
182-183, pl. 2, fig. 64.

Original description ; poor figure of male.

1879. Battery, JAMES S. The Natural History of Mgeria pictipes G. & R.

<North American Entomologist, Buffalo, Vol. I, pp. 17-21, Pl. III.
General account of injury to a plum tree, with notes on seasonal history
and habits; descriptions of stages and figures. (Plate not seen.)

1881. Epwarps, Henry. Ageria inusitata n. sp. <Papilio, N. Y., Vol. I, pp.
201-202.

Description of pictipes as a new species from New Hampshire and Massa-
chusetts, under the name #geria inusitata.

GrotrEe, AUGUSTUS RADCLIFFE. A/geria pictipes G. & R. <Bul. No. 2, Vol.
VI, Geol. & Geograph. Survey, U. S. Dept. Interior, Washington (author’s
edition), p. 257.

Few references. Notes that the sexes are much alike and tells how they
differ from those of male peach borer.

ance

Paes *

ee,

oo oe ae le alien tna Sie te mica ec

1882.

1884.

1896.

THE LESSER PEACH BORER. 47

Ketiicorr, D. S. Algeria pictipes G. & R. <Canadian Ent., London.
Corsaro, Vol;-XIII, p.° ¥.
Brief note. Common at Buffalo, N. Y., on old plums, doing grave injury

in some instances. Also on cherry. At Hastings Center, N. Y., found on
wild cherries. Adults in June and July.

MARTEN, JOHN. Algeria pictipes, G. & R. <10th Rept. State Ent. on
Noxious and Beneficial Insects of State of Illinois. (5th Ann. Rep.
Cyrus Thomas), Springfield, pp. 106, 109.

Under bark of plum. Brief description of larva and pupa.

GROTE, AUGUSTUS RADCLIFFE. A/geria pictipes Grote & Robinson. <New
check list of North American moths, p. 12.

Aj. pictipes and the synonymic inusitata Hy. Edwards are listed separately.
(Not seen. )

FERNALD, CHARLES H. Stand. Natl. History (Kingsley), Boston, Vol. II,

p. 464. 3
Mention ; attacks plum trees and is similar in habits to the peach borer.

WEED, CLARENCE M. Plum Tree Borer (A/geria pictipes). <American

Naturalist, Phila., Vol. XXTIf, p. 1108, Pl. XLIITI, fig. 7:
Review of Kellicott (1891). Figure.

BEUTENMULLER, WILLIAM. A/geria pictipes G. & R. <Annals N. Y.

Acad. Sciences, N. Y., Vol. V (1889-1891), p. 204.
Larva on plum; rare,

SMITH, JOHN BERNHARD. Sesia pictipes Grt. & Rob. <Cat. of insects
found in New Jersey. (Final Rep. State Geologist, Vol. II), Trenton,
p. 289.

Mentions the species as generally distributed, but not common.

KeLuicottT, D. S. The Plum Tree Borer (geria pictipes). < Journal
Columbus (Ohio) Hort. Soc., Vol. V (1890), pp. 16, 19, PI. I, fig. 7.

Brief notes. Sexes similar and like male peach borer. Plum favorite food ;
plentiful on wild black and red cherry; probably on cultivated cherry.
Larva mainly infests trunk and branches; abundant at Columbus. Recom-
mends knife.

SMITH, JOHN BERNHARD. List Lep. Boreal America, Phila., p. 20.

Listed as Sesia pictipes G. & R.

BEUTENMULLER, WILLIAM. <AZgeria inusitata Hy. Edw. <Bul. American
Mus. Naw ist.. N. Y., Vol. 1V, p, 172. (author’s edit., N. Y¥., Oct. 18;
1892).

Listed as type in Henry EHdwards’s collection. One male, Andover, Mass.

. Ketuicotr, D. S. Notes on the Azgeriide@ of Central Ohio. <Canadian

Hnt., London, Ontario. Vol. XXIV, p. 46.

Few lines. Quite abundant at Columbus, Ohio. Seriously injuring wild
and cultivated cherry, as well as plum.

. BEUTENMULLER, WILLIAM. Algeria pictipes Grote & Robinson. < Bul.

American Mus. Nat. Hist., N. Y., Vol. V, p. 25.
Hstablishes inusitata Hy. Edwards (1881) as a synonym of pictipes.
WEBSTER, FRANCIS MARION. Insects reared from Black Knot, Plowrightia
morbosa. < Ent. News., Phila., Vol. IV, p. 267.

Reared from the fungus on cherry and plum.

BEUTENMULLER, WILLIAM. Sesia pictipes (Hy. Edwards). <Bul. Ameri-
ean Mus. Nat. Hist., N. Y., Vol. VIII, pp. 134-135.

Wrong author given. Synonymy; secondary sexual characters. Larva on
plum, wild cherry, juneberry, beach plum. Canada, New Hampshire, Massa-
chusetts, New York, New Jersey, Pennsylvania, Ohio, Illinois, and California.

WEBSTER, 'RANCIS MARION. Bul. No. G8, Ohio Agric. Exp. Sta., Columbus,
p. 25

Mention as “the peach borer, Sesia pictipes.”

48

1897.

1898.

1899.

1900.

1901.

1902.

1903.

1905.

1906.

DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

BEUTENMULLER, WILLIAM. Sesia pictipes (G. & R.). <Bul. Amer. Mus.
Nat. list: (NOY... Violiolx sp 220:

Larva under bark of plum, cherry, beach plum, chestnut, and juneberry,
usually some distance up from base of tree; also on black knot fungus.

Luecer, Orro. The Plum Tree Borer (Sesia pictipes G. & R.). <Bul. No.
61, Minnesota Agric. Exp. Sta., St. Paul, p. 119, fig. 63. .
Same as Lugger, 1899.

Idem. The Plum Tree Borer (Sesia pictipes G. & R.). <4th Ann. Rep. ~ |
Ent. State Exp. Sta. Univ. Minnesota f. 1898, St. Paul, p. 65, fig. 63. |
Short summary account. Apparently increasing. Larva feeds mainly in —

trunks and branches of wild and cultivated plums and cherries. Figure of ©

adult. Recommends use of pruning knife.
BEUTENMULLER, WILLIAM. Synopsis of food-habits of the larvze of the

Sesiidie. <Canadian Ent., London, Ontario. Vol. XXXII, pp. 301, 302.

Sesia larve sometimes found in borings madé by other insects. Under |

bark of cherry, plum, and juneberry, some distance from base of tree, or in —

the limbs.

SMITH, JOHN BERNHARD. Sesia pictipes (G. & R.). <Insects of New j
Jersey. Supplement 27th Ann. Rep. State Bd. Agric., 1899, Trenton, p.—
472. :

Listed from Newark, Staten Island, Philadelphia, etc. Adults in June and :
July. Larva on plum, cherry, beach plum, and sometimes peach, but rarely ~ |
injurious.

BEUTENMULLER, WILLIAM. Sesia pictipes (G. & R.). <Monograph Sesii-
dz of America, North of Mexico. Memoirs American Mus. Nat. Hist., —
NY. Volo. pp. 2262229. 231) 291-292 RP ls eae ne as

Systematic treatment, with synonymy, distribution, description, and food j
plants; colored figure of female. Moths out June and July. Time of adult
emergence (p. 226), synoptic table of larve of the Sesiide (p. 229), and ’
secondary sexual characters of pupe (p. 231).

Dyar, HarrRISON Gray. Sesia pictipes Grote & Robinson. <List of North —
American Lepidoptera. Bul. 52, U. S. Nat. Mus., Washington, p. 369. |

Distribution given as “ U. 8.”

HoLuanp, W. J. Synanthedon pictipes Grote & Robinson. <The Moth ~
Book: N: Y:, p. 386, Pl Xi, fe. 24.

Brief account. Synonymy and food plants. Adults on wing in June and ;
July. Good colored figure of female. b

WASHBURN, F. L. Plum Tree Borer. <Bul. No. 84, Minnesota Agric}
Exp. Sta., St. Anthony Park, p. 82, fig. 70. Ibid., Eighth Ann. Repm
State Ent. Minnesota f. 1903.

Sesia. Listed as injurious to plums, with figure of male. Cut out and
burn infested parts. Lugger’s (1899) figure. i

KELLOGG, VERNON LyMAN. American Insects, N. Y., fig. 558 (p. 392).

Figures male. Sesia.

BEUTENMULLER, WILLIAM. Sesia pictipes Gr. & Rob. <Insects affecting ~
park and woodland trees (Felt), Memoir No. 8, Vol. II, N. Y. State
Museum, Albany, pp. 428, 458-454.

Brief account based mainly on Bailey (1879). Description of adults.

QUAINTANCE, ALTUS Lacy. The Lesser Peach Borer (4/geria pictipes G. &
R.). Yearbk. U. 8. Dept. Agric. f. 1905, Washington, p. 335, Pl. XXXII |
figs. 3 and 4. ; q

Brief account. Found abundant on old or diseased peach trees in Georgia — |
and Maryland during 1905. Figures both sexes and pupal cast in cocoon. —
Recommends digging out.

STARNES, HucH M. Bul. No. 73, Georgia Exp. Sta., p. 154.

Mentioned as the “ wild cherry borer (Synanthedon pictipes),’’ and as being
often mistaken for male peach borer,

Bos, De A. B. Bb: Bul..68, Part V. D. F. I. I., January 8, 1908.

PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

THE LESSER APPLE WORM.

(Enarmonia prunivora Walsh.)

By A. L. QUAINTANCE,
In charge of Deciduous Fruit Insect Investigations.

INTRODUCTION.

During the past three years the species known as Enarmonia pru-
nivora has been found very commonly infesting the fruit of the apple
in various parts of the United States, in some sections so abundantly
as to cause serious loss to orchardists, the insect ranking in impor-
tance as an apple pest close to the codling moth.

The small, fusiform, flesh-colored larve, about three-eighths of an
inch long, injure the fruit around the calyx by eating out shallow
cavities or boring holes into the flesh from one-fourth to one-half inch
or more in depth, in the ripening fruit occasionally penetrating to the
seeds. The surface of the fruit, especially in the calyx basin, is also
injured, the larvee working beneath the skin and eating out galleries
or large blotch mines, frequently with holes or borings extending
more deeply into the flesh. The work of this species resembles rather
closely that of the codling moth, and the similarity of the larv:
to the codling moth larva and a further similarity in the life his-
tories and habits of the two species have doubtless been responsible
for the almost complete oversight in the United States of this species
as an important enemy of the apple.

HISTORY.

The lesser apple worm was discovered by Walsh in Illinois during
July, 1867, in the course of a study of the plum curculio (Conotrache-
lus nenuphar Hbst.). Walsh found the larva in plum and about a
month later bred out numerous moths from the same fruit. In the
Prairie Farmer for December, 1867, page 359, under the caption
“The plum moth,” he makes brief reference to his discovery, and the
same year, in the First Report of the State Entomologist of Illinois,

49

5O DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

page 78, presents figures and a full description, with interesting
observations on its feeding habits, ete. He records having bred the
moth the year previous from the “ black-knot” of plum, from the
cockscomb-lke hollow gall (wlmicola Fitch) on the leaf of an elm,
which is produced and inhabited by aphides, and also from a sessile
hollow gall about the size and shape of a large pea or small cherry on
the leaf of red oak (Quercus rubra) and described by Mr. Bassett as
Quercus singularis.

The rearing of moths from larvee in curculio-infested plums and
“ black-knot ” and from elm and oak galls led Mr. Walsh to surmise
that the larve did not infest sound plums and “ black-knots,” but fol-
lowed the injury caused by the curculio, and in the elm and oak galls
he believed the larvee to be guests, it being uncertain whether they fed
upon the tissues of the gall, upon the gall insects, or, in the case of the
elm leaf gall, upon the sugary dust secreted by the aphides. Glover,
in his report xs Entomologist of the United States Department of
Agriculture for 1867, page 73, briefly refers to Mr. Walsh’s discovery,
adding nothing, however, in the way of personal observations.

In Riley’s First Missouri Report, page 65 (1869), brief reference
is made to the plum moth in connection with a consideration of the
plum-feeding habits of the codling moth, and again in the Third
Report, page 6 (1871), it is mentioned as feeding on apples as they
mature. Later in the same report (p. 25), under the caption “ Two
true parasites of the plum curculo,” Doctor Riley points out
Walsh’s error in supposing that Sigalphus curculionis Fitch was not
a parasite of the plum curculio, but of his plum moth, adding that
this last insect had been bred by him from galls (Quercus frondosa
Bassett), from haws, from crab apples, and abundantly from culti-
vated apples. In a footnote to an article on the codling moth in his
Fifth Report, page 5 (1873), Riley comments further on this species
as follows: “ There is another and smaller worm, namely, the larva
of what Mr. Walsh called the plum moth (Semasza prunivora Walsh),
which is quite common on haws and apples. It does not penetrate
deeply into the apple, but remains around the calyx and generally
spins up there, and it so closely resembles the young apple worm that
the two might be easily confounded.” In the American Entomolo-
gist for 1880, page 131, in an article on parasites of the plum curculio,
Doctor Riley quotes from his previous article on this subject in his
Third Report, page 25.

The species is next mentioned in economic literature by James
Fletcher in his report as Entomologist and Botanist to the Central
Experimental Farm (Canada) for 1896, page 261, where he records
that in Victoria, B. C., in 1895, specimens of a small caterpillar were
found feeding on the surface of the fruit of the apple, particularly
at the calyx end, eating the skin and mining a short distance beneath

THE LESSER APPLE WORM. 51

it. Similar larve were also received from Lachine Locks, Quebec,
some of which, however, were working beneath the skin of the apple
and producing large blotch mines. This is also probably the insect
~ complained of by Mr. R. M. Palmer, in British Columbia, in a letter
- quoted by Fletcher in this same report. In his report for 1898, page
199, Fletcher again comments on this species to the effect that for
many years the apple growers of British Columbia had noticed a
small caterpillar answering in everything but size to the codling moth
larva. The insect had been abundant, but the moth was not obtained
until 1897, when a few were bred out by Mr. E. A. Carew-Gibson
_and forwarded by Doctor Fletcher to this Bureau, being determined
here as identical with Walsh’s plum moth. Fletcher records having
_ bred this species at different times from apples and haws at Ottawa,
_ from near Toronto, and from Lachine, Quebec. Single specimens
had been received occasionally from Quebec and Ontario, but the
insect had not been sufficiently abundant to attract attention.
_ Fletcher’s observations in British Columbia in the summer of 1897,
- and also observations by Messrs. Palmer and Carew-Gibson, led these
i gentlemen to fear that, from the numbers of the insect that were being
found, the species might develop into a pest of importance. The
I ‘ ~ great ay of the injury of this insect to that done by the codling
~ moth was noted, and also its general confusion by growers with this
“attr species. tailor. in a ies to Doctor Fietchinr, Mr. Carew-
Gibson reported that the insect had been found through all the lower
~ mainland and islands of British Columbia, usually attacking apples,
_ but occurring also quite often in plums and prunes. - In concluding
his article Fletcher remarks that he considers it unlikely that this
insect will ever develop into a serious pest of apples and plums, and
regards its injury in British Columbia during the years mentioned
iy as exceptional and due to the failure of wild crabs to produce fruit.
In Bulletin No. 61 of the Minnesota Agricultural Experiment
Station, page 295 (1898), Lugger, under the caption “ The apple
bud moth,” presents a brief note, stating that in addition to the
apple this insect infests also the plum and cherry, and can become
decidedly destructive by eating the buds of apple before they expand,
causing in this way more injury than if the leaves were eaten. The
-darve are said to have the habit of feeding inside of cherries, thus
causing them to drop.
In his report for 1900 Fletcher states, on the authority of R. M.
) Palmer, that this insect occurred in nearly all the fruit-growing dis-
__ tricts of British Columbia except the Okanogan Valley, but in smaller
numbers than in 1898-99.
\ Without question the larva of this insect is the one referred to by
) Mr. C. B. Simpson in Bulletin No. 41 of this Bureau, page 23 (1903),
on the codling moth, under the heading * Unknown caterpillar work-

7

=

set)

7
*

52 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

ing on outer surface of apples,” and the work of which he well illus-_
trated in figure 2 of Plate Il. The injured apples were brought to
the attention of the Bureau of Entomology by Mr. D. W. Coquillett,

in October, 1901, the fruit having been purchased in the open market

in Washington; it probably came from near-by orchards in Virginia

or Maryland. In November, apples showing this same injury were

found by Doctor Howard. A brief description of the larva is given

by Simpson; none, however, was reared to the adult stage.

In Bulletin No. 22, new series, of the Division of Entomology,
Chittenden, writing of “ Insects and the weather; observations dur-
ing the season of 1899,” refers to the plum moth (Grapholitha pruni-_
vora) as having been quite abundant in some orchards, attacking and
destroying both plums and apples.

Webster and Newell, in an article on “ Insects of the year in Ohio
in 1901” (Bulletin No. 31, new series, Division of Entomology, p.
89), record having bred Grapholitha pr univora from berries of a
species of Crategus.. This species is again mentioned by Fletcher 1 in
his report for 1905, page 25 (1907).

Finally, Messrs. Gintieane Headlee, and Brooks, in writing of the
second brood of the codling moth (Bulletin 131, N. H. College Agric.
Exp. Station, p. 25), mention the occurrence in late August of young
larve, evidently just hatched, eating on the surface 08 the fruit.
These small larve of the Baan brood feed “upon or just under
the surface, often around or in the calyx, or where a leaf or another
apple comes in contact with the skin, and rarely bore into the apple
as does the first brood. Rarely do these worms of the second brood
become full grown in this latitude, but late in September, when
half grown, they form their winter cocoons. The difference in the
food habits of this second brood has been observed by many grow-
ers and has led some to the behef that the work is that of a different
insect.” From the foregoing description of the work and habits of —
this larva, and from the figure presented of injured apples, it is
possible that the insect in question is the species under consideration.

ORIGIN AND DISTRIBUTION. |

The lesser apple worm” is doubtless a native insect, as indicated
by its feeding on indigenous species of Crategus, crab apples, and —
wild plums. The fact that it attacks cultivated plums and apples is |
not surprising in view of the close relationship of these wild and |
domestic fruits, and finds parallel in the case of numerous other |
American species which have become destructive to cultivated crops.

a This name, first used by Fletcher for this species, is adopted in preference to |
Walsh’s name, “ plum moth,” on account of the greater injury to apples.

THE LESSER APPLE WORM. 53

_ In the literature of the species it has been recorded from the fol-
lowing States and Provinces: Illinois (Walsh); Missouri (Riley) ;
British Columbia, Ontario, and Quebec (Fletcher) ; Minnesota (Lug-
ger); Ohio (Webster and Newell) ; District of Columbia (Simpson
and Chittenden), and New Hampshire (?) (Sanderson, Headlee, and
Brooks). The insect has been bred by the Bureau of Entomology
from fruit from the following places: Tazewell, Tenn.; Raleigh,
N.C.; Macy, Ind.; Niagara-on-Lake, Canada; Youngstown, N. Y.;
North East, Pa.; Baltimore, Riverdale, and Arundel, Md.; Pomona
-and Fort Valley, Ga.; Arlington, Afton, and Winchester, Va.;
Nebraska City, Nebr.; Bentonville and Siloam Springs, Ark.;
Garrison, Tex.; Ardmore, Ind. T.; Albert Lea, Minn.; Agricultural
College, Mich; Tryon, N. C., and Gerrardstown, W. Va.

FOOD PLANTS AND DESTRUCTIVENESS.

i

|
: Walsh bred this species from plum and “black-knot” and from
elm and oak galls; Riley bred it from haws, crab apples, cultivated
_.apples, and also from galls (Quercus frondosa Bassett). Fletcher
records it from apples, haws, plums, and prunes, and Lugger states
_ that it infests the apple, plum, and cherry, feeding on the buds of
3 the apple before they expand and working Sian the fruit of the
cherry. It has been noted by Chittenden as feeding on plum and
apple, and on this latter fruit by Simpson and by Mean Sanderson,
_Headlee, and Brooks. Bureau of Entomology records show that this
species has been bred from apple, Cratewgus spp., peach, and plums—
_ wild and cultivated. The larva of what proved to be this insect was
| also found during the summer of 1907 in the Ozark regions of Arkan-
sas, boring down the terminal shoots of young, vigorous, growing
apple trees, and also infesting “ water sprouts” on older trees.
While the insect has frequently been bred from cultivated varieties
of plums of the Japanese, Chickasaw, Americana, and Domestica
_ types, including prunes, its injuries to these fruits have not thus far
been observed to be very extensive. The larve feed upon the young
plums early in the season, causing them to drop, and later bore into
_ the maturing fruit. Their attack on apples, however, in some locali-
ties results in very important loss.
Injury to young apples by the first brood of larve may be quite
extensive. Thus, in an investigation of the subject by the writer in
apple orchards in the Ozark regions of Arkansas, from July 18 to
_ 25, the past summer, this species was found to be quite as abundant
as the codling moth; and this conclusion was reached also by Mr. E.
L. Jenne, of this Bureau, who was stationed at Siloam Springs, Ark.,
for the season. At picking time the fruit from unsprayed trees in
this region was quite as frequently injured by this species as by the
codling moth, the two insects in unsprayed orchards injuring a

1
iP
|
|
i”
1

|

ecient mines jerome experi mals So

54 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

large percentage of the crop. Almost equally serious injury from the
lesser apple worm to fruit at time of harvesting was noted by the
writer in orchards in the vicinity of Afton, Va., during the fall of
1905. Observations on this species by Mr. Fred Johnson, of this
Bureau, at North East, Pa., during 1906, indicate that it is in that
locality quite as abundant and destructive to apples as is the codling
moth, attacking also Domestica varieties of plums. During the sum-
mer of 1906, in orchards in southeastern Nebraska, this insect was
observed by Mr. Dudley Moulton, of this Bureau, and the writer to
be everywhere abundant and destructive, and late in the season almost
equally so with the codling moth.

Frequent examinations in the Washington markets of apples in
barrels, coming mostly from orchards in Maryland, Virginia, and
West Virginia, show often an injury by this species of from 15 to 20
per cent of the fruit, some of this occurring after the apples have
been barreled, as proved by the presence of the larva. From these
statements may be judged something of its present status and capa-
bilities as an apple pest.

CHARACTER OF INJURY.

The great similarity of the injury to apples by this species with
that of the larva of the codling moth and the similarity of the larva
itself to an immature apple worm no doubt account for the fact that
its considerable economic importance in the United States has been
thus far overlooked. There are, however, certain differences in the
character of injury of the two species, and in most cases the work of
the lesser apple worm, in the absence of the insect itself, may be posi-
tively recognized. Injury by the first brood is perhaps confined more
to the calyx end of the apple than later in the season. Cavities or
holes from one-fourth to one-half inch deep are eaten into the flesh
more or less around the calyx lobes and core within, the larve eating
directly through the skin at the base of the sepals, or more commonk

especially where two are in contact or where an apple is touched by a
leaf. Much of the fruit thus injured falls or ripens prematurely.

winding or blotch mines, which are quite conspicuous. Under the

Bul. 68, Bureau of Entorology, U. S. Dept. of Agriculture. PLATE VII.

FIG. 1.—APPLES SHOWING SURFACE INJURY BY LESSER APPLE Worm (ENARMONIA
PRUNIVORA). (FROM SIMPSON.)

FiG. 2.—PORTIONS OF APPLES SHOWING WORK OF LESSER APPLE WORM (ENARMONIA
PRUNIVORA).

