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U. S. DEPARTMENT OF AGKICULTURE^J9l0

BUREAU OF ENTOMOLOGY — BULLETIN NO. «9. • U J -rf ^

L. O. HOWARD. Entoraolo«i»t and Chief of Bureau.

THE GRAPE ROOT-WORM

WITH ESPECIAL REFERENCE TO INVESTIGATIONS
IN THE ERIE GRAPE BELT PROM
1901 TO L909,

BY

FRED JOHNSON and A. G. HAMMAR,

Engaged in Deciduous Fruit Insect Investigations.

IN COOPERATION WITH TITE OFFICE OF TIIE STATE ZOOLOGIST,
PENNSYLVANIA DEPARTMENT OF AGRICULTURE.

Issued October 2(5, 1910.

\Y A SHI NO TON :

GOVERNMENT PRINTING OFFICE.
1910.

B UREA U OF ENTOMOLOG Y.

L. O. Howard, Entomologist and Chief of Bureau.
C. L. Marlatt, Assistant Entomologist and Acting Chief in Absence of Chief.
R. S. Clifton, Executive Assistant.
W. F. Tastet, Chief Clerk.

F. H. Chittenden, in charge of truck crop and stored product insect investigations.

A. D. Hopkins, in charge of forest insect investigations.

W. D. Hunter, in charge of southern field crop insect investigations.

F. M. Webster, in charge of cereal and forage insect investigations.

A. L. Quaintance, in charge of deciduous fruit insect investigations.

E. F. Phillips, in charge of bee culture.

D. M. Rogers, in charge of preventing spread of moths, field work.
Rolla P. Currie, in charge of editorial work.

Mabel Colcord, librarian.

Deciduous Fruit Insect Investigations.

A. L. Quaintance, in charge.

Fred Johnson, S. W. Foster, E. L. Jenne, P. R. Jones, A. G. Hammar, R. W.
Braucher, C. W. Hooker, J. R. Horton, W. Postiff, J. B. Gill, agents and
experts.

E. W. Scott, C. H. Gable, J. F. Zimmer, entomological assistants.

Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture.

Plate I.

The Grape Root-worm (Fidia viticida).

Fig. 1.— Female beetle ovipositing. Fig. 2.— Beetle on the lower side of a grape leaf. Fig. 3.— Egg
cluster with average number of eggs. Fig. 4. — Grape cane showing eggs beneath the bark.
Figs. 5, 6.— Full-grown larvae. Fig. 7.— Pupa in cell. Figs. 8, 9.— Lower and upper views of
pupa. Fig. 10. — Openings in the ground from which beetles emerged. Figs. 3, 5, 6, 8, 9, enlarged;
figs. 2, 10, about twice enlarged; fig. 7, about three times enlarged; fig. 1, five times enlarged;
fig. 4, natural size. (Original.)

U. S. DEPARTMENT OF AGRICULTURE,
BUREAU OF ENTOMOLOGY — BULLETIN NO. 89.

L. O. HOWARD. Entomologist and Chief of Bureau.

THE GRAPE ROOT-WORM

WITH ESPECIAL REFERENCE TO INVESTIGATIONS
IN THE ERIE GRAPE BELT FROM
190? TO 1909.

BY

FRED JOHNSON and A. G. HAMMAR,

Engaged in Deciduous Fruit Insect Investigations.

IN COOPERATION WITH THE OFFICE OF THE STATE ZOOLOGIST,
PENNSYLVANIA DEPARTMENT OF AGRICULTURE.

Issued October 20. 1910.

WASH] NGTOH

GOVERNMENT PRINTING OFFICE.

1910,

LETTER OF TRANSMITTAL.

U. S. Department of Agriculture,

Bureau of Entomology,

Washington, D. C, June 8, 1910.
Sir : I have the honor to transmit herewith for publication a manu-
script entitled "The Grape Root- Worm, with Especial Reference to
Investigations in the Erie Grape Belt from 1907 to 1909," by Fred
Johnson and A. G. Hammar, agents and experts, of this Bureau.

The grape root-worm is by far the most serious pest of American
varieties of grape at the present time and its ravages have caused a
great depreciation in the value of vineyard properties as well as a
marked reduction in the yield of fruit. The present report furnishes
a careful account of the life history and habits of the pest, embodies
a report on the work undertaken by the Bureau of Entomology in
the spring of 1907 in the Erie Grape Belt, at the instance of vine-
yardists, and provided for by Congress, and points out practical
remedial measures whereby the vineyardists will be able largely to
avoid future losses.

During the years 1908 and 1909 the work has been in cooperation
with the office of the zoologist of the Pennsylvania state department of
agriculture, as further detailed in the preface.

I recommend the publication of the accompanying manuscript as
Bulletin No. 89 of this Bureau.

Respectfully, R. S. Clifton,

Acting Chief of Bureau.

Hon. James Wilson,

Secretary of Agriculture.

2

I' R E F ACE.

The grape root-worm, the subject of the present report, is an
insect which during the last ten or fifteen years has attracted much
attention on account of its ravages in vineyards along the southern
and eastern shores of Lake Erie, comprising in general the grape-
growing territory of northern Ohio and the Erie and Chautauqua
grape belts of Pennsylvania and New York, respectively. American
varieties of grapes, exclusively grown in the above-mentioned regions,
have heretofore been singularly free from insects attacking the roots
of the plant. The Phylloxera, so destructive to the roots of vinifera
varieties in Europe and in California and elsewhere in the United
States where these are grown, fortunately does not seriously injure
varieties of American grapes. The grape root-worm, however, has
come to be recognized as the most serious of the two hundred or
more species of insects in the United States which feed directly or
indirectly upon our native grapes.

The destructiveness of the insect in the Erie grape belt in the
general neighborhood of North East, Pa., led, through the represen-
tations of prominent vineyardists, to a provision by Congress for an
especial investigation of the pest by the Bureau of Entomology.
This work was begun in the spring of 1907, and a laboratory was
established at North East, Pa., which place has been continued as
headquarters during the years 1908 and 1909. During the latter
two years, by contract entered into between the Hon. James Wilson,
Secretary of the United States Department of Agriculture, and the
Hon. N. B. Critchfield, secretary of agriculture of the State of Penn-
sylvania, the investigation has been in cooperation with the office
of the state zoologist of the Pennsylvania department of agricul-
ture. The work has covered a wide range of investigations, in-
cluding a thorough inquiry into the life history and habits of the
insect, large-scale experiments with remedial measures, and the
demonstration of the effectiveness of measures known to be of
value, including the renovation and improvement of young and old
vineyards already seriously injured.

Mr. Fred Johnson has been in immediate charge of the field work
during the entire period of the investigation, and was assisted in
1907 by Messrs. W. B. Wilson and P. R. Jones, the former engaged in
field work and the latter in life-history studies. During the years

3

4

THE GRAPE ROOT-WORM.

1908 and 1909 Mr. A. G. Hammar was detailed to the grape root-
worm investigation and devoted his attention particularly to life-
history studies, assisted by Mr. E. Selkregg. Prof. H. A. Sur-
face, state zoologist of Pennsylvania, assigned, as a representative
of the Pennsylvania department of agriculture, Mr. F. Z. Hartzell
during 1908, and Mr. H. B. Weiss during the year 1909. These
gentlemen assisted in field operations and rendered most efficient
service, contributing much to the success of the investigation. In
the present report Mr. Johnson has prepared the manuscript detail-
ing results of field experiments and Mr. Hammar the manuscript
detailing results of life-history studies, and most of the illustrations.

The results obtained by this study, as detailed in the subsequent
pages, will, it is believed, furnish entirely practicable and economical
measures for the control by vineyardists of this serious insect pest.
It is essential, however, in order that satisfactory results may be
secured, that the recommendations given be followed in a thorough
and timely manner.

The authors desire to express their thanks to the following vine-
yardists of North East, Pa. : Mr. George Blaine, Mr. W. S. Wheeler,
Mr. R. Davidson, Mr. W. E. Gray, Mr. H. S. Mosher, and Mr. A. I.
Loop, for their direct assistance in the conduct of this investigation
by placing large blocks of their vineyards at the disposal of the
Bureau of Entomology for several seasons and assisting in conduct-
ing experiments thereon. They also wish to thank the large number
of vineyardists whose interest in the work during its progress has
been a source of inspiration and gratification to them throughout
this period.

A. L. QUAINTANCE,

In Charge of Deciduous Fruit Insect Investigations.

CONTENTS.

Page.

Introduction 9

History 10

Origin and distribution 12

Food plants 13

Character of injury and destructiveness 14

Beetles related to the grape root- worm beetle 15

Beetles frequently mistaken for the grape root- worm beetle 16

Description 19

The egg 19

The larva 19

The pupa 20

The adult or beetle 21

Seasonal history 22

The adult or beetle 22

The process and time of emergence 22

Variation in the time of emergence 25

Feeding before and after egg deposition 25

Mating and its bearing upon egg deposition 28

Process of egg deposition 28

Variation in the number of eggs per cluster 29

Number of separate ovipositions by individual females 29

Number of eggs deposited by individual female beetles 30

The oviposition period for the season of 1909 31

Longevity of male and female beetles 32

The egg : 33

Incubation period of the egg 33

The larva 35

Vitality of the newly hatched larva 35

Feeding and development of the larva before wintering 35

Wintering of the larva in an earthen cell 36

Spring feeding of the larva 37

Time and making of the pupal -cell 37

The post-larval stage 38

The pupa 39

The process of pupation 39

Position of the pupa in the cell 39

Time of pupation in the field and in breeding cages 39

Duration of the pupal period 10

Life cycle of the grape root-worm as determined by rearing 40

Seasonal variations in the life history of the grape root-worm 41

Rearing and experimental methods 44

Summary of life-history studies of the grape root -worm 50

5

6 THE GRAPE ROOT-WORM.

Page.

Natural enemies 50

Predaceous insects 50

Parasitic insects 51

Life history of Fidiobia flavipes Ashm 52

A dipterous parasite 55

Double parasitism 56

Vineyard conditions in the Lake Erie Valley 57

Remedial measures for the control of the grape root- worm 59

Evolution of preventive measures 59

Cultural methods for the destruction of pupae 61

Effect of poison sprays on the beetle in the field 63

Cage experiments with poison sprays against the beetles 64

Field experiments with poison sprays against the beetles 66

Comparative effectiveness of arsenate of lead and arsenite of lime 68

Results of vineyard experiments with poison sprays 70

Results of vineyard renovation experiments 75

Renovation experiment on an old vineyard 75

Methods of obtaining and recording results 78

Renovation experiment on a young vineyard 80

Sprays 83

Arsenical poisons 83

Combining insecticides with fungicides 84

Preparation of Bordeaux mixture 84

Plants for preparation of the spray mixture 85

Time of application of sprays 86

Number of spray applications 86

Pressure to be maintained in spray applications 88

Spraying apparatus 88

Horse-power sprayers 88

Gasoline-engine sprayers 88

Compressed-air outfits 88

Carbonic-acid-gas sprayers 89

Hand pumps 89

The care of spraying apparatus 89

Nozzle adjustment 89

Nozzles 89

Recommendations 89

Destruction of the adults or beetles 89

Destruction of the pupae 90

General treatment of infested vineyards 91

Bibliography 93

Index 98

[L LUSTRATIONS.

PLATES.

Page.

Plate I. The grape root- worm (Fidia viticida). Fig. 1. — Female beetle oviposit-
ing. Fig. 2. — Beetle on the lower side of a grape leaf. Fig. 3. —
Egg-cluster with average number of eggs. Fig. 4. — Grape cane,
showing eggs beneath the bark. Figs. 5, 6. — Full-grown larvae.
Fig. 7. — Pupa in cell. Figs. 8, 9. — Lower and upper views of pupa.
Fig. 10. — Openings in the ground from which beetles emerged.
Frontispiece.

II. Feeding marks on grape leaves, made by the beetle of the grape root-
worm. Fig. 1. — Appearance of fresh feeding marks. Fig. 2.—
Feeding marks which have become enlarged with the growth of the
leaf 14

III. Feeding marks on the larger roots and underground part of the stem

of a grapevine by larvae of the grape root-worm, resulting in the
death of the plant 14

IV. Destruction of root fibers by larvae. Fig. 1. — Five-year-old grapevine

with normally developed root-system; enlarged portion showing
root fibers. Fig. 2. — Four-year-old grapevine, showing result of
feeding by larvae of the grape root- worm 16

V. Ridge of soil under trellis. Fig. 1. — Vineyard view in the spring,
showing ridge of undisturbed soil under the trellis. Fig. 2. — Vine-
yard view, showing ridge of soil under trellis as formed at the last

cultivation of the preceding summer. North East, Pa 62

VI. General view of Mr. Roscoe Davidson's vineyard at North East, Pa.,
where spraying experiments against the grape root- worm were con-
ducted during 1907, 1908, and 1909 70

VII. Views of experimental plats in Mr. Roscoe Davidson's vineyard at
North East, Pa. Fig. 1. — Retarded growth of vines in the un-
sprayed plat. Fig. 2. — Vigorous growth of vines in the sprayed

plat 74

VIII. Views of the Porter experimental vineyard, showing comparative
growth of the vines in 1907 at the beginning of the experiment
(upper figure), and in 1909 at the end of the experiment (lower

figure). North East, Pa 80

IX. Condition of fruit on vines in plats of the Porter experimental
vineyard. Fig. 1. — Average condition of berries in the untreated
plat. Fig. 2.— Average condition of berries in the treated plats.
North East, Pa., 1909 80

X. Spraying outfits for vineyards, in use at North East, Pa. Fig. 1. —
Spray-mixing plant. Fig. 2. — Gasoline-engine sprayer in opera-
tion. Fig. 3. — Compressed-air sprayer. Figs. 4, 5. — Horsepower
or geared sprayers 86

TEXT FIGURES.

Fig. 1. Map showing distribution of the grape root- worm (Fidia viticida) I'J

2. The California grape root-worm (Adorns obscuriis): Adult or beetle. . . . L6

3. The grapevine Fidia (Fidia lonyipcs): Adult or beetle 16

7

8

THE GRAPE ROOT-WORM.

Page.

Fig. 4. The grapevine flea-beetle (Halticachalybea): Adult 16

5. The rose-chafer ( Macrodactylus subspinosus) : Adult or beetle 17

6. The redheaded Systena (Systena frontalis): Adult or beetle 18

7. The grapevine Colaspis (Colaspis brunnea): Adult or beetle 18

8. The grape root- worm (Fidia viticida): Larva and details 19

9. The grape root- worm : Pupa and details 19

10. The grape root- worm: Adult or beetle 20

11. The grape root- worm: Structural parts of beetle 21

12. Diagram showing time and development of a single individual of the

grape root-worm under average conditions, as observed in 1909, at
North East, Pa 23

13. Curve showing time and relative emergence of beetles of the grape root-

worm from the ground in rearing cages at North East, Pa., 1909 24

14. Curves showing variations in time of emergence of beetles of the grape

root- worm from different kinds of soil. From rearing experiments
during 1909 at North East, Pa 25

15. Curve showing time of egg deposition and relative abundance of eggs

laid in rearing cages by beetles of the grape root- worm at North East,

Pa., during 1909 32

16. Diagram showing variation in time of emergence of beetles of the grape

root- worm during 1907, 1908, and 1909, at North East, Pa 42

17. Temperature curves showing the daily records of the maximum and

minimum temperature during the breeding period of 1909 at North
East, Pa 43

18. Portion of the outdoor rearing shelter used in the rearing of insects at

North East, Pa., during 1909 45

19. Wooden-frame box with glass bottom and wire-screen cover used in

studying the pupal stage of the grape root- worm beetle 45

20. Earthen pot with glass cyclinder used in rearing the grape root- worm. . 46

21. Rearing cage with glass sides used in the study of the larva of the

grape root- worm beetle 47

22. Earthen pot with wire-screen cover used in rearing the grape root-

worm 48

23. Diagram illustrating seasonal history of the grape root- worm as observed

during 1909 at North East, Pa 49

24. Fidiobia flavipes, an egg-parasite of the grape root-worm: Adult and

enlarged antenna 52

25. Diagram showing the relation between the three generations of the

Fidiobia parasite and the relative occurrence of eggs of the grape
root- worm at North East, Pa., during 1909 55

26. Larva of an undetermined insect parasite of the eggs of the grape root-

worm 56

27. Lathromeris fidise, an egg-parasite of the grape root- worm: Antenna and

forewing 57

28. Horse hoe used in removing the soil from beneath the trellis in vine-

yards 61

29. Young grapevine, unsprayed, showing extensive feeding by beetles of

the grape root- worm. North East, Pa., 1909 66

30. Young grapevine sprayed with arsenate of lead against the beetles of the

grape root- worm. North East, Pa., 1909 87

31. A large nozzle of the cyclone type 89

THE GRAPE ROOT-WORM

WITH ESPECIAL REFERENCE TO iN V ESTICATTOXS
IN THE ERIE GRAPE BELT FROM 1007 TO 1909.

INTRODUCTION.

During the past decade the insect Fidia viticida Walsh (PI. I),
a chrysomelid beetle known to the vineyardists of the Lake Erie
Valley as the " grape root-worm" beetle, which in the larval stage
feeds upon the roots of the grapevine, has become by far the most
destructive insect pest attacking the grape in that region.

The following pages present the extent and findings of an investi-
gation conducted at North East, Pa., during the seasons of 1907,
1908, and 1909. These investigations were undertaken in order to
make a thorough study of the life history and habits of this insect,
to conduct experiments with a view to its control, and to make field
experiments to demonstrate the practical commercial value of those
methods giving greatest promise of effective results.

Since the grape root- worm is a grape pest of long standing, a brief
resume of its history is given, both from the standpoint of entomolog-
ical classification and from that of the development of remedial
measures for its control.

Its origin, distribution, and food plants are considered, brief de-
scriptions of allied beetles and of those beetles found upon grape-
vines likely to be mistaken for the grape root-worm are given,
and also a description of the character of the injury to the vine
wrought by the insect and the extent of its destructiveness.

The technical descriptions of the different ages of the insect are
followed by a presentation of life-history studies involving many
careful experiments with numerous individuals. These studies were
undertaken to determine the length of the stages and the time at
which the different changes occur. This work was conducted for
three consecutive years with a view to determine the effect, in the
development of the insect, of seasonal variations due to varying
climatic conditions, and it has been productive of very interesting
results which have an important bearing on the time of application
of remedies. Soil conditions and altitude of vineyards are also con-
sidered in this same relation.

10

THE GRAPE ROOT-WORM.

Preceding the discussion of remedial measures a brief summary is
given of the conditions in vineyards in the Lake Erie Valley since
their invasion by the grape root-worm, dealing with the age and con-
dition of vines at the time of its advent, the increase in area of new
vineyards, the insect's comparative destructiveness to old and newly
planted vines, and the relative responsibility of the pest for the
fluctuations of crop yields during the past decade.

Cultural methods are considered with special reference to the
destruction of pupae in the soil.

In the presentation of the data dealing with poison sprays for the
destruction of the beetles, details of experiments are given, first, to
show the efficiency of arsenicals as a direct killing agent of the beetles
in confinement and also in the open field; second, to show the rela-
tive value of arsenate of lead and of arsenite of lime; and, third,
to show the cumulative value of poison-spray applications on large
vineyard areas, both in crop yield and in vigor of vines as a result
of three consecutive years of this treatment.

Following this experimental data on poison sprays the details are
given of field demonstration experiments with two run-down vine-
yards, conducted for three consecutive seasons. One, an old vine-
yard of about 10 acres, the other a young vineyard of about 5 acres.
The condition of each of these vineyards at the time the experiment
was undertaken is described and the plan of treatment — covering
general vineyard practice, such as pruning back of badly injured
vines, fertilizing, cultivation, and spraying with arsenicals — is given,
accompanied by the collected data showing the results of this treat-
ment in lessening deposition of eggs by the grape root-worm beetles,
in the diminution of grape root-worm larvas in the soil about the
roots of the vine, in the increase in crop yield, and in the general
effect of this combined treatment upon the health and vigor of the
vines.

The remaining pages contain a brief discussion of arsenicals as
stomach poisons against the grape root-worm beetles, the desirability
of combining them with a fungicide when spraying for this pest,
spraying methods and spraying machinery as related to vineyard
treatment, and recommendations as to time and manner of making
applications.

HISTORY.

The first record of the beetle, Fidia viticida, the adult of the grape
root-worm, as a pest of economic importance upon grapevines was
made by B. D. Walsh in 1866 in the Practical Entomologist (see
Bibliography), and it is also to him that we are indebted for the first
description of this species of the genus Fidia. Yet as far back as
1826 this insect appears in entomological literature under a variety

BISTOBY.

of names. The first reference we find to this species is in M. J.
Sturm's Catalog Insecten Sammlung, at that date (1826) under the
name of Colasjris flavescens. Under a later catalogue (1843) by the
same author it is listed under the name of Fidia lurida Dej. Dejean,
in his Catalogue des Coleop teres (1837), names two species, Fidia
lurida Dej. and Fidia murina Dej.

The genus Fidia was first characterized by Baly in 1803, who used
the name Fidia suggested earlier by Dejean. Crotch, however, in
1873, described this insect under the name of F. murina and Lefevre,
in 1885, described it under F. lurida. In 1892, when Dr. George H.
Horn revised the Eumolpini of Boreal America, F. murina and V.
lurida were found to be synonyms of Fidia riticida as described by
Walsh in 1867.°

Since 1866, when this insect was first reported as occurring in
destructive numbers in Kentucky, it has developed into the most
serious insect infesting vineyards east of the Rocky Mountains. At
that date only the adult form and its injury to the vine by feeding
upon the foliage was known. Walsh assumed that the larval habits
of the pest were similar to those of the grape flea-beetle (Haltica cha-
lybea 111.), and that it would be found the most destructive in this
stage feeding upon the foliage. In the former assumption he was
correct, for it is the injury of the larval form which is inimical to
infested vines, not upon the leaves, however, as Walsh supposed, but
upon the roots, as shown by later investigations. The year following,
the insect was reported from St. Louis and Bluff ton, Mo., and in
1868 Prof. C. V. Riley, in his first report on injurious and beneficial
insects of Missouri, mentions it as "the worst foe to the grapevine
in Missouri." In 1870 specimens were received by Riley from Bun-
ker Hill, 111., and in 1872 Mr. S. H. Kridelbaugh reported it present
in Iowa in injurious numbers.

It was not until 1893, however, that some light was thrown upon
the earlier stages of the pest. In December of that year Prof. F. M.
Webster, then entomologist of the Ohio Agricultural Experiment
Station, received larva? from the vicinity of Cleveland, Ohio, where
they were said to occur in great numbers about the roots of vines.
Later there developed from these larvae the complete form which
proved to be the beetle Fidia viticida, hitherto the only stage of the

aThe validity of the technical name of the grape root-worm (Fidia viticida Walsh)
might be questioned. The names lurida and murine were used previous to viticida,
but as nomina nuda; the specific description was first given in lSb'7. when Walsh described
the insect under the name Fidia viticida. Baly in IStio characterized the genus and
designated lurida as the type of the genus, though the species under that name had
not yet been described. The specific name viticida Walsh has the priority, since
the valid name murina was first used in 1873 by Crotch, and lurida in 1885 by Lefevre,
both writers using the early manuscript name ol Dejean.

12

THE GEAPE ROOT-WORM.

insect known to entomologists. During the season of 1894 Professor
Webster made a detailed and accurate study of the life history of the
insect, described its immature stages, and made numerous field
experiments to determine effective methods of control, which are
referred to in another part of this bulletin..

In 1896 Prof. J. T. Stimson recorded injury caused by this insect
in Arkansas. Dr. John B. Smith, in his Catalogue of Insects of
New Jersey, 1900, reports its occurrence throughout that State.
Dr. L. O. Howard reported it from Bloomington, 111., in 1901. In
later years the insect appeared as a pest in the grape region of Penn-
sylvania and New York, where from 1900 to 1906 it was the subject
of detailed studies, treating both of its life history and remedial
measures, by the late Prof. M. V. Slingerland, of Cornell University,

Fig. 1.— Map showing distribution of the grape root-worm {Fidia viticida). (Original.)

and by Dr. E. P. Felt, state entomologist of New York. The reports
of the investigations by the former are embodied in the bulletins of
the entomological division of Cornell University, and the publica-
tions of the New York State Museum contain reports of those
made by the latter; all publications of these two investigations are
listed in the bibliography accompanying this bulletin.

ORIGIN AND DISTRIBUTION.

The grape root-worm has at present been recorded only from
North America, and it is without doubt a native species, feeding
originally on wild grapevines, as it still does to some extent.

The insect is widely distributed in the Mississippi Valley and in
the Eastern States. The map (fig. 1) shows the distribution as
recorded at present.

FOOD PLANTS.

13

In literature the insect is reported from the following States:
Arkansas (Riley, Howard, and Stimson); Illinois (Walsh and Kiley);
Iowa (Kridelbaugh) ; Kansas (Webster); Kentucky (Walsh); Mis-
souri (Riley); New Jersey (Smith); New York (Lintner, Slingerland,
and Felt); Ohio (Webster); Pennsylvania (Slingerland and Felt).

According to records of the Bureau of Entomology the insect
occurs in Illinois, Kentucky, Michigan, Mississippi, Missouri, New
York, North Carolina, Ohio, Pennsylvania, Texas, Virginia, and
West Virginia.

In the collections of the National Museum are specimens from the
following States: District of Columbia, Illinois, Kansas, Maryland,
Missouri, Nebraska, New York, North Carolina, Ohio, Pennsyl-
vania, Texas, and Virginia.

From the following localities it has not yet been recorded, but
probably does occur as these are neighboring sections of infested
places: Southern parts of Indian Territory, Tennessee, and Wiscon-
sin; northern parts of Alabama, Georgia, Louisiana, and South
Carolina.

FOOD PLANTS.

From early records of this insect it is evident that the beetle of
the grape root- worm was observed feeding upon wild grapes long
before it was known to infest cultivated varieties. Riley reported
the beetle feeding upon the leaves of wild grapes and upon the red-
bud (Cercis canadensis). Several writers have found it feeding
upon the foliage of the Virginia creeper (Ampelopsis quinquefolia).
With the extensive cultivation of improved varieties of native
species of grapes, the insect has found in these a more available food
plant. The larval form and its underground habits became first
known through its abundance and destructiveness in vineyards.

On the wild grapevine the grape root-worm does not breed in
extensive numbers, because the conditions in woodlands are Less
favorable than those existing in vineyards. The chances for the
newly hatched larvae to reach the roots of the wild grapevine are
greatly limited, since the plants spread their aerial growth exten-
sively and in such a manner that the parts of the vine above ground
are not directly above the root system. Tinier such conditions
numbers of the larva? on dropping to the ground do not reach the
needed food plant and probably perish. A single female beetle,
however, lays a considerable number of eggs, and out of the many
hatching larva? the chances are that always several will survive to
perpetuate the species.

In the course of this investigation at North Fast, Pa., several
attempts were made to locate the larva* on roots of wild grapevines,
but in no instance were larva4 found or any signs of feeding observed on

14

THE GKAPE ROOT-WORM.

the roots. In the breeding work, however, larvae were reared on
wild grapevines, which shows that it is possible for the larva? to
exist on these plants. In 1909 larvae hatching July 26 were placed
in large earthen pots (fig. 22) in which, some time previously, wild
grapevines had been planted. On examining the cages in the fall
of the same year (1909) a number of larvae were found to have
attained their normal growth, as compared with other larvae reared
under similar conditions on cultivated vines.

CHARACTER OF INJURY AND DESTRUCTIVENESS.

The injury wrought by this pest on the grapevine occurs both
above and below the surface of the ground ; however, by far the greater
damage results from its work upon the roots. The injury above the
ground is done by the beetles; that upon the roots by the grubs or
larvae.

The first intimation that the observant vineyardist is likely to
obtain of the presence of this pest upon his vines is the appearance,
late in June or early in July, of chainlike markings upon the upper
surface of the foliage (PI. II). These markings are made by the
beetle. Ordinarily this scoring of the leaves is not sufficient to
materially affect the health of full-grown thrifty vines. Where the
beetles are very numerous, however, and the foliage sparse, it not
infrequently happens that the leaves are so badly scored that in a
short time they take on a brown appearance and hang about in
shreds. In the case of newly planted vines (fig. 29) extensive
feeding by the beetles greatly retards the growth of the young plant
and proves a great obstacle in the starting of a new vineyard. On
the thick-leaved varieties of grapes, such as the Concord, Worden,
and Niagara, this feeding does not extend through the heavy pubes-
cence on the lower surface. The pubescence holds together only a
short time, however, and soon either dries out or is torn apart by
the growth of the leaf. On the thin-leaved varieties, as the Dela-
ware, and on the wild species of grape, holes are eaten entirely
through the leaf, usually assuming the characteristic chainlike irregu-
larity of form.

It is, however, to the larvae of this pest feeding upon the roots of
the vines that the direct cause of the injury and death of so many
vines is due. The work of the larvae upon the roots may be recog-
nized, when the vines are removed from the soil, by the absence of
root fibers, by channels along the larger roots, and by pittings on
the main trunk. (See PI. III.) Vines that have become well
established before the infestation by larvae will sometimes withstand
the attack of a considerable number of grubs, especially if the soil
is rich and has been well tilled. The evidence of continued heavy
infestation is indicated by absence of fibers upon the whiplike roots

Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture.

Plate II.

Feeding Marks on Grape Leaves, Made by the Beetle of the Grape Root-worm.

Fig. 1.— Appearanee of fresh feeding marks. Fig. Feeding marks which have become en-
larged with the growth of the leaf. Natural si/e. (Original.)

Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture.

Plate III.

Feeding Marks on the Larger Roots and Underground Part of the Stem of a
Grapevine by Larv/e of the Grape Root-worm, Resulting in the Death of the
Plant. Lower Figure Natural Size. iOriginalj

BEETLES RELATED TO GRAPE ROOT-WORM BEETLES.

15

(PL TV, fig. 2, in comparison with fig. 1) extending from the main
root a distance of several feet. The extremities of such roots are
frequently dead and in a decaying condition, and the portion near
the stem is much channeled and pitted by the feeding of the larger
larvae (PL III). The life of such vines during this infestation has
been sustained by the throwing out of new fibrous roots either at
the crown or from the large lateral roots at a short distance from the
base of the vine. If the number of larvae increases sufficiently to
eat off these new fibers, the whole vine declines quite rapidly, and the
effect of the attack is readily recognized by a sickly stunted growth
of vine and undersized clusters of fruit, and in extreme cases by the
early shedding of foliage and actual shriveling of fruit before the
ripening period.

BEETLES RELATED TO THE GRAPE ROOT-WORM BEETLE.

The grape root-worm is a member of the large group of leaf-eating
beetles known as the Chrysomelidae. To this family belong the
common Colorado potato beetle
(Leptinotarsa decemlineata Say),
the elm leaf-beetle (Galerucella lu-
teola Mull.), the asparagus beetle
(Crioceris as para gi L.), several
important pests of the genus
Diabrotica, the grapevine flea-
beetle (Haltica chalybea 111.), and
many other injurious beetles.

Closely related to Fidia viti-
cida Walsh (fig. 10) is the Cali-
fornia grape root-worm (Adoxus
obscurus L.) (fig. 2), of which
there are two varieties, namely,
a black form, known as A. obscu-
rus, and a bicolored form, known
as A. obscurus vitis. Both vari-
eties occur in this country and
have been reported from sev-
eral widely separated States and
from Canada. It is found generally in Europe and throughout
Siberia. At present it is becoming injurious to vineyards in Cali-
fornia, infesting the European varieties of the cultivated grape. A
valuable contribution to the knowledge of this insect was published
by Mr. H. J. Quayle a in 1908. In habits this beetle is in most
respects similar to the eastern grape root-worm, Fidia viticida, and
the two pests can thus be combated with similar methods. It will,
however, be necessary to take into consideration the local conditions

FIO. 2. — The California crape root-worm [Adoxtu
dbseurut)'. Adult or beetle. Much enlarged.
(Original.)

o Bul. 195, Gal. Agr. Exp. Sta., 1908.

16

THE GRAPE ROOT-WORM.

and variations as to the habits of the beetles in order to accomplish
effective results.

There are at present 6 species of the genus Fidia known to Boreal

America and by including
those occurring in Central
America there are 14 known
species. Of these, Fidia viti-
cida Walsh and Fidia lon-
gipes Melsh. have been re-
corded as being injurious to
the native varieties of the
domesticated grape. Fidia
longipes (fig. 3) is found gen-
eral^ throughout the Mis-
sissippi Valley and in the
Eastern States. It is, how-
ever, less common than F.
viticida. In Missouri and
Kentucky it occurred in in-
jurious numbers on the Con-
cord and on Norton's Vir-
ginia varieties of grapes.
The earlier stages of this
beetle are not yet known.
For characteristic distinction of the species of Fidia reference is
made to the works of Lefevre, Jacob}', Horn, and Schseffer, as listed
in the appended bibliography
(p. 93).