In lower figures, injury at calyx and stem ends: in upper figures, injury to flesh under bloteh
mines. (Original. )

nde

=

-

oo

arantihalll

we Kee

;
4

i

Loh AS oa gE Pitt

ai
a

4)

THE LESSER APPLE WORM. 55

skin the larva as it grows may excavate cavities or holes extending
into the flesh from one-fourth to one-half inch, or deeper. This sur-
face injury, which may occur on the ends or sides, while perhaps not
more serious in its effect than the borings at the calyx and stem ends,
is more conspicuous and greatly disfigures the fruit. (See figs. 1 and
= ri. VEL.)

Larve of this species apparently do not reach full development as
early in the fall as those of the codling moth, and many find their
way into the barrels, where they continue to feed, in some instances
observed doing considerable damage, the introduction of the infested
fruit being favored by the inconspicuous nature of the injury when
occurring in the ends of the apples.

DESCRIPTION.

Egg.—tThe egg stage has not been observed.
Larva.—Full-grown larve (at time of leaving fruit in fall for
hibernation) measure from 6 to 8 mm. in length. The body is some-

ph t i \ Ni

Fic. 11.—Lesser apple worm (Enarmonia prunivora): a, Adult or moth; b, same, with
wings folded; c, larva; d, pupa in cocoon, ready for transformation to adult; e, young
apple, showing at calyx end empty pupa skin from which moth has emerged. Enlarged
about three times. (Original.)

what fusiform, uniformly reddish flesh-colored above, lighter below,

the intensity of coloring varying in different individuals from deep
reddish pink or purplish to almost or entirely white. Head bilobed,
retractile, brown to dark brown, in some specimens more or less mot-
tled with dusky. The ocellar spots, a spot caudad on cheek, and tips
of the well developed and strongly toothed mandibles, black; sutural
lines dark brown to blackish; width 0.75 to 0.85 mm., and about as
long as wide. Thoracic shield prominent, yellowish, transparent,

56 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

often with darker markings on caudal margin near median line.
Anal plate brownish, with comblike structure on caudal curvature
composed of from 5 to 7 closely set dark brown spines, the outer spine
on each side considerably reduced. Spiracles small, dark brown;
thoracic legs well developed, whitish, distal end dark, claw black.
Abdominal prolegs well developed, each with a single circle of from
25 to 27 strongly curved, sickle-lke hooks. Tubercular areas disk-
like, whitish, with a single, slender, hght-colored seta. On third
abdominal segment: Tubercle I central, on dorso-lateral region; tuber-
cle II caudo-ventrad of I, on posterior annulet; tubercle III about
its width above spiracle; tubercles IV and V coalesced, directly below
| spiracle, about twice as far from it as is tubercle ITI, the seta of
i | tubercle IV being considerably reduced; tubercle VI caudo-ventrad
\ a of IV and V, and tubercle VII with three sete situated near base of
proleg.* (See fig. 11, ¢.)

| Cocoon.—About 6 mm. long and a third as wide. Exterior more

or less covered with bits of bark or other material, concolorous with
| | | surroundings; within densely lined with whitish silk. (See fig. 11,

|

|

|

\

|

d, é.)

Pupa.—About 5mm. long. Color uniformly brown, except thoracic
region, leg and wing sheaths, which, as pupa nears maturity, are
| darker. On dorsum of abdominal segments 3 to 7, between the spir-
acles on each side, are 2 rows of short, stout spines, projecting
caudad, one row near cephalic border of segment and one near center
i | or on caudal margin, the spines of caudal row smaller and more
i | | numerous. Remaining segments (except 1 and 2, which are spineless)
Ai with but a single row. Anal segment truncate, the 7 to 8 stout spines
Wh set on caudal margin. Cremaster of from 5 to 8 slender hairs hooked
ne at tip and arising about equally distant from each other on caudal
wi region of anal segment. Spiracles slightly elevated, dark brown.
| Wing sheaths and those of third pair of legs about equal in length
Hi) and reaching middle of fourth abdominal segment. In emergence
of adult, the pupa works out from cocoon about one-half its length,
Vi the empty exuvium remaining in this position in the cocoon. (See

i | fig. 1s d, é.)
Adult or moth.—The description of the adult as given by Walsh in
his first report as Illinois State entomologist, page 80, is herewith
| presented : |

a a Ground-color of front wing, black. The basal one-fourth irregularly covered
wa | with rust-red, so as to leave only a few black markings. On the costa, and
| | he rather more than one-third of the way to the apex of the wing, a pair of streaks
: obliquely directed toward the posterior angle of the wing; the inner streak of

«The description of the larva by Simpson (Bulletin No. 41, Division of Ento-
mology, p. 28) is not entirely in accord with the above. 'The length is said to

be five-eighths inch, and for the “ pre-spiracular” tubercle three setz are re-
corded.

THE LESSER APPLE WORM. 57

q
the pair is on its extreme costal end clear white, elsewhere pale steel blue, and
extends nearly to the disk of the wing, where it almost unites with a subquad-
rangular pale steel-blue blotch, which is usually seen there without difficulty,
though it is occasionally subobsolete; the outer streak of the pair is only half
as long as the inner one, towards which it converges very slightly without
actually uniting with it, and is colored in the same manner. Further along on
the costa, and not quite two-thirds of the way to the apex of the wing, there is
another such pair of streaks, parallel with the first pair and similarly colored,
the inner one of which, when it has become as long as the inner one of the
other pair, sweeps in a gradual curve round the disk of the wing till it almost
attains the inner margin, a little way from its tip; while the other streak of the
two is so very short that the steel-blue part of it is subobsolete and can only
be seen in certain lights. Beyond this second pair of streaks, and rather more
than three-fourths of the way along the costa to the apex of the wing, is
another streak, parallel with all the others and similarly colored, which strikes
he outer margin about one-third of the way from the apical to the posterior
angle, where it terminates in a pale streak in the fringe. And beyond this
again, and equidistant from it, from each other, and from the apex of the wing,
there is on the costa a pair of short white streaks, the inner one much the
shorter of the two. Thus along the costa we have a series of 7 very conspicuous
short white streaks, arranged 2, 2, and 3. The terminal one-fourth of the
front wing is mostly rust-red, with a series of abbreviated, black, longitudinal
lines, springing from the other edge of the curved prolongation of the inner one
of the second pair of streaks on the costa; and beyond these short black lines
are two very oblique, short, pale steel-blue streaks, one springing from the pos-
terior angle and the other a little above it from the outer margin. Disk of the
front wing rust-red, with many indistinct, short, black, longitudinal lines, and
on its center the pale steel-blue blotch already referred to. On the middle of the
inner margin, a large elongate-triangular, rust-red patch, the apex of the
triangle directed towards the apex of the wing,and attaining the disk, the base
of the triangle occupying nearly one-fourth of the inner margin. The triangu- ~
lar patch is bisected lengthwise by a very elongate and slender black triangle,
the apex of which attains its apex; and the rust-red space on each side of this
last triangle is again indistinctly bisected lengthwise by a still more elongate
triangle composed of confluent black atoms. Fringe dusky, with a black basal
ine all along it. Hind wing dusky-gray at base, shading into black at tip. On
he middle of the outer margin in the male, but not in the female, an elongate
emioval patch (fig. 3a) of metallic brassy scales, brighter in certain lights.
fringe of the male (fig. 3a) long, sparse, and grayish-white on its anal half,
hort, dense, and dusky with a basal black line for its remaining half. Fringe of
he female (fig. 3) nearly of uniform length, coarse and dusky throughout on
he half next the wing, then suddenly fine and grayish-white on its outer half.
te dy brown-black. Face and palpi grayish-white. Shoulder-covers largely
ipped with dull rust-red. Tips of the abdominal joints pale fuscous above.
egs dusky. All beneath, including the legs, with a more or less obvious
ilvery-white reflection. [See fig. 11, a, b.]

SEASONAL HISTORY AND HABITS.

Our knowledge of the life and habits of the lesser apple worm is
still very incomplete, and it is hoped that numerous points may be
leared up during the course of another season. It is certain, how-
aver, that in several important respects the life habits are quite
imilar to those of the codling moth.

— 10090—Bull. 68—09

a)

58 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

So far as observed, the winter is passed in the full grown larval con-
dition. Cocoons are formed in cracks and crevices of the bark of
apple trees, under bark scales, and probably wherever suitable protec-
tion may be found. Observations by Mr. 8. W. Foster, of the Bureau
of Entomology, October 21, 1907, in an orchard badly infested with
this insect in the vicinity of Washington, revealed larve in cocoons in
cracks in the bark and crevices, the small size of the larve enabling
them to work into very small openings. In a breeding cage under
out-of-door conditions, in the insectary yard at Washington. larve
from fruit of Crateegus spun cocoons in cracks in the bark and under
the bark scales of a portion of a limb of pear tree which had been
introduced, and a few larvee penetrated as deeply as possible in cracks
in one end of the limb. The cocoons are made of bits of surrounding
bark and are thus rendered difficult of detection; the interior is lined
with whitish silk. First-brood larvee often pupate in the calyx end of
apples, or in plums, after these have fallen to the ground, and several
instances have been observed where pupation has occurred in small,
dry, and withered apples on the trees, and also in the fruit of Crate-
gus. In breeding cages larvee have been observed to fold over flaps of
apple leaves, making their cocoons in the protection thus formed. A
few larve have been found under bands around apple trees, as used

for capturing codling-moth larve, though not in sufficient numbers to—

indicate that the larve in summer go to the trunks of trees in
numbers for pupation.

The overwintering larve pupate in the spring, the moths probably
emerging about as.is true for the codling moth. Observations by Mr.

Fred Johnson, at North East, Pa., are to the effect that full-grown ||
larvee are abundant in apples during early July. At Siloam Springs, ©

Ark., the past summer, Mr. E. L. Jenne secured moths June 20, 25

and 30, from apples collected May 31, and full-grown larve were

found in apples that were collected at eae Vaz Tae 26, 1907, the™
moths emerging July 12, and subsequently to ae 21; also full-
grown ieee were found in apples sent in by Mr. L. M. Smith,
Raleigh, N. C., June 8, 1907, and moths emerged June 28, July 1,
and subsequently until the 23d. From apples from Bomone Ga.

received June 4, one moth emerged July 8. Apples collected at

Winchester, Va., June 15, by Mr. 8. W. Foster, gave adults July 3
and 9. Other breeding records for 1907 bear out those cited, though
it should be noted that moths have been reared from fruit over

practically the entire season, indicating an overlapping of genera- |

tions perhaps more pronounced than is the case with the codling

moth. However, in the Ozarks, in Arkansas, by July 18 to 25, 1907,

75 per cent of the fruit “aye by this insect had Ngee been
deserted and the remaining larve were practically all full grown.

i

|

|
'

CHE LESSER APPLE WORM. 59

At Nebraska Ci... |, Nebr., during 1906, Mr. Dudley Moulton found
full-grown larve in apples during late June and early July, moths
issuing from July 6 to August 24, reaching their maximum, however,
during late July and early August. The pupal stage was found to
last from fourteen to sixteen days.

In 1905 full-grown larvee were found in wild plums as early as
April 28, at Fort Valley, Ga., and during the same spring mature
larve were received in a sending of Japan plums from Garrison,
Tex., by Prof. F. W. Mally, under date of May 20; and also in wild
plums sent in by Mr. C. R. Jones, from Ardmore, Ind. T., a few
days later.

At least two annual generations of larve are evident, though in the
more northern States the second may prove to be only a partial one.
Larve are notably later in leaving the fruit in the fall than is true
_ of the codling moth, and are hence very commonly found at picking
_ time, and it is likely that their occurrence has thus led to belief in an
additional brood of the latter species, especially on the part of
-orchardists. Owing to their comparatively small size the larve may

be readily overlooked, especially when in the calyx end, and infested

fruit thus often goes into the barrels. In several instances which we
have noted, important injury has been done by the larvee to barreled
fruit, the disfigurement of the surface being especially common.

|
|
:

IDENTITY.

The recorded feeding of this insect upon such diverse food as the
~“ black-knot ” of plums, elm and oak galls, and upon apples, plums,
and Crategus, naturally brings up the question of the identity of
the insects secured from these several sources. On this point Walsh
Wsays:

Three specimens bred from Black-Knot Aug. 31—Sept. 7, three others bred from
the Elm Gall (Ulmicola Fitch) July 24-Aug. 5, and a single one bred from Oak-
Gall (Q. singularis Bassett) on Sept. 2, none of them differed from the plum-
fed specimens in any important point. I sent a single specimen bred from the
‘Black-Knot to the late Dr. B. Clemens about a year before his lamented death ;
but he never, so far as I know, investigated its classification. For the satisfac-
tion of the incredulous I may add that I sent specimens bred respectively from
the Plum and Elm Gall to the distinguished English entomologist, H. T. Stain-
ton, who is well known to have made the smaller moths his special study for
years ; and that he agrees with me that they are perfectly “ identical.”

Also according to Stainton, as stated by Walsh, the species is most
closely allied to the European Semasia janthinana Dup., which has
also been bred from gall-like growths on hawthorn twigs. Riley also
records breeding the species from galls (Quercus frondosa Bass.), in
the Third Missouri Report, page 25. No further records of the insect

4VWirst Report State Entomologist of Illinois, p. $1.

60 DECIDUOUS FRUIT INSECTS AND INS‘CTICI -&s.

occurring in galls or black-knot have been found'l.© ae writer, and
we have not been able to breed it from these, in -.1e limited trials
thus far made.

The moths which we have secured during the past three years from
plum, apple, and Cratzgus, and from terminal shoots of young apple
trees, have been carefully compared by Mr. August Busck, of this
Bureau, whose assistance we desire to acknowledge in this connection,
and all have been found to belong to the same species, namely, Z’nar-
monia prunivora Walsh.

PARASITES.

Only one hymenopterous parasite is recorded from. this species,
namely, Wirax grapholithe Ashm., in apples from Washington, D. C.,
May 3, 1881. The insect which Walsh supposed was parasitic on this
species, namely, Sigalphus curculionis Fitch, as shown by Riley is a
parasite of the plum curculio (ODO IE GGIES nenuphar Hbst.), as
has been known for many years.

METHOD OF CONTROL.

From the similarity in feeding habits of the lesser apple worm and
the codling moth it would appear likely that proper spraying with
arsenicals for the latter insect would also be effective in controlling to
a considerable extent the former, and observations in orchards in
Nebraska, the Ozarks, and Virginia show that this is the case.

The larvee of the first generation, which mostly attack the fruit at
the calyx end, are no doubt destroyed by the poison held in the calyx
cavity, though, as has been noted, larve often bore into the fruit at
the base of and outside of the calyx lobes. In some instances exam-
ined the calyx cavity and stony tissue of the core just under the skin
have been left almost or quite intact. Feeding in this way larve would
scarcely be poisoned. The comparatively small numbers taken from
under bands of burlap around the trees, as used for the codling moth,
show but little value from this procedure as used specifically against
the lesser apple worm. Thorough spraying for the codling moth will

perhaps best serve to keep the other pest in control, and where appli-—

cations are made for the second brood of the former insect, these cer-
tainly will be of great use in reducing injury from the lesser apple
worm late in the season.

foe. A. B. BH. Bul. 68, Part VI. D. F. I. L, April 24, 1908.

PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

GRAPE ROOT-WORM INVESTIGATIONS IN 1907.

By FRED JOHNSON,

Engaged in Deciduous Fruit Insect Investigations.
INTRODUCTION.

For several years past the control of certain insect enemies of the
_ grape has been a problem of increasing importance with the vine-
_ yardists of the Lake Erie valley. The insect causing most alarm is
_ the grape root-worm (Fidia viticida Walsh). It was in 1899 that
} serious injury to the grape vine, which proved to be the work of this
' pest, was first noticed in the famous Chautauqua grape region, at Rip-
; ley, N. Y. For several years previous to the discovery of this insect
~ in Chautauqua County, it had made serious inroads into the vineyards
_ of the Ohio grape region, and was, in 1895, the subject of investiga-
_ tion by Prof. F. M. Webster, then entomologist of the Ohio Agricul-
‘ tural Experiment Station, to whom we are indebted for the first
_ records of its complete life history and methods of control, a report
; of which was published in Bulletin No. 62 of the Ohio Agricultural
i Experiment Station.

i Since 1900 this pest has esha the subject of investigations in Chau-
_ tauqua County, by Dr. E. P. Felt, State entonidlopist of New York,
and Prof. M. V. Slingerland, of the Agricultural Experiment Station
~at Cornell University, both of whom made a life-history study of the
insect and conducted field experiments in jarring and spraying the
"vines to reduce the number of beetles. The results obtained by these
- gentlemen are embodied in Bulletins 59 and 72, New York State Mu-
-seum, by Dr. E. P. Felt, and in Bulletins 184, 208, and 224, of the
Cornell University Agricultural Experiment Station, by Prof. M. V.
Slingerland. In Farmers’ Bulletin No. 284, on Insects and Fungous
Enemies of the Grape East of the Rocky Mountains, by Messrs. A. L.
Re intance and C. L. Shear, the grape root-worm is described, and its
life history and methods of contr rol are briefly stated.

61

62 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.
A BRIEF CONSIDERATION OF VINEYARD CONDITIONS.

During the past eight or ten years changes have occurred in both
market conditions and in the age, area, and productivity of vine-
yards throughout the Lake Erie valley, which deserve brief consid-
eration for full appreciation of the present active interest of vine-
yardists in this insect problem.

In 1900, when the grape root-worm first appeared in injurious
numbers in the Lake Erie valley, the grape industry was just emer-
ging from a period of depression which had caused, for several years
previous, an almost complete cessation in planting of new vineyards.
The period of low prices had resulted in indifferent care, amounting
in some cases to positive neglect, thus creating a condition very favor-
able to the increase of this pest. The tendency of most vineyardists
at that time was to pull out declining vineyards rather than to go to
the expense of fighting insect foes. Furthermore, the fact that prac-
tically all vineyards had been for several years in bearing and had a
well-established root system permitted the insect to become thoroughly
disseminated through them before the unsuspecting owners were
aware of its presence in numbers sufficient to affect the vigor of their
vines. Thus it happened that a combination of circumstances con-
spired to favor a general spread of the insect without creating wide-
spread alarm.

With the steady rise in the anne of grapes since 1900, however,
this condition has been reversed. iusto of acres of new vine-
yards have been planted, and the more progressive vineyardists are
commencing to appreciate fully what an enormous amount of injury
has been done to their old vineyards, and are greatly alarmed at the
sapidity with which many young vineyards are falling a prey to this
pest.

A study of the production of grapes in the Lake Erie valley since
the advent of the grape root-worm shows a steady decline in yield.
The figures given below are taken from the “ Chautauqua Grape
Belt,” a newspaper which is largely devoted to the grape interests of
that region, and every year publishes carefully gathered statistics on
grape production.

Grape crop production from 1900 to 1907.

Carloads.

Yield -for A900». So Siete ee eee 5 ots: ete ae ee 8, 000
BOD ce Bice ha Bk Se Is ie ee ee 6, 669

PQQ 2 sa se ie LS a ee ne te 5, 062

190382 ee Ln Ee Be SE oat ae eee ee ee 2, 954

1904__ SE a) Se see eels NS weeny eM LS 7,479

U9O5 cee ee ee ee ee ee 5, 365

19062 2 es ee 5, 463

GRAPE ROOT-WORM INVESTIGATIONS IN 1907. 63

The true significance of these figures, however, is not realized
unless we take into consideration that there are now nearly 10,000
acres more of bearing vineyard than there were in 1900, which should
of themselves produce nearly 1,800 carloads of fruit.

An analysis of the 1907 crop report brings out forcibly the deterio-

ration of the old established vineyards. In the three townships of
Portland, Westfield, and Ripley, in which there has been much less
new planting than in the townships at either the eastern or western
extremities of the grape belt, and which therefore come nearer to giv-
ing the true decline of old vineyards, there was a decrease of 585 car-
loads of grapes below the crop for 1906. Placing the value of grapes
at $25 per ton, the lowest price paid for grapes in 1907, there was a
shrinkage in value approaching $175,000 in these three townships.
While some of this decline in production may be due to depletion of
soul, lack of proper cultivation, and adverse weather conditions, yet
many vineyardists who are careful observers are now convinced that
a high percentage of this loss is due directly to the ravages of the
grape root-worm.
— It is a fact notorious to all vineyardists that wood production in
nearly all vineyards has greatly decreased. In the issue of the
“Chautauqua Grape Belt” for January 7, 1908, the statement is made,
in predicting a light crop for 1908, that in most vineyards the wood
growth is 65 per cent of the normal wood growth of several years ago,
and in many vineyards is as low as 25 per cent. Extended observa-
tions during the past year convince the writer that this statement is
by no means exaggerated.

It was because of the existence of such conditions as are described
above that the vineyardists of North East, Pa., became alarmed for
the future of their vineyards, and appealed to the Secretary of Agri-
culture for assistance. In compliance with this request investiga-
tions were commenced by the Bureau of Entomology in the spring of
1907.

WORK UNDERTAKEN AT NORTH EAS™, PA.

The main features of the work against the grape root-worm at
North East, Pa., during the past summer have been: (1) A close
study of vineyard conditions to determine the amount of injury for
which this insect is responsible, and the amount of injury done to
vines of various ages; (2) the conducting of large-scale spraying
experiments in vineyards but recently infested, with a view to fur-
nishing protection from the insect and maintaining the present stand-
ard of crop production; (3) beginning large-scale experiments to
determine the possibility of bringing badly injured vineyards up to
a state of profitable production, and to ascertain the best means of
furnishing protection to young vineyards just coming into bearing.

64 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. ©
EXTENT OF INJURY TO NEWLY BEARING VINEYARDS.

As an illustration of the extent of injury done by this pest to young
vineyards which came under the writer’s observation during the past
summer, the condition of a block of vineyard growing on a level
piece of ground in a clay loam soil near the lake shore may be cited.
The vines had borne but three crops, and previous to the attack of
the grape root-worm were very thrifty. The original planting con-
sisted of 3,234 vines. An examination of the vineyard on June 17,
1907, showed that 548 vines had been so badly injured by the grape
root-worm that they had to be cut back to the ground; 897 vines
were cut back to the lower wire and bore no fruit that season, and
the remaining 1,794 vines were cut back to one or two canes. This
treatment, made necessary by root-worm injury, resulted in a cur-
tailment of 75 per cent of the crop.

Figure 1, Plate VIII, shows the condition of the above-mentioned
vineyard September 2, 1907. Figure 2, Plate VIII, shows vines in
a younger vineyard only a few yards distant, bearing their first crop
of fruit and not yet infested by the grape root-worm. (The owner
informed the writer that at the same age the vines shown in figure 1
were quite as thrifty as those shown in figure 2.)

Another young vineyard, 6 years old, on a loose gravel soil, showed
an even worse condition. In one section of 1,620 vines, 485 vines
were killed outright in a single season, and nearly all the rest of the
vines were so seriously injured that they had to be very severely
cut back. The crop record of this vineyard is given below, and shows
a decline in crop value, in 1907, of $379.80, or 87.17 per cent less than
in 1906.

TABLE 1.—Crop record of vineyard injured by grape root-worm.

Number | Number
Naar: . Of Net Value

of :
trays. | baskets. weight. | of crop.