BEETLES FREQUENTLY MIS-
TAKEN FOR THE GRAPE
ROOT-WORM BEETLE.

There are several different
kinds of beetles injurious to the
grapevine, and these when found
in numbers are frequently mis-
taken for the grape root-worm
beetles. It is essential that an
insect pest should be properly
determined before any success-
ful control measure can be prop-
erly recommended. Although
most leaf-eating beetles can
be controlled with a poison spray, as used against the grape root-
worm, there exists a marked difference in the time of appearance of

Fig. 3.— The grapevine Fidia {Fidia longipes): Adult or
beetle. Much enlarged. (Original.)

Fig. 4.— The grapevine flea-beetle (Haltica chaly-
bea): Adult. Much enlarged. (Original.)

Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture.

Plate IV.

Fig. 2. — Four-year-old grapevine, Bhowing result of feeding by larvae oi the grape root-worm.

(Original.)

Destruction of Root Fibers by Larv/E.

BEETLES MISTAKEN FOR GRAPE ROOT-WORM BEETLES. 17

the different pests, so that an application intended for one may not
at all affect another. The descriptions with figures of the following
beetles and of their more characteristic habits will aid the vineyardist
in distinguishing the grape root- worm from other injurious species.

The grapevine flea-beetle (Haltica chalybea 111.) (fig. 4), measuring
about one-fifth of an inch in length, is readily recognized by its brilliant
metallic color, which varies from steel blue to green. It is of a robust
shape, with thickened thighs well adapted for jumping. With the
opening of the buds of the grapevine in the spring the beetle generally
makes its appearance. The larva?, which are found in the early part
of the summer, feed,
like the adult, upon the
leaves of the grape.

The rose-chafer
(Macrodactylus subspi-
nosus Fab.) (fig. 5) ap-
pears as a rule at the
time of the blossom of
the gr^pe. It is a slen-
der beetle about one-
third of an inch long,
with the body tapering
a little towTard each ex-
tremity. It is covered
with a grayish-yellow
down, which gives rise
to its color. The pale
reddish legs are long,
at the joint armed with
prominent spines, and
terminate in very long
black claws. The an-
tennae, or "feelers," are
short and have at the
end a laminated club-
like structure. The beetle readily attracts attention because of its
activity and great abundance wherever present. It preferably feeds
upon the clusters of the blossom, and to some extent upon young
grape-berries and leaves.

The red-headed Systena (Systena frontalis Fab.) (fig. 6) somewhat
resembles the previously described beetle. It is, however, smaller,
measuring about one-sixth of an inch in length, and is black in color
except for a pale reddish area between the eves. This beetle has ot*
late become quite injurious to young grapevines, feeding upon the
leaves to such an extent that it often kills the vines.

51282°— Bull. 89—10 2

Fig. 5.— The rose-chafer (Macrodactylus subspinotms): Adult or
beetle. Much enlarged. ^Original.)

The feeding

18

THE GEAPE ROOT-WORM.

marks of the beetles are quite characteristic, consisting of round
patches eaten into the parenchyma from the upper surface of the
leaves. It is a very shy little creature, and on the slightest dis-
turbance jumps off and hides beneath the foliage. Young vineyards
when infested should be promptly sprayed with a mixture of from
5 to 8 pounds of arsenate of lead to 100 gallons of water. This
gives the plants a very good protection. The earlier stages of this
insect are not known.

The grapevine Colaspis (Colas pis brunnea Fab.) (fig. 7) in its gen-
eral appearance resembles the grape root-worm beetle. It is, how-
ever, slightly smaller, has no
pubescence, and is of a pale yel-
lowish color. It is nearly one-
fifth of an inch long, with the
body densely punctate. On the

Fig. 6.— The redheaded Systena (Systena fron- Fig. 7.— The grapevine Colaspis {Colaspis brunnea):
talis): Adult or beetle. Much enlarged. Adult or beetle. Much enlarged. (Original.)
(Original.)

wing covers the deep punctures are arranged in double longitudinal
rows or striae. The beetle feeds upon the grape foliage in a manner
more or less similar to that of the grape root-worm beetle.

It is not within the scope of this paper to treat the various insect
problems, such as those of the grape leaf hopper (TypMocyba comes
Say), the grapeberry moth (Polychrosis viteana Clem.), the grape cur-
culio (Craponius insequalis Say), and others, which from time to time
confront the vineyardist. These pests demand special treatment,
and in cases of serious infestation an entomologist should be con-
sulted. It hast however, been our observation that well cultivated

DESCRIPTION.

19

and properly sprayed vineyards are less subject to the attacks of
insects. Such infestations are very frequently the direct outcome of
neglect in the general care of vineyards, as is more fully considered
elsewhere in this bulletin.

DESCRIPTION.
THE EGG.

(PI. I, figs. 3-4.)

The eggs of the grape
root-worm beetle are small
yellowish - whit e objects,
measuring 1.15 mm. in
length and are about one-
third as broad as long. In
form the egg is cylindrical, with the two ends almost hemispherical.
As the shell is very flexible and the eggs are generally laid crosswise
on the canes, they often assume a slightly curved shape. Through
the semitransparent shell the segmentation of the embryo can be
seen, and later, as the young larva attains its full development, the

Fig. 8.— The grape root-worm {Fidia viticida). Larva: a,
Side view of full-grown larva: b, front view of head; c,
maxillae and labium. Much enlarged. (Original.)

Fig. 9.— The grape root-worm. Pupa: a, Upper view. 6, lower view; C, normal position of pupa in
cell; c, d, showing the pupa supported by the spines in the cell; e, hind part of body, showing
terminal spines. Much enlarged. (Original.)

head with the dark-colored mandibles becomes clearly visible. Prof.
F. M. Webster observed the larva backing out from the eggshell in
the process of hatching.

THE LARVA.

(PI. I, figs. 5-6; text fig. S.)

The full-grown larva varies in length from S to ID mm. It is
whitish, with the head, thoracic shield, and spiracles pale brown.

20

THE GRAPE ROOT-WORM.

The mandibles and the margin of the clypeus and areas around the
antennae are almost black. The anterior margin of the upper lip is
armed with short and stout spines (tig. 8, 6), and as the inner surface
is reenforced by chitinous ridges extending inward, its function is
probably that of a scraper. The setae on the head and on the cervical
shield are rather prominent ; those on the sides and back of the body

are less conspicuous. The
ventral parts of the abdomi-
nal segments are armed with
strong spines, which are
particularly large on the
fourth to the eighth seg-
ments. These project ob-
liquely backward and are
properly termed ambula-
tory setae. The legs are
slender and proportionately
very small. Normally the
larva assumes a curved posi-
tion (fig. 8, a). The anterior
portion of the body can be
straightened out at will, but
the hinder parts remain
curved, which is character-
istic of the larvae of most
underground beetles. The
newly hatched larva is little

Fig. 10.— The grape root-worm: Adult or beetle. Much over 1 mm. in length and
enlarged. (Original.) Qf f ^ . ^ ^

are relatively large, and the setae of the entire body are long and
prominent.

THE PUPA.

(PI. I, figs. 7-9; text fig. 9.)

The length of the pupa is from 8 to 10 mm. When newly trans-
formed it is whitish, with a slightly pinkish tinge, which in a few days
after pupation disappears and the pupa becomes white. The upper
part of the head and anterior margin of the thorax are armed with
large spines; each anterior and posterior femur is armed with one
curved hooklike spine and two straight, more slender spines. The
middle femora have only hairlike bristles. The posterior end of the
abdomen carries two stout, flattened hooks, curved upward, and
several pairs of spines and bristles (fig. 9, c and d). The pupa in the

DESCRIPTION.

21

cell is supported by these larger spines and its body is not in touch
with the moist walls of the cell. As these large and strongly chiti-
nized spines do not occur in either the larval or the adult form of the
insects, it is probable that
their main function is to sup-
port the pupa in the cell.

THE ADULT OR BEETLE.

(PI. I, figs. 1-2; text figs. 10, 11.)

The original description of
the beetle as made by Walsh
is given below:

Fidia viticida, new species.
Chestnut rufous, punctured and
densely covered with short grayish
white prostrate hairs, so as to appear
hoary. Head rather closely punc-
tured, with a very fine longitudinal
stria on the vertex. Clypeus and
mandibles glabrous and black, the
clypeus with a subterminal trans-
verse row of punctures, armed with
long golden hairs, the mandibles
minutely punctured on their basal
half. Palpi and antennas honey-
yellow verging on rufous, the antennae
| as long as the body, with joint 4
fully £ longer than joint 3. Thorax
finely and confluently punctured,
about as long as wide, rather wider
behind than before, the sides in a
convex circular arc of not quite 60°,
the males with the thorax rather
longer and laterally less strongly curved than the females. Elytra punctato-striate,
the striae subobsolete, the punctures approximate, and rather large but not deep, the
interstices flat and with close-set fine shallow punctures. Legs with the anterior tibiae
•of the male suddenly crooked | of the way to their tip; anterior tibia* of the female as
straight as the others. Length $ .24-. 27 inch; 9 .24-. 28 inch.

The ovipositor of the female (fig. 11, d, e) consists of a more or less
solid terminal portion and a membranous proximal part. Ordinarily
it remains completely withdrawn within the abdominal cavity, where
the terminal part lies within the membrane, which is folded into three
parts. Meso-ventrally the membrane is supported by a slender ehi-
tinous rod (tig. 11, e). In the terminal portion arc a pair of chitinous
rods. Fully extended, the ovipositor is three4 times the length of the
abdomen.

Fig. 11. — The grape root-worm: Structural parts of the
adult or beetle— a, Front view of head, showing biting
mouth parts; 6, lower view of labium and maxilla?:
c, antenna or "feeler; " d, terminal portion of the
ovipositor; e, ovipositor with membranous portion
extended; /, front leg of male beetle; g, front leg of
female beetle; h, claws of tarsus. All parts greatly
enlarged. (Original.)

22

THE GRAPE ROOT-WORM.

SEASONAL HISTORY.

The grape root-worm attains its growth during the feeding period
of the larvae. The pupal stage, following the long larval period, is a
process of transformation, whereby all the internal organs, and to
some extent the external parts, become reconstructed, resulting, with
the throwing off of the pupal skin, in the appearance of the beetle.
It is during this latter stage and in the early part of the summer that
reproduction occurs.

The diagram (fig. 12) will, it is believed, greatly aid the reader in
comprehending the development and the activity of the grape root-
worm in its various stages throughout its life cycle. This illustra-
tion has been compiled from both field and rearing observations
and represents the life of a single beetle under average conditions.

In the following consideration of the life history of the grape root-
worm is presented the results of rearing experiments and field obser-
vations for the year 1909. In most respects that year was normal
as regards climatic conditions and the insect developed as might be
expected under average conditions. In view of the extreme varia-
tions in the development of the insect during 1907 and 1908, the
records of observations for these years have been treated under
the topic " Seasonal variations in the life history of the grape root-
worm." The rearing and experimental methods relating to the tables
of the life-history work are described separately on pages 44-50.

THE ADULT OR BEETLE.

THE PROCESS AND TIME OF EMERGENCE.

Prior to its emergence the beetle spends several days in the pupal
cell and at the time of the shedding of the pupal skin is of a light
turbid yellowish cast, and is comparatively soft and for a time help-
less. On an average the beetles remain 4 days in the cell, while the
parts of the body harden. In Table XV (p. 38) are given 25 observa-
tions on the length of time the beetles remain in the cell after trans-
formation. In one instance a beetle remained in the cell 7 days.
The minimum length of time was 2 days. Dead beetles have been
found in cells, both in the breeding cages and in the ground in vine-
yards. This occurrence, however, has not been found sufficiently
common to cause any material reduction in the number of insects.

The time required by the beetle in passing through the soil to the
surface varies considerably with the distance to be covered and the
texture and moisture of the soil. It has been possible to make only
a few observations on the process of emerging. These were made in
breeding cages with glass sides, in which the beetles have worked
their way out to the edge of the soil next to the glass. One beetle
which left the cell July 6 emerged July 9. On its way upward it had

SEASONAL HISTORY.

23

to dig around a flat pebble, and as a result passed through 31 inches
of soil. Another beetle left the cell July o and emerged July 6, having
penetrated the soil for a distance of 1 inch. A third beetle left the
cell July 16 and emerged Jul}' 19, in which time it worked through 2
inches of soil. In the process of digging, the beetles make use of the
mandibles and to some extent also of the legs. The cells become
partly filled with earth by material being pushed behind and beneath
the beetle. In this process the channel is refilled and only a small
hole is left on the surface to indicate where the beetle emerged (PI.

Fig. 12.— Diagram showing time and development of a single individual of the grape root-worm
under average conditions, as observed in 1909, at North East, Pa. ^Original.)

I, fig. 10). In vineyards where the ground remains undisturbed such
openings can be readily found during the emergence period of the
beetle.

In 1909 the first beetles observed in the tield were collected by the
senior author June 28, and, sinee daily observations were made of
vineyard conditions, this record probably represents the earliest
occurrence of the beetle for the season. In the breeding cages the

24

THE GRAPE ROOT-WORM.

first beetle emerged July 1, which shows a fairly uniform emergence
of beetles in captivity as compared with their emergence in the field.
The results of the emergence experiments are given in Table I.

Table I. — Date of the emergence of S98 grape root-worm beetles (Fidia viticida) from
the ground, as observed in the breeding cages in the spring and early part of the summer
of 1909 at North East, Pa.

Date.

Number
of beetles.

Date.

Number
of beetles.

Date.

Number
of beetles.

July 1

5

July 9

36

July 17....

8

July 2

9

July 10....

39

July 18....

4

July 3

16

July 11....

19

July 19. . . .

5

July 4

11

July 12....

36

July 20. . . .

2

July 5

15

July 13. . . .

22

July 22....

6

July 6

27

July 14....

16

July 23....

1

July 7

34

July 15. . . .

26

July 24....

5

July 8

31

July 16....

14

July 25. . . .

2

Total . .

148

Total . .

208

Total . .

33

Date.

July 27.
July 29.
July 30.
Aug. 5.
Aug. 9.

Number
of beetles.

Total

In figure 13 the curve shows more graphically the relative emer-
gence of these beetles. It will be noted from this curve that after

■gpi

JULY i 2

31 AUG 2 3 1 5 b 7

Fig. 13.— Curve showing time and relative emergence of beetles of the grape root-worm from the
ground in rearing cages at North East, Pa., 1909. (Original.)

the first emergence the beetles continued to appear in rapidly increas-
ing numbers, reaching a maximum July 10. The decrease in the
number of beetles emerging after this date was more gradual, and
emergence continued until late in the season. In the cages the last
beetle emerged August 9, while in the field a single beetle was still
found in the cell August 14. From July 1 to July 5, inclusive, 14.1
per cent had emerged; from July 6 to July 16, 75.4 per cent had
emerged; and the remaining 10.5 per cent emerged later. Thus the
great majority of over 75 per cent emerged during a period of 10 days,
and the maximum of emergence took place about 2 weeks after the
first beetle had been observed in the field.

SEASONAL HISTORY.

25

VARIATION EN THE TIME Of EMERGENCE.

Tlie variation found in the time of emergence of beetles in different
vineyards and even in different sections of the same vineyard is due
to various factors, such as temperature, moisture, porosity and tex-
ture of the soil, etc.

Since larvae are found more abundantly in the looser porous soils
than in the heavy, compact clay soils, and since the former soils are
warmer, it is but natural that the insect should emerge earlier under
these conditions. This fact is confirmed by observations presented
in figure 14, which shows the relative emergence of beetles from three
grades of soil. For these experiments a number of larvae were col-
lected in the early spring from different localities in the vicinity of
North East, Pa. They were confined in large earthen pots (fig. 22)
with the same kinds of soil in which they had been collected. Since
these larvae were supplied with a sufficient amount of food and the

*rit:rT":1:;::j :;;i::::t::::!::::j:::liu::!::
spttpst j :r «=~pnf«

::{::::!:::: , :.::)::::::. ::!::::. ::::.::
. .. .. .!....!:.: !: ' ! " -t : :ptt:t.:.;j: „.p„tt

'A.