Pounds.
1904s2. sae a 8 he a Dee Be oe Oe 295 None. 11,630 $127.51
TO a ae Ag A I eee 613 696 23,705 410.77
AS, 0 6 Sa ee ee mee Yar I Ne BU ED Pe a ay ee 581 588 21,130! 435.72

1Q07. [27221 Ok os ee re Bia a ee a ee | 93 | None. 3,195 55.92

Figure 1, Plate IX, shows the stunted condition of the vines in
the above-mentioned vineyard, as a result of the grape root-worm
injury. Figure 2, Plate IX, shows a normally thrifty uninfested
vineyard at North East, Pa. It should be stated in addition that
both of these injured vineyards had received the best of care, so far
as cultivation and general management are concerned, with the ex-
ception of spraying the vines to protect them from the beetles, and
previous to 1906 both vineyardists were highly pleased with the
vigorous condition of their vines. The illustrations cited above are

Bul. 68, Bureau of Entomology, U.S. Dept. of Agriculture. PLATE VIII.

VINES INJURED BY GRAPE ROOT-WORM COMPARED WITH UNINJURED VINES.

Fig. 1.—Six-year planted vines making but a weak growth because of injury to roots by
grape root-worm. Fig. 2.—Two-year planted vines not yet attacked by grape root-
worm. At the same age vines in figure 1 were equally thrifty. (Original.)

Bul. 68, Bureau of Entomology, U. S. Dept. of Agriculture PLATE IX.

VINES INJURED BY GRAPE ROOT-WORM COMPARED WITH UNINJURED VINES.

Fig. 1.—Young vines almost ruined by feeding of grape root-worm upon their roots,
Fig. 2.—A normally thrifty vineyard at North East, Pa., uninfested by grape root-
worm, (Original.)

GRAPE ROOT-WORM INVESTIGATIONS IN 1907. 65

by no means exceptional, and a careful survey would reveal hundreds
of acres of these newly bearing vineyards in various stages of de-
cline. It was to these new vineyards that the vineyardist looked for
the maintenance of the industry in the future, but their present con-
dition shows that when unprotected from the grape root-worm they
succumb to the attacks of this pest even more rapidly than do old
established vines.

This rapid decline in young vines, due to grape root-worm attack,
has opened up the question of the advisability of attempting to ren-
ovate these old, run-down vineyards, some of which are now yield-
ing a ton or less of grapes per acre and of which there are several
thousands of acres throughout the grape belt.

RENOVATION EXPERIMENT ON AN OLD, RUN-DOWN VINEYARD.

Early in the spring of 1907 a vineyard of 10 acres was secured at
North East, Pa., which had been so badly injured by the grape root-
worm that the decline in grape production had fallen from 34 tons
of grapes per acre, in 1905, to three-fourths ton per acre in 1907.
The vineyard is to receive severe pruning, thorough cultivation,
hberal applications of fertilizers, and thorough spraying. This treat-
ment is to continue for a series of years.

The results of this treatment during the past summer are an in-
creased growth of canes over last year, and a great reduction in the
deposition of grape root-worm eggs—a direct outcome of the poison
spray application, as indicated in the following table:

TABLE II.—Showing egg deposition on sprayed and check plats.

CHECK (UNSPRAYED) PLAT.

Average num-

Number of egg clusters found. | Esti-
Dates of When. id si mated | Num- | Num- ber of eggs.
applica- esanined num- | ber of | ber of |
tion. ic : ber of | vines. | canes.| Per Per
Large. | Medium.| Small. | Total. eggs. | vine.” haaabe:
poet EE Ti 4 I- TESis
August 12... 97 150 238 485 | 11,730 25 76 | 469. 2 | 154. 37

SPRAYED PLATS.

K »

Formula: 5 pounds blue vitriol (copper sulphate), 5 pounds lime, 3 pounds arsenate of
lead, 50 gallons water.

PLAT NO. 1. | | |
| | |
July 22.772 _/}August 13... 1 21| 84 56 | 1,440 25 66| 57.6| 25.71
PLAT NO, 2. |
July ta august 13...| 4 17| 25 46 | 960 25 85 | 384)! 11.29

As has been previously stated, the wood growth in this vineyard
was light as a result of serious injury to the roots of the vines by the

enna

66 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

grape root-worm and from severe pruning in the spring. For this
reason it might be urged by some that this experiment was not a fair
test of the efficacy of a poison spray, because, it is said, beetles desert
vineyards in this condition for those having a dense foliage. That
there were a large number of beetles present, however, is shown by
the heavy deposition of eggs in the untreated check, even though the
foliage was light.

SPRAYING EXPERIMENT IN A NEWLY INFESTED VINEYARD.

Since a part of the campaign against this pest is to determine if
thorough and timely spraying, conducted for a series of years, will
prevent the deterioration of thrifty vineyards but recently infested,
an experiment was planned in another vineyard. This vineyard is
20 years old, on gravel soil, making a good growth of canes and luxu-
riant foliage. It is infested with the grape root-worm, but is not yet
showing evidence of deterioration. The block contains about 6 acres;
1 acre was left unsprayed for check and the method of examination
to determine results was the same as in the preceding experiment.

The following table gives the record of egg deposition in this block,
as a result of the spray applications:

TABLE III.—Showing egg deposition on sprayed and check plats.

CHECK (UNSPRAYED) PLAT.

hee : Esti- Average num-
| Number of egg clusters found.
Disites oft): vapen vosaene ‘ ae mated | Num- | Num- |_ ber of eggs.
applica- eae sea ber of | ber of PE Tc Ss
tion. i : f er of | vines. | canes. er er
Large: | oy | Small. | Total. eggs. sinieen canes
JANIE MSt 22 so. oe | 52 | 136 | 213 401 | 8,810 25 69 | 352.4 | 127.67
SPRAYED PLATS.
Formula: 5 pounds blue vitriol (copper sutphate), 5 pounds lime, 3 pounds arsenate of lead,
50 gallons water.
PLATNO.1. -
a 23. _|}August 2 ye 4 13 13| 30] 720 25 72| 28.8| 10
PLAT NO.2.
sale par) |PAUBUsL Oe 4 19 20 43 | 970 25 61| 381] 15.9

METHODS OF RECORDING RESULTS.

The figures on egg deposition given in the tables above were ob-
tained by carefully removing all of the loose bark from the bearing
canes and the trunks of 25 consecutive vines, and recording the num-
ber of egg clusters found. Since the egg clusters varied in size, they
were classified—after the eggs in a large number of clusters had been
counted to ascertain the actual number—as large, when containing 50

62>) ee

GRAPE ROOT-WORM INVESTIGATIONS IN 1907. 67

eges or over; medium, when containing about 30 eggs; and small,
when containing about 10 eggs. Examinations were made in three
parts of the vineyard. An unsprayed check plat of 1 acre was left
on one side of the vineyard and the egg clusters found on 25 con-
secutive vines, at a date after the maximum number of eggs had been
deposited, were recorded in the manner just described. A similar ex-
amination was made on 25 consecutive vines in the sprayed portion,
six rows over from the check plat, and a further examination on 25
sprayed vines on the opposite side of the vineyard, the main object
of this last examination being to determine the uniformity of egg
deposition throughout the vineyard.

RECOMMENDATIONS BASED ON OBSERVATIONS AND RESULTS OF
SEASON’S WORK.

The work of the past season, at North East, Pa., indicates that
thorough and timely spraying of infested vines with arsenate of lead
will, by preventing the deposition of a sufficiently high percentage of
eggs, reduce the number of grape root-worms to such an extent that
they will not seriously affect the growth of the vines. In order to
make the spray effective, however, the first application must be made
either immediately before, or as soon as the first beetle is seen in
the vineyard.

Since the emergence of the beetles from the soil is governed largely
by weather conditions, especially those of temperature, no definite
date for making the first application can be given. For instance, the
records of Felt and Slingerland show that in normal seasons the
beetles commence to appear during the last week or ten days in June,
whereas, in 1907, none was found in vineyards by the writer until
July 15, although he had spent a large portion of every day in the
vineyards for a week or two preceding that date. Hence, it is very
necessary to watch the development of the larve and pupe in the soil.

The emergence of the beetles in our breeding cages during the past
season coincides very closely with the appearance of the beetles in
vineyards. The first two beetles appeared in the cages on the morn-
ing of July 14; by the 15th a large number had emerged, and the same
day the beetles were very numerous on foliage in vineyards on gravel
soil. Nearly 50 per cent of the beetles which matured from 750 larve,
placed in the soil in our breeding cages, emerged on the third and
fourth days after the first beetle appeared. This simultaneous emer-
gence of so large a percentage of beetles shows the necessity of having
the first spray application upon the vines by the time the first beetles
appear, or, at least, to have the spraying equipment in readiness so
that the application may be made with the least possible delay.

The time of emergence of the beetles can be determined quite closely
by examining the condition of the pupx in the soil every few days

68 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

during the latter part of June; or, still better, by collecting a hun-
dred or so full-grown larve about the last of May and placing them
in a shallow box, the bottom of which consists of a pane of glass, the
box containing about 8 inches of moist soil. Some of the larve will
go through the soil to the glass surface, where their transformations
may be watched and the time of emergence definitely determined.

In making the spray applications care should be taken to cover all
parts of the foliage. For thorough work, 100 gallons of liquid spray
per acre is necessary and a pressure of not less than 100 pounds should
be maintained. Two such thorough applications—one as the beetles
emerge, and another not more than a week later—judging from the
results obtained in our work of the past season, will prove sufficient
to reduce the infestation of this insect to a point where it will not
seriously affect the vitality of the vines.

The formula used in our experiments during the past season is the
Bordeaux mixture formula, recommended by the Bureau of Plant
Industry for combating the black rot of the grape, to which was
added 3 pounds of arsenate of lead, the latter ingredient being the
insecticide.

Spray formula recommended.

Copper sulphate (bluestone or blue vitriol) _-_________ pounds__ 5
Nresh stone tne soo see eras EE AES eth Maliad: at hg TJ GO 282 Yay
Arsenate Of dipadla 2 Sees, eee ee wp De dQ2t 22 8s
WALD 262 255s ee ge gallons__ 50

U.S. D. A., B. E. Bul. 68, Part VII. D. F. I. I., April 29, 1908.

PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

DEMONSTRATION SPRAYING FOR THE CODLING MOTH.

INTRODUCTION.
By A. L. QUAINTANCE,
In Charge of Deciduous Fruit Insect Investigations.

Although the codling moth (Carpocapsa pomonella 1.) has received
a large amount of attention from entomologists, horticulturists, and
others during the past fifteen or twenty years, and methods for its
satisfactory control have long been known and practiced by orchard-
ists, itis nevertheless true that a large number of apple growers either
do not spray for this insect or, from lack of thorough and timely
applications, do not secure satisfactory results. In connection with
other work at some of the field stations in the deciduous fruit insect
investigations of the Bureau of Entomology, it has been possible to
make demonstration sprayings in the control of the codling moth to
serve as object lessons for the orchardists of the neighborhood. The
usefulness of the work is shown by its popularity among fruit growers,
and indicates that, in general, work of this character is perhaps as
much needed as work along purely investigative lines.

DEMONSTRATION SPRAYING IN VIRGINIA IN 1907.
By S. W. Foster.

The orchard of Mr. J. J. McHenry, where this demonstration was
made, is located near the foot of the Blue Ridge Mountains near
Afton, in Nelson County. This orchard site is very favorable, hay-
ing a northern exposure with an elevation of about 1,000 feet, and
being partly protected on the western side by a mixed forest.

Mr. McHenry’s orchard consists of about 400 Yellow Newtown
Pippin trees and 220 trees of the Winesap, Limbertwig, and Shock-
ley varieties, all of which were reported to be 28 years of age. Some
years ago this orchard was very profitable, but the prevalence of the
codling moth, together with some of the more important fungous
diseases, as bitter rot and apple scab, soon reduced and practically
cut off all profits. Along with this the orchard for some time re-
- ceived little or no attention, and only within the last two or three
years had there been any attempt toward spraying and the giving

69

70 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

of systematic care. But for various reasons, principally that of
neglecting to apply sprays at proper times and in a thorough man-
ner, the results had been very unsatisfactory. The work herewith
reported, and carried out in cooperation with Mr. W. M. Scott, of
the Bureau of Plant Industry, included the entire orchard and was
designed to give freedom from the codling moth and fungous diseases
as well. The entire orchard was sprayed except a few trees for pur-
poses of comparison.

Location of unsprayed trees used in determining results —The un-
sprayed trees used for counts of fruit in this demonstration were
selected just prior to the first spraying. With two exceptions the
trees were in each of two rows running through the middle of the
orchard, five rows apart. Two pippin trees (one to be sprayed and
one to be left unsprayed) were also selected near the edge of the
orchard for possible comparison with other treated and untreated
trees.

Treatment.—As bitter rot and apple scab had in previous years
caused serious injury to the fruit in this orchard, a treatment was
planned to control both insects and fungous diseases, namely, the
application of Bordeaux mixture with an arsenical added. Six
applications of Bordeaux mixture were made, using for the first
application 4 pounds of bluestone and 6 pounds of quicklime to
50 gallons of water, and for the subsequent applications 5 pounds
of bluestone and 5 pounds of quicklime to 50 gallons of water. Arse-
nate of lead, 2 pounds to 50 gallons of the mixture, was used with
the first, second, and fifth applications.

Times of application.—The first application (4-6-50 formula of
Bordeaux mixture plus 2 pounds arsenate of lead) was applied just
after the blossoms fell, to fill the calyx cavities of the apples with
poison, and, owing to continued unfavorable weather, was very
much prolonged, from April 30 to May 9. The second application
was made three weeks later, about the time it was thought that the
moths from the over-wintering larvee would begin to deposit eggs in
numbers, that is, from May 21 to 27; the third application, five
weeks later, June 24 to 26; the fourth, July 10 to 13. The fifth,
containing arsenate of lead, for the second brood of larve, was
apphed soon after the first adults began to emerge from the cocoons
of the first-brood larve, July 25 to 29. The sixth, being the last,
was a treatment with Bordeaux mixture alone, and was applied
from August 12 to 15.

The outfit used consisted of a large hand pump with two hori-
zontal cylinders mounted on a 200-gallon tank, and two leads of
hose with 15-foot extension rods, with double Vermorel nozzles.
A platform elevated about 4 feet over the rear end of the tank proved

very advantageous, especially for the first application, as it enabled

—-*

DEMONSTRATION SPRAYING FOR THE CODLING MOTH. 71

one man to cover the tops of the trees completely and direct the

spray downward. |
Results.—The following tables show the comparative results from

sprayed and unsprayed trees:

TaBLE I.—Comparison of sound and wormy fruit from 5 sprayed and 5 unsprayed trees,
Winesap variety, McHenry orchard, Afton, Va., 1907.

Windfalls. | Fruit from tree. > | s ZA | 2s
“a0 Gy LS E | as |32 | Se
Date of spraying and| Total Ay Mohs a < 4 —5 (5S o=
tree number. crop. GS led] 4 =| 2 = é Se ae =
Sei kee | oe 2. <a> £ = eo |So8| 5
S Zo S Zo = Ss oF IS42 RR] o5
| 2 eens 2 = = 2 S 2 ee ao
| eee ne H > = aH ram =, a am
Sprayed Apr. 30, May | | |
21, June 24, July 10, |
July 25, Aug. 12. Bushels.| No. | No. | No. No. No. | No. | No. | No. | No.

PEG Mee es acts 2 Sc 19. 25 37 | 168 205 217 | 4,008 | 4,225 254 4,176 | 4,430 94.26
fie A ee ee | 11.75 26} 180} 206 165 | 2,567 | 2,732 | 191 | 2,747 | 2,938 | 93. 50
eee Y 42-75 42} 126] 168] 97 | 2,631 |2,728| 139 | 2,757 | 2,896 | 95.20
Re oS sk 8.25 43 | 172 215 | 36 | 1,670 | 1,706 | 79 | 1,842 | 1,921 | 95.88
Were | 11.00| 56]. 180] 236 7 | 2,155 | 21242 | 143 | 2335 | 2)478 | 94.23

Trees 1 to5com-

Bined: 2 2... <5 63. 00 204} 826 1,030 602 13,031 13,633 806 13, 857 |13, 663 94. 50
Unsprayed:

LEE a St pe 4.00) ) "2 715 54 769 531 318 849 | 1,246 372 | 1,618 | 22.99
Peek: B.S aces 9.25 | 1,255 | 115 | 1,370) 521) 291 812 | 1.776 406 ) 2,182 | 18.60
eee © Ie oe 5.50 455 53 508 419 | 309 728 874 362 | 1,236 | 29.28
neck: 1). 5. 0- os 5.00} 532] 8 617 307 196 503 281 | 1,120 | 25.08
GHeck Wie) = 222 os. 5.50} 660] 62 722 475 201 676 1,135 263 | 1,398 | 18.81

A, B, G: D, i De / / :

combined..... 32.25 | 3,617 | 369 | 3,986 | 2,253 | 1,315 | 3,568 | 5,870 | 1,684 | 7,554 | 22.29

| | |

Table I shows an average of 94.50 per cent of fruit not wormy
from the sprayed trees against 22.29 per cent of fruit not wormy
from the unsprayed trees. This is a saving of 72.21 per cent of the
crop in favor of sprayed trees.

TaBLeE 1].—Comparison of sound and wormy fruit from 5 sprayed and 5 unsprayed trees,
Newtown (Albemarle) Pippin variety, McHenry Orchard, Afton, Va., 1907.

| Windfalls. Fruit from tree a ae ee
Pe fees pss fae
Date of spraying | Total. | Bs fe MR | ie “ag Poe =8 |"o. lose
and tree number. crop. | FI SE bed) a = SE s. ). oS d ee Pat ae
3S i arb As en oF |S3 8] o3
sc ° z 2) | = ° ©
| | = Ele | & Fle | a |e |e -] me
Sprayed Apr. 30, May / |
21, June 24, July 10, |
July 25, Aug. 12: Bushels.| No. No. No No. No. No. No. No. | No.
Lp Cee 14.25 | 28 392 420 49 3,044 3,093 77 | 3,436 | 3,513 | 97.81
Me oe a oe 13. 75 | 53 473 526 31 | 2,355 | 2,386 84 | 2,828 | 2,912 | 97.11
ig 2 fee 13. 75 42 447 489 114 | 2,160 | 2,274 156 | 2,607 | 2,763 | 94.36
flere Mee eee amen 21.25 124 608 732 164 3,186 3,350 288 | 3,794 | 4,082 | 92.95
POO DS. oo Sew oe | 18. 00 116 | 1,010 | 1,126 192 | 2,653 | 2,845 308 | 3,663 | 3,971 | 92.24
Trees 1 to 5) ! )
combined.....) 81.00 | 363 | 2,930 | 3,293 550 13,398 13,948 | 913 (16,328 (17,241 | 94.7
a a ba ) )

[03] <a, ee 23. 50 | 1, 504 611 | 2,115 | 2,240 | 1,089 | 3,329 | 3,744 | 1,700 | 5,444 | 31.22
Sneek Bees... <. 12.00 929 316 | 1,245 980 389 1,369 | 1,909 | 705 | 2,614 | 26.96
Chen... es 11.00 | 1,380 129 | 1,509 444 166 610 | 1,824 295 | 2,119 | 13.92
Gheek Dy: se... 9.50 | 1,348 | 89 | 1, 437 372 | 126 498 | 1,720 215 | 1,935 | 11.11
Oreck) BaF eek 12.00 536 353 889 1, 604 26 «1,680 | 2,140 379 | 2,519 | 15.04

ANB, OD; FE, |

) | | |
combined.....| 68. 00 | 5, 697 | 1, 498 | 7,195 5,640 | 1,796 | 7, 436 fi 387 3,204 14, 631 | 22. 51

Fe) DECIDUOUS FRUIT INSECTS AND INSECTICIDES,

The five sprayed trees show an average of 94.70 per cent of fruit
not wormy as against 22.51 per cent, the average percentage of fruit
not wormy from the unsprayed trees. This is a saving of 72.19 per
cent of the crop for the treated trees.

Leaving out the wear of apparatus, such as pump, wagon, ete.,
the cost of the six applications for the entire orchard is given as fol-
lows: Two men 223 days at $1.25 per day, $56.25; 2 men 223 days
at $1 per day, $45; 2 horses 223 days at $1 per day, $45, making a
total cost for labor of $146.25.

For the 620 trees, 14,100 gallons of spray were required, the mate-
rial costing as follows: Arsenate of lead, 324 pounds at $0.125 per
pound, $40.50; copper sulphate, 1,260 pounds at $0.08? per pound,
$110.25; lime, 11 barrels at $0.80 per barrel, $8.80, making a total
cost for material and labor of $305.80, or an average cost for all spray-
ing of 49 cents per tree.

The 5 sprayed Winesap trees gave a yleld of 18 barrelsof No. Lapples,
1 barrel of No. 2’s, and one-half barrel of culls. The price received
for these grades of red fruit was $3.25, $2, and $1.75, respectively,
per barrel. This gives a total receipt of $61.35 for the 5 sprayed
trees or $12.27 per tree. This, minus 49 cents, the cost of spraying,
leaves a net return of $11.78 per tree. The yield of the 5 unsprayed
trees was 1} barrels of No. 1 apples, 1 barrel of No. 2’s, and 3 barrels
of culls, giving a total return of $11.31 for the 5 trees, or $2.26 per
tree, leaving a difference of $9.25 as a net gain per tree in favor of the
sprayed trees.

The net gain was even more favorable with the Yellow Newtown
Pippin variety, the 5 sprayed trees yielding 204 barrels of No. 1 apples,
1 barrel of No. 2’s, and one-half barrel of culls. The prices received
for these grades of this variety were $4.25, $3, and $1.75, respectively,
per barrel, giving a total of $90.97 for the 5 trees, or $18.19 per tree.
This, minus 49 cents, the cost of spraying, leaves a net return of $17.70
per tree. The 5 unsprayed trees gave only 1? barrels of No. 1 apples,
3 barrels of No. 2’s, and 73 barrels of culls; at the same price this gives
a total of $29.12 for the fruit from the 5 unsprayed trees, or $5.82
per tree, leaving a difference for the sprayed trees of $11.88 net gain
per tree.

DEMONSTRATION SPRAYING IN PENNSYLVANIA IN 1907.

By FRED JOHNSON.

The apple orchard used in this demonstration is situated on a
high bluff along the shore of Lake Erie about a mile north of the
village of North East, Pa. It is bounded on three sides by steep
_ banks, with woods on the north and east, and open on the south

DEMONSTRATION SPRAYING FOR THE CODLING MOTH. 73

and west. There are about 250 trees in the orchard, consisting
mainly of Baldwins, with several rows of Greenings on the north
side which were not used in the work. The trees are about 30
years old; most of them about 25 feet high, with corresponding
spread of limbs.

_ Previous to the spring of 1907 the orchard had been in sod for
many years, and no pruning had been done for a like period. The
orchard was kept under observation during the summer of 1906,
and the condition of the fruit at harvest time was carefully noted.
Under the management to which the orchard had been subjected
for many years, the grass had been cut for hay, no spraying had
been done, and no fruit had been picked from the trees, although
in 1906 the ground beneath a large number of them was covered
with fallen fruit, indicating that a fair crop of fruit had set. Some
of this fruit was picked up and sold at $0.17 per hundredweight
for cider-making purposes. Practically all of this fruit was injured
by the codling moth and the plum curculio.

On September 5, 1906, a Baldwin tree was selected as fairly
representing the condition of the trees in the orchard, and all of
the fruit then on the ground was picked up and classified as to
injury by codling moth and plum curculio, and all fruit which fell
to the ground after this date, and that picked at harvest time, was
likewise classified.

The total picked and dropped fruit, amounting in all to 2,766
apples, showed 95.62 per cent injury by the codling moth, and 62.55
per cent bearing egg and feeding punctures of the plum curculio.

The owner of the orchard, at the suggestion of the writer, decided
to prune and cultivate the orchard in 1907, and it was placed at the
disposal of the Bureau of Entomology for spraying experiments.
The trees were pruned very early in the spring and the sod broken up
and cultivated twice later in the summer. One hundred and fifty
trees, all Baldwins, with the exception of a few scattered Astrachans,
were laid out into 15-tree plats, including a check plat, and treated
with Bordeaux mixture and an arsenical in a way to ascertain the
value of applications at different dates. One of these plats received
the usual ‘‘demonstration’’ treatment for that latitude, and it is from
this plat and the check plat that the data to be given were obtained.

Three applications of spray were made: (First) June 10, immedi-
ately after petals fell; (second) July 2, three weeks later, when first
eggs of codling moth were being deposited; (third) August 9, when
adults were beginning to emerge and to deposit eggs for the second
brood. The 5-5-—3-50 formula was used—that is, 5 pounds copper
sulphate, 5 pounds stone lime, 3 pounds arsenate of lead, and 50
gallons of water.

10090—Bull. 68 —09-———G

74 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

The applications were made with a gasoline-power sprayer mounted
on low trucks, with a 4-foot derrick, using 10-foot bamboo rods and
double nozzles. In the operation of spraying a pressure of about 100
pounds was maintained and between 4 and 5 gallons of liquid were
used per tree at each application. ;

The sprayed trees were separated from the untreated check trees
by two rows of trees which were also sprayed to act as a barrier and to
prevent the overflow of codling moth which might breed on the
unsprayed plat during the summer.

Table III gives the results obtained from three trees in both the
sprayed and unsprayed plats, by actual count and examination of
windfalls and picked fruit.

TasLe III.—Comparison of sound and wormy fruit from 3 sprayed and 3 unsprayed
trees, Baldwin variety, Sprague Orchard, North East, Pa., 1907.

|

: W indfalls. Fruit from tree. > = 3 Ps
— |= | Abbe | es Uae
Dates of spraying Total bs 1a eS Allies > iss 5 — 5 on
and tree number. crop. FR isg| 3 = eq 3 Le ae = oS
CU NAS I 6 So Waien|| se Sal etal eck =
= EB) 8 = See ate Mees te BH | fa
Sprayed June 10, July
2, and August 9: Bushets.\ No. |, Nowe Noe No. No. No. No. No. No.
Tree No. 1...----- 9.25 29:) 935") 157 19 | 2,151 | 2,170 41 | 2,386 | 2,427 | 98.31
TreeiNO: Wei so. =~ 5. 50 74 | 264 338 17 | 1,279 ; 1,296 91 | 1,543 | 1,634 | 94. 43
Tree INO./3:2s2co-- 5. 50 76 | 281 357 26 | 1,099 | 1,125 102 | 1,380 | 1,482 | 93.12
Trees Nos. 1 to | |
3 combined. .- . 20. 25 172 | 780 952 62 | 4,529 | 4,591 234 | 5,309 | 5,543 | 95. 78
Unsprayed: B
Check Ae .'5-2 60222 3. 00 324 34 358 547 90 637 871 124 995 | 12. 46
Check Biogas ss. - 3.75 | 599} 262) 821 303 237 540 862 499 | 1,361 | 36. 66
CheckiG=532555---- 5. 25 599 | 255| 854 626 222 848 | 1,225 477 | 1,702 | 28.03
Checks A to C | | on
combined... -. 12.00 | 1,482 | 551 | 2,033 | 1,476 549 | 2,025 | 2,958 | 1,100 | 4,058 | 27.11

Table IV gives the yield of windfalls and picked fruit in bushels
and its market value for 14 trees in the sprayed plat and for the same
number of trees in the unsprayed plat.

Taste I1V.—Comparison of yield and character of fruit from 14 sprayed and 14 unsprayed
trees, Baldwin variety, Sprague Orchard, North East, Pa., 1907, with value of crop.

: 8 Value
No. | First- | Second Value | Value |
Date of spraying. of class | class Cas Ciders.| Total.| first | A can- welne oe
trees.| apples.) apples. ; class class.| 2eTs- :

Bush. | Bush. |Bush.| Bush. | Bush.| Dolls. | Dolls. | Dolls.| Dolls. | Dolls.
June 10, July 2, and

AUZUST Qos5 Jans = ee 14} 43.25 | 20.25 4} 20.75 | 88.25 | 43.25 | 13°50) | 12:20))|) “32 10) Sointe
Unsprayedichecks!s52| 0) aU4s |S seces- |-------- 22 | 58.00 | 80.00 |....-.-- aes 6.60 | 8.70 | 15.30

The picked fruit was packed in two grades, the first grade bringing
$3 per barrel, the second grade $2 per barrel. The windfalls and

ae

OF aE ae an ee eae eee eS.

DEMONSTRATION SPRAYING FOR THE CODLING MOTH. 75

culls were also sorted into two grades. Those above 2 inches were
used for canning and sold for 60 cents per hundredweight, while
those of the smaller grade were used for cider-making purposes and
sold for 30 cents per hundredweight.

The total amount of spray applied to the 14 trees was 182 gallons,
about 13 gallons per tree for the three applications, at a cost of about
2 cents per gallon, or $3.64 for the 14 trees.

The time required to make the applications was about one and one-
half hours for each time, or about four and one-half hours for the
three applications.

Two men and a team were used in the work, and the wage paid was
40 cents per hour for man and team, and 17.5 cents per hour for the
additional man, making the cost of labor $2.59 for the four and one-
half hours, the total cost of labor and material being $6.23. Allowing
$1 for gasoline and wear and tear on the machine, there was a total
expenditure of $7.23. Deducting this amount, together with $15.30
(the value of the crop from the untreated check plat), from $61.05 (the
value of the crop from the sprayed plat), there is a net gain of $38.52
on the 14 trees, or $2.75 per tree for the sprayed trees.

DEMONSTRATION SPRAYING IN OHIO IN 1907.

By A. A. GrRavtr.

An orchard belonging to Mr. A. P. Roudebush, a prominent farmer
and fruit grower of Owensville, Clermont County, Ohio, and one of the
largest in that vicinity, was selected for this spraying demonstration
against the codling moth. This orchard consisted of about 400 trees
of such well-known varieties as Ben Davis, Rome Beauty, Grimes
Golden, etc. The orchard was in sod; the trees were vigorous, from
about 25 to 30 feet tall, and well shaped, but needed thinning. Dur-
ing the past two or three years they had been treated with not more
than two applications of Bordeaux mixture and arsenate of lead. The
codling moth was a well-established pest in this orchard, and the
owner was discouraged over the difficulties which he had encountered
in combating it.

The plat selected for this work consisted of a single row of 27 Ben
Davis trees, 10 years of age, in the southwestern portion of the
orchard, and adjoining an orchard of young trees; in the center of
the next row to the northeast 10 trees of similar variety and age were
left untreated for purposes of comparison. Four applications of
Bordeaux mixture and an arsenical were made, using 5 pounds of
lime, 5 pounds of bluestone, 2 pounds of arsenate of lead, and 50 gal-
lons of water. Spraying was done on the following dates: May 10,

76 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

June 14, July 25-26, and August 15. The table below shows the

results, as determined from 5 sprayed and 5 unsprayed trees in each _

plat:

TaBLe V.—Comparison of sound and wormy fruit from 5 sprayed and 5 unsprayed trees,
Ben Davis variety, Roudebush Orchard, Owensville, Ohio, 1907.

Windfalls. Fruit from tree.

— + »-:

| ° a ai

: ame ° o =

Date of spraying and | Total BS i Bb SS g ee B iS oe
number of trees. crop. S GE = E SE a a ae S S

< Zo S 2 AS S s si) ele S a a

om pnts la ice = ea ees = as BH |e

Sprayed May 10, June
145) Diuly, 925; and
August 15: Trees 1 | Bushels.| No. | No. | No. No. No. No. No. No. ;
to 5 combined...... 9.8 78 | 1,997 | 2,075 121 | 1,571 | 1,692 199 | 3,568 | 3,767 | 94.72
Unsprayed: Checks A | |
to E combined..... 3.25 | 1,992 | 2,218 | 4,210 651 68 719 | 2,643 | 2,286 | 4,929 | 46.38

The tabulated results show that the four applications gave about
94 per cent fruit free from codling moth injury and trebled the yield
in bushels, while the total marketable crop in bushels was more than
twice doubled. In the checks the percentage of wormy fruit in the
total yield was 46.38 per cent, whereas in the sprayed trees it was
but 5.28 per cent. The contrast between the treated and untreated
trees at harvest time was marked, even to the casual eye, because the
latter had been partly defoliated by various leaf-feeding insects,
and the attack of the codling moth and plum curculio had been dis-
astrous to the fruit yet remaining; whereas the foliage and fruit of
treated trees were in almost perfect condition. The four treatments
also prevented over 50 per cent of the injury of the plum curculio,
which is a more serious enemy of apples in this vicinity than is the
codling moth.

The four applications required 450 gallons of the mixture at a cost
of $0.016 per gallon, a total cost of $7.20 for the Bordeaux mixture
and poison. Adding the cost of labor for 2 men at $1.50 per day and a
team at $2 per day for one and one-half days, which 1s $7.50, the cost of
the whole operation was $14.70, or at the rate of $0.54 per tree. Placing
the price of apples per bushel at $1, the net returns from a single
unsprayed tree would be about 36 cents, whereas the net returns from
a single sprayed tree would be $1.31, a net gain of about 95 cents
per tree. As will be seen from the table, the crop in this orchard was
quite light. With a normal crop the percentage of benefit would
have been much larger.

U. 8S. D. A., B. E. Bul. 68, Part VITI. D. F. I. 1., January 20, 1909.

PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

THE GRAPE-LEAF SKELETONIZER.

(Harrisina americana Guérin-Méneville.)

3y P. R. JONEs,

Engaged in Deciduous Fruit Insect Investigations.
INTRODUCTION.

For the last sixty years or more the species known as //arrisina
americana has been brought to the attention of entomologists and
vineyardists by the characteristic feeding of the yellowish, black-
spotted larve in soldierlike rows upon the foliage of the grape. As
this is the only Lepidopterous insect that feeds in a gregarious man-
ner upon grape foliage it will be easily recognized. Although it has
been known for a number of years, many points have been lacking
in the knowledge of its life history and habits, and it is hoped that
the following pages will present some facts that hitherto have not
been mentioned, as well as give a summary of what has been learned
about the insect up to the present time.

HISTORY.

There is considerable doubt as to where this insect was first figured
and described. In G. Henderson’s edition of the Animal Kingdom
it is figured by Baron Cuvier (1837) under the name Agloape ameri-
cana Boisduval, but no description is given. <A description and
figure are published by Guérin-Méneville, the insect being listed as
Agloape americana Boisduval. The dates of issue in the latter case
(1829-1838) are evidently erroneous, as there are in the volume fre-
quent references to articles published in 1840, 1841, and some as late
as 1843; the volume was, therefore, probably not issued before 1844
or 1845. Harris, in 1839, described the species as Procris americana
and figured its various stages. This appears to be the first published

7

sa

78 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

description, as Harris says in a note after the description: “ This
insect appears to be the same as the one figured in Guerin’s Icono-
graphie and Griffith’s Cuvier, under the name of Agloape americana
Boisduval, but it is not an Agloape, for it has a distinct spirally-
rolled tongue.” He makes no mention of a description and appar-
ently had not seen any. The specific name should be attributed to
Guérin-Méneville, as he is the author of the book in which the figure
first appeared, and because he does not at any place give specific
credit to Boisduval, who undoubtedly described it.

The first economic account of the insect appears in Hovey’s Maga-
zine of Horticulture for June, 1844, where Harris, under the name
Procris americana, gives a full account of its relation to European
species, its natural food plants, life history, and habits. He mentions
it as first brought to his notice in 1830 by Professor Hentz, who found
larvee upon a vine at Chapel Hill, in North Carolina.

In 1855 Townend Glover reports it as injurious in the vicinity of
Washington, D. C., and gives a short general account.

Harris, in 1862, gives an account of it which is practically the same
as the one which appears in Hovey’s Magazine, but shorter.

Walsh (1866) next determines the insect and gives a short account
of it, in answer to a letter.

In 1867 C. V. Riley gives a brief account, with notes on its hfe
history and habits. Bethune then (1867) published a short general
account of it.

In 1869 Walsh and Riley determined some insects to be Procris
americana Boisduval. Riley (1870) gives the most detailed account
published up to the present date and treats of its identity, food plants,
life history and habits, natural enemies, and remedies. During the
same year he again writes concerning it, but the account is taken from
the previous one.

Lintner (1879) gives a short general account and again (1883)
mentions it in answer to a letter. The next account of it is a short
account by Atkinson, in 1888.

Neal, in 1890, presents most of the knowledge up to the present date
and records some original observations as to the number of broods
and varieties of grapes preferred. :

Toumey (1893) records it from two localities in Arizona and gives
a short review of its manner of working.

J. B. Smith (1895) next writes concerning it and gives a detailed
account of its life history and habits, with some new points on local
distribution. During the same year (1895) Slingerland reviews the
chief points in its life history in answer to a letter.

Starnes (1898) gives a general account of it and mentions the fact
of its being more prevalent in the West and South than in the East.

Cet he he

ee ee

THE GRAPE-LEAF SKELETONIZER. 79

The latest economic reference is that of J. B. Smith (1903), who
figures it as one of the insects sometimes troubling grapes.

ORIGIN AND DISTRIBUTION.

The grape-leaf skeletonizer is probably a native species, from the
fact that it feeds upon Virginia creeper and wild grapes in addition
to the domestic varieties of grape. Harris mentions it as related to
Procris ampelophaga, of Europe, which is injurious to the vineyards
of Piedmont and Tuscany, and Riley states that it is related to the
European Procris vitis.

In literature it has been recorded from the following States and
Provinces: Canada (Bethune); New England (Walsh); New York
(Slingerland) ; New Jersey (Smith); Washington, D. C. (Glover) ;
North Carolina (Walsh) ; Georgia (Starnes) ; Florida (Neal) ; Ohio
(Lintner) ; Missouri (Riley); and Arizona (Toumey).

In the files of the Bureau of Entomology there are records as fol-
lows: Orange, N. J.; Dalton, Philadelphia, and Williamsport, Pa.;
Berwyn, Cambridge, Sharptown, and Sullivan, Md.; Washington,
D. C.; Afton, Va.; French Creek and Lewisburg, W .Va.; Raleigh,
N. C.; Columbia and Timmonsville, 8. C.; Poulan, Ga.; Jackson-
ville, Oakland, Stephensville, and Umatilla, Fla.; Auburn, Ala.;
Masengale and Poplarville, Miss.; Mandeville and New Orleans, La.,
and Hermosillo, Mexico.

FOOD PLANTS AND DESTRUCTIVENESS.

Harris states that this species feeds very readily upon Ampelopsis
quinquefolia; Riley writes that its natural food is Virginia creeper
and wild grapes: while both record it as being fond of cultivated
grapes. Toumey states that it was found upon Vitis arizonica, and
Neal records it as living naturally upon wild grapes and Virginia
creeper but that it prefers cultivated grapes, especially if exotic or
choice. Riley mentions that a Mr. Jordan, of St. Louis, Mo.; states
that it attacks Concords but never the Clinton or Taylor varieties in
his vineyards. During the past summer the writer noticed that it was
especially fond of certain hothouse varieties in an abandoned green-
house upon the Department grounds.

CHARACTER OF INJURY.

The young larve during the first three or four instars feed only
on the outer epidermal layer of the leaf, completely skeletonizing it.
(See fig. 12.) This is done on both the upper and lower surfaces;
according to the writer’s observation there is preference for the up-

DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

80

sts record the lower surface as

Later the. larve, which until now have fed in a

1

oO
>

per surface, but several entomolo

g preferred.

¥

bein

as

ae

ANN \
AAS NYY

s

Ls

4

=,

—
——

—>==

==

~=

Ss

=S

—s

S
=S

—

——
—S

Young larye feeding on

ape-leaf skeletonizer (Harrisina americana) :
af.

er

.—The

12

io)
=
&

(Original. )

le

iduals or into small groups

ssue of the leaf except the larger veins.

‘ate into single indiv

al

le by side, sep
and eat the whole ti

TOW SIC

DESCRIPTION.

EGG.

lor,

in co
eylindrical-oval or capsule shaped, with an irregular hexagonal sculp-

x

dilute lemon-vellow

The egg (fig. 13) is small, shining,

From a number of eggs measured the maximum length is

0.600 mm. and the minimum 0.533 mm.; the ma

turing.

0.383

1s

dth

xX1mMuUumM W1

THE GRAPE-LEAF SKELETONIZER. 81

mm. and the minimum 0.316 mm. The average size of the egg is
0.566 mm. by 0.349 mm.

The eggs are deposited on the underside of the leaves in clusters,
and from 12 clusters counted, '
the minimum contained 7 eggs,
the maximum 260, the average
cluster containing 107.9 eggs.
Observations on 1,035 eggs
gave the average length for
the egg stage as 7.92 days,
with a maximum of 9 days
and a minimum of 7 days, the
average mean temperature for
the period of incubation of the
various eggs being 77.5° F.,
with cloudy weather prevail-

ANY NAN}
X\\ in a
aw

A Fie, 13.—The grape-leaf skeletonizer (Harri-
Ing. The eggs under observa- sina americana) : a, Egg, greatly enlarged ;

b, cluster of eggs in natural position on

tion were from the second Rs
leaf. (Original. )

generation of moths, and the
length of the stage would probably be somewhat greater for the first
generation on account of lower temperature.

LARVA.

First instar.—Body yellowish-white, translucent. Head similar in
color to body, retractile, broader than body, which gradually tapers.
Segments 2-13 with a transverse median row of spinelike bristles,
about 0.2 mm. in length, extending to venter on each side; whitish
when viewed under a 34-inch objective, but the dark-colored joints
cause them to appear blackish under a small magnification. Thoracic
feet small, pointed, color similar to body; abdominal feet small,
visible only as small wartlike protuberances. Length, 1-1.25 mm.;
width of head, 0.18-0.25 mm. (variable).

Second instar.—Body dilute-yellow, head retractile, darker, eyes
and mandibles dark brown. Tubercular areas now distinct under a
%-inch objective as a transverse row of wartlike clusters of whitish,
segmented bristles about 0.2 mm. in length, with apex, joints, and
bulb at base of the bristles black. All the segments laterally, and
dorsum of the anterior and posterior segments with long, whitish.
segmented hairs about 0.75 mm. in length. Thoracic feet small,
pointed, dilute-brownish; abdominal feet, more distinct now, appear-
ing as small stumplike projections. Length, 1.666-2 mm.; width of
head, 0.283-0.333 mm.

Third instar.—Body orange-yellow, head retractile, dilute-brown,
eyes and mandibles brownish-black. Segments 2-13 show wartlike

82 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

tubercles, with bristles similar to those in the preceding instar,
0.2-0.25 mm. in length, with the black on the apices, joints, and bulbs
at the base more pronounced, causing the tubercles to appear black to
the naked eye. ‘All the segments laterally, and dorsum of the an-
terior and posterior segments with long, segmented, whitish hairs
variable in length. Thoracic feet small, pointed, dilute-brown,
darker at the tip; abdominal feet larger, apex with a circlet of black
bristles, all the feet similar in color to the rest of the body. Length,
3.54.5 mm.; width of head, 0.666 mm. (nearly constant).

Fourth instar.—Body sulphur-yellow, head retractile, dilute-brown,
darker on exposed portion, mandibles and eyes brownish-black.
Head when viewed from above oval-
pyramidal in form. Tubercular areas
very prominent now to naked eye,
appearing as black, bristly, wartlike
patches, this appearance due to the
black tips of the whitish, jointed bris-
tles; joints and bulbs at base of bristles
blackish. Tubercular areas on dorsum
of segments 7, 8, 9, and more especially
7 and 9, fainter to naked eye than on
other segments, as the bristles are not
so heavily tipped with black nor are
the joints black. Dorsum of anterior
and posterior segments and all segments
laterally with long, whitish, segmented
hairs of variable length. Thoracic and

abdominal feet yellowish, longer, but
Fic. 14.—The grape-leaf skeleton- - é :

iner. (Herrisina americana): marked the same asan the thicd simaeare

Full-grown larva, at left; a, lat- Length, 7-8 mm.; width of head, 1.05—

su gn liens hee Se ote eOG mma (nearly constant).

of posterior segments. En- Fifth instar.—Body deep sulphur-

aie has ace yellow, head retractile, dilute-brown,
darker on exposed portion, mandibles and eyes brownish-black.
Shape of head similar to that in the fourth instar. Tubercular
areas now very prominent to naked eye and appearing as black,
bristly, wartlike patches. Bristles under 3-inch objective same as in
the fourth instar, but more distinct and longer (0.20-0.33) mm. in
length). Tubercular areas distinct on all segments, and to naked eye
with a shght opaque-bluish cast. Dorsum of anterior and posterior
segments, and all segments laterally, with long, segmented, whitish
hairs, longer than in fourth instar. Thoracic feet yellow, tipped with
black; abdominal feet yellow, with a terminal circle of black bristles.
Length, 8-10 mm.; width of head, 1.15-1.45 mm. (variable).

f
»

THE GRAPE-LEAF SKELETONIZER. 83

Sixth instar (full-grown larva) (fig. 14).—Cylindrical and uniform
in shape, color deep sulphur-yellow. Head oval-pyramidal in form,
dark brown, lighter above, retractile, concealed beneath first pro-
thoracic segment. Mandibles and maxille dark brown, maxillary
palpi yellow, translucent, eyes black. Tubercles flat, wartlike areas,

appearing to naked eye as a transverse, me- Wy,
dian row of black dots. Under a 4-inch |M Wl

objective, tubercles wartlike, covered with
short, thick, segmented, white bristles tipped
with black, joints and bulb at base of bris-
tles dark colored (length, 0.20-0.33 mm.).
Tubercles arranged: I, subdorsal; II and
III, lateral; III, just above spiracle; IV,
substigmatal; V, above base of leg. Sub-
dorsal tubercles confluent on segment 2.
Segments 5-14 with tubercle III wanting,
segments 7-14 with tubercle V wanting,
subdorsal and lateral tubercles confluent on
segment 13, subdorsal tubercle confluent on Y
segment 14, the rest wanting. Anterior and 16. 15." The ee
posterior segments dorsally and all segments — cana): Cocoon. Enlarged.
laterally with a number of long, whitish, ‘0'"®”

segmented hairs, variable in length. Spiracles round, light brown,
present on first prothoracic and on all abdominal segments except
anal, the one on segment 13 smaller than the rest. Thoracic feet
translucent, yellow, small, pointed, with a single black claw at tip
and also a few hght-colored hairs on sides. Abdominal
feet pale yellow, apex with a row of small, black, bristle-
hike claws. Length, 11-13.5 mm.; width of head, 1.483-
1.666 mm. (variable).

COCOON.

Cocoon (fig. 15) flat, oblong-oval in shape, composed of
a tough, white, cottony, parchmentlike material, opaque
when dry, but showing pupa underneath when wet.