• "'\

:•—+—•<•• S ■■■ \-

JUL.Y til S i J I 1 it, n

// /> il if a /? ,i If le ll JZ ib

Fig. 14.— Curves showing variations in time of emergence of beetles of the grape root worm from
different kinds of soil. From rearing experiments during 1909 at North East, Pa. (Original. )

pots were placed in the ground in the open, it is believed that their
normal conditions had been changed but slightly. The emergence
of beetles from the sandy and gravelly soil was seven days earlier
than the emergence from the clay soil.

In the vicinity of North East, Pa., the authors have observed that
the emergence of the beetle in vineyards situated on the hills is one
week later than the emergence in vineyards in the valley. This delay
is not merely confined to the time of emergence of the beetles, but
has been observed in practically all the different stages of the insect,
as can be verified from the various tables of field observations.

FEEDING BEFORE AND AFTER EGG DEPOSITION.

At the time of emergence from the ground the beetle seems to
possess a keen appetite. It readily finds its way to the grape foliage,
and generally feeds upon the first leaf thai it encounters. The leaves
of the lower shoots are frequently found badly mutilated as a result

26

THE GRAPE ROOT-WORM.

of this first feeding. The voracity with which newly emerged bee-
tles feed is indicated in the poison -spray experiments described on
page 65. Fifty per cent of newly emerged beetles were killed the
first day, against 10 per cent of older beetles, both sets being sub-
jected to identical conditions.

The feeding of the beetle is confined mainly to the upper surface
of the leaves; the parenchyma is devoured, leaving characteristic
chainlike feeding marks, as shown in Plate II. With individual bee-
tles the length of time of feeding previous to egg deposition varies
considerably. In Tables II and III is given the record of 16
individual females, showing a feeding period before oviposition vary-
ing from 9 to 24 days, with an average of 15.9 days.

Table II. — Oviposition, feeding , and length of life of individual male and female beetles
of Fidia viticida in captivity during the summer of 1909 at North East, Pa.

1.

2. 3.

1

4.

5.

6.

June 30

June 30

June 30

June 30

July 2

July 2

July 8
July 22
31

July 25
31

July 26
40

July 28
25

July 8
July 21
17

July 26

6

July 8-9
July 15

26

July 16
19

July 27
14

July 29
61

July 14
July 21
15

July 13
July 15
17

July 28
14

Aug. 3
5

Aug. 8
4

Eggs

Second oviposition

July 19
35

July 26
36

July 29
31

July 31
14

Aug. 4
14

Aug. 7
23

Eggs

Third oviposition

Eggs

Fourth oviposition

Eggs

Fifth oviposition

Eggs....

Eggs

Seventh ovinosition

Eggs

Fip-hth ovinosition 1

Eggs

Ninth oviposition

Eggs

Death of male

Aug. 8
Aug. 1

Aug. 26
Aug. 2

Aug. 19
Aug. 3

July 23
July 23

Aug. 25
Aug. 9

Death of female

Aug. 31

Davs of feeding before oviposition

Eggs per cluster:

Minimum

Average

Maximum

Total number of eggs

Length of life of male

22.0
4.0

25.0
31.8
40.0
127.0
39.0
31.0

21.0
2.0

6.0
11.5
17.0
23.0
57.0
32.0

15.0
4.0

14.0
30.0
61.0
120.0
50.0
33.0

21.0
1.0

15.0
15.0
15.0
15.0
23.0
23.0

13.0
4.0

4.0
10.0
17.0
40.0
54.0
38.0

17.0
6.0

14.0

25.5
36.0
153.0

Length of life of female

60.0

SEASONAL HISTORY.

27

Table II. — Oviposition, feeding, and b ivjOi of life of individual male, and femnU h'tth.<
of Fidia vif icidu in captivity during the summer of 1909 at North East, Pa.— Cont'd.

Number of experiment.

Date of emergence of beetles.

Mated .

First oviposit ion

Eggs

Second oviposition..

Eggs

Third oviposition. . .

Eggs

Fourth oviposition. .

Eggs

Fifth oviposition

Eggs

Sixth oviposition. . .

Eggs..........

Seventh oviposition.

Eggs

Eighth oviposition..

Eggs

Ninth oviposition. .

Eggs

July 3

July 14

July Hi
14

July 9 July 10

(July 12
\ to 15
July 22
25

July 25
51

July 28
43

July 30

[July 14

July 19
19

July 20

35

33
2
28
5
21
7
18

Aug. 8
15

Aug. 13
29

Aug.
Aug.
Aug.

10.

July 10

July 14

July 22

23

July 20
48

Julv 27

26

Aug. 3
43

Aug. 0
24

II.

July 11

Aug. 10 July 23 Aug. 14 Sept. 9 Aug. 14
Aug. 23 July 24 Aug. 26 Aug. 22 Aug. 6

July 22

July 27

22

July 29
15

Aug. 3
28

Aug. 5
25

Aug. 8
11

Aug. 9
11

12.

July 12

July 28

Aug. 3
35

Death of male. .
Death of female.

Days of feeding before oviposition,

Times of oviposition

Eggs per cluster:

Minimum

Average

Maximum

Total number of eggs

Length of life of male

Length of life of female

Aug. 25
Aug. 23

13.0
1.0

14.0
14.0
14.0
14.0
53.0
51.0

13.0
9.0

15.0
29.2
51.0
263.0
32.0
45.0

9.0
2.0

19.0
27.0
35.0
54.0
13.0
14.0

12.0
5.0

23.0
32.8
48.0
164.0
35.0
47.0

16.0
6.0

11.0
18.6
28.0
112.0
60.0
42.0

22.0
1.0

35.0
35.0
35.0
35.0
33.0
25.0

Number of experiment.

15.

Date of emergence of beetles July 12 July 27 July 27

July 30

Totals.

Mated

First oviposition

Eggs

Second oviposition..

Eggs

Third oviposition. . .

Eggs

Fourth oviposition ..

Eggs

Fifth oviposition

Eggs

Sixth oviposition. . .

Eggs

Seventh oviposition.

Eggs

Eighth oviposition..

Eggs

Ninth oviposition. . .

Eggs

July 27
July 28
25

Aug.

Aug.
Aug.
Aug.

1

22
3
35
5
19
7
16
Aug. 11
19

Aug. 14
18

Aug. 19

23

Aug. 23

23

Aug. 6
57

Aug. 8
43

Aug. 9
25

Aug. 13
8

Aug. 14
37

Aug. 17
46

Aug. 19
16

Aug. 20
19

Aug.
Aug.

Aug.

Aug.

6
7
20
8
22
13
4

Aug. 18
39

Aug. 23
28

Aug. 23
35

Aug. 26
20

Sept. 10
29

Sept. 14
23

416

2S0

294

I5S

120

52

52

Average.

26.0
'27.8
25.5
'26.' 7
22.' 6
24.0
17.3
19.0
15.7

Death of male. . .
Death of female.

Aug. 25

Aug. 28
Aug. 26

Days of feeding before oviposition .

Tiiiies of oviposition

Eggs per cluster:

Minimum

Average

Maximum

Total number of eggs

Length of life of male

Length of life of female

16. 0
9.0

36. o

200. 0

44.0

10. 0

8.0
8.0

31.4
57.0
251.0
82. o

30. 0

Aug. 14
Aug. 27

Sept. 22
Aug. 15

11.0 I
5.0

4.0

22. 6
39. 0
113.0
18. 0
31.0

24. 0
4.0

20.0
20. 7
35. 0
117.0
54.0
Hi. 0

255
71

15.9
4.4

388. 3

24. 0

L781
553
582

112.0
38. l
33. 1

28

THE GRAPE ROOT-WORM.

Table III. — Summary of oviposition experiments, recorded in Table II, showing the final
average, maximum, and minimum, of egg deposition by individual female beetles in
captivity, at North East, Pa., 1909.

Observations.

Average.

Maximum.

Minimum.

Number of days previous to first oviposition

15.9

24

9

Number of times of oviposition

4.4

9

1

Number of davs between ovipositions

3.6

15

1

Number of eggs per cluster

24.0

61

4

Number of eggs per female

112.0

263

14

In Table V (p. 30), giving records of experiments with a large
number of beetles in stock jars, where only the minimum length of
time could be verified, this feeding period is shown to have covered
from 9 to 10 days. Feeding is continued for almost the entire length
of life of the beetle, and it has undoubtedly a direct bearing upon the
number of eggs deposited.

MATING AND ITS BEARING UPON EGG DEPOSITION.

Mating of beetles has been observed a few days after their emer-
gence. It has been found to take place several times before the first
egg deposition, the day previous to oviposition, and also after each
oviposition. Repeated mating, however, is not essential in bringing
about further egg depositions, as shown in one instance under obser-
vation (Table II, jar No. 13). In this jar the male and the female
beetles were confined together shortly after emerging. Mating took
place July 27, 28, and 30. The male beetle escaped August 5, yet
oviposition by the same female occurred on August 7, 11, 14, 19, and
23 without further mating.

PROCESS OP EGG DEPOSITION.

As the time of egg deposition approaches, the female beetles cease
feeding for a day or two and become sluggish and somewhat inactive.
They generally seek the shady places and are at this period to be
found on the canes of the vines, where they are less easily detected.

The eggs are deposited almost entirely under the loose bark on the
canes and trunk; very rarely, however, they are placed on other parts
of the vine. The female inserts the eggs beneath the loose bark by
means of the protrusible ovipositor (fig. 11, e) and places them side
by side in a cluster of a single layer. An adhesive substance, secreted
by the female, glues the eggs together, and the entire mass is fastened
either to the cane or to the inner surface of the loose bark (PI. I, figs.
3, 4). Individual female beetles have been observed to move along
the canes in search of suitable places for egg deposition. In this
process the hind end of the body touches the cane, and as the insect
slowly passes along the ovipositor is inserted into the cracks or crev-
ices, apparently testing the fitness of these places for egg deposition.
A female beetle is shown in Plate I, figure 1, photographed in the act
of oviposition.

SEASONAL HISTORY.

29

VARIATION IN THE NUMBER OF EGOS PER CL1 9TEB.

Under average conditions the eggs for each oviposition are all laid
in a single cluster. In this respect exceptions occur when the female
is disturbed in the act of oviposition or when the space is too small to
hold all the eggs. On the other hand, it has been frequently found
that eggs have been laid side by side by different females, so that
from the appearance of the cluster separate depositions could not be
told apart. In the breeding experiments clusters containing from 30
to 35 eggs have been found quite frequently, and these figures repre-
sent, approximately, the average number of eggs per cluster. Table
II gives the egg deposition of 16 female beetles. As here there had
been interference to some extent, and the beetles had been confined
in captivity, the average number of 24 eggs per cluster was compara-
tively low. The maximum number of eggs in one cluster was 61 and
the minimum 4 (Table III). In the rearing cages the period for
each separate oviposition occasionally extended over from 1 to 2
days, rarely 3 days; normally, however, the eggs were all laid at
once and in a single cluster.

NUMBER OF SEPARATE OVIPOSITIONS BY INDIVIDUAL FEMALES.

Different female beetles have displa}^ed considerable diversity in the
number of times of oviposition. In the experimental work 8 individ-
uals failed to deposit any eggs ; others, as recorded in Table II, ovipos-
ited from 1 to 9 times, or, on an average, 4 or 5 times. Similarly, the
length of time between each oviposition is variable. An average of 4
days elapsed between each oviposition. Often the interval has been
only 1' da}T, while in the other extreme in one case the interval was 15
days. (See Table IV.)

Table IV. — Number of days between ovipositions of (he grape root-norm as observed
during 1909 in breeding cages at North East, Pa. (Supplementary to Table II.)

No. of ex-
periment.

Periods between ovipositions.

Total.

A \ -er-
ase per
female.

I.

II.

in.

IV.

V.

VI.

VII.

vm.

1

3
5

1

2

6
5
14

2.0
5.0
4.7

2

3

11

2

4

5

13
7

6
3

5
2

24
19

8.0
3.8

6

4

3

7

8

3
4
4

2

3

2

3

3

2

1

5

22
4
15
13

2.7
4.0
3.7
2.6

9

10

1

5

7
2

3
3

11

1

12

13

4
2
1

3

2
1
5
15

2
4
5
4

2

T

5

4

3

3
2

5

4

26
14
16
22

3.2
2.0
4.0
7.3

14

15

16

Total....
Average..

52
4.0

53
4.8

37
3.4

21
3.0

14

2.8

7

2.3

7

2.3

9
4.5

200

53.0
4.07

30

THE GRAPE ROOT-WORM.

NUMBER OF EGGS DEPOSITED BY INDIVIDUAL FEMALE BEETLES.

The total number of eggs laid per female seems to depend upon the
vitality of the individual insect, and undoubtedly also upon the
amount of feeding by the adult. In the experiments of Table II
the average was 112 eggs per female, with a maximum of 263 and a
minimum of 14 eggs. In Table V is presented the results of the so-
called ''stock-jar" experiments, in which several beetles were
confined.

Table V. — Egg deposition of the grape root-worm by about 57 female beetles in eight
stock jars, as observed in 1909 at North East, Pa.; with a summary of the length of
life of the beetles for each stock jar.

Stock jars.

II. III.

IV.

VI. VII.

VIII.

Number of
beetles.

25.

12.

Date of the
emergence.

July

July 10.

July 11.

July 12.

July 13.

July 16. July 19.

July 22.

Date of ovi-
position:
July 19..
July 20. .
July 21..
July 22..
July 23..
July 25..
July 26..
July 28..
July 29..
July 30..
July 31 . .
Aug. 1...
Aug. 3...
Aug. 4...
Aug. 5...
Aug. 6...
Aug. 7...
Aug. 8...
Aug. 9...
Aug. 11..
Aug. 13..
Aug. 14..
Aug. 19..
Aug. 23..
Aug. 27..

Total ovi-
position

Eggs per
female. .

107
70
64
96
94
43
81
22

121

76.5

in;,

33
44
21

328
31.2

29

138
55.2

37.1

443
55.3

150
25.0

472
134.9

246
82.0

LENGTH OF LIFE OF BEETLES.

Maximum

number of

days

50

48

23

47

53

13

46

53

Average num-

ber of days..

21.6

20.3

12.0

15.9

23.5

5.0

28.7

20.2

Minimum

number of

days

0

5

4

3

2

3

6

1

SKASONAL IIISTOKV.

31

The number of female beetles for each jar has been estimated to be
at least half of the total number placed 1 herein. The average number
of eggs per female for each separate experiment varied considerably.
In jar 7 there were approximately 135 eggs per female, in jar 6 only
25 eggs per female, or a final average for the eight jars of only 55
eggs per female. In considering the average egg deposition in the
breeding cages there were found to be about 75 eggs per female.

THE OVIPOSITION PERIOD FOR THE SEASON OF 1909.

The oviposition period and the number of eggs deposited for the
entire season is directly influenced by the time of emergence and
occurrence of the beetles. In Table VI is given the total egg depo-
sition of beetles in captivity.

Table VI. — Records of the total egg deposition of the grape root-worm in breeding cages
at North East, Pa., during 1909.

Date.

July 8

July 13

July 15

July 16

July 18

July 19

July 20

July 21

July 22

July 23

July 2b....

Total

Eggs.

29

83
104
153

43
155
149

88
427
121
225

1,577

Date.

July 26
July 27
July 28
July 29.
July 30
July 31.
Aug. 1 .
Aug. 2.
Aug. 3.
Aug. 4.
Aug. 5.

Total

Eggs.

360
62
333
379
137
123
185
28
421
71
223

2,322

Date.

Aug. 6.
Aug. 7.
Aug. 8.
Aug. 9.
Aug. 10
Aug. 11
Aug. 12
Aug. 13
Aug. 14
Aug. 16
Aug. 17

Total

Eggs.

291
353
397
102
19
74
29
101
152
26
46

1.590

Date.

Aug. 18.
Aug. 19.
Aug. 20.
Aug. 23.
Aug. 26.
Aug. 27.
Sept. 3.
Sept. 10
Sept. 12
Sept. 14
Sept. 20

Total.

Eggs.

39
81
19
163
20
23
40
29
22
23
15

Total number of eggs: 5,963.