Fie. 16.—The Length, 10-12 mm.; width, 5 mm.
grape-leaf
sk eletonizer
(Harrisina
americana): : , fe ee : : a :
Pupa. En upa (fig. 16) uniformly orange-colored in fresh speci-
larged. (Orig- mens, brown in older ones; oblong-oval, broadest at
inal. . ‘ ~ :

; abdominal segments 3, 4, and 5. Eyes and _ spiracles
darker than rest of body. Spiracles raised wartlike projections, sub-
conical in shape, eight pairs, the eighth pair the longest. Spiracles
arranged on latero-dorsal aspect of abdominal segments 2-9. Ante-

PUPA.

84 DECIDUQUS FRUIT INSECTS AND INSECTICIDES.

rior third of dorsum of abdominal segments 3-8 covered with very
short, decumbent black bristles, the row not extending quite as far
as the spiracles on either side. Cremaster wanting, replaced by six
very short black bristles which are nearly obsolete in some specimens
and appear as black dots. Bristles arranged on the submedio-dorsal
aspect of the anal segment as two median pairs and one lateral
bristle on the outside of the median pairs. Wing sheaths, and leg
sheaths of first pair of legs, subequal, antennal sheaths longer, all
extending to about fifth abdominal segment, those of third pair of
legs projecting slightly beyond. Length, 6—9 mm. }

Observations upon a number of pup during the month of July,
1908, in Washington, D. C., show the minimum length of this stage
to be 9 days, the maximum 12 days, while the average length for the
period is 10.9 days. The average number of days spent in the cocoon
is 14.8. The average mean
temperature for the month
of July, or the time the
pup under observation
were in the cocoons, was
hose ale

ADULT.
(Pigst7.)

Uniformly — blue-black,
except a yellow collar
which extends nearly to
ventral side. Wings, legs,
and eyes similar in color
to rest of body. Antenne

Fie: 17.—The grape-leaf skeletonizer (Harrisina pectinate, more so in male
americana): Male moth; a, antenna of male at than In female, and plu-
left, of female at right; b, venation of front and kT. eer hoa
hind wings. Enlarged; a, much enlarged. (Orig- M10S€ 1 Male, engt 1 about
inal.) five-sixteenths of an inch

in male, four-sixteenths of an inch in female. Abdomen longer, more
slender in male than in female and curved upward. Abdomen with

a fan-shaped, somewhat bilobed caudal tuft.

Length of moth, S11 mm.; length of wing, 11 mm.
Expanse of wing, 22-24 mm.
The following is the original description by Harris:

Blue-black, with a saffron colored collar and a fan-shaped, somewhat ‘bilobed,
black caudal tuft. Expands from 10 lines to 1 inch,

THE GRAPE-LEAF SKELETONIZER. 85

SEASONAL HISTORY.
NUMBER OF GENERATIONS.

Former writers have generally attributed two generations and
a partial third to this insect; in fact, all, with the exception of Neal.
who states that there are three broods in Florida, are of the opinion
that there are two broods. Extended observations and studies dur-
ing the past summer reveal the fact that there are not two full gen-
erations in the vicinity of Washington, D. C. Seasonal history
studies show that moths from the over-wintering pup appear dur-
ing the latter part of May or chiefly during the first ten days of June.
Eggs from these moths were found June 11, 1908, and also a few very
young larve. By June 30 some larve were almost fully grown, but
the majority of full-grown larve did not appear until about July 14,
although a number of pupez from the early-developing larve were
found on July 7, showing a long period from the appearance of the
first full-grown larve to the appearance of those which attained their
growth at the latest date.

The second generation of moths, or those from first-generation
larvee, appeared continuously from July 18 to August 15, giving a
very extended period of emergence and accounting for the tendency of
former writers to attribute the late-appearing ones to a third genera-
tion.

The largest number of moths appeared from July 20 to 25. A
number of those larve which had attained their growth by July 14
hibernated as pupe and did not emerge as moths, thus showing clearly
that there was not a full second generation.

Eggs from the second-generation moths were most numerous from
July 20 to 23, with many second-generation larve appearing on July
27. Some of the second-generation larve were full-grown on August
24 and were spinning cocoons on that date and up to September 16,
when all had gone into cocoons.

LIFE CYCLE.

The average length of the life cycle was found by adding together
the average lengths of egg stage, larval period, time spent in cocoon,
and life of moth. The average length of the egg stage was 7.92 days,
the average length of the larval period 40.5 days, the average time
spent in cocoon 14.8 days, and the average length of life of a moth
3.5 days; thus, the average length of the complete life cycle was found
to be 66.72 days. The minimum life cycle, found by taking the mini-
mums of the various periods and adding them together, was 53 days.

All of these averages were taken from a very large series under
observation. While the above figures should not be taken and used
to find how many generations there are in any given locality, they
will give some clue to the time required for the development of a

|

86 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

generation. Temperature conditions undoubtedly influence greatly
the lengths of the various life periods.

HABITS.

Late in May or in the early part of June the over-wintering pupa
makes a narrow slit in one end of the cocoon and exposes a small
part of the anterior portion. The pupa case then splits and the
moth emerges, the operation requiring from about 15 to 20 minutes.
Sometimes the wings become their normal size in a short time, but
in other cases 24 hours elapsed before the moth was perfect. The
moths mate on the next day, or second day following. One pair un-
der observation, having emerged on July 22, in the night, mated early
July 23, and was observed in copulation from 7.30 until 11.30, a
period of 4 hours. This was probably near the normal period, as the
pair had not been out of the cocoon long. Oviposition usually fol-
lows soon after. In the pair mentioned above, one cluster of 69
eggs was deposited during the night of July 23. During oviposition,
which took place early in the morning, or more often in the late after-
noon or evening, the moth was observed to be on the underside of a
leaf with the wings at right angles to the body. The abdomen was
slightly bent, and the moth seemed to be depositing the eggs in rows.
The period required for the oviposition of a cluster is several hours,
depending upon the size of the cluster deposited. The flight of the
moths appeared to be feeble, and they were sluggish, especially on
cloudy days, the period of greatest activity being on clear days at
midday. The length of life of the moth is from 2 to 5 days without
food, although in the case of one pair under observation the male
lived from 3 to 34 days and the female from 6 to 64 days.

The eggs are deposited on the underside of the leaf. Upon
hatching, the larve start feeding from a common center, moving
backward, and in a short time are side by side in a soldierlike forma-
tion, the feeding line usually being a curve. Although the larvee
may feed for a short time upon the lower surface, they are more fre-
quently found upon the upper, as this is better adapted to their style of
feeding—namely, skeletonizing or removing the outer epidermal layer
of the leaf. This manner of feeding is usually followed until the
larvee reach the fifth instar, when some begin to eat holes through
the leaf. From now on the larve gradually cease skeletonizing the
leaf and eat the whole tissue, leaving only the larger veins.

Preparatory to molting, the larve crawl to the underside of the
leaf and molt in a group, with their heads in the center. After molt-
ing they feed, moving backward, and gradually form a curved line.
This was observed a number of times, although the larvee had been
feeding before in different groups on the upper surface of different
Jeaves,

THE GRAPE-LEAF SKELETONIZER. $7

When the larve are full grown they seek some secluded place in
which to pupate, usually spinning their cocoons on fallen leaves or
in trash around the vine, or, when confined, to the sides of the cage.
The period covered by one group of larve in spinning their cocoons
will vary from 1 to 2 weeks, although the time required for the for-
mation of each individual is not more than 2 or 3 days.

The winter is passed in the cocoon, the insect being in the pupal
stage.

IDENTITY.

The shght variation in appearance of the moths and the differently
marked larve bring up the question of identity. Dyar“ thinks there
is little difference between the moths of Harrisina americana and
those of H. texana which Stretch separated by the presence of an-
other vein, because moths of both kinds were taken together in the
same locality. He found, however, two kinds of larvee, those of /7/.
texana having the dorsum of joints 2-13 broadly bright-yellow, and
banded between each joint with blackish and again across the middle
of each, including the warts, with purple-brown. The larve of Har-
risina australis were similar to those of 7. tevana. He further says,
“Tf it were not for the two kinds of larvee, I would not hold these
three forms separate.” Credit is due to Dr. H. G. Dyar, of this
Bureau, for examining all of the material in the Bureau collection
and for determining it all as belonging to one species, Harrisiia
americana Guer.

NATURAL ENEMIES.

Up to the present time only one parasite had been recorded from
this insect, namely, the chalcidid Perilampus platygaster Say, which
Riley mentions as being a parasite of the larva. This summer, how-
ever, the writer reared a little hymenopterous parasite which was de-
termined by Mr. J. C. Crawford, of the U. S. National Museum, as a
braconid, Glyptapanteles sp., and also an ichneumon, Limneria sp.,
which was reared from larve sent in by C. M. Streeter, Dalton, Pa.

REMEDIES.

While the insect has never proved a serious pest in large vineyards,
and is usually more troublesome in gardens or back yards where there
are only a few vines, it has been found sufliciently numerous at
times to demand attention and remedial measures.

The gregarious feeding habit of the larve makes hand-picking in
small areas the most efficient treatment, as one person can go over a
large number of vines in a short time and destroy a very large num-
ber of the larva, since they will be found in large groups upon the

“Proceedings of the Entomological Society of Washington, Vol, V, p. 826,

|

88 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

leaves. This should be done as soon as the larvee are noticed upon the
foliage, as all from each cluster of eggs will then be in a single group,
whereas, if the treatment be deferred until the larvee have separated
into individuals or small groups, as mentioned before in this paper,
much more labor will be involved.

An arsenical treatment, applied as soon as the larvee are in evidence,
would prove effective. Two applications are necessary, one for each
generation of the larve. The time of application will vary greatly,
being early in the South and becoming later in northern States, ac-
cording to the time the larve appear upon the grapes, which is the
best standard for determining when the treatment should be applied.

The arsenical used may be either arsenate of lead, Paris green, or
arsenite of lime. Arsenate of lead is preferred on account of its bet-
ter sticking qualities, and also because it is less likely to injure the
foliage. Three pounds of any good brand of the latter added to the
ordinary Bordeaux mixture (5-5-50 formula) will make a very effi-
cient remedy.

Since the larve spin their cocoons in the leaves and trash at the
bottom of the vines, clean culture is to be recommended. Where
clean culture is followed, and where spraying is practiced for the
erape-berry moth, grape root-worm, and grape curculio, this insect
need never be feared.

BIBLIOGRAPHY.

The following bibliography contains practically all of the liter-
ature on LHarrisina americana. All of the articles have been seen
and verified, except where mention to the contrary is made.

1832, GrirFItTH.—Agloape americana Boisd.<Cuv. Reg. Lep., p. 84 bis., fig. 11.
Figured but not described.
18338. Hargis, T. W.—Procris dispar.<Cat. Ins. Mass. (Not seen.)
1836.. BorspuvAL, J. A.—Procris americana. <Sp. Gen. Lep., I, p. 16, fig. 7.
Figured but not described.
1837. HenpEerson, G.—Agloape americana.<Cuv. Reg. An., Vol. IV, Pl. 1, fig.
ni
Figured but not described.
1839. Harris, T. W.—Procris americana. Cat. N. A. Sphinges. <Silliman’s
Journ. Sci., vol. 36, p. 282.
Figured and described for first time.
1844. GuiétRIN-MENEVILLE, F. E.—Agloape americana Boisd.<Icon. Cuv. Reg.
An., Vol. III, p. 501, 1829-1888 (1844).
Figured and described.
1844, Harris, T. W.—Procris americana Boisd.<Hovey’s Mag. Hort., June,
1844, Vol. X, pp. 201—205.
First economic reference and general account of life history and habits.
1854. WALKER, Francis.—Ctenucha (Agloape) americana Boisd. <Cat. Lep.
Brits. Musso. Ui apse286:
Description.
1855. GLover, TowNnEeND.—Procris americand.<Agric. Rep. U. S. Com, Pat-
ents (1855), pp. 59-88,
General account,

THE GRAPE-LEAF SKELETONIZER. 89

1856. Fircu, Asa.—Procris americana.<3d Rept. Ins. New York, p. 398.
General account.
1860. CLEMENS, BRACKENRIDGE.—Agloape americana.<Proc. Acad. Nat. Sci.
Phila., vol. 12, p. 539.
1862. Harris, T. W.—Procris americana.<JInj. Ins. Veg., 2d ed., p. 336, fig.
163.
General account.
1862. Morris, J. G.—Procris americana.<Syn. Lep. N. Am., p. 134. (Not
seen. )
1862. CLEMENS, BRACKENRIDGE.—A gloape americana.<Syn. Lep. N. Am., App.,
; p. 284.
1864. PackarD, A. S.—Harrisina americana.<Proc. Essex Inst., p. 31.
Describes genus and H. sandborni, n. sp. Mentions H. americana.
1866. WaLsH, B. D.—Procris americana.<Am. Ent., Vol. II, p. 10.
Short account in answer to letter.
1867. Ritey, C. V.—American Procris.<Trans. Il. Hort. Soc., Vol. I, pp.
105-107.
Short general account with some notes upon life history.
1867. BrTHUNE, C. J. S.—Procris americana Boisd. <Can. Farm., November
27. Vor EV, p. 351.
Short general account, mostly quoted from Fitch. =
1868. Grorr, A. R. and Ropinson, C. T.—Acoloithus americana.<Cat. Lep.
N. A. (Not seen. )
1868. KirRKPATRICK, J.—Grape insects.<Ohio Farmer s—b No. 3, pp. 5-6.
(Not seen. )
1869. WatsH, B. D., and RiLey, C. V.—Procris americana.<Am. Ent. and
Bot, Vol--EL-p. 27.
Determine some insects to be above species.
1870. Ritey, C. V.—Procris (Acoloithus) americana.<2d Mo. Rep., p. 85.
Most detailed account of life history, habits, etc., found in literature.
1872-8. StretcH, R. H.—Harrisina americana Boisd.<Illus. Zyg. and
Bombyec. N. A., p. 180.
Account of genus and figures. Describes H. terana.
1879. LINTNER, J. A.—Procris americana Boisd.<Cult. and Co. Gent., Vol.
Saar, pe 11.
Short general account.
1883. LINTNER, J. A.—Procris americana Boisd. <Cult. and Co. Gent., Vol.
XLVIII, p. 621.
Short general account. with reference to number of broeds and distribution.
1888. ATKINSON, G. F.—Procris americana. <1ist Ann. Rept. S. C. Agr. Exp.
Sta., pp. 19-56.
Short general account.
1890. Neat, J. C.—Procris (Harrisonia acoloithus) Americana. Bul. 9, Fla.
Agr. Exp. Sta., p. 11.
Very good account, with reference to food plants, habits, and distribution.
1893. ToumMrey, J. W.—Procris americana Harris.<Bul. 9, Ariz. Agr. Exp.
Sta., p. 28.
Short account, with reference to distribution and habits.
1895. Smiru, J. B—Harrisina americana Boisd.<Ann. Rep. N. J. Agr. Exp.
Sta., pp. 365-506.
Very good account, with original observations as to habits and distribution.
1895. SLINGERLAND, M. V.—Procris americana.< Rural New Yorker, p. 521.
Short general account in answer to query.
1898, Srarnes, H. N.—American Procris,<( Ann. Rep. Dept. Agric. Ga., Vol.
XXIV, pp. 3877-498.
Short general account.

10090—-Bull, 68 —09——7T

ql

90 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

1902. Dyar, H. G.—Harrisina americana Guérin-Méneville.<List N. A. Lep.,
p. 360. . ee,
Synonym, tezana. Distribution, Atlantic States. Var. australis Stretch.
1903. Dyar, H. G.—Harrisina americana Harris. Review of the North
American species of the Lepidopterous Family Anthrocerid.< Proce.
Ent. Soc. Wash., Vol. V., pp. 322-3381.

Reviews genus and describes larva. Doubtfully reestablishes H. texana. H.
australis is probably a variety of H. texana.

1903. SmitH, J. B.—Grape Procris.<Rep. Ent. Dept. N. J. Coll. Exp. Sta.,
pp. 555-659. )
Mentions and figures as a grape insect.
1903. HoLttanp, W. J.—Harrisina americana Guérin-Méneville.< Moth Book,
Di-S(2:
Figures and gives a short account taken from Riley’s Second Report on the
Insects of Missouri.

)

i SD ALB. hy Bal. 68; Part IX. D. F. I. I., February 11, 1909.

PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

THE PEACH-TREE BARKBEETLE.

(Phleotribus liminaris Harr.)

By H. F. WILson,

Engaged in Deciduous Fruit Insect Investigations.
INTRODUCTION.

By way of introduction it is perhaps necessary to give an account
of the present degree of importance, from an economic standpoint,
which this beetle has reached in northern Ohio. For the last four
or five years this insect has been doing a great amount of injury to
apparently healthy trees. The history of Scolytide in general shows
that certain species may be present in orchards for years without
doing any appreciable damage. Then, owing to favorable climatic
or other conditions, they may develop in large numbers and accom-
plish considerable injury. Such seems to be the history of Phl@o-
tribus liminaris.

The attention of Prof. H. A. Gossard, of the Ohio Agricultural
Experiment Station, was called to this insect by Mr. W. H. Wright,
in charge of a large farm at Lakeside, Ohio, Mr. Wright having
reported to him that large blocks of peach trees in the orchard were
dying from an unknown cause. Upon investigation Professor Gos-
sard found that this orchard was seriously infested with Ph/@otribus
liminaris.

At the instance of Professor Gossard, investigation of this species
was undertaken in the spring of 1908 by the Bureau of Entomology
in cooperation with the Ohio Agricultural Experiment Station, and
the writer, representing the Bureau, and working under the joint
direction of Professors Gossard and Quaintance, was assigned to
the work, with headquarters at Lakeside, Ohio. Through the courtesy
of Mr. Wright a suitable building and experimental orchards were se-
cured. All breeding cages were kept under out-of-door conditions,
and as far as possible outside conditions were watched in comparison
with those in the breeding cages. Data were secured on all stages of
development of the insect, and the results obtained are considered

fairly complete for a single season’s work.
; 91

92 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

In all, 43 experiments with remedial and preventive measures were
conducted during the summer, results of which are given herein.
Field observations in this locality seemed to show that apparently
healthy trees are attacked and, although the beetles probably do not
form egg burrows in these, the loss of sap from the burrows made by
the adults in the bark is sufficient to cause the trees to become very
much weakened.

HISTORY.

The first published notes on this insect were made by Miss M. H.
Morris, about 1849-50. At that time Miss Morris credited Zomicus
liminaris as being the cause of “peach yellows,” and so expressed her
belief in several articles published in different magazines of that time,
stating that the beetles were quite numerous about peach trees suffer-
ing from “ peach yellows.” These suggestions made by Miss Morris
probably led Harris to include the insect in his treatise on “The
Insects Injurious to Vegetation,” published in 1852, where he briefly
describes it under the name Zomicus liminaris, this later being
changed to Phlawotribus liminaris. The following extract gives his
description :

There is another small barkbeetle, the Tomicus liminaris of my catalogue,
which has been found in great numbers by Miss Morris under the bark of
peach trees affected with the disease called the ‘“‘yellows” and hence supposed
by her to be connected with this malady. I have found it under the bark of a
diseased elm, but bave nothing more to offer from my own observations con-
cerning its history, except that it completes its transformations in August and
September. It is of a dark-brown color, the thorax all punctured, and the
wing covers are marked with deeply punctured furrows and are beset with
short hairs. It does not average one-tenth of an inch in length.

The beetle spoken of above as working in elm bark was later found
by Mr. E. A. Schwarz, of this Bureau, to be Zylesinus opaculus Lec.,
he having examined the specimens used by Harris and named it the
elm barkbeetle.* (This specimen, in Mr. Harris’s collection, was
called Zomicus liminaris and catalogued as such, as is shown by
copies, taken by Doctor Hopkins, of the original notes.) ?

For many years this insect did not become sufficiently important
to demand special study, either of its life history or for the deter-
mination of remedial measures. Reference to this species has been
made at different times, as in the annual reports of the entomologist
of the Canadian experimental farms, and by entomologists in the

4 Attention is here called to Mr. Schwarz’s article on p. 149, Vol. I, No. 3,
Proceedings of the Entomological Society of Washington (1889), on Hylesinus
opaculus.

®The genus Phiwotribus is being revised by Doctor Hopkins, who will dis-

cuss the synonymy and other systematic features in a bulletin of the technical
series of this Bureau.

stomatgionte Smet Be.

aa A i Ne i Sai a Se al te Bide PAT ee

Bul. 68, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE X.

WORK OF THE PEACH-TREE BARKBEETLE (PHLCEOTRIBUS LIMINARIS).

Fig. 1.—Gum exuding through burrows made in bark of peach tree. Fig. 2.—Exit holes in
bark of peach tree. (Original.

as

oe Le

THE PEACH-TREE BARKBEETLE. 93

United States; and more recently experiments have been carried out
by the Ontario experiment station in the district of Niagara. In
looking over the past literature it is noticed that the injury done by
the beetle has increased materially with the increased planting of
peach and cherry, and the species has thus become one of economic
importance.

Until the present season (1908) few direct measures had been
taken to combat this barkbeetle, and very little, if anything, was
known concerning its life history. Not until recently has it become
very injurious to fruit trees, and these are limited to peach, cherry,
and wild cherry. The beetles will, however, work on plum trees
when confined to that food. So far but three localities have been re-
ported as being visited with injury to any great extent, these being in
the fruit district lying about Lakeside and Gypsum, Ohio; in the
vicinity of Cayuga Lake, New York, and in the Niagara district,
Ontario Province, Canada. The effects of the beetles’ work are very
serious in all trees attacked.

The peach-tree barkbeetle is a native of this country, and until
cultivated trees were introduced must have held to forest trees for
food and breeding places. The work of the beetle is similar to that
of the fruit-tree barkbeetle (Scolytus rugulosus Ratz.), and there
exists a marked similarity in the beetles themselves by which the
two species may be easily confused.

DISTRIBUTION.

Observations and reports show the distribution, in so far as known,
to be as follows: New York, Pennsylvania, Maryland, Virginia, West
Virginia, Ohio, and Michigan, and from the Niagara district, Onta-
rio Province, Canada. Field notes on this species, in the branch of
forest insect investigations, Bureau of Entomology, taken by Doctor
Hopkins and Mr. W. F. Fiske, indicate that the species is found
throughout almost all of West Virginia, and that it occurs in. North
Carolina and New Hampshire.

OCCURRENCE IN OHIO.

The date of the first appearance of this insect in Ohio is in ques-
tion, as it has undoubtedly been in the State for some time, although
it has not done any great amount of damage until recently. Some

of the orchardists stated that they had seen its work for eight or ten

years, but did not know the cause. An area of about 8 or 10 miles
square about Lakeside, Ohio, including the adjacent islands, is badly
infested. Outside of this locality the beetles occur east and west to

94 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

a slight degree; and as the beetles have been taken at Youngstown,
Ohio, and are reported from West Virginia and Michigan, it is very
probable that this species is at present more or less generally dis-
tributed throughout the State.

At Lakeside a lime manufacturing company bought up most of
the land comprising the peninsula for commercial purposes. On
this land are many remnants of orchards, which are uncultivated
and unecared for, and are attacked by scale and numerous other in-
sects. These trees are gradually being destroyed by the insects and
are seriously attacked by Phlewotribus liminaris. Pieces of bark 2
to 3 feet long and extending half way around the trunk will be com-
pletely cut from a tree 8 inches in diameter by the larve, The dead
trees in these orchards were uninfested when observed, but the bark
was full of exit holes and the trees were girdled. (See Pl. XI,
fig. 2.) Until these infested trees are all killed they will afford
ideal breeding places for the beetles while they attack the near-by
orchards in large numbers, either for food or in efforts to make egg
burrows. These abandoned orchards undoubtedly have much to
do with the large number of beetles present in this locality. Plate
XI, figure 1, shows a view of one of these orchards which was cut
back for the purpose of renovation. The result was that the trees
developed a strong growth and were almost free from attack at the
end of the season.

The reasons for the attack by beetles on apparently healthy trees,
while important to know, can not yet be explained. Several orchards
were observed where the beetles were attacking the trees in numbers
without forming egg burrows. These orchards had borne crops con-
tinuously each year, but appeared to be becoming gradually weaker
each season, and large quantities of sap oozed out and collected at
the base of the trees during the summer months. In one case in
which an orchard had been very badly injured, whitewashing the
trees was tried, and the present season (1908) the trees appear healthy
and thrifty with but few beetles present, these having worked into
the smaller branches above the whitewash.

EXTENT AND CHARACTER OF INJURY.

When the beetles are present in large numbers their injury to the
trees is quickly brought to the attention of the orchardist by the large
amount of sap exuding from the trees through the many small bor-
ings made both in the trunk and limbs of the tree. (See PI. X, fig. 1.)
In some instances from 1 to 3 or more gallons of sap will flow from
a single tree during a season. The writer observed one wild-cherry

Bul. 68, Bureau of Entomology, U. S. Dept. of Agriculture. PLATE XI.

WORK OF THE PEACH-TREE BARKBEETLE (PHLCEOTRIBUS LIMINARIS).

Fig. 1.—Orchard severely pruned April 19,1908. Photograph taken July 7,1908. Fig. 2.—Gum
exuding through burrows made in bark of cherry tree. Fig. 3—Removing stumps of trees
supposed to have been killed by the barkbeetle. (Original.)

THE PEACH-TREE BARKBEETLE. 95

tree about 14 inches in diameter and from 75 to 80 feet high which
had apparently been killed by the beetles, the bark having been
completely eaten away from the tree.

The adults or beetles (see fig. 20, a, b) produce the primary injury
to healthy trees, the work of the larve being secondary. The healthy
trees, by repeated attacks of the adults, are reduced to a condition
favorable to the formation of egg burrows. When the beetles are
ready to hibernate in the fall they fly to the healthy trees and form
their hibernation cells. These latter are injurious to the trees, for
through each cell there will be a tiny flow of sap during the following
season. (See Pl. XI, fig. 2.)

The greater the number of hibernation cells, the greater will be the
amount of sap exuded; also, when the beetles come out of their winter
quarters in the spring they bore into the bark of healthy trees from
one-quarter to one-half of an inch, either for food or in an endeavor
to form egg burrows. Later the beetles leave these burrows, either
because the burrows become filled with sap or because the beetles seek
the sickly trees for breeding purposes. Many more small channels
are thus formed in the bark and from these sap oozes during the
summer. Two means are therefore supplied by which the sap may
flow from the trees—and this it does in many cases, forming large
gummy masses around the trunks. Such losses for three or four years
in succession necessarily reduce the trees to a very much weakened
condition, and it then becomes possible for the beetles to form egg
burrows and for the larve to finish the destruction of the tree. Plate
XI, figure 3, shows the remains of an orchard presumably killed by
Phleotribus liminaris.

LIFE HISTORY.
HIBERNATION.

The insects spend the winter as adults in hibernation cells just be-
neath the outer layer of bark on both healthy and unhealthy trees.
In the fall, from October to freezing weather, the adults of the fall
generation are continually emerging and migrating to growing trees.
They bore in through rough places on the bark and burrow along
from one-quarter to five-eighths of an inch, forming hibernation cells,
the openings to which are closed with the exudation from the bur-
row. In these cells they remain throughout the winter. The latest
formed adults of the fall brood remain in the pupal cells until spring
before cutting out, so that hibernation occurs both on dead and living
trees, those on the live trees hibernating in regular hibernating cells
and those on dead trees hibernating in the pupal cells.

96 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

With the first warm weather in spring—as early as the last of March
in the latitude of Lakeside, Ohio—the beetles begin cutting their way
out from their hibernation cells. They do not immediately leave these,
but remain from four days to a week or more, most of them feeding
for a while and then migrating to trees,
wood piles, and brush heaps, or to any-
thing upon which they can feed and in
which make brood chambers.

ELE ADU

HABITS.

The beetles fly but little during the
morning hours, migrating from tree to
tree for the most part between the hours
of noon and night. During the day the
beetles move about on the trees, the
females seeking places in which to bur-
row and the males searching for burrows
already started in which the usuaily
accompanying male is lacking. After
nightfall flight and movement over the
tree cease.

The male beetles probably commence
feeding as soon as they cut their way
out of the pupal cell, and continue to
feed more or less as long as they live.
When in the brood chamber they ex-
crete a brown bead-like frass, the food
for this sex evidently being cut loose
and passed back by the female. The
female commences feeding as soon as
she has cut into the edge of the bark,
and feeds until she is too feeble to form
egg cells.

The burrows of Phlewotribus liminaris
can be very easily distinguished from

those of Scolytus rugulosus, both from
RXG. 18." Work of the peach tree ~ the: outside. and soheahe icide aclmnmas

barkbeetle (Phlaotribus limi- i

naris): Galleries in limb of bark. The opening of the burrow of

eaten November 20, 1908 the former as ery easily distinguished

from the fact that the exudation from
the burrow is held together by a fine, apparently silklike thread,

Hu

ih

which is secreted by both male and female. This holds the exudation

over and partly in the mouth of the burrow. After going into the
sapwood the female constructs a niche which later forms an arm

Gabe. eds! Lhe eee ie isis

)
|

_ ee ee ae ee ee eee ae ae ie ae 2 we ee SS

THE PEACH-TREE BARKBEETLE. 97

of the egg burrow. While an extension opposite this is being made
the males copulate with the females at this point. At other times
the males remain between the mouth of the burrow and this niche,
occasionally going deeper into the burrow. Copulation ordinarily
takes place at the fork in the burrow, and has been observed a number
of times to last as long as fifteen minutes after the cutting away of
the bark. The female rests with the posterior end of the abdomen
just at the edge of the fork, the male operating from the adjoining
niche. The sole function of the male seems to be that of attending
the female, as none has ever been observed working.

The forks of the burrow may or may not be nearly equal in length,
but usually they vary to quite an extent. They are, however, always
more or less horizontal, Hf
running around the axis
of the hmb. (See figs. 18
and 19.) After being fer-
tilized the female imme-
diately sets about deposit-
ing eggs, and at this time
the abdomen is very much
swollen. During the con-
struction of the burrow
copulation occurs several
times, so that the length
of the burrow appears to
depend upon the num-
ber of times of copulation. AAT |
As soon as the egg is de- Re ial

5 Fic. 19.—Work of the peach-tree barkbeetle (Phleo-
posited the female covers tribus liminaris) : Galleries in wood of peach tree,
it with frass, so that the May 18, 1908, Lakeside, Ohio. Enlarged. (Orig-
main burrow is a circular pet
tube of sawdust, outside of which occur the eggs. The method of
egg deposition is as follows:

Having made the egg cell, the female backs out to the niche where,
after turning around, she backs into the cell again, clinging to the
side of the burrow. The egg is then placed in the cell, and after
again turning around the female covers it with the sawdustlike frass.
The egg cells are filled as soon as they are finished, and each is made
as soon as the burrow has been extended far enough to make room
for it. |

From ten days to two weeks are necessary for the completion of
the burrows. The males and females in the same burrow live until
after most of the larve have developed into the next brood of beetles.
The completed burrows of this species are more nearly equal in length

98 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

than those of Scolytus rugulosus, the maximum length being about
25 inches, with an average of 2+‘; inches.

There are two complete broods each year—the summer brood and
the fall brood, the latter being the hibernating one, the beetles ap-
pearing in early spring. Beetles of the summer brood appear in
maximum numbers during the last half of August, as shown more
in detail in the following table:

TABLE I.—Hmergence of summer brood of beetles of Phleotribus liminaris.

Beetles Beetles

Beetles from in- Beetles from in-
Date. @ reared in | sectary on | Date. a reared in | sectary on

cages. window | cages. window

screens. screens.
Jy 16232 aes ees a 2 GORI PATS S25: Sok ae ena nnere AQHA Seine aiveaees
232 Re acca ae ee eee atta erate 30 263). Pace nha 60 1, 500
2D Beer eco senocta Meese scees 74 | Dots meat eecereeete eeee 86 1, 000
26-22 sheers aoe 83'scameeeeeee Bi) ee Sama ee Sale See 69 600
DI] pen ate eee Sree | erase ete ae 300 | DO Rte Ese ya henner 72 1, 000
DS sie Cone eee a em ae Neate serie este SED Sis fet iacet oaeeeece 154 200
2G a See, ae ee SiON pea Gc deetne fe Rene pie yA hee TN eg ee ia oe
Sil eee a Oe Bet an ed 82 450 DRE AME Sor sens ARE Ce 40 200
U No taieie: ae Aen Sree gp eee GS aie hore eres ern a etait ee ate ee 67 TD
Gee pee eet Se EN ll | ea TE 350 dO eae asa ates 18% |.) eee
Geos eee cess 84 500 les ersten 2 Ae eee oer Pato fil NRE eden 5.9
Qi See sed Be ctor Se IU OM USE r Seba e WB 235 Stet Me teehee 91 40
Ae EE fe Fee aa 258 450 | ae ac peice sere BY Beene ar &
DES Sah eos oan seaemeeee oe 1, 200 1 Rese ee ope tS 29) | wee ae
BUG Bete sh ee es ee | a cre 750 TS a ae ne i dD al eats eae
ee eh aia) co ae I we ee pare 750 DD Bis hae ee BP Aaa OA
See Ree ek oles 317 1750 DAN OM AL eile comet te DAN a es eres
USA Nts eae ee ieee ee 327 2,500 | 20 ree ee cei aie a Gi PSs ae
DE token See, Sam eco IAS )al ge See See OGG. Qe Reh eee sence A Oe ooo ee

@The first column shows beetles actually counted and taken from a breeding cage; the
second row of figures shows, somewhat estimated, numbers of beetles gathered on screens
at windows. All counts made between 4 and 6 p. m.

bYhis table shows August 21 to be the date of maximum emergence of beetles.

DESCRIPTION,

Average length, 2.25 mm., average width, 0.75 mm. Body elongate, subcylin-
drical, strongly punctured and with yellowish bristles arising from the punc-
tures; color varying from light brown to almost black. Head globular, nearly
vertical in front, anterior part fringed; eyes narrowly oblong, closely joined to
the scape and extending about half their length below it; mandibles short and
broad, distal part curved and strongly acute; mouth parts partly inclosed, gular
suture distinct; funiculus of antenne five-jointed; club compressed, composed
of 3 triangular segments; first joint longer than wide, globular; scape circular,
clavate. Thorax almost cylindrical, strongly angled at caudal end. First and
second coxze widely separated, globular; femur stout, outer edge serrated; tibia
stout, compressed, lower half of outer edge serrated and ending in an apical
tooth; tarsus stout, shorter than tibia, third joint bilobed, fourth indistinct,
fifth as long as first and second together ; tarsal claws simple. Ventral side of
abdomen and posterior edge of last segment strongly concave; elytra anteriorly
rounded and deeply margined, sides parallel, surface with regular striz which
contain circular, regularly placed depressions, elevated parts with yellowish
bristles arising from faint punctures.

THE PEACH-TREE BARKBEETLE. 9
THE EGG.

The eggs of the first generation may be found about the third week
in April, and, from that time on, the eggs of the first and second gen-
eration can not be separated, owing to the irregular emergence of
beetles and the irregular forming of egg burrows. Eggs can be found
in all stages of development up to the first week in October. The
egos of the second generation begin to appear about August 1.

Owing to the small series of eggs observed, the following data on
length of the egg stage are not given as conclusive: Eggs of the first
generation require from
17 to 20 days to hatch,
while the eggs of the
second generation hatch
in about 8 to 10 days.
The egg (fig. 20, ¢) is
milky white when first
deposited, being ellip-
tical in shape, opaque,
and measuring 0.06 mm.
in Jength by 0.0385 mm.
in diameter. The egg-
shell is fairly tough and
the eggs may be very
easily taken out of the
egg cells. When work-
ing without interruption
the female deposits from
2 to 10 eggs each day,
in addition to making
the cells.

The number ef eggs
in ees burrows of this Fic. 20.—The peach-tree barkbeetle (Phlawotribus limi-
species varies, since the naris) : a, b, Adult, dorsal and lateral views: c¢, egg ;
eggs are not always de- d, larva; e, pupa. Greatly enlarged. (Original.)
posited at equal intervals. Each brood chamber may contain between
80 and 160 eggs. In the vicinity of Lakeside, Ohio, eggs can be found
from April 20 until October 1. The egg burrow is not always made
next to the sapwood, as in a tree where the bark is very thick the
chambers are formed in the latter about one-fourth of an inch from
its outer edge.

THE LARVA.

When the embryonic larva has become fully developed it lies in
a curved position in the shell. After moving about a short time

100 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

it eats its way out at or just above the bottom of the egg and begins
to feed along the under surface of the bark. When first hatched
the larve are slightly longer than the egg but are less in diameter.
After emerging from the eggshell they are found lying in a slightly
curved position in the larval burrows. At first they are white but
soon assume a pinkish tinge due to the bark in the digestive tube.
The larye at first feed slowly and are several days getting away
from the eggshell but progress faster as they grow larger. As
they work out of the eggshell the sawdustlike excrement passed
through the body fills these and holds them in place as the larvee
work out. The excrement voided by the larve marks their path,
appearing like very fine sawdust.

The larve work away from the brood chambers at right angles,
following, for the most part, the grain of the wood. For from one-
half to three-fourths of an inch the larval burrows lie side by side,
but later they diverge, so that the exit holes (Pl. X, fig. 2) form an
irregular ellipse around the brood chamber. The larval burrows
measure from 14 to 2% inches in length. When about to pupate in
bark, which is about one-eighth of an inch or more in thickness, the
larvee work toward the outer edge of the bark and there form pupal
cells. In these cells the larve continue to develop from one to three
or more days before casting the skin and becoming pupe.

Some 25 to 30 days are required for the full development of the
larve. At the end of this time, having finished feeding, they void
the excrement before pupating and have then a white appearance.
Through the life of the larve the head is covered with a fine yellow-
ish pubescence, which is more abundant about the mouth parts than
elsewhere. (Full-grown larva, fig. 20, d.)

Description of full-grown larva.—Length, 2.15-2.75 mm.; width across thorax
(widest part of insect), about 1.16 mm. Head subelliptical, about 0.6 mm. wide,
yellowish, apex lighter; mandibles brownish, dark at tip. Body white, curved,
tapering from thorax to rounded caudal end, quite wrinkled; legless, but on
ventral surface of thoracic segments a small group of setze at points of position
of the adult’s legs. Head with a few sparse sete and a few on body. Body
covered all over with many minute, short, stout spines.

THE PUPA.

The pupe (fig. 20, e€) are quite active, moving the abdomen con-
tinually back and forth. From 4 to 10 days are spent in the pupal
stage, the pupa gradually assuming a dark color. When the pupal
skin is cast, the beetles are very tender; they require from 4 to 6 days
to completely harden and usually do not cut their way out from the
pupal cells until they have fed a little, after which they remain in
the pupal cells for from several days to two weeks longer.

THE PEACH-TREE BARKBEETLE. 101

Description of pupa about 3 days old.—Length, 2.5-2.66 mm.; width at widest
part, 1.08-1.11.mm. Body uniformly white, except along sides of abdomen,
which may show faint yellowish tinge. Eyes reddish brown: mouth parts
(interior) faintly brownish. Abdomen ending in two lateral, whitish, minutely
spinulose, brown-tipped horns.

PARASITES.

At the present date (December, 1908) no parasites of this species
are known. Where Scolytus rugulosus and Phlewotribus liminaris
bred in the same trees the usual parasites of S. rugulosus were found
in great abundance, with a corresponding decrease in the number of
adult S. rugulosus, while P. liminaris came out in numbers corre-
sponding to the larval chambers. Efforts were made to rear the para-
sites upon limbs full of P. liminaris, but without success. Many
minute mites—which, however, are not parasites—are found in and
about the burrows and clinging to the hairs about the legs of the
beetles and the ventral side of the thorax. They live on the excre-
ment of the beetles and decayed matter in the burrows, simply using
the adult beetles for the purpose of being carried from one place to

another.
EXPERIMENTS WITH REMEDIES.

A list of the general experiments and a summary of the results is
given below. Each experiment was made on a plat containing the
number of trees mentioned.

No. 1.—Used 16 trees. One part by weight of lime; 2 parts by weight of

‘cement; milk used to make a stiff whitewash and applied with a broom to 96

trees, 32 of which were used in experiment No. 2, with the addition of manure.
Thirty-two more were used for experiment No. 3, with an application of com-
mercial fertilizer. Sixteen trees of each plat were given a second application,
forming experiments Nos. 4, 5, and 6.

Date of application, April 9, 1908S.

No. 2.—Used 32 trees of experiment 1. Barnyard manure spread in a
7-foot circle about each tree, to get value of fertilizers.

Date of application, April 9, 1908.

No. 3.—Used 32 trees of experiment 1. Commercial fertilizer applied in a
7-foot circle about each tree.

Cement applied April 9, 1908; fertilizer applied May 7, 1908.

No. 4.—Used 16 trees of experiment 1, making a second application.

First application, April 9, 1908; second application, July 3, 1908.

No. 5.—Used 16 trees of experiment 2. making a second application.

First application, April 9, 1908; second application, July 7, 1908.

No. 6.—Used 16 trees of experiment 3, making a second application.

First application, cement, April 9, 1908; fertilizer, May 7, 1908. Second ap-
plication, July 3, 1908.

No. 7.—Used 2 pounds fish-oil soap per gallon of water (dissolving soap in
boiling water) for first application. Used 1 pound of soap to 6 gallons of water
for second treatment. Twenty-four trees treated, 16 to be used for experiments
8 and 9.

First application, April 10, 1908; second application, July 7, 1908.

102 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

No. 8.—To each of S of the 24 trees treated in experiment 7 added barnyard
manure to find value of fertilizers.

First application, April 10, 1908; second application, July 7, 1908.

No. 9.—To remaining 8 trees of experiment 7 added commercial fertilizer,
4 pounds to each tree, spreading in a 7-foot circle.

Fertilizer added May 7, 1908; second application, July 7, 1908.

No. 10.—One gallon carbolineum mixed with 20 pounds of flour, then 25
gallons water added to make emulsion; sprayed 72 trees, 48 of which were
used for experiments 11 and 12 to get value of fertilizers.

Sprayed whole tree April 10, 1908; sprayed trunks and limbs below foliage
July 6, 1908.

No. 11.—Used 24 trees of experiment 10, and added been yard manure, spread-
ing it about tree in 7-foot circle.

First application, April 10, 1908; second application, July 7, 1908.

No. 12.—Used 24 trees of experiment 10, and added 4 pounds of commercial
fertilizer to each tree, spreading it in 7-foot circle about tree and harrowing in.

First application, April 10, 1908; second application (3 pounds commercial
fertilizer), July 6, 1908.

No. 13.—Used 1 gallon carbolineum, emulsifying it with 4 pounds soap (dis-
solved in 4 gallons of water), and diluting the whole to § gallons; sprayed 144
trees, 96 of these to be used in four more experiments.

Application made April 10, 1908.

No. 14.—Used 48 trees of plat 13. Sprayed twice.

First application, April 10, 1908; second application, July 6, 1908.

No. 15.—This was to have been a third spraying, but was found unneces-
sary on account of absence of beetles.

No. 16.—Used 24 trees of experiment 18. Barnyard manure (to get value of
fertilizers) spread about trees in a 7-foot circle.

First application, April 10, 1908; second application, July 6, 1908.

No. 17.—Used 24 trees of experiment 13. Commercial fertilizer added, 4
pounds to each tree, spread in a 7-foot circle to get value of fertilizer.

First application, April 9, 1908; second application, July 3, 1908 (3 pounds
fertilizer).

No. 18.—Sprayed 6 trees with pure carbolineum without seeming injury to
the trees.

Application made April 9, 1908.

No. 19.—Used 25 pounds of lime, 15 pounds sulphur, 6 pounds resin, 3 pounds
arsenate of lead, and 50 gallons of water. Applied the mixture with a brush
to trunks and large limbs of 6 trees.

Application made April 17, 1908.

No. 20.—Same as experiment 19, plus barnyard manure. Two of 6 trees in
experiment 19 used. ;

Application made April 17, 1908.

No, 21.—Same as experiment 19, plus commercial fertilizer. Two of 6 trees
in experiment 19 used.

Application made April 17, 1908.

No. 22.—One gallon carbolineum, 1 gallon lard, and 25 pounds resin. Painted
trunks and larger limbs of 5 trees.

Application made April 17, 1908.

No. 23.—One bushel tobacco stems boiled for one hour in 4 gallons of water;
one-half bushel stone lime and 4 quarts salt added; one-half pint crude carbolic
acid used in each 12 quarts of the liquid. All gum and rough bark scraped from
the trees and the paint put on with a broom.

Applied the mixture to 72 trees April 22, 1908.

THE PEACH-TREE BARKBEETLE. 103

No. 24.—Used 24 trees of experiment 23. Same treatment, plus barnyard
manure spread in 7-foot circle about each tree.

Application made April 22, 1908.

No. 25.—Used 24 trees of experiment 23, plus commercial fertilizer spread in
7-foot circle about each tree.

Applied April 22, 1908; fertilizer applied May 7, 1908.

No. 26.—One gallon chloronaptholeum, emulsified with 4 pounds of soap (dis-
solved in 4 gallons of water) ; then added water enough to dilute to 25 gallons.
Sprayed 120 trees.

First application, April 22, 1908; second application, July 7, 1908.

No. 27.—Used 24 trees of experiment 26; added barnyard manure, spreading
it in a 7-foot circle about each tree.

First application, April 22, 1908; second application, July 7, 1908.

No. 28.—Used 24 trees of experiment 26, adding commercial fertilizer, 4
pounds to each tree, spreading it in a 7-foot circle.

First application, April 22, 1908; fertilizer added May 7, 1908; second applica-
tion, July 7, 1908 (3 pounds fertilfzer added).

No. 29.—One gallon chloronaptholeum mixed with 22 pounds flour to emul-
sify, added to 30 gallons water, and put on 120 trees with spray pump.

First application, April 17, 1908; second application, July 13, 1908.

No. 30.—Used 24 trees of experiment 29: added barnyard manure to get
value of fertilizer. ;

First application, April 17, 1908; second application, July 13, 1908.

No. 31.—Used 24 trees of experiment 29, adding commercial fertilizer, 4
pounds, to each tree.

First application, April 17, 1908; fertilizer added May 7, 1908; second ap-
plication, July 13, 1908.

No. 32.—Six pounds arsenate of lead to 50 gallons water: 3 pounds lime
added to neutralize the free arsenic. Put on heavy spray; pruned trees before
spraying; 170 trees sprayed. :

First application, April 20, 1908; second application, July 13, 1908.

No. 33.—Boiled lime and sulphur spray (15 pounds lime, 15 pounds sulphur,
50 gallons water). Excessive application made to 200 trees.