With the exception of a few early records, which were obtained
from beetles collected in the field June 30, these records represent
the total oviposition by the greater proportion of the beetles emerging
in breeding cages (listed in Table I), and for their entire length of
life. As the date of the emergence of these beetles was normal and
simultaneous with the occurrence of beetles under natural conditions
in the field, it is thought that this record of egg deposition may
closely approximate oviposition in vineyards. In considering the
relative number of eggs laid at different dates, it will be found
(Table VI; fig. 15) that previous to July 22, 13.5 per cent were
deposited; from July 22 to August 8, 71.4 per cent, and after August
8, 15.1 per cent. Previously it has been shown how the time of
emergence of the beetle varied, as a result of the development of the
insect under different conditions. Thus oviposition in the same
sections of the grape belt must differ under similar variations. The
extreme of such variations has been especially marked in vineyards

32

THE GRAPE ROOT-WORM.

located on the hill as compared with those in the valley. In Table
XI is shown the time of hatching of eggs in the two named localities.
On the hill the eggs were one week later in hatching, mainly as the
result of later deposition.

Fig. 15. — Curve showing time of egg deposition and relative abundance of eggs laid in rearing
cages by beetles of the grape root-worm at North East, Pa., during 1909. (Original.)

LONGEVITY OF MALE AND FEMALE BEETLES.

On an average the beetles have lived in captivity one month. In
Table VII will be found a full account of the length of life of individual
male and female beetles.

Table VII. — Length of life of individual male and female beetles of the grape root-worm
as recorded in breeding cages at North East, Pa., during 1909.

No.

Sex.

Date.

Days.

Emerg-
ence.

Died.

Male.

Fe-
male.

1

3

June 30

Aug. 4

35

2

9

...do....

July 22

22

3

3

...do....

July 26

26

4

9

...do....

July 27

27

5

3

...do....

July 22

22

6

9

...do....

July 21

21

7

3

...do....

Aug. 19

50

8

9

...do....

Aug. 3

34

9

3

...do....

Aug. 8

39

10

9

...do....

Aug. 1

32

11

3

...do....

Aug. 26

57

12

9

...do. ...

Aug. 2

33

13

3

...do. ...

July 22

22

14

9

...do....

July 23

23

15

3

July 2

Aug. 25

54

16

9

...do....

Aug. 9

38

17

3

...do....

Escaped.

18

9

...do. ...

Aug. 31

60

19

3

July 3

July 23

20

20

9

.. .do

July 24

21

21

3

July 9

Aug. 10

32

22

9

...do....

Aug. 23

45

23

3

July 10

Aug. 27

"'48

No.

Sex.

Date.

Days.

Emerg-
ence.

Died.

Male.

Fe-
male.

24

9

July 10

Aug.

11

32

25

3

.. .do

Aug.

6

27

26

9

...do....

Aug.

4

25

27

3

...do....

Aug.

14

35

28

9

...do....

Aug.

26

47

29

3

...do....

Aug.

23

44

30

9

...do....

Aug.

24

45

31

3

July 11

Aug.

22

42

32

9

.. .do

Sept.

9

CO

33

3

July 12

Aug.

28

34

9

.. .do

...do

28

35

3

...do....

Aug.

5

24

36

9

...do....

Aug.

25

44

37

3

...do....

Aug.

6

25

38

9

...do....

Aug.

26

41'

45

39

3

June 15

Aug.

25

40

9

...do

...do.

41

41

3

July 27

July

28

1

42

9

.. .do

Aug.

26

30

43

3

...do....

Aug.

14

18

44

9

...do....

Aug.

27

31

45

3

July 30

Aug.

15

16

46

9

.. .do

Sept.

22

54

SEASONAL HISTORY.

33

The summary of these records (Table VIII) shows that the female
beetles on an average, not individually, survived the males by 4 day-.

Table VIII. — Summary of the length of life of individual male and female beetles of

Table VII.

Sex.

Average.

Maximum.

Minimum.

Male

Day a.
32.1

Day*.
54

Days.

1

Female

36.4

m

21

The maximum length of life for the males was 54 days, while that
for the females was 60 days. In Table V is given further a summary
of the length of life of the beetles in the stock jars, where no separate
record has been made as to life of male and female individuals.

THE EGG.

IXCUBATIOX PERIOD OF THE EGG.

The time necessary for the hatching of the eggs depends largely
upon the prevailing temperature and probably also upon moisture
conditions. Experiments to test the effective limits of these influ-
ences have not been made, but the results of these factors Lave been
in a general way well marked as is evident from the difference in the
time of hatching of individual egg clusters throughout the season
(see Table IX). In different sections of vineyards the hatching
probably varies slightly, since some eggs are located in well shaded
places, while others are so situated as to receive more heat from the
sunlight. In the middle of the hatching period eggs which were kept
in an open outdoor shelter hatched, on an average, in 12 days. The
rate for hatching for the entire egg period is shown in Table IX.
51282°— Bull. 89—10 3

34 THE GRAPE ROOT-WORM.

Table IX. — Incubation period of eggs of the grape root-worm as observed in 1909 at

North East, Pa.

No. of

° v^r"
tion

Date.

Days.

No. of
obser-

tion

Date.

Days.

Laid.

Hatched.

Laid.

Hatched.

1

July

15

July

29

14

49

Aug.

7

Aug. 23

16

2

...do.

July

30

15

50

Aug.

8

Aug. 20

12

3

July

16

...do.

14

51

...do.

Aug. 21

13

4

July

18

July

3i

13

52

...do.

Aug. 22

14

5

...do.

Aug.

1

14

53

...do.

Aug. 23

15

6

July

i<j"

...do.

13

54

...do.

Aug. 24

16

7

July

20

...do.

12

55

Aug.

*9

...do....

15

8

...do.

Aug.

"2

13

56

...do.

Aug. 25

16

9

July

21

...do.

12

57

Aug.

16"

...do....

15

10

...do.

Aug.

Z

13

58

...do.

Aug. 26

16

11

July

22

Aug.

2

11

59

...do.

Aug. 27

17

12

...do.

Aug.

3

12

60

Aug.

U

Aug. 26

12

13

July

23

Aug.

4

12

61

...do.

Aug. 27

13

14

July

25

Aug.

6

12

62

...do.

Aug. 28

14

15

July

26

...do.

11

63

...do.

Aug. 29

15

16

...do

Aug.

"i

12

64

...do.

Aug. 31

17

17

July

27'

...do

11

65

Aug.

16

...do....

15

18

July

28

Aug.

"%

11

66

...do

Sept, 1

16

19

July

29

...do

10

67

Aug.

'u

...do....

15

20

...do

Aug.

"9"

11

68

...do.

Sept. 2

16

21

...do

Aug.

10

12

69

...do.

Sept. 4

18

22

July

30"

Aug.

9

10

70

...do.

Sept. 5

19

23

...do

Aug.

10

11

71

Aug.

is"

Sept. 4

17

24

...do

Aug.

11

12

72

...do.

Sept. 5

18

25

...do

Aug.

12

13

73

...do.

Sept. 6

19

26

July

31 "

Aug.

11

11

74

...do.

Sept. 7

20

27

...do

Aug.

12

12

75

...do.

Sept. 10

23

28

Aug.

T

...do

11

76

Aug.

i9"

Sept. 3

25

29

...do

Aug.

13'

12

77

...do.

Sept. 4

16

30

Aug.

"2"

...do

11

78

...do.

Sept. 6

18

31

Aug.

3

...do

10

79

...do.

Sept. 7

19

32

.. .do

Aug.

\X

11

80

...do.

Sept. 8

20

33

.. .do

Aug.

15

12

81

.. .do.

Sept. 9

21

34

...do

Aug.

16

13

82

...do

Sept. 10

22

35

Aug.

"4

Aug.

17

13

83

...do

Sept. 11

23

36

Aug.

5

Aug.

16

11

84

...do.

Sept. 12

24

37

. . .do

Aug.

17

12

85

Aug.

26'

Sept. 6

17

38

...do

Aug.

18

13

86

.. .do.

Sept. 7

18

39

...do

Aug.

19

14

87

...do.

Sept. 8

19

40

Aug.

Aug.

18

12

88

...do.

Sept. 9

20

41

...do

Aug.

19

13

89

Aug.

26"

Sept. 18

23

42

...do

Aug.

20

14

90

...do.

Sept. 19

24

43

...do

Aug.

21

15

91

Sept.

3"

Sterile.

44

Aug.

Aug.

18

11

92

Sept,

10

Sterile.

45

.. .do

Aug.

19

12

93

Sept.

12

Sterile.

46

...do

Aug.

20

13

94

Sept,

13

Sterile.

47

...do.

Aug.

21

14

95

Sept.

14

Storile.

48

...do

Aug.

22

15

96

Sept.

20

Sterile.

Table X. — Summary of Table IX; time of incubation of grape root-worm eggs for 1909.

Incubation.

Average.

Maximum.

Minimum.

Days.

Days.

Days.

For the entire egg period

14. 67

24

10

For the maximum egg period, July 22-Aug. 8, inclusive

12.3

16

10

Eggs laid at approximately the same date by the same female
varied in the time of hatching to the extent of several days. The
embryological development becomes particularly prolonged later in
the season with the advent of colder weather. All the eggs laid dur-
ing the month of September failed to hatch.

The rate of hatching of eggs in the field has been recorded in
Table XI.

SKASONAL HISTORY.

35

Table XL— Field observations on the hatching of eggs of the grape root-worm in the
valley and on the hill in the vicinity of North East, Pa., 1909.

In the volley.

On the hill.

Date.

Number

of
clusters
counted.

Percent-
age of
clusters
hatched.

Date.

Number
of

clusters
counted.

Percent-
age of
clusters
hatched.

Julv 30. . .
Aug. 4 . . .
Aug. 12..
Aug. 19..
Aug. 20..
Sept. 2...

41

70
67
90
103
78

39
42
70
91
97
100

July .30. . .
Aug. 13 . .
Aug. 19 . .
Aug. 26 . .
Sept. 2. . .
Sept. 9..
Sept. 16. .

48

56
76
66
97
98

87

10
40
60
77
81
92
100

THE LARVA.

VITALITY OF THE NEWLY HATCHED LARVA.

On hatching, the minute larva drops to the ground and makes its
way to the roots of the vine through cracks and crevices in the soil
and by burrowing. In this struggle to reach the food supply there
is probably always a high percentage that perishes, for the number of
eggs deposited is much larger than the number of larvae found Later
in the ground.

The power of the young larva to exist for a time without food,
however, is remarkable. In the breeding of the insect a number of
newly hatched larva?, confined in a glass tube, were kept alive for 8
days without food or moisture. Interesting experiments showing
the burrowing and traveling powers of the young grub were carried
out by Dr. E. P. Felt in 1902. This gentleman found that one larva
had traveled a distance of over 47 feet in 7 hours, or an average of
6 feet an hour. In another experiment he found that 14 young
larvae out of 40 penetrated through loose earth in a glass tube 17
inches long in a period of 4 days. This tube was one-half inch in
diameter and bent so that 4 inches were vertical. In our breeding
cages young larva1 were found to feed upon the humus of the soil
before reaching the root fibers: therefore it is not surprising that
many larvae do penetrate to the roots, even under unfavorable con-
ditions, and that they are found in vineyards in compact clay soil.

FEEDING AND DEVELOPMENT OF THE LARVA BEFORE WINTERING.

During the summer and until late fall the larviv feed extensively,
and on an average attain three-fourths the full size and frequently
full growth before wintering.

The young larva feeds mainly upon the finer routs and root libers
of the grapevine. Later it attacks the larger roots, devouring the
bark in longitudinal furrows, as shown in Plate III. Sometimes the

36

THE GRAPE ROOT-WORM.

feeding may even extend to the underground portion of the stem.
Most of the larvae are found within a distance of from 2 to 3 feet of
the crown of the vine, and at a depth varying with the root system
of the vines and the character of the soil.

The rate of growth of the larva varies under different conditions.
The time of hatching, the abundance of food, and the ease with which
food can be obtained are determining factors. As a rule the larvae
are found more abundantly in loose,- porous soils, and especially on
exposed ridges in the vineyards. (Table XII; fig. 14.)

Table XII. — Occurrence of larvae of the grape root-worm in different soils. Summary
of field diggings for 1907, 1908, and 1909, at North East, Pa.

Year.

Date of digging.

Total
number
of larvae.

1909.

|/May 13-Jurie 8 ! 831

\May31 1 1

fMavl8-June9 96

\Junel2 3

(May 24-June 25 1 539

I May 19-June 25 439

May 27-JuIy 10 102

June 1- Jul v 10 ' 20

Number
of vines
examined.

Gravel. .
Clay

Gravel. .
Clay

Silt a ...
Gravel. .
Loam . . .
Clay

Number
of larvae
per vine.

6
1

6
5
3

0.4

a Very light porous soil.

From rearing and field observations we have found that the larvae
are less abundant and slightly retarded in their development in clay
soils. This is natural in that the larvae can not move about to obtain
food in this soil so readily as in soils of looser texture.

The growth of some larvae is sometimes delayed to such an extent
as to hinder them from transforming at the normal period in the
spring. Hence these belated larvae remain an additional year in the
ground and transform in the spring of the second year. The causes
of delay in the development and the percentage of belated larvae
have been described in detail on pages 41-44.

WINTERING OF THE LARVA IN AN EARTHEN CELL.

As the time for hibernation approaches the grubs penetrate deeper
into the ground, generally slightly below the roots of the vines. An
earthen cell is made in which the larva spends the winter. It was
observed in the field in the fall of 1909 that the 2-year-old larvae,
referred to above, were the first to hibernate. Some of these were
already in the wintering cells by the middle of August, when most
of the larvae of the new brood were still extremely small or had not
yet hatched. In Table XIII is shown the relative occurrence of
larvae in wintering cells in the different vineyards. The actual
percentage is higher than given, because in the process of digging
many cells were broken, and thus escaped being noticed.

SEASONAL IIISTOHV.

37

Table XIII. — Percentage of hibernating larvx of the grape root-worm as found in
vineyards during the full of 1909 a' Xorth East, I'a.

Curtis vineyard, in
the valley.

Algren vinevard, in
the valley.

Young vinevard, on
the hill.

Date of
digging.

Percent-
age of
larva?

in cells.

Date of
digging.

Percent-
age of
larvae

in cells.

Date of
digging.

Percent-
age of
larvae

in cells.

Oct. 5

5

Oct. 4 ...

0

Oct. 12...

0

Oct. 12. . .

20

Oct. 14...

0

Oct. 20. . .

3

Oct. 19...

12

Oct. 19. . .

14

Oct. 28...

16

Oct. 28...

83

Oct. 25. . .

36

Nov. 12..

33

SPRING FEEDING OF THE LARVA .

In the spring, with normally developed larvae, comparatively
little feeding takes place. In the early part of May, 1909, the
larva? in the rearing cages were still in their wintering cells, and
the condition in the field in most places did not permit the larvae to
become active previous to that time. Since occasional pupal cells
were found on May 24 in the field (Table XIV) and continued to
appear in rapidly increasing numbers, the time of spring feeding
may, on an average, have lasted 20 to 25 days.

Table XIV. — Appearance of larva- of the grape root-worm in cells previous to pupation

at North East, Pa., 1909.

Date of
digging.

Soil

Total Number

r-onflition number of larvae
condition. oflarv.p_ in cells.

Mav 19..
May 24..,
Mav 25..

Mav 2& !
Mav 27..
May 29. .
June 1 . .
June 2. .
June 3. .
June 4. .

Gravel.
Sandv .

do.

Loam . .
Gravel.
Clav...
Silt . . . .
Clav. ..
Cra vol.
Silt. ...
Gravel.

230 .

35
140

33

32

47

79
6 .

63
54

Percent-
age of
larvae

in cells.

8.6
2.S

21.2
6.2
8.5

29.1

2.8
39.0

TIME AND MAKING OF THE PUPAL CELL.

The pupal cells are found from 2 to 3 inches below the surface of
the ground. Like the wintering cells, they are made by a peculiar
rolling and twisting motion of the larva, whereby t ho cavity is
enlarged, the earth becomes packed together, and the inside smoothly
finished. The cell is quite spacious and would readily accommodate
a larva twice the size of the ow ner. Usually 15 days are required to
complete the pupal cell. As recorded in Table XVI, the average
length of time spent by the larva* in the cell IS -1 days, which includes
the post-larval stage described below. Should the cell be disturbed

38

THE GRAPE ROOT-WORM.

or destroyed some time before the post-larval period, a new one is
readily made, and, as a rule, within a shorter time than was required
for the making of the first cell. As recorded in Table XV, individual
No. 21, a larva made the second cell and pupated within 9 days.

Table XV. — Observations on the transformations and habits of the pupa and the beetle
of the graps root-worm in the soil, from breeding experiments at North East, Pa., 1909.

Number of individual.

1

2

3

4

5

6

7

8

9 :

10

11

12

13

14

15

16

17

18

19

20 June

21 ...do.