First application, April 24, 1908; second application, July 13, 1908.

No. 34.—Self-boiled lime-sulphur wash (15 pounds lime, 10 pounds sulphur,
50 gallons water). Water added slowly so as to prevent burning, stirring
vigorously during the process. Sprayed 300 trees.

First application, May 18, 1908; second application, July 15, 1908, to trunks
and larger limbs.

No. 35.—A stock solution of kerosene emulsion, 20 per cent strength, was
made and to each gallon of stock solution 24 gallons rain water were added.
Applied with spray pump.

Application made April 20, 1908.

No. 36.—Fumigated 6 trees with hydrocyanic-acid gas for one hour, first
scraping off all gum and rough bark. Treatment given August 24, 1908.

No. 37.—Tree tanglefoot. Put bands around 12 trees and then covered
bands with tanglefoot. Application made April 25, 1908.

No. 38.—Renovation block. Pruned back severely about 100 trees (girdling
4 trees for traps and not treating them further); applied fertilizer twice and
kept trees cultivated all summer.

First application, April 19, 1908; fertilizer added May 7, 1908 (4 pounds per
tree). Second application, July 3, 1908 (38 pounds fertilizer added).

104 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

No. 39.—A duplicate of experiment 17 tried on 200 trees; ro whitewash
was applied as a second treatment.

Emulsion applied April 21, 1908; whitewash ape September 1, 1908.

No. 40.—Placed pieces of branches as traps in trees of small orchard to see
if beetles would settle on them.

No. 41.—One-half barrel kerosene emulsion used instead of water to make a
good stiff whitewash, applying with broom to plat of 200 or 300 trees.

First application made May 4, 1908; second application, July 9, 1908.

No. 42.—One gallon of chloronaptholeum added to every barrel of white-

wash used. Whitewash made as thick as possible and aoe with a broom
to plat of about 200 trees.

First application, May 6, 1908; second application, July 9, 1908.
No. 43.—One gallon of Avenarius carbolineum added to each barrel of white-
wash used: whitewash made as thick as possible and applied with a broom to a
plat of about 200 trees.

All fertilizer used in above experiments was of the following
formula:

Per cent.
Phosphorie ‘acid. 2 2 A ee ee ee ee ee 8
INDITOREN 22 ee ak eee Se ET es 5
Potash 22.255 S28 et ee ee ls ee ere 2

All trees fertilized made a growth of rich green foliage and the
trees looked healthy, yet many of them were again attacked by the

beetles.
RESULTS OF EXPERIMENTS.

The first 6 experiments seem to show that whitewash acts as a re-
pellent, not affecting the beetles once they are in the bark, but if the
trees are kept well coated the beetles do not seem to attack the white-
washed parts. The addition of fertilizer to the trees causes a strong
flow of sap which, exuding through the burrows, seems to repel the
beetles. The treatments given in Nos. 7, 8, and 9 seemed to have no
effect whatever. In experiments 10, 11, and 12 the beetles in the tree
at the time of application appeared to be killed, but the mixture did
not act as a repellent and beetles settled on the trees again in a short
while. Experiments 18, 14, 15, 16, and 17 were more promising, and
two applications a season would undoubtedly keep the beetles down.
The expense of these experiments, however, makes them impracti-
cable as tried here. In experiment No. 18 all beetles attacking the
trees at the time of application were killed, and others did not settle
on the trees during the entire season.

The cost of the materials used in this experiment, however, makes
the treatment impracticable. Experiments 19, 20, and 21 had no
effect whatever, neither killing the beetles in the trees nor repelling
others. In experiment 22 all trees treated were killed. Experiments
23, 24, and 25 gave very good results, the whitewash sticking well and
the beetles not attacking the trees until long after the whitewash had
fallen off. Experiments 26, 27, and 28 seemed to have had very little
effect on the beetles in the bark and did not repel later attacks. Ex-

THE PEACH-TREE BARKBEETLE. 105

periments 29, 30, and 31 failed to give any beneficial results, the
emulsion being very poor, as the oil became partly separated from the
mixture before the latter could be applied. Experiments 32, 33, 34,
85, 36, and 37 gave only negative results, neither killing the beetles in
the burrows nor repelling later attacks. In experiment 38 a plat of
100 trees was used. Fifty of the trees were very severely cut back and
4 or 5 of them, being too weak to recover, died. The other 50 trees
were sprayed with lime-sulphur wash. At the end of the season the
pruned trees had produced a strong, healthy foliage and the beetles
were attacking them but little. The untrimmed trees were badly
attacked and had thrown out a scant, sickly-looking foliage. Experi-
ment 39 gave satisfactory results. All of the beetles in the trees at the
time of application were killed and no more settled on them until
about the last of September; then, a few having settled, the trees were
whitewashed and further injury was stopped. The cost of this treat-
ment, as made here, prevents it being practicable for a large orchard
unless the amount of material used can be reduced with equally good
results for the weaker emulsion. Experiment 40 showed that the
beetles attack the trees in which these cut branches were placed with-
out settling on the cut branches. Experiments 41, 42, and 43 showed
the most practicable, and at this time the most likely remedies. These
are the combinations of a whitewash and an oil, the whitewash
probably being the main factor in repelling the beetles. The cost of
these experiments was 11 cents per tree for each application. The
trees in these plats, while not entirely free from further attack
during the season, suffered considerably less than surrounding plats

of trees.
METHODS OF CONTROL.

Pending further investigation, the following treatments are sug-
gested as being practicable and to a certain degree favorable:

For trees seriously injured.—Severely trim back the trees and apply
barnyard manure or commercial fertilizers; then apply a thick coat
of whitewash three times a season, the first application to be made the
last week in March, the second application during the second week
in July, and the third application about the 1st of October.

For trees apparently healthy but slightly attacked—Paint the
trees with a thick coat of whitewash three times each season as in the
previous treatment, applying it to the trunks and larger limbs. The
whitewash applied at the times specified will act as a repellent, the
emergence of the beetles being slightly later than the dates given for
the different applications. Add one-fourth pound table salt to each
pail of whitewash, thus making the latter more adhesive. All of the
dead or nearly dead limbs and trees should be removed and burned as
fast as they appear in an orchard, as this will destroy the breeding
places.

10090— Bull. G8—O09

8

106

1850.

1852.

1854.

1856.

1860.

1876.

1881.

1882.

1883.

1884.

1885.

1887.

DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

BIBLIOGRAPHY.

Morris, M. H.—Discovery of the cause of “ yellows” in the peach tree.
<American Agriculturist, Vol. IX, May, pp. 144-145.

Morris, M. H.—The “yellows” caused by an insect. < Horticulturist,
Vol. IV, May, pp. 502-503.

HaLpEMAN, S. S.—Proc. Acad. Nat. Sci. Phila., Vol. V, p. 6.

Observations of Miss Morris in 1849 referred to: “ It wounds the bark (of

peach trees) by boring through it and feeding upon the living portion.”

Harris, T. W.—Treatise on insects injurious to vegetation.

Contains original description.

Harris, T. W.—Report on some of the diseases and insects affecting fruit
trees and vines. < Proc. Amer. Pomol. Soc., 1852-1854, pp. 210-218.

Harris, T. W.—Report on some of the insects affecting fruit trees and
vines. (Reprint of 1852.) <Journal U. S. Agric. Soc., pp. 197-210.
(See American Pomological Soc., 1854.)

Fitcu, Dr. AsA.—Injury to peach trees (also elm bark). <Third Rept.
Ins. New York, pp. 38-39.

Morris, M. H.—The peach tree and its enemies. <Horticulturist, Vol.
XV, pp. 118-120.

Morris, M. H.—Notes on peach. <(Gardeners’ Monthly, Vol. II, May, pp.
130-1381.

Harris, T. W.—Treatise on insects injurious to vegetation, 1862, p. 88.

LECoNTE, J. L.—Causing the “yellows of peach trees” (according to
Harris and Miss Morris). <(Trans. Amer. Ent. Soc., Vol. II, p. 148.

. Coox, A. J.—Insects injurious to the farm, garden, and orchard. <Thir-

teenth Ann. Rept. Sec. State Board of Agric., Mich., for 1874, pp.
138-139. Separate, 1875, pp. 35-386.

LEeConTE, J. L., and Horn, Grorce H.—The Rhynchophora of America
north of Mexico. <Proc. Amer. Phil. Soc., Vol. XV, No. 96.

Ritey, C. V.—Peach tree bark borer. <(Rural New Yorker, vol. 40, De-
cember 24, p. 515, figs. 1-4, s. b. No. 42, pp. 28-26.

DEVEREAUX, W. L.—The peach bark borer (Phle@otribus liminaris), Harris.
<Rural New Yorker, vol. 40, December 24, p. 866.

Injury to peach twigs, wild cherry, and,plums. <Ann. Rept. Com. Agric.,
New York, 1881-2, p. 65.

DEVEREAUX, W. L.—-Insect notes. <(Rural New Yorker, vol. 42, May 19,
Daolo:

DEVEREAUX, W. L.—The peach bark beetle (Phlwotribus liminaris).
<New York Examiner, July 24.

Habits and life history.

LINTNER, J. A.—Peach and cherry borers. <(Country Gentleman, vol. 50,
July 9 sp: ole.

LINTNER, J. A.—Insects and ‘‘ yellows” in the peach. <(Cultivator and
Country Gentleman, vol. 52, Nov. 3, p. 8387.

LINTNER, J. A.—Report of the State entomologist to the regents of the
University of the State of New York for the year 1885. <39th Ann,
Rept. State Mus. Nat. Hist. f. 1885, p. 124.

2
,

1888.

1889.

1890.

1891.

1892.

1893.

1894.

1895.

1896.

1897.

1902.

1904.

THE PEACH-TREE BARKBEETLE. 107

LINTNER, J. A.—Fourth report on the injurious and other insects of the
State of New York. <41st Rept. N. Y. State Mus. Nat. Hist., pp.
144, 204, 208.

ScHwakz, E. A.—[Unsigned note.] <Proc. Ent. Soc. Wash., Vol. I,
p. 113.
Phleotribus liminaris does not occur under elm bark; the species under
elm bark is Hylesinus opaculus. MUarris probably confounded the two species.
ScHWARZ, E. A.—On the types of Tomicus liminaris Harris. <Proe.
Ent. Soc. Wash., Vol. I, p. 149.

LINTNER, J. A.—Fifth report on the injurious and other insects of the State
of New York. <42d Rept. N. Y. State Mus. Nat. Hist., pp. 319, 325.

LINTNER, J. A.—The peach bark borer. <Popular Gardening, Vol. V,
June, p. 198.

PacKARD, A. §.—Insects injurious to forest and shade trees. <5Sth Rept.
U. S. Ent. Comm., p. 530.

Cherry insects cut from bark of living tree.

LINTNER, J. A.—Seventh report on the injurious and other insects of the
State of New York. <44th Rept. N. Y. State Mus., pp. 351-352.

LINTNER, J. A.—EHighth report on the injurious and other insects of the
State of New York. <45th Rept. N. Y. State Mus., p. 299.

Hopkins, A. D.—Catalogue of West Virginia Scolytidie and their enemies.
<Bul. 31, W. Va. Agr. Exp. Sta., p. 141.
Habits, distribution, enemy, dates of observation. Infests peach, cul-
tivated cherry, and wild cherry.
Horxins; A. D.—Catalogue of West Virginia forest and shade tree in-
sects. <Bul. 32, W. Va. Agr. Exp. Sta., p. 213.

LINTNER, J. A.—Ninth report on the injurious and other insects of the
State of New York. <46th Rept. N. Y. State Mus., pp. 365-368.
SLINGERLAND, M. V.—Some dangerous bark beetles. <Rural New Yorker,

October 21, p. 700.

COocKERELL, T. D. A.—Notes from New Mexico. <Ins. Life, Vol. VII,
No. 2, p. 210.
Attacks various fruit trees.

FLETCHER, J.—Report of the Entomologist and Botanist. <Rept. Expl.
Farms Canada for 1894, pp. 212-216.

FLETCHER, J.—Report of the Entomologist and Botanist. <Rept. Expl.
Farms Canada for 1895, pp. 155-156.

FLETCHER, J.—Report of the Entomologist and Botanist. <Ann. Rept.
Expl. Farms Canada for 1896, pp. 255-256.

FLETCHER, J.—Report of the Entomologist and Botanist. <Ann. Rept.
Expl. Farms Canada, f. 1901, pp. 242, 249.

Titus, E. 8S. G., and Pratt, F. C.—Catalogue of the exhibit of economic
entomology at the Louisiana Purchase Exposition, St. Louis, Mo.,
1904. <Bul. 47, Bur. Ent., U. S. Dept. Agric., p. 29.

Listed under “ Insects Injurious to Peach” as “the native peach bark-
beetle (Phlw@ophthorus liminaris Harr.).”’

|

108 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

1905. CuRRIE, RottaA P.—Catalogue of the exhibit of economic entomology at
the Lewis and Clark Centennial Exposition, Portland, Oreg., 1905.
<Bul. 53, Bur--Ent; USS: Dept. Agric: p10:

Same as Titus and Pratt (1904). :

1906. Fett, E. P.—Insects. affecting park and woodland trees. <59th Ann.

Rept. N. Y. State Mus., 1905, Vol. IV, p. 452, pl. 66, fig. 1.
One-page account. One original figure showing antenna.

PN i k.

Page.

Acoloithus americana, bibliographic reference..................-------+------- 89

maers tnusiiala, bibliographic references. .....-...._. 2.2 .0--2eeel-s-s0%5-ee 46, 47

i MTN ER. / Sse 2 sn SE ec eee 32

peeves. mauneyagise FOLCTENCES:. -.. 2... -. ck dan pes aE 2 A eeee eee 46-48

Agloape americana, bibliographic references. ......-....--..----------------- 88, 89

aE ISETS CORETIOONG 2. 2 a. Sond ed | eee 77,78

RMCRMIINTIEE METIONS 2.2 2 SS Stk ae eet oe eee ae ee 3

budding and blossoming, with relation to feeding habits of pear thrips. 3-5

jen plant.of Prathkrips pyrt.. =: ..>-. 0-22-2240. 205. 563 ee Sern Zeer 5,11
Alsophila pometaria. (See Canker-worm, fall.)

Amelanchier canadensis, food plant of Synanthedon pictipes.......------------ 33

Ampelopsis quinquefolia, food plant of Harrisina americana .......-..---------- 79

ene? Wi EAI Oe UTI 8. aU eas 2s eee do oe a ae 14

cnnnr ese Sue CH Alt OH-Clmk oon 50.2 ee se Le eee 50

Apple, budding and blossoming, with relation to feeding habits of pear thrips... 4-5

Me Dnt Of Ale piNia NOME, 22 12 or SE a a 17

Hnaeionia PrumwMord.. 3555 | i. Saas Doe le 49, 50-53, 59

Nn Ite oben PA ots Fa ee pe eee 5, 11

FE Ciera ot k= 2S eee 17

Pans OME UiEeS 222. Se A BS ee ee ae 23

injury to foliage and fruit from larve of pear thrips...-.-...--..---.-.-- 6

Me Rometiia suerte a PeMmed yy... 225-222 252. ~~ <2 deen ce ee eee
worm, lesser. (See Enarmonia prunivora.)

ETERS gs be ae Se a a ne a 3
budding and blossoming, with relation to feeding habits of pear thrips. +

food plant of Euthrips pyri.. Sn Oe See ee I
Arbutus menziesii, food plant of ee PO iics cea - os os anes oe 6
Arsenate of lead against codling moth.-...........-....------------ Osis Soha eee 70
RE WOR gas ore oS i ee ae ee 67

PERCUCe DAS BUSES 2 oo 54. 105-4 has se nee eee - 102-105

Sprite eummet wr. 2 So Sos ake oe al 21-22

and Bordeaux mixture against codling moth...............-- 73, 75

grape-leaf skeletonizer ........ : 88

root-worm .......-... 65, 66, 68

Arsenical spraying against lesser apple worm.............:.-.--------.-----.-- 60
Arsenite of lime against grape-leaf skeletonizer..............--.----------+--- 88
Astichus tischerix, parasite of Tischeria malifoliella........-........------------ 29
Banding trees against spring canker-worm............-.-.------..---..---.--- 22

Barkbeetle, fruit tree. (See Scolytus rugulosus.)
peach-tree. (See Phleotribus liminaris.)
Beach plum. (See Prunus maritima.)

Pee Or Beene POTN CANmOLWOPR) ©. 2 02-0. 665 te sed Doce ns oe ewe ee eee 22
nied OF SUNANINGHON SICMDE.. i. 5 L625. <8 os Dak Le ane ee een ene 45

110 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

Page
Bitter rot, Bordeaux mixtureja remed y-22- 295.26) soca ee 70
Blackberries, damaged by Tischerta malifoliella.2-—. 2. 22-2 26
Blackberry. (See Rubus villosus.)
Black knot, insects reared therefrom, bibliographic reference..............-- 47
on cherry and plum, food of Synanthedon pictipes...........------ 33
plum, Enarmonia prunivora reared therefrom ..........-.-. 50, 53, 59
Bordeaux mixture against apple scab and bitter rot ...................---.-- 70
lesser peach: borers: + )2.h./:44 275.2 ee ste ee eee 46
and arsenate of lead against codling moth ................. 73, 75
grape-leaf skeletonizer........ 88
FOOt-WOnml 5 52 See 65, 66, 68
kerosene-lime emulsion against trumpet leaf-miner of
the apple: 222225 See ee 30
and Paris green against trumpet
leaf-miner of the apple -.-.- 30
in sprays against spring canker-worm): 4-12). 554.256 ee 22
Bracon melittor, parasite of Synanthedon pielupes.-- =<" ee 45
Campoplex, parasite of Synanthedon pictipes..2- 22-22. 42582 a a ee 45
Canker-worm,. fall; asa. pests. 2.2 2. 2262. oe Re ee 17-18
control, reeommendations..........-. Lib soap ee 22
spring. (See Paleacrita vernata.)
Canker-worms, conditions governing multiplication and injury to trees....-.-. 17-18
Carbolic acid against peach-tree barkbeetle 2. —2.225.2-4--ns4- e ee 102-105
Carbolineum: against peach-tree barkbeetle-2 2. .5 222.2252 2406 ee ee 102-105
Carpocapsa pomonella. (See Codling moth.)
Castanea dentata, food plant of Synanthedon pictipes......-.--.-..---2--------- 33
Ceanothus thyrsiftorus, food. plant of Ewuthrips pyrt=.2 2.2 = sss eee 6
Cement against. peach-tree barkbeetle.- 22-2 2 oo 52 een eee eee 101-105
Cherries, wild. (See Prunus serotinus and P. pennsylvanicus.)
Cherry, blooming period..<.cscs 2. 2 Eos eee ee ee 3
budding and blossoming, with relation to feeding habits of pear thrips.. 4-5
food ‘plant.of Alsophila pometaria.. © 2234-00 oe 17
ANOr mond Prunworas.- =>: ass S22 Se eee 51, 53
PANS Pyrt. 2 Sa eee sea e ee OL Ae ee 5, Lk
Paleacrita verte: sa, ee 8 2 Be A ee 17
Phieotribus laminas: o 2-2 Sea Be ee ee 93
injury front oviposition ol pear Uaripse ses ecs-ee > ee ee eee &
to foliage and fruit by larvee of pear thrips! = =) 522-2 ee eee 6
wild, iood plant.of Phimotribus lnvinariset =. 92525-2205 see = eee 93, 94
Chestnut. (See Castanea dentata.)
Chloronaptholeum against peach-tree barkbeetle..........-...-.-..--..---- 103-105
Cirrospilus flavicinctus, parasite of Tischeria malifoliella.......-.-..---------- Zo
Closterocerus trifasciatus, parasite of Tischeria malifoliella...........--.------- 29
Clean culture against grape-leaf skeletonizer...............--.---------------- 88
Codling moth, demonstration sprayime e245 3s nee ee 69-76
in‘ Obio.in: 1907s ee 75-76
Pennsylvanian 1907222 2 seen as 72-15
Vireinia an TOO tx ss ee ee 69-72
similarity of Hndrmowa primivore-22os 2. see ee eee 49, 54, 57
Conotrachelus nenuphar, association with Enarmonia prunivora in injury to
plums. oi... veo Rees ee ee eee 49-50

INDEX. ty va

Page
Conura n. sp., parasite of Synanthedon pictipes...........22222-220200eeeeeeeee 45
iereod nands acainest spring Canker-worm.........2.-.002c0sccnnacecsanscaenes 22
Crab apple, food plant of Enarmonia prunivora.......0-.----+--22-20eee00% 50, 52, 53
sweet-scented. (See Pyrus coronaria.)

Sraveous, 1ood plant of Enarmonia prunwword...--2.-2220-220. 23 Weneueeeee 52, 53, 59
TU RCNCIED TROL OV ICLIAS = ou 0's sat & abt IO a gies locas era pee 26
Ctenucha (Agloape) americana, bibliographic reference........-.-.-....-------- 88
Paltiyation in control of spring canker-worm..-...... 226-222-022 00see0cneesne 20
: trumpet leaf-miner of the apple.........--........-- 30
THCRMOG p-APAAaApOCAR ULES... S22 = nc> -2 okie pave See w oie MER ee ee 12-14

Dewberry. (See Rubus canadensis.)
Dorymyrmex pyramicus, enemy of Synanthedon pictipes.......-.-.--------++---- 45
lachertus i. sp., patasite of Synanthedon pictipes.....--.-2.-2.---+-2-s0+4-e-- 44-45
Hicsmus pullaius, parasite of Tischeria maltfoliella.......--2-22--222200---006- 29
Mimic. pia Of Alsaphila pometaria....2..-.--.--+p2-0e-45= 15 aeeoneeeees 17
ete ODO CWIUS «2/3 is ae vs eb eee ee 92, 107
Pe INE WON NIO <3 od ono wn Jayna Ae Rp 2 2 2 AE eee 17
gall, Enarmonia prunivora reared therefrom.........-..-.---.-+----<- 50, 53, 59
RIED ina OI ete SS 2 sje ok Ebest oda oe la ee 49-60
POmunGrMIObh <0 15.5 2-20. rade tahoe. ote 56-57
PUN sa a ae oc sin os oak a ale lee oe ae SS 56
SOL CEL oS a eS a eee ae I yy = EEN TS 60
mnIghAOINe S029 Sonos ok os oe ee ee! 55-57
PeameimeMCss. a 51.-2. 2. nea oe Stee ae ee 53-54
Smene Ditton, es 2. 2280. alae D2 <p ee 53
eee ein eels ew oo ay 39 Se eee a er 59
MISES st oe. oo. age ass ne ae 53
Pee te 6. oe aS Poe eae oe 57-59
“TES es Srpopt Glan akc ato er 49-52
fern re rere kk A> asses de. ogee pe en 59-60
MMMM OINATACLORS. pect oc 3. =< 2)oeins 2 sis. + a 5 ne Oe 54-55
Ree eee seh OS onl die ne we 55-56
Ate eee tA te Ss on oS te 2 52
ELI GUISES, EE Sa ee a nr eS 60
NT oh SE Orn 2 a ea a Be 56
RemmOnme MOP Vraciss os ies << = 2,5" SW - SS 57-59
pian (ocodlune moth. os... .. <2 .5+= <e<eeeees 49, 54, 57
iulophnas DW. sp., parasite of Tischema malifoliella............--...+0+-ceeeuee 29
re ee a ee RW ae ao in ws eee 2 ee ee ee .-. LM
es eM RTISINGE St a5, Su ee one we Ss oa ts we ll
Rane EE PERS Greig Sag os 2 dw Sc aon in 8S ee 10-11
eontrol,methods 9nd Natural factors..-......2--5..5. ...5-s--02. BG
Piiiivaom raethoedsiin-control. .....-.- 2 sssiuwe.ns sees aes 12-14
Renee RCM eRe Sh So 5S sn a ee we ok Ne see Sa ee 1-2
ree ing Cad a ab a's.n o's Seeing teen eee oe 7
are i nee e ee Re tea 6c pvla.t Sd ania e one ge ga Maen aS oi 14-16
feeding habits, in relation to budding and blossoming of trees.... 3-6
Rr RR eee Ss ls yy ain a le SN ene a a 6-7
Sai Be MUMS eR ION es O8 Geeks has ARK i alongs gh ne nie eben 5-6
eR GR ea Con he ny ss Kcienie gun tase SoS Sues heeee bee 7-11
Puiu eM TO GNC GROG, 200. c Fan gel ood s Send leg hos wang ees cin 2-7
Pee U GDR ab hten © he Guee 5. «a Gichie ante Soy Ons Raw Gun senens on 8-9
De TET eens, ful wei e ghee! Oe oak oa oh a cinin <5 6 tb sa eee 7-11

jae DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

: Page

Euthrips pyri, mouth parts....--.... oS Pea aie ce COO Nee ee tee ee 2s
nymph or pupas<2 5: o)zJe25. jee eee oes eee 9-10

OCCUNTOM CO 5555 25/0 05 oe Zee eget a en ng Se 1-2

OVIPOSITION: os 52 5:5 c 88 Soe ceeigis | IIIS eee eee cee eee 7-8

OVIPOSMOL Sse we Sen MO eee eee cs ee 7

SPEAVS UNSAISIACUOLY «85> kee ape ae ae ee 12

Fertilizer, commercial, against peach-tree barkbeetle.....................-- 101-105

constituents, used in experiments against peach-tree barkbeetle...-- 104
Fidia viticida. (See Grape pias
Fig, food plant of Euthrips pyri-. Pind anhed ic cain Seth RES ee SRS Oh SNe oe ae
Fish-oil soap. (See Soap, fish-oil. an
Foster, 8S. W., Johnson, Fred, Girault, A. A., and Quaintance, A. i , paper,

a Demouehetian Spraying for the Codling Moth” nh ti Be yet Sh a 69-76
Wunier, enemiesiot Huiirips pyriv. kanes see ote ee eee eee 15-16
Fungus, black-knot. (See Black knot.)

Grape; food plant of Huthrips pyr: 2, 25.52 wage ee eee eee 5-11
LLGHTISING GMNETICONG xe oo sae Seta ee eee 77-79

Grape-leaf skeletonizer. (See Harrisina americana.)
Gall, elm, Enarmonia prunivora reared therefrom---2.: 4222-4. -- see 50
Hawthorn, Semasia janthinana reared therefrom.............-.---..-.--- 59
oak, Enarmonia prunivora reared therefrom....-.-..-...--..--------- 50, 53, 59

Girault, A. A., paper, “‘The Lesser Peach Borer (Synanthedon pictipes G. & R.)”. 31-48
Quaintance, A. L., Foster, S. W., and Johnson, Fred, paper,

‘‘Demonstration Spraying for the Codling Moth’’..........-- 69-76

Glyptapanieles sp., parasite of Harrisina‘americana.: 4023-2 eee ee ee 87

Grape root-worm and vineyard conditions in Lake Erie Valley................. 62-63
control recommendations based on observations and results

of sedson’s work, 1907 22.2 ec 3 a ree ee 67-68

history... s%5 02.00) She. oS aoa Nelo agi Soe re aaa 61

injury to newly bearing vineyardss..2222 2-2 esos ae 64-65

investigations im 190722222 coos eh eee eee 61-68

methods of recording results from spraying experiments. ..... 66-67

renovation experiment on an old, run-down vineyard. ...... 65-66

spraying experiment in a newly infested vineyard. -......-.-.- 66

work undertaken at North Bast, Pa, 2) 220222. ee 63

varieties attacked by, Aarrismia amerncand.s4.32-.222 2s fe 79

wild, food ‘plant of Zormsina amencuna=-223-ce- == 5 Soe ee eas eee 79

Grapholitha prunivora=Enarmonia prunivora.....--.----------+-+-+----+0+2-0- 52

Gresarious habits of Harnsing anicneonasesaaye = ee ss ee 77, 80, 86, 87

Hand-picking against grape-leaf skeletonizer...........-------------+-+----- 87-88

LOTT USUI GINVETI COTO 5a. cs Sea eis Sees 2 page ato oe se a 77-90

adults o 2 i vs5 2st ee Soe AG Bees eae ees eee ey 84

bibliopraphy = 2.20.22: -2.928 yeas See eee 88-90

COCOOD.. 225-550 5262 eb <5) ee Ae Be eee 83

comparison with H) terana_ 2.2) 222 re ee 87

description: Of stages... - 22.0: 3 52 pe Se ee a eee 80-84

destructiveness.....--.- fe le he tea he a ee 79

distri bution. 53.5200) Aoi 6 see ee ae eee eee 79

OOP ost cic a see ew Sid see Sega Mena ee ee ea 80-81

eENeMIeSs. - fs. se seh aede dey ees Oe ee ee 87

food planta... a450 "5 Se ea 79
generations. .....2hses- sts a seee See ee eee ee 85

Page.
PINON, DORM IB Crus ES) at be wee ake on aewvekes os 86-87
REE i Os ro Vipin yd eel oe Oe 77-79
SRM ra Ge hee oa Sarge eee bec oe eee 87
PONTE ONEROUS ooo. os oo CURES i See woe ae oe 79-80
RT a ite iS Sa nang ed a Reena as sb tak alee 81-83
UWE aie = 5. 22 wel ee nee Rates sk oa eae 85-86
NE a tn AS Saas aw eC Lae ey eaten ec ae 79
SMR 2 ue te Sa fo oo agen eee Ae ease ee 83-84
related to Procris ampelophaga and P. vitis.........-.-.-- 79

Teme OR 2 oe ale ead) ae 2 Pa ee ee ee ee eee 87-
Genes SERIE 2... uc.) 2. Doe aes SE eae eee 85-86
pasrans bibloprapiie reference. -.. -.- -.. - 22. .--c4-5--244---26s0 90
Bmgeerdt, pibhosrapiic Telerence - 2.2 ......-3-3502--1----2---- ee 89
neg aM MOPrapinic Telerence: . ..- =... -. 235-2. -424 Judean eo eee 90
grecrenern trom H_ americana cs: 20259555 45.5 eee eee 87

Haw (see also Cratzegus).

"food plant of Enarmonia prunivora..........-.2..22-22222-2+-222--2- 50, 51, 53
Hawthorn galls, Semasia janthinana reared therefrom.....-..-....------------ 59
Horismenus popenoei, parasite of Tischeria malifoliella..............----------- 29
Hydrocyanic-acid gas against peach-tree barkbeetle..............---------- 103, 105
Hylesinus opaculus, mistaken for Phleotribus liminaris.........--.---------- 92, 107

Johnson, Fred, Girault, A. A., Quaintance, A. L., and Foster, S. W., paper,
‘‘Demonstration Spraying for the Codling Moth” ............ 69-76

paper, ‘‘Grape Root-Worm Investigations in 1907”-..........-- 61-68

Jones, P. R., paper, ‘‘The Grape-Leaf Skeletonizer ( Harrisina americana Guérin-
TE SaaS eS Se ee era anne See Re ye 77-90

Juneberry. (See Amelanchier canadensis.)

Kerosene emulsion against peach-tree barkbeetle..............------------- 103-105
trumpet leaf-miner of the apple......-.-...---.-.-.--- 30
lime emulsion against trumpet leaf-miner of the apple-..-........--. 30

with Bordeaux mixture against trumpet leaf-miner of
the apple. °. <2... ceeeeeee 30

and Paris green against trum-
pet leaf-miner of the apple. 30

Da ennnet wecn-itee barkweetie.__........----2-------.--4-<--.--s005 102-105
Leaf-miner, trumpet, of the apple. (See Tischeria malifoliella.)
Lilac, wild California. (See Ceanothus thyrsiflorus.)
Pamee smn wean -ireo barkhectie..<-._- 2... .-......+-2-+.---++-.-2--eee 101-105

kerosene emulsion. (See Kerosene-lime emulsion.)

stone, against peach-tree barkbeetle...........................----.-- 102-105

sulphur wash against lesser peach borer. .........-.-.--:---------------- 46
peach-tree barkbeetle. ....:~..2...9--.-1<4s-<.- 103-105
Limneria sp., parasite of Harrisina americana. ..........---------------------- 87

Madrofia. (See Arbutus menziesii.)
Manure against peach-tree barkbeetle..................-------------------- 101-105

Mesostenus, parasite of Synanthedon pictipes.......-...-------------+-+-+-------- 45
Microbracon, parasite of Synanthedon pictipes.............-.-------+--+-+---+---- 45
Mirax grapholithz, parasite of Enarmonia prunivora..............-----..------ 60
eR CSG UUIECUD UNG oe wend k wa ewe ale eS wie id diana ie cee ns 2

ES i 7 a ee a ee ee Ea 101
Moulton, Dudley, paper, ‘‘The Pear Thrips (Zuthrips pyri Daniel)”’.......... 1-16

Oak, red. (See Quercus rubra.)

114 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

Page
Orchard management against lesser peach borer................--.------------ 46
Paleacrita verndany 228 2. Te ee ee 17-22
AS! A. POSb a eset ce. ES ye Be Sa te ae an ete nae aeaneey eeet 17-18
control, demonstialion: work ese" eae a een eee ee 20-21
recommendations... eee See ee eee 21-22
Nalbitse 2255. 2252 fe 59 Me Vs Se a ee ae 18-20
hiedhistorys 2... acces = foe sae en ee Wee ee eee 18-20 —
Paris green against srape-leat skeletonaer-2e>-- 22. es aser see eee nee 88
spring. cankert=worm.< 73.22.4265 ae Jase ee eee 20-24
with kerosene-lime emulsion against trumpet leaf-miner of the
apples: Ohe Sk Baie eee Bae iet ie 30
and Bordeaux mixture against trum-
pet leaf-miner of the apple. .-.-.. 30
Peach, blooming periods... 20 ot 1a ee ey i ee 3
borer, lesser. (See Synanthedon pictipes.)
name used for Synanthedonpictupes= 52425... ee ee 32
(see also Sanninoidea exitiosa).
budding and blossoming, with relation to feeding habits of pear thrips. 4
food plant ob fnarmonia pruniwords 2.5 A ee ee 53
Huthrips pyre: 2 aeeee eer 5
Phieotribusiliminarish.) 29.2 ee ee 91-108
tree barkbeetle. (See Phleotribus liminaris.)
‘Pear, blooming period sie... ss...) se) See ee a 3
budding and blossoming, with relation to feeding habits of pear thrips... 4-5
food: plant.of Huthrips pyri. 2.2222 ae 2 ee ee 5-11
injury to foliage and fruit by larvee of pear thrips...............22..--.-- 6
thrips. (See Euthrips pyri.)
Perilampus platygaster, parasite of Harrisina americana...........-...--------- 87
Phigotribus luminaris.2 5s. Sh ee ee ee 91-108
adult; desériptiom 2) 22. eee 6 ee a eee 98
habits) 2.02222 225 a Re ee 96-98
bibliooraphiysiie tee ees ee eee 106-108
eontroltmethods: -3-222554.400 oe fee eee eee 105
distribution 2. 52) 22 ee ee oe eee 93
COP ee els old BRE e ees ee ee 99
hibernation: /. 22592 4". Seta ea ee 95-96
history 2io soccer 5 Se ae eee 92-93
injury; character aud extents.) 5.5345 20. eee 94-95
larval sb oc eee Fe Ee es 2 Ce een 99-100
lite hhastor yy: <2 $224 ts 3 ee eee 95-101
occurrence in Ohio's: {cere as eee on eee 93-94
parasites 212 4.3 7 a ee ‘101
PUPA. 3 26 6345 ae es Se 100-101
remedies, €xperments-255.. ae one eee 101-105
similarity of work to that of Scolytus rugulosus......---- 93
supposed cause of ‘‘peach yellows” ......-.-..---.------ 92
Phygadeuon ? sp., parasite of Tuscherva malijolhellas 322s ee een ee 29
Pimpla annulipes, parasite of Synanthedon pictipes®= 233.2 2 se see oe ee 45
Plowing in control of spring canker-wormn: - 22232228 9s eee a eee 20-21
trumpet leaf-miner of the apple...........--.---.---- we 30

Plowrightia morbosa. (See Black knot.)
Plum, beach. (See Prunus maritima.)
curculio. (See Conotrachelus nenuphar.)

INDEX. 115
Page.
Plum; £000. Plant Of LAOrMORU PTUNWOT. vacic cree wen cine dans esr ewes 49-53, 59, 60
et et oo Weed Sat ine Re - Soe ds ea 5, 11
OR IIETIOUTS 52 on ae occ e he Seg a aslo + a's orn idae Se 93
MINEO) IGN PUOS..5 2's oda ric nied a es oe oe 33
moth, early name for Enarmonia prunivora......------------------- 49, 50, 52
tree borer, name for Synanthedon pictipes.......--------- eee PO 32
wild, food: plant of nas Monts PrUMwvora. a2 aie obs 2 aoa ole Fe wae 52, 53
SUMONINEGON WUT POR ae 8 ats as PR a ic een Ge 33
Poison oak. (See Rhus diversiloba.)
Prittier eek agama apring canker-wormt: . 20's. Jie 24 .ts eee een ay de 22
iProcris amenecond, bibliographic references. ..... - 44. s2n2.-845saee 2s aon 88, 89
=P ISINE CIN ONG. 2. 23.2. ete es ee ee 77,78
ampelophaga, related to Harrisina americana......------------------+-- 79
aqapen. piblieotapnic Trelerences.. 2 2... 62. so Ue whe ee eee 88
Tis Tel Abed tO HOTT SIN AMETICONUE.... 24 2 hs.c Saw ce gee se ee oes r)
Remereret a A OTM 8 as i on Se ee ee 3
budding and blossoming, with relation to feeding habits of pear thrips. 4-5
food. plat iol Fino, Mond. Prunavora c=. 2555506 ane se ae ee 51, 53
EAERTUDS DU o-oo ee Pe See See. as ee ee 5, 11
injury to fruit and foliage from larve of pear thrips........-......----- 6
Enemies aeaanat peach-tree barkbeetle: .. 222.26 2.4. n 2 ene Ma Se see eee 103-105
Prunus maritima, food plant of Synanthedon pictipes........----------------- 33
pennsylvanicus, food plant of Synanthedon pictipes........--.--------- 33
serotinus, food. plant of Synanthedon pictipes. ....-=-------+-+--------- 33
Pyrus coronaria, food plant. of Tischeria malifohella.. -.....--2-.---2222ct-- 26
TOSELICGIC «Gt ee. Us ee eee 26
mali too plant of: Tischeria malifoliella.... 2212-2202 2254 5 Se see eee 26
Quaintance, A. L., Foster, S. W., Johnson, Fred, and Girault, A. A., paper,
‘‘Demonstration Spraying for the Codling Moth”’ .....-- 69-76
paper, ‘‘The Lesser Apple Worm (Enarmonia prunivora
DA eEan toes fe. re Se. ig 49-60

“The Spring Cankerworm (Paleacrita vernaiu Peck)”’. 17-22
“The Trumpet Leaf-Miner of the Apple ( Tischeria

marvonecia Clemens)”. -..0.22.-.:-.'. -. -tceme eee 23-30
Quercus frondosa, Enarmonia prunivora reared therefrom .........------------ 50, 53
rubra, Enarmonia prunivora reared from galls........-....-----.------ 50
singularis, Enarmonia prunivora reared therefrom........-...-.------- 50,59
To mianieE EueInISH OFF utirr pe $yFi.o.- 2... -..--.------ se ee - la ccendann = 14
Raspberry. (See Rubus occidentalis.) :
Pee ene ire PATKMECUIC a0. oyo2...- ~~... +22 54-8eee sot san ess 102
Ans @iversviova, 100d plant of Puthrups pyri...---....------. 22 ----seeesees- 6
mauncemonnuagp:, enemy of Thrips tabaci......-..... ~~ --~---....--+.+e0eees- 14-15
Rootworm, grape. (See Grape rootworm.)
ean eoronnd, 1000 plant of Tischeria roseticola.....-.. -.-.-2.-.--+.--..5000- 26
Rubus canadensis, food plant of Tischeria malifoliella ..........--.---+---++-- 26
occidentalis, food plant of Tischeria malifoliella...............--------- 26
mingeus, 200m PIawG OF Tischeria xnea... .. -- ~~. - -. -.-sno nd ewes ence ant 26
malfoliela : 04 .ucdeuwe scckaee eae 26
an eee encenres PATEK DECLIO ... 5... .. .. 0. ~ 652 eee ee eens ven ecenes 102-105
Sanninoidea exitiosa, confusion with Synanthedon pictipes.............-------- 31
a EL OR ooo S. n as n g v wne w ow ewe ewe eec sete acetws 101
similarity of work to that of Phleotribus liminaris...... ~~~. 93

Semasia janthinana, Enarmonia prunivora closely allied... ...........-------- 59

116 DECIDUOUS FRUIT INSECTS AND INSECTICIDES.

Page
Semasia prunvwora= ENar mons Pruinvword =e eee ee 50
Sesia pretvpes, bibliographic references 24 oe es es ee ee 47,48
== Synanthedon pictipes: oe eae ee ee eee BY
Sigalphus curculionis, not parasite of Enarmonia prunivora, but of Conotrachelus
DENWPNGR 2. fa cos 7 22 SS Ree BS se ee ee Eee Oe ae SE .- 50, 60
Snake-flies. (See Raphidians.)
Soap-against peach-tree barkbeetle.. 222832 52.2-2- 2 ee oe eee ee 102-105
fish. ‘oil, against: peach-tree barkbeetle. 214 Sus aes. 2b a ee ee 101-105
Spiders, enemies of Buthreps pyrtcs. 5. S555 . Bo oe ee ee 14
Spraying against grape-leaf skeletonizer .-..--..5...-2-2-.2222---22- 22+ +222 8g
lesser apple: Worth. 5 soe ue eae ne eee ee eee Be alee 60
spring. Canlker-wormis i.) ~ 5 ose oe ee ee 20-22
trumpet. leai-minerof the apple: *2-s2522 2.444 eee 30
demonstration, for the codlmmg moth ashe. 2255 ee ee ee 69-76
Sprays unsatisiactory against: pear thrips: 22222-2022 = setae sess ice eee 12
Sulphur aeamst peach-tree: barkbeetles.2:2h 122-2 3 ee ees eee 102-105
Symptesis lithocolletidis, parasite of Tischeria malifoliella.....-...-....--------- 29
nigrofemora, parasite of Tischersa malijoliella®:_ 22-2220. 2 ee 29
Synanthedon prelipes. asec. ~ 2255s 2s ee A aa eee 31-48
adults 2282. 32S. ok SE ee ee 40-42
bibliography 2..-.sie: ota sese Sat er 46-48
description, original: s. 22.3625: hg ee eee 32
injury, character‘and extent:<- 2°22 = ee 33-34
GOCOOW 2s ies SS 2 is ee ee apa 39
distribution: <2 Soc 220k ee ee eee 34
CPP snore ellen see eee ee ee eee 30-36
enemies: 05 )20 soos ae SR ea ee ee 44-45
food: plants: 252 32.) ae 228 ee 33-34
peneraiionss.. 22 5 ees. SPs a 2 eee 42-44
habits.s2.o2: 95>. foes ie Sie a 35-42
hibernation... 5:..0-2.55..0 3) tse ees ee 35
history 2s. s2 SSS oe ee ee ee ee 31-32
Verve lsh set Oe ee OL oo eee 36-39
life ey clés s.22 2s ee eee 44
history 22s. c 255502 BSE ee a ee 35-42
literature: . 20236. Sed eases So ee eee
name) AChentHe).-c 655 Coes ee ee ee 32
HAMES, COMMON» .25o.9 26" So Se ee ete 32-33
prevyentivess 2.222.525 Sas ee as Se ee meee 45-46
PUPA. s 220 So cok ee ee ee eee ee 39-40
yemiedses: jo. 25. set doe Go eee ee ee 46
seasonal history ..02222..-228.2 025 2 ee ee ee
Tanglefoot, tree, against peach-tree barkbeetle -.....................-----+:- 103-105
Tar against spring canker-worm.2/..2225.0 S326 232). 95 =e ee eer ee 22
Thrips, pear. (See Euthrips pyri.)
Thrips tabaci, host of Rhyncholophiis spss 2-4 a2 o> see ee eee 14-15
Tobacco-stem decoction against peach-tree barkbeetle-.-.. ato OM SEAS Cia ee 102-105
Tomcus iminaris—Phleotribus timinariss 2 ee a ee 92
Trap bands against peach-tree barkbeetle: .2..245-. 2425445) eee See 104-105
Trumpet leaf-miner of the apple. (See Tischeria malifoliella.)
Tischerva zenea.on Rubus villosiis...-c. So 2525. ae eee 26
malfoliella acs sc o23 Shee S Pas fee Sk ee ee ee 23-30

Page.

fo ED OE A ES aS a a a 24-26

Li i chia) Saas oe Fe bhp =o nase se odes 29

Cae EG oy aed a i ea ain ws nae 2's ae 24-25

1006 fe, 8 SSR ee ae ee en oo oan 26-27

DRE et Me Fo sere ov aE ES Stra w= o> = <n Se 23-24

ee 2 ee, le a ene © a" 25

hp CYeis ol et oy eee oe = ain wee 28-29

(1: oe he eter ss | + ke a ere Eh 24

MERIRR Eee oo Son a los » Sees nin = > ye 29

RO ie geet nis at. - . See win ie 2 So ee

Seenutan MILOEY....--_....... Sppeuiites ins. cannes 27-29

Mer. ooo. - eee ee eee 30

Sree ce (Ot. HOsG. ONFOUNG... 2... eo ee ee ee ee ee 26

Ulmicola gall, Enarmonia prunivora reared therefrom...........-------------- 50, 59

Urogaster tischerix, parasite of Tischeria malifoliella.........-.-.-..------------ 29

Vineyard conditions in Lake Erie Valley, in relation to grape root-worm ..-...- 62-63
Virginia creeper. (See Ampelopsis quinquefolia.)

Vitis arizonica, food plant of Harrisina americana..........--.-.-------------+-- 79

Walnut, English, food plant of Huthrips pyri...............--.--------------- SE |

Whitewash against peach-tree barkbeetle ....................-..------------ 104-105

‘‘Wild-cherry borer,’’ name used for Synanthedon pictipes................----- 32

_ Wilson, H. F., paper, ‘‘The Peach-tree Barkbeetle (Synanthedon pictipes G.

I sels 2 SSeS yt, 9.0 Alas aR ape is a 91-108

Woodpecker, enemy of Synanthedon pictipes..........----------------------- 45

‘‘Worming,’’ remedy against lesser peach borer..........-....--.--.--------- 46

Yellows, peach, erroneously supposed to be caused by Phleotribus liminaris. . . 92

Zagrammosoma multilineata, parasite of Tischeria malifoliella...............--- 29

O