22 | May

23 i June

24 June

25 May

26 L.do.

Date.

Making
of cell.

May
May
May
May
May
Mav
Mav
May
..do.
May
May
May
Mav
May
Mav

Mav
...do.
..do.
..do.

26

May
. . .do.
...do.
...do.
June

May
June
June

Pupa-
tion.

June 17
..do...
..do...
June 15
June 20
June 19
June 21

L . . do

June 20
June 21
June 24

I June 20
June 21
...do....

I. ..do....

! June 20
June 18
June 21
..do...
..do....
..do....
June 16
June 24
June 21
June 22
June 26
June 23
..do.
June 25
..do.
June 2
June 22
June 23
June 25
June 26
June 25
June 29
June 21
June 10
June 23
..do ....

Trans-
formed
to beetle.

Total.

June 30
July 1
July 2
June 30
July 7
July 9
July 10
...do....
July 2
July 9
..do....
..do....
July 10
...do....
July 9
..do....
July 7
July 10
July 9
..do....
July 6
July 12
July 11
July 13

..do

July 11

..do

..do. ...
July 12
July 14
July 23
July 10
July 12
July 11
July 14
July 15
July 17
July 8

Left the
cell.

July 6
(Died).
..do...
July 5

July 14

...do

(Died). .
July 13
July 14
July 13
...do...
July 14
July 13
July 16
July 13
...do...
...do...

July 13
July 16

July 16
(Died). .
July 14

..do

...do.
...do....
July 18

July 17
July "l7'

July 11 July 15

Days.

Making
cell.

Pupal
stage.

10
18
15

513

Table XVI. — The making cf the pupal cell, the pupal period, the beetle in the cell;

summary of Table XV.

Average.

Maximum.

Minimum.

Days.

Days.

Days.

The making of the pupal cell

21.4

33

9

Pupal stage

17.8

21

12

Beetle in cell

4. 1

7

2

THE POST-LARVAL STAGE.

During the post-larval stage the grub undergoes marked structural
changes and is in this condition extremely delicate and helpless. The
body is slightly shortened, and the curved grublike appearance is modi-

SEASONAL HISTORY.

fied to a more cylindrical form. To some extent the legs become
shorter and remain practically motionless. The white color- changes
to a light pinkish tint, which is especially marked toward the extreini*
ties. Should the cell be destroyed during this period the larva is
incapable of making a new one, and in many instances, as has fre-
quently been observed in the breeding experiment, the larva fails to
pupate.

THE PUPA.

THE PROCESS OF PUPATION.

Pupation is the result of the changes brought about during the post-
larval stage. In the process of pupation the larval skin splits on the
back of the thorax and on the head, and the skin is ruptured along the
median line and in front along the V-shaped suture toward the mouth
(fig. 8, h). As the pupa frees itself from the larval skin it is of a
rather elongated form. The appendages are short, and the skin on
these parts is wrinkled in a circular manner. The light pink color is
particularly marked on portions around the spines, head, prothorax,
the points of the legs, and on the hind end of the body. The pupa is
at this stage very restless, turning the abdomen in a circular motion,
which, together with a contracting motion, brings about the expansion
of the appendages and the assuming of the normal shape of the pupae.
Unlike many pupae of beetles of this group, the larval skin is com-
pletely freed from the pupa. Within a short time the pupa becomes
whiter in color and the prominent spines turn darker as they harden.

POSITION OF THE PUPA IN THE CELL.

Within the cell the pupa is continually moving, often changing its
position and constantly turning the abdomen in a circular manner.
Normally the pupa lies on its back, and the soft body of the tender
creature is kept from close contact with the moist walls of the cell by
the spines on the appendages and on the back of the body (fig. 9),
This function of the spines is undoubtedly of great importance in the
development of the pupa, since4 this is the critical period of the insect,
when the organs and in fact all the parts of the insect are recon-
structed in the formation of the adult or beetle. The pupa 1^ com-
pletely helpless when removed from the cell and is incapable of
making a new one, and if left on the surface of the ground or covered
up with earth it almost invariably perishes.

TIME OF PUPATION IN THE FIELD AND IN BREEDING GAGES.

In the field during the summer of 1009 the first pupae were found
June 11, while in the breeding cages the first pupa was found June L5.
The time of pupa t ion is Indicated in Table XVII, show ing t he relat ive
occurrence of the pupae in the field.

40

THE GEAPE ROOT-WORM.

Table XVII. — Time of transformation of larvse and pupse of the grape root-ivorm in
the field, as observed in the vicinity of North East, Pa., 1909.

Vineyard.

Date
exam-
ined.

Number
of vines
exam-
ined.

Number
of larvje.

Number
of pupa?.

Number
of beetles
in cells.

J. D. Curtis's
vineyard,
porous silt.

June 12
June 21
June 25
June 30
July 6
July 10

286
6
2
2

32
47
54
4

7
6
6
6
6

2
24
4

O.E. Pierce's
vineyard,
gravel soil.

June 11
June 21
June 25
June 30
July 6
July 10

101

5
5

49
13
12

6
6
6
7

6

3

V ineyard ,
loamy
soil.

June 23
June 25
Jane 30
July 7
July 10
July 17

I

6
6
6

A
O

3
1
1
1

24
5

17
2
1

2
2
1

W h it man's
v i n e y ard,
clay soil.

June 23
June 25
June 30
July 7
July 10
July 17
July 26

6
6
6
6
6
6
6

1
1
1
1

6
5
2

1

1

It is possible to establish the time of pupation by knowing the time
of emergence of the beetle and the length of time of the pupal stage.
Judging by the late emergence of the beetles, August 9, and by the
finding of beetles in cells in the field August 14, pupae must have
occurred up to the end of July. Based upon these records the curve
of figure 23 has been constructed.

DURATION OF THE PUPAL PERIOD.

The pupal stage on an average lasts 17 daj^s (see Tables XV and
XVI). The maximum length of time observed was 21 days and the
minimum 12 days.

LIFE CYCLE OF THE GRAPE ROOT-WORM AS DETERMINED BY

REARING.

Several attempts were made to rear this insect from eggs, and to
carry it through the different stages to complete the life cycle. In
the course of these experiments many failures occurred. The mor-
tality in certain experiments was high; in other instances a large per-
centage became materially delayed in development and the larvse
wintered a second season, and only a small number completed the
life cycle within one year. (See Table XX.) The records from these
latter observations are given in Table XVIII, with dates of hatching
in 1908 and the dates of reaching maturity the following year.

SEASONAL HISTORY.

41

Table XVIII. — Complete life cycle of 19 grape root-worms at North East, Pa., reared
from eggs laid during 1908; adults emerged in 1909.

Num-
ber o f
indi-
viduals.

Dai

Hatch-
ing of
eggs,
19()8.

e of

Emer-
gence of
beetles,
1909.

Number
of days
for the

we
cycle.

1

July 16

July

9

358

1

do

July

10

359

1

:..do".\\.

July

13

362

1

...do....

July

15

364

1

. . .do ....

July

17

366 .

4

July 20

July

352

1

...do

July

8

353

4

...do....

July

10

355

2

...do

July

11

356

1

...do

July

30

375

1

July 25

July

20

366

1

...do... .

July

27

367

19

6, 810

SUMMARY.

Days.

Average 358.4

Maximum 375

Minimum 352

SEASONAL VARIATIONS IN THE LIFE HISTORY OF THE GRAPE

ROOT-WORM.

In comparing the records for the time of emergence of the beetle
for the three consecutive years of 1907, 1908, and 1909 a marked
difference in the date of emergence will be found (fig. 16). This varia-
tion is partly due to the relative lateness of the spring and partly to
the climatic conditions prevailing during the entire development of
the insect in the ground.

The climatic conditions for the years 1906 to 1909, inclusive, have
been strikingly varied and, as will be seen, the life of the insect tor
these years has been affected accordingly. The mean temperature
for 1906 was 1 degree above normal and the precipitation averaged
about 1 inch below normal. August! and September being particu-
larly dry and hot. Frost occurred June 11 and 12 ami snow on
October 10, 11, and 12. The year 1907 was marked with an abnor-
mally low temperature, a late spring, and an early fall, with a rather
high precipitation for the summer months. The month of May was
the coldest on record during a period of eighteen years. In 1908, on
the contrary, the mean temperature was above normal and the
summer was marked by two periods of severe drought, the dry condi-
tions being especially felt during the end of August. In most respects
1909 (fig. 17) was nearer the average.

Although 1906 was a favorable season, during which the larviv
attained a normal growth, yet owing to the late and cold spring of
1907 the emergence of the insect was very materially delayed and

42

THE GRAPE ROOT-WORM.

limited to a very short period (see fig. 16). The first beetle in the
field was observed July 11. In the spring of 1908, on collecting
larvae in different vineyards two distinct sizes were found, as possibly
due to climatic conditions of previous seasons. The larger larva?
were full grown, while the smaller varied from one-third to three-
fourths grown. In the rearing cages the full grown larvae trans-
formed normally and without further feeding. Of the smaller larvae
few matured at the normal time, many were quite belated, while quite
a number wintered, thus spending two years as larvae in the ground.
As a result of the early season of 1908 the beetles commenced to
emerge by June 16. The emergence extended over a long period;

JUNE

15 20 25 J

JULY

0 5 /O /5 20 25 3

AUG.

0 5 /o /J

J

f

1

Trmrrrr

Tm

Wffnf

M

till

If

TnfflT

Fig. 16. — Diagram showing variation in time of emergence of beetles of the grape root-worm during
1907, 1908, and 1909 at North East, Pa. (Original. )

the latest beetles to emerge appeared in the rearing cages July 28.
This longer emergence period was partly due to the delay in the
development of larvae that hatched in 1907. In the spring of 1909
the larvae were again of a more uniform size as a result of the long
season of 1908, and the emergence in 1909, as recorded in figure 16, was
about normal. On examining larvae in the field in the early fall of
1909 data were obtained as to the prevailing number of 1-year and
2-year old larvae (Table XIX). At the dates of these observations
only a few of the new-brood larvae had attained one-half their growth
while many of the eggs had not yet hatched, and since the 1908 brood
larvae were full grown the two broods could then be readily told apart.

SEASONAL HISTORY.

43

44

THE GRAPE ROOT-WORM.

Table XIX. — Percentage of 2-year-old larvae of the grape root-worm as recorded in
vineyards in the vicinity of North East, Pa., in the fall of 1909.

Vineyard in silt soil in the valley.

Vineyard on loamy soil in the
valley.

Vineyard on gravelly loam on
the hill.

Date of
digging.

Num-
ber of
vines
exam-
ined.

Total
num-
ber of
larvae.

Per-
centage
of old
larvae.

Date of
digging.

Num-
ber of
vines
exam-
ined.

Total
num-
ber of
larvae.

Per-
centage
of old
larva?.

Date of
digging.

Num-
ber of
vines
exam-
ined.

Total
num-
ber of
larvae.

Per-
centage
of old
larvae.

Aug. 17

to
Oct. 12

| 32

328

3.0

Aug. 10

to
Sept. 20

} ^

449

0. GG

Sept. 2

to
Oct. 7

} "

517

5.0

The percentages of twice-wintering larvae in Table XIX represent
only records of early observations when a number of larvae had not
yet been hatched. It is of interest to note that the percentage of
2-year-old larvae was largest in vineyards located on the hill, owing
to the prevailing shorter season on the hill as compared with the
season in the valley. The time of transformation of the insects in
other stages has similarly been affected by the climatic conditions of
the past three years.

In Table XX is shown the relative number of maturing insects and
twice-wintering larvae which were reared from eggs deposited at
known dates in 1908.

Table XX. — The relative occurrence of transforming and twice-wintering larvae of the
grape root-worm reared from eggs laid in cages in 1908, at North East, Pa.

Date of hatching
1908.

Number of

beetles
emerging,
1909.

Number of
larva? win-
tering, 1909

July 16

July 20

July 25

July 28

Total

5
12

0

12
0

0 .

3

19

15

In the rearing experiments other factors beside climatic conditions
have influenced the results and no direct conclusion should be drawn
from these observations beyond the point of establishing the fact that
under unfavorable conditions individual insects of this species do
remain two years in the ground before maturing.

REARING AND EXPERIMENTAL METHODS.

The underground habits of the larvae of the grape root-worm have
made the rearing of this insect comparatively difficult, and certain
obstacles have been overcome only by persistent and continued
experimenting. The rearing work in most cases has been planned

SEASONAL HISTORY.

45

Fig. 18. — Portion of the outdoor rearing shelter used in the rearing of insects at North East, Pa.,

during 1909. (Original.)

Stage of the grape root-worm beetle. (Original.)

46

THE GRAPE ROOT-WORM.

on a large scale, so that variations would be minimized and the final
averages would represent approximately normal conditions. The
numerous separate experiments have involved the handling of a lar°-e
bulk of rearing material, which, together with the simulation of nor-
mal conditions, has to some extent necessitated special rearing
devices and methods of handling. The experiments have been con-

Fig. 20.— Earthen pot with glass cylinder used in rearing the grape root-worm. (Original.)

ducted either in the field or under an open breeding shelter, a portion
of which is shown in figure 18. This consisted of a temporary struc-
ture of light wooden framework covered with waterproof canvas.

Most of the rearing material was obtained in the spring, some time
previous to the transformation of the larvae. During the past two
years of the investigation the insects were to some extent reared

SEASONAL HISTORY.

47

from eggs laid in the cages, and these larva-, together with larva*
of the previous year, were carried through the winter in rearing
cages.

The pupal records have been obtained fro jn experiments in medium-
sized wooden boxes, having glass bottom, 0 inches long, 8 inches wide,
and 5 inches high (fig. 19). Each box contained 2 to 3 inches of
earth, and in order to duplicate outside weather conditions as nearly
as possible the soil in these boxes was permitted to become almost
dry during dry periods and during rainy periods water was propor-
tionately added. To exclude the light from below, the boxes were
placed upon burlap. Previous to the emergence of the beetles a
wire screen cover was
placed over each box.
The shallow layer of soil
caused many larva? to
penetrate to the bottom
of the cages, where they
appeared next to the
glass; and as the pupal
cells, made of earth
packed together, were
next to the glass the
activity of the insect
inside could be readily
observed. By means of
a glass and porcelain
blue pencil a number
was fixed next to each
cell, and by using this
number a detailed rec-
ord could be kept from

the time the cell was FlG< 21. — Rearing cage with glass sides ased in the study of

i-i the larva of the grape root- worm beetle. (Original.)

made to the time the

adult emerged. In the study of the underground habits of the insect
the device shown in figure 20 proved to be useful. The glass cylin-
der in the earthen pot was about half filled with soil, and to exclude
the light the lower portion of the cylinder was wrapped with black
paper. Several cells were made next to the glass, and on emerging
the beetles were observed in the process of making their exit through
the soil.

Cages similar to the one shown in figure 21 were convenient for the
study of the habits of the larva, and they were particularly useful
in experiments extending over periods of one and two years. In width

48

THE GEAPE ROOT-WORM.

these cages varied from 1 to 2\ inches, and were of a uniform height of
20 inches. The two larger sides consisted of plate glass with outer
wooden shutters on either side which could be removed for the exami-
nation of the contents.

The emergence records of Table I, as shown by curve in figure
13, are the results of about 15 separate experiments with larvae
transforming in large earthen pots filled with soil. Since the time
of emergence of the beetles and their relative occurrence has a

direct bearing upon the
time of application of poison
sprays against this pest,
special attention and care
were exercised in preparing
these experiments. In the
early spring approximately
1,000 larvae were collected
in different vineyards in the
vicinity of North East, Pa.
In many instances soil from
different localities, which
varied from loose sandy soils
to heavy clay, was trans-
ferred with the larvae to the
rearing pots (fig. 2.2) . Pro-
vision for the spring feeding
of the larvae was made by
planting young grapevines
in the pots. Finally the
pots were placed in the
ground in the open field and
were left undisturbed for the
rest of the season. Before
the beetles commenced to

Fig. 22.— Earth en pot with wire-screen cover used in rear- appear wire Screen covers
ing the grape root- worm. (Original.) were placed QVer each pot,

so that a complete daily record could be kept of the number of
beetles emerging from each separate pot.

By preserving the beetles from the above-mentioned experiments,
rearing material of known source and age was obtained for further
experiments. The daily catch of beetles throughout the emergence
period was transferred to so-called " stock jars," from which insects
were taken as needed for miscellaneous experiments. The "stock
jars" shown in the rearing shelter (fig. 18) consisted of large-sized
glass jars covered with thin cloth. A layer of moist sand was placed

SEASONAL HISTORY.

49

in each jar, which made it easier for the insects to move about and
made the conditions more natural. Grape foliage, constituting the
food of the beetles, was supplied daily, and to prevent unhealthy con-
ditions in the cages the old leaves were always removed. For op-
position short pieces of grapevine cane were placed with the beetles,
and as egg depositions progressed these canes were removed daily
and replaced by fresh ones. In determining the number of eggs
deposited, the loose bark had to be peeled off the pieces of cane and
the eggs in each cluster carefully counted. In determining the egg
deposition of individual females and the length of life of male and
female beetles, pairs when found in copulation in the stock jars were

MAY

5 10 15 20 25

JUNE

5 10 IS 20 25

JULY

5 IO 15 20 25

AUG.

5 10 IS SO 25

SEP

5 io is %

r.

0 2S

OCT.

5 io is 20 %S

NOV.

5 io i5 20 as

y

OL

odl t

J/s

fit

a?

pa

Ol

To

fl

r?e

rs

f

PS

f'

3

ro

/

>

-

Ol

'/

0

i 0

n

%

— -

-

ot

I

f

*$

7-

u

.,

te

n

c

«>

ft/

r

Fig. 23.— Diagram illustrating seasonal history of the grape root-worm as observed during 190V at

North East, Pa. (Original.)

isolated previous to the earliest egg deposition. The observations on
the habits of these individual beetles are given in Table II.

Since the greater portion of the beetles from the emergence cages
was used in obtaining the egg records, and since these insects ovi-
posited undisturbed during the entire season, it is believed that the
records in figure 15 represent the relative occurrence of eggs in the
field.

Eggs used in determining the length of time of incubation were
kept in glass tumblers under the outdoor breeding shelter.

In conjunction with the rearing work. Held observations were con-
stantly made, and in certain instances collections of the insect in its
different stages were regularly made in the same localities for a given
length of time. Thus it has been possible to check the rearing obser-
51282°— Bull. 89—10 4

50

THE GRAPE ROOT-WORM.

vations with field conditions, and whenever differences have occurred
corrections in the summary (fig. 23) have been made to approximate
field conditions.

SUMMARY OF LIFE-HISTORY STUDIES OF THE GRAPE ROOT-WORM.

The life history of the beetle (see fig. 12, p. 23) may be briefly sum-
marized as follows: The grape root- worm produces only one genera-
tion a year; the larva feeds on the roots of the grapevine, and in this
stage the insect is found in the ground for the greater part of the year.
In early June the full-grown larva makes an earthen cell a few inches
below the surface of the ground, within which it pupates about the
middle of June ; the pupal stage lasts generally twenty days, and the
beetle or adult begins to emerge from the ground in late June or early
July, while a few belated beetles continue to appear in the early part
of August. On an average the beetle feeds for from 10 to 13 days on
the grape foliage before ovipositing. The eggs are laid beneath the
loose bark on the canes of the vines, and hatch on an average in 12
days; the young larva drops to the ground and soon finds its way to
the roots of the vine ; generally the larva becomes three-fourths grown
and sometimes attains its full growth in the fall. Previous to win-
tering it penetrates deeper into the ground, below the roots, and there
constructs an earthen cell in which it passes the winter.

The diagram (fig. 23) shows the relative occurrence and the time of
transformation of the grape root-worm in its various stages. It has
been prepared from field observations and rearing records of 1909 and
is a summary graphically presenting the life-history studies.

Local variations in the times of development of the different stages
of the insect, as described in preceding pages, may be brought about
by various factors, such as differences in the texture of the soil, rela-
tive abundance of food, and altitude and exposure of vineyards.
The seasonal variations, as shown by the difference in the time of
emergence of beetles during 1907, 1908, and 1909, and also by the
occurrence of larvae that remained two winters in the soil, are the
direct results of climatic influences. The insect has a strong tendency,
however, to develop normally, even under adverse conditions.

NATURAL ENEMIES.
PREDACEOUS INSECTS.

Several predaceous insects have been found feeding upon the larvae
of the grape root-worm. During the process of digging for larvae,
both in the spring and fall, various species of carabid beetles and their
larvae have been found in the ground. These insects are entirely pre-
daceous and probably feed upon the grubs of the grape root-worm
whenever the latter come within their reach. Dr. E. P. Felt recorded

NATURAL ENEMIES.

51

Staphijlinus vulpinus Nordm. as probably predatory on the larvae.
In the spring of 1909 in one instance a "June-bug" larva (Lachnos-
terna sp.) was found by the junior writer feeding upon a larva of the
grape root-worm beetle. When first discovered the grape root-worm
was already half devoured, and while the operation was being watched
the remaining portion was completely eaten.

The eggs of the grape root-worm are subject to the attacks of a
number of different predaceous insects. Professor Webster observed
in Ohio a small brown ant (Lasius brunneus Latr. var. alienus) and
three species of mites {Tyroglyphus [RMzoglyphus] phyUoxerse [Riley],
Ileteropus [Pediculoides] ventricosus Newport, and the third, resembling
Hoplophora [Phthiracarus] arctata Riley), feeding upon the eggs. Mr.
P. R. Jones, of this Bureau, in 1907, at North East, Pa., found a
coccinellid larva (Hippodamia convergens Guer.), and a malacoderm
larva (family Telephoridse) feeding upon the eggs of the grape root-
worm. The determinations of these coleopterous larvae were made
by Mr. E. A. Schwarz, of this Bureau. The junior author in 1909, at
North East, Pa., collected a small ant, determined by Mr. Th. Per-
gande, of this Bureau, as Cremastogaster lineolata Say, var. ?, which
carried off eggs from a cluster on a grape cane. The larvae of a lace-
wing fly (Chrysopa sp.) have been observed from time to time extract-
ing the egg contents by means of their pointed, tubelike mandibles,
which are peculiarly well fitted for the purpose.

PARASITIC INSECTS.

Two minute hymenopterous egg parasites, Fidiobia flav. ipt s Ashm.
and Laihromeris (Brachysticha) jidix (Ashm.), were reared from eggs
of the grape root-worm in Ohio by Professor Webster. The late
Professor Slingerland recorded Fidiobia flavipes in the Lake Erie
section in 1900, and later, during the present investigation by the
Bureau of Entomology at North East, Pa., this minute egg parasite
has been constantly noticed by different members of the staff.
Laihromeris Jidise (Ashm.) has been only once observed at North East .
Pa., as recorded on pages 56-57. The two parasites mentioned above
were described by the late Dr. William II. Ashmead" in 1S94 from
specimens reared by Prof. F. M. Webster. The original description
of Fidiobia is given herewith:

Fidiobia flavipes sp. n. Female, length, 0.0 mm. Black, polished ; legs ami antenme
yellow; thorax without distinct furrows, smooth, with only slight imlieations of furrows
posteriorly, but not sharply defined; wings hyaline, veinless; abdomen oblong, sessile,
the first segment wider than long, the second very large, occupying most of the remain-
ing surface, the following being usually retracted with it. and thus making the abdomen
appear truncated at apex.

"Cinti. Soc. Nat. Hist., vol. 17, L894, pp. 170-172.

52

THE GRAPE ROOT-WORM.

LIFE HISTORY OF FIDIOBIA FLAVIPES ASHM.

During the summer of 1909 the junior author had opportunity to
rear Fidiobia Jiavipes Ashm. (fig. 24) and to make some observations
relative to its habits and occurrence in the Lake Erie grape belt.

The parasitized root-worm eggs can be readily recognized in that
they assume a brownish-yellow cast and become gradually darker
with the development of the parasite. The grape root-worm eggs
when first deposited are whitish, but soon take on a yellowish cast.
In view of the semitransparent eggshell it is possible to observe the
development of the different stages.

Parasitized eggs were obtained in the vineyards July 13, from
which adults issued on August 3. These adults were then placed in a
vial August 4, with fresh eggs which had been laid in breeding cages

the previous day. On August 7 an
irregular area could be distinguished
in the center of each egg, indicating
a breaking up of the yolk tissue.
On August 11 the parasitized eggs
were already of a dark yellowish-
brown cast. In one extremity of
the egg there began to appear an

Fig. 24.— Fidiobia Jiavipes, an egg-parasite of ii.11 1 1

the grape root-worm: Adult and enlarged empty Space and the larva COllld
antenna. Very greatly enlarged. (Orig- be distinguished feeding toward the

mal ) opposite end. On August 14 most

of the parasite larvae pupated. Two or three days after pupation
the eyes could be distinguished in the form of black spots, and a few
days previous to the time of the emergence of the adults the entire
pupa assumed a dark color. The minute hymenopterous flies emerged
August 28, 29, and 30.

In summarizing these data, we get 10 days for the egg and larval
stages, 14 to 15 days for the pupal stage, or a total of 24 to 26 days
for the whole life cycle. It is possible to recognize parasitized eggs
3 or 4 days after they become infested. Adult insects lived from 5
to 7 days in a test tube without food.

To determine the development of parasites from root-worm eggs of
different ages and also to test in a general way the resistance of eggs
of different ages to parasitism, the following experiments were carried
out as summed up in Tables XXI and XXII:

NATURAL E M EMI Bfl .

53

Table XXI. — Parasitism of y rape root-norm eyys by Fidiobin fin ipt s at Sorth //</./.
Pa., 1909, the eyys ranying in aye from 1 to 9 days.

Grape root- worm

Obser-

Parasit-

vation.

Oviposi-

Normally
ii4 ic mug.

Hatched.

ized.

1

Julv 30
JulV 31
Aug. 1
Aug. 3
Aug. 4
Aug. 5
Aug. 6
Aug. 7
Aug. 8

Aug. 11
Aug. 12
Aug. 13
Aug. 14
Aug. 17
...do

x

<>2
3

X

X
X

4

X

5
6

X
X

7

Aug. 21
Aug. 24
Aug. 26

X

8

X

9

X

a Parasites placed with the host August 9. New parasites emerged September 10 to 12. Thirty-two to
thirty-four days to complete the life cycle. Experiment No. 2 consisted of 15 root-worm eggs, of which 13
became parasitized and 2 eggs developed root-worms normally. Eggs within two to three days of hatching
escaped parasitism.

Table XXII. — Parasitism of eyys of the yrapc root-norm by Fidiobia ft u ipes, at Xorth
East, Pa., 1909, eyys varying in aye from fresh to 10 days old.

Num-
ber of
obser-
vation.

Root- worm eggs.

Num-
ber of
eggs.

Emerg-
ing root-
worm
larvae.

Hatch-
ing of
para-
sites.

Oviposi-
tion.

Normally
hatching.

1

Julv 25

Aug. 6

15

15

2

Julv 26

Aug. 7

20

20

3

Julv 28

Aug. 8

38

37

4

Julv 30

Aug. 10

13

12

5

Aug. 1

Aug. 11

18

18

6

Aug. 2

Aug. 13

19

19

7

Aug. 4

Aug. 14

99

21

Parasites placed with host August 4, having emerged August 3. New adults emerged August 30 to
September 3. Twenty-seven to thirty-one days to complete the life cycle. Root-worm eggs within two
to three days of hatching escaped parasitism.

For each experiment egg clusters of the grape root-worm, each of
a given age, ranging from 1 to 10 days, were subjected to the para-
sites. The insects with the host were confined in large-size glass
vials, which were covered with fine cloth. In Table XXI it is probable
that the parasites oviposited shortly after being confined with the
host, since they had emerged a few days previous to their confinement
with fresh eggs. In the first experiment (Table XXI) the parasites
were confined three days with the hosts. The two experiments of
Tables XXI and XXII are practically identical, the second being made
to check the results with those of the first one. The records for the
normal hatching of the eggs are from another sot of records, since
such data could not be obtained from parasitized eggs. The results
of either experiment show that the parasites did not affect eggs which
were within two or perhaps three days of hatching. There was
no marked difference in the time of the development of the parasites
from eggs of different ages.

54

THE GKAPE ROOT-WOKM.

The percentage of parasitized eggs in the field varied considerably
in different sections of the grape belt, as well as in parts of the same
vineyard. It was always highest where eggs were most numerous.
This was especially brought out in the different sections in the experi-
mental vineyards, where the sprayed areas were but slightly infested
with root-worms.

Thus, Davidson's vineyard, consisting of 12 acres, located half a
mile north of the city, showed in 1908 the following results:

Average
number of
Per cent eggs per

parasitized. vine.

Unsprayed young Concord vines 18 268. 8

Sprayed young Concord vines 9. 5 12. 4

Unsprayed old Concord vines 13.2 319. 2

Sprayed old Concord vines 20 23. 6

Unsprayed Niagara vines 35 56.0

Sprayed Niagara vines Free. 1.2

The Porter vineyard, located a few miles east of the town and con-
taining 10 acres of old Concord vines, gave the following results:

Unsprayed plat had 14.7 per cent parasitized eggs.
Sprayed plat had 5.5 per cent parasitized eggs.

By comparing the records taken during August from three different
vineyards located within a radius of from 2 to 3 miles east of N rth
East, Pa., Algren's vineyard on August 4 showed 2 per cent of para-
sitized eggs; Young's vineyard, August 24, showed 16 per cent; and
Wheeler's vineyard, August 27, 96 per cent.

A marked increase of parasitism was observed with the advance-
ment of the season. The records given below, obtained by H. B.
Weiss, from Mr. Young's vineyard, illustrate this fact:

Per cent.

July 30 5

August 13 10

August 19 14

August 26 16

September 2 20

Similar records from other vineyards were not as uniform as those
just given, but since the percentage varies with the amount of eggs
present, no great uniformity can be expected unless the eggs are found
more or less evenly distributed in the vineyards.

By breeding the parasites two full generations and a partial third
were produced. Infested eggs were obtained in the field July 13, from
which adults emerged August 3. These were placed with fresh eggs
August 4, and new adults issued August 28. The third generation
developing from these adults was much delayed by cold weather, but
at the time of concluding the field work for the season on November
22 the adults were about to emerge.

NATURAL ENEMIES.

The diagram (fig. 25) shows the relation of the three generations of
parasites as observed in the breeding cages to the time of oviposition
and the time of hatching of the host eggs. With the data in hand it
is not possible to determine the period covered by each generation.
The records only show the appearance of the first adults for the three
generations. A few conclusions can, however, be drawn from the above
diagram. Adult parasites must have existed in vineyards at the
time of earliest oviposition of the grape root-worm. Adults producing
the second generation appeared before the greater portion of the root-
worm eggs had hatched, and since eggs could become parasitized
within two days of hatching, the second generation is apt to infest
more eggs than either the first or the third generation. In fact, the
third generation appeared so late that it only reached a very few
belated eggs.

Fidiobia flavipes is an important factor in the control of the grape
root-worm. Professor Webster, who for several years studied the

</i ]j|;)i'li|'i7lfTt4t .-><> r>e r oTj o
01 r7Tr " — 1

-o • : j : " ~ ' ~~ .:: .

£ ; ■ ■ j "p-p--1 — r-^—l — r-=p

hco— ^ — — — : y

T. ; i S«c<jnc{ am r rait i on

frro r-f-frahon ■--

3oo :v;f~ I. ' ', ' ; /. '.

2oo .-4_p_, — t- JzX — —Li

-— *p-

■ft err a rrrrrrri^rr- Vrr'r..'r

OO 'f'tittf.rfr err ^

' ^r-fc At'i £ rf '

cc . 1— — /- ■

JULY 10 15 20 25

30. AUG. 5 10 15 20 2

5 30SEPR

10 15 20 25 3C

Fig. 25.— Diagram showing the relation between the three generations of the Fidiobia parasite and
the relative occurrence of eggs of the grape root- worm at North East, Pa., during 1909. (Original.)

grape root-worm in Ohio, reported in 1896 that the decrease in num-
bers of the beetle was largely due to this and other parasites. Though
the data on hand for North East, Pa., for the years 1907, 190S, and
1909 are not sufficient to show any increase in occurrence, it is our
impression, from extensive observations, that the insect is becoming
more and more numerous.

A DIPTEROUS PARASITE.

Along with Fidiobia flavipes there occurs another grape root-worm
egg parasite (fig. 26), which is at present only known in the larval
stage. It is supposed to be a dipterous insect, in view of ihs resem-
blance of the larva to dipterous forms. It was lirst observed by the
senior author and Mr. P. K. Jones, of the Bureau of Entomology, who
in 1907, at North East, Pa., collected several parasitized egg clusters.

56

THE GRAPE ROOT-WORM.

During the summer of 1909 parasitized eggs were in evidence in
the field from July 20 to August 30, and were found locally quite
abundant, though less so than Fidiohia Jlavipes. Professor Webster
informed the junior writer that he had found a similar parasite in
Ohio in 1896. Table XXIII shows the relative occurrence of para-

Pig. 26. — Larva of an undetermined insect parasite of the eggs of the grape root-worm. (Original.)

sitized eggs as observed at various stages in different localities during
1909 at North East, Pa.

Table XXIII. — Percentage of eggs of the grape root-worm parasitized by a dipterous
insect, as observed in vineyards in the vicinity of North East, Pa., 1909.

Date.

Vineyard.

Per cent.

Julv 20

Davidson

1

Julv 22

Porter

1

July 24

Mosher

3

Aug. 4

7

Aug. 12

do

22

Aug. 19

do

12

Aug. 20

do

14

It will be noted that there is an increase in the occurrence of the
parasite toward the end of the season, as was observed with Fidiobia.

Koot-worm eggs parasitized by this insect are in their early stages
opaque-white in color. Later the eggshell becomes semitransparent
and iridescent. The larva of the parasite when full-grown is almost
twice the length of the host and lies folded within the egg. The
whitish larvae are very active on emerging from the hosts. They
were found to penetrate several inches in the soil in glass jars. Though
the larva is quite common, all attempts to rear the insect to obtain
the adult or fly have so far proved fruitless.

DOUBLE PARASITISM.

August 30, 1909, a cluster of 115 root-worm eggs was collected,
which were infested by the dipterous parasite. The egg along the
border of the cluster, unlike the rest, a few days later assumed a pink
color, but at the same time showed the iridescence characteristic of
this parasite. Dipterous larvae emerged September 3 from the eggs
of the central portion of the cluster. From the eggs along the border
of the cluster a hymenopterous fly (Lathromeris Jidise Ashm.) (fig. 27)

VINEYARD CONDITIONS IN LAKE ERIE VALLEY.

57

emerged. The host had been eonfined indoors during the winter,
thus bringing out the hvmenopterous parasite on February 2. It is
probable that the root-worm eggs were first parasitized by the dip-
terous insect and that later the eggs along the margin of the cluster
were parasitized a second time by LatJi-
romeris jidix. The dipterous and the
hvmenopterous insects are undoubtedly
both primary parasites.3

VINEYARD CONDITIONS IN THE
LAKE ERIE VALLEY.

Before entering upon a discussion of
methods of control undertaken against
the grape root-worm during this inves-
tigation it may be well to consider some of the changes which have
occurred in vineyard conditions throughout the Lake Erie valley since
the advent of this pest.

In 1900, when the grape root-worm first appeared in injurious
numbers in the Lake Erie valley, the grape industry was just emerging
from a period of depression which had caused, for several years pre-
vious, 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
favorable to the increase of this pest. Furthermore, the fact that
practically 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. 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. Thus it happened that a com-
bination of circumstances conspired to favor a general spread of the
insect without creating widespread alarm.

With the steady rise in the value of grapes since 1900, however,
this condition has been reversed. Thousands 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
rapidity with which many young vineyards are falling a prey to this
pest.

The maximum crop yield for the Lake Erie grape belt occurred in
1900, and amounted to S.000 carloads of fruit. At that time there

Fig. 27.— Lathromeris fidUf, an egg-para-
site of the grape root-worm: Antenna
and fore wing. Very greatly enlarged .

(Original.)

a The authors are indebted to Mr. A. A. Girault, of the othYe of the state entomologist
of Illinois, for the determination of the above-named parasites.

58

THE GRAPE ROOT-WORM.

were about 30,000 acres of vineyards in bearing. Since 1900 fully
10,000 acres of bearing vines have been added to this area, yet the
yield for 1908 was only a little more than one-half that of 1900.

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 production from 1900 to 1909.
Yield for— Carloads.

1900 8,000

1901 6,669

1902 5,062

1903 2,954

1904 7,479

1905 5,365

1906 5,465

1907 5,186

1908 4,232

1909 7,561

These figures denote a steady decline in crop yield traceable to a
variety of causes, namely, depletion of soil, lack of proper cultivation,
adverse weather conditions, and lack of proper fertilization. There
are thousands of acres of vineyard throughout the belt that have
borne many crops and have never received a pound of fertilizer. It
is doubtful, however, if all of these factors combined could of them-
selves have resulted in such unfavorable vineyard conditions as have
been brought about by the ravages of the grape root- worm. We
make this statement advisedly after several seasons of careful study
of the habits and depredations of the pest.

The table presents certain points of interest. Thus, in 1903 there
was an especially light crop of 2,954 carloads followed by a large
crop in 1904. About the same conditions prevailed during the
respective years 1908 and 1909. It should be borne in mind that a
considerable percentage of the phenomenal increase during the years
1904 'and 1909 must be credited to the greater vigor of the plants
following the light crops of the preceding years and to extremely
favorable weather conditions.

In the early history of this infestation, as previously mentioned,
practically all of the vineyards of the belt contained old vines with a
well-established root system able to withstand for several seasons even
a heavy infestation of the larvae before a marked decrease in yield
was noticeable. With the extensive planting of new vineyards since
the thorough dissemination of this pest its swift and deadly work
has become more apparent. Numerous instances have come to our
notice where young vineyards bearing the second or third season's
crop have been so severely injured that hundreds of vines died

REMEDIAL MEASURES.

59

outright in a single season, while the rest were so weakened that they
had to be cut back so severely that in the following season they were
unable to produce more than from 15 to 25 per cent of a normal
crop. Persons not thoroughly familiar with the habits of the pest
have frequently charged this death and weakened condition to a
variety of causes, such as winter killing, deep plowing, overbearing
of young vines, etc. In practically every case of this kind coming
under our observation we have found overwhelming evidence of
injury wrought upon the roots by the larva? of this pest. There is
no doubt that the overbearing of young vines which possess a limited
root system and then become subject to a heavy infestation of grape
root-worm larvae will serve to greatly weaken the vine, and that
severe winter weather following this heavy infestation of larvse, and
consequent weakening of the vine, will accelerate the death of the
vine during the winter. Yet these are but secondary evils to* which
the vines, primarily weakened by injury from the insect during the
growing season, finally succumb. This is also true of drought condi-
tions occurring in August and September. During the drought
which occurred in these months in 1906 numerous cases came under
our notice where young vines bearing a heavy crop of fruit and having
made a heavy growth of vine early in the season were so badly
injured by larvae hatching from eggs deposited in July that they
were unable to mature the fruit, which actually shriveled on the vine
by the last week in August. Other injured vines which carried
through their crop died during the following winter. It is the rapid
decline in yield of large numbers of vines in young vineyards through-
out the whole grape belt and the steady though less perceptible
shrinkage in yield of the other vineyards that make it impossible
for the increased planting of recent years to more than hold its own
with the crop production of the period previous to the general infes-
tation of vineyards by this pest, and it will require the greatest care
and watchfulness on the part of those planting new vineyards to
carry their young bearing vines through that critical period when
they are producing their first two or three crops and at the same
time establishing a root system sufficient to continue the production
of successive profitable crops.

REMEDIAL MEASURES FOR THE CONTROL OF THE GRAPE ROOT-
WORM.

EVOLUTION OF PREVENTIVE MEASURES.

Although the occurrence of this insect in numbers sutlicient to
cause great damage to the foliage of grapevines was brought to the
attention of Walsh in 1866, no remedial measures were suggested by
him. The first record of an attempt to control the pest was made

60

THE GRAPE ROOT-WORM.

in 1870 by C. V. Riley, who relates an instance where a vineyardist;
having observed that the beetles have the habit of falling from the
foliage to the ground when the vines are jarred and that they have a
tendency to "play possum/' and also that they were readily devoured
by his chickens, was able to destroy many of them in his vineyard
by having a boy drive his flock of chickens through the vineyard
while he shook the beetle-infested vines in front of them.

In 1872 Kridelbaugh suggested handpicking of the beetles from
the vines and also the use of an arsenical spray.

Not until 1895, however, when Professor Webster made his inves-
tigation of the pest in Ohio, were methods for its control seriously
considered. During his investigation Professor Webster conducted
experiments with salt, kainit, tobacco, kerosene emulsion, and carbon
bisulphid against the larvae in the soil, all of which appear to have
given -indifferent results. The carbon bisulphid, although partially
effective, was likely to injure the roots of the vines and was also
too expensive to be practicable. He also used kerosene emulsion
against the adults, both on the foliage and after they had fallen to
the ground. Pyrethrum in solution was used in the same manner,
but with very indifferent results. Arsenical sprays were applied to
the foliage in an attempt to poison the beetles, using London purple
and Paris green, 4 ounces to 50 gallons of water, and arsenate of lead,
1 pound to 150 gallons of water. Although there was evidence that
some beetles were destroyed by the use of these arsenicals, the results
were far from conclusive. Later experiments in Ohio with arsenicals
against the pest gave more encouraging results, yet the practice of
spraying as a method of control never became general. Therefore
in 1900, when the insect appeared in destructive numbers in the
vineyards of Chautauqua County, N. Y., it was again the subject of
experimentation by both the late Prof. M. V. Slingerland, of Cornell
University Agricultural Experiment Station, and by Prof. E. P. Felt,
of the New York State Museum to determine effective methods of
control.

During the early part of the investigation it was shown that early
in June the larvae come near the surface of the soil to make the pupal
cells in which they transform to beetles, and that thorough stirring
of the first 3 or 4 inches of the soil, especially beneath the trellis, will
expose and destroy a large number of the pupae. On account of the
somewhat unsatisfactory and inconclusive results obtained with
arsenical sprays in former years in Ohio, Doctor Felt gave consider-
able attention to the perfecting of a device for collecting the beetles
by jarring them into troughlike receptacles containing kerosene oil
which could be operated either by hand or by horsepower where
large areas of vineyard have to be treated. That large numbers of
the beetles can be captured and destroyed by this method is demon-

RKM KDIAL M KASl'KKS.

61

strated in Doctor Felt's reports of his experiments published by the
New York State Museum. (See Bibliography, p. 93.)

Experiments with arsenical sprays against the pest during the
early part of the New York investigations, although giving more
encouraging results than those obtained in Ohio, were not so con-
clusive as could have been desired. By persistent experiment with
improved spraying apparatus and increased strength of arsenicals,
and thorough and heavy applications where desirable, Professor
Slingerland was able toward the end of his investigations to secure
results with poison sprays which showed that in the hands of the
thorough vineyardist very effective results could be obtained.

Unfortunately these field experiments with arsenicals were not
conducted for a number of consecutive seasons on the same blocks of
vineyards. This makes it impossible to determine the cumulative

Fig. 28.— Horse hoe used in removing the soil from beneath the trellis in vineyards. (Original.)

benefits of the treatments in preventing infestation on the sprayed
portion as compared with the injury wrought by the insect on the
untreated portion of the vineyard.

CULTURAL METHODS FOR THE DESTRUCTION OF PUPiE.

Prior to the appearance of the grape root-worm in destructive
numbers in the Lake Erie grape belt about the first cultural operation
of the season performed by vineyardists was to remove the soil
from beneath the trellis with a horse hoe (fig. 28) to a depth of 3 or 4
inches. This operation removed all of this layer of soil beneath the
trellis with the exception of a few inches directly around the base
of the vine which was removed later with a hand hoe. Almost
immediately following these operations a furrow was thrown back
under the trellis with a 1 -horse plow, and the remaining space between
the rows of grapes was stirred with a gang-plow and followed by sev-
eral cultivations during the season. With the discovery that the
grape root-worm larva has the habit of coming near the surface of

62

THE GKAPE ROOT-WORM.

the soil to make its pupal cell, this plan of cultivation has been some-
what modified. In order to encourage the larva to come still higher
above the roots of the vine to pupate than it would have done under
ordinary cultural methods it has become customary to throw up a
ridge of soil beneath the trellis at the last cultivation of the preced-
ing summer (see PL V, fig. 2). Observations have shown that it is
highly desirable that this ridge be formed under the trellis late in the
summer rather than in the early spring, since in the former case the
soil becomes of a uniform compactness by the time the larvae are
ready to migrate nearer to the surface to pupate; whereas, if the
ridge is formed in the spring a layer of trash and leaves accumulating
under the trellis during the winter is sandwiched in this ridge, and in
no case in our examinations have we found pupal cells above this
layer of trash. In the operation of horse hoeing this spring-formed
ridge away from the vines it frequently happens that only the layer
above the trash is thrown away, hence the pupae, which are all
beneath the trash, are undisturbed.

Undoubtedly this modification in the plan of early cultivation of
vineyards is an important aid in the destruction of this pest at a
time when it is in its most critical stage of development. Instances
have come directly under our observation where we have seen great
numbers of the pupae exposed to the air and sunlight or become the
immediate prey of birds and predaceous insects. The operation is
probably of greater value in sandy and loose gravelly soils than in
stiff clay soils, for in the former the earthen cells fall apart quite
readily with the disturbance of the soil, leaving the pupae exposed;
whereas in the clay the soil is more likely to turn over in lumps, leav-
ing many of the cells intact. In addition to this, in soils of a sandy
or gravelly nature the loose earth around the vines may be removed
by the horse hoe to a much greater depth and more pupae disturbed
than in the case of stiff clay soils, where it frequently happens that
the operation of horse hoeing amounts to little more than a scraping
of the weeds from the surface of the ground, especially if the season
be a dry one. In fact, the drying out of the soil is the chief draw-
back to placing reliance on this operation as a means of controlling
this pest.

It not infreque ltly happens that a dry period may occur along the
Lake Erie Valley during the month of June which renders it difficult to
make horse hoeing as thorough and as timely as it should be to derive
the greatest benefit from this operation in the destruction of the
pupae. In the summer of 1907 when the development of the pupae
was unusually late the operation of horse hoeing was postponed by
some vineyardists until the last of June and early July in order to
perform it at a time when the maximum number of the insects were
in the pupal stage, and considerable complaint was forthcoming

Bui. 89 Bureau of Entomology. U S. Dept. of Agriculture.

Plate V.

Ridge of Soil Under Trellis.

Big. 1. — Vineyard view In the spring, snowing ridge of undisturbed soil nnder the trellis.
Fig- 2.— Vineyard view. Bhowing ridge of >"il under trellis as formed at the last eultivation
of the preceding summer. North Bast, Pa. (Original.)

REMEDIAL MEASURES.

63

from large vineyardists concerning the undesirability of suspending
horse hoeing until so late a date. In 1907 we saw many hundreds
of acres of vineyard in the condition shown in Plate V, figure 1, in
which cultivation had been suspended to await the development of
the pupae. Under normal conditions this cultivation would have
been performed several weeks earlier, and since early and thorough
tillage is essential to good vineyard management, it is not well to
place entire reliance on this operation to control the pest. Never-
theless it is an operation that should be utilized whenever soil and
moisture conditions will permit, and these are most favorable in
sandy and gravelly soils and in seasons of moderate rainfall during
the month of June. The most beneficial results from this operation
are obtained by horse hoeing as deeply as possible without scraping
the roots, followed by thorough and deep hand hoeing around the
crown of the vine, at which point by far the greater number of pupse
are to be found.

During this investigation we have never felt warranted in placing
entire dependence upon this method of destroying pupae to control
this pest, but have regarded it as a valuable supplementary aid
obtained by a slight modification of general vineyard practice at no
additional expense to the vineyardist and that other means mus; he
employed to destroy the beetles developing from pupae which escape
destruction by this method. Since we were unable to find vineyard-
ists with heavily infested vines who were willing to allow us to con-
duct an experiment covering several acres for several consecutive
seasons, depending entirely on the destruction of pupae by cultivation,
it is impossible to present definite data as to the exact value of this
treatment.

EFFECT OF POISON SPRAYS ON THE BEETLE IN THE FIELD.

The use of poison sprays against the beetles of the grape root-worm
after they have emerged from the soil and commenced to feed upon
the foliage of grapevines has been recommended by many ento-
mologists since the insect has become of economic importance as a
vineyard pest.

Extensive experiments with arsenicals were made by Webster in
Ohio in 1S95, and also by Slingerland and Felt in Chautauqua County,
N. Y., in a number of field experiments conducted during the seasons
from 1902 to 1906.

Although in many of these experiments the results obtained indi-
cated a considerable degree of benefit from the use of arsenical poi-
sons, especially in those made by Slingerland from 1904 to 1900, there
has always been an element of doubt as to the value of arsenical
sprays applied to the vines as a direct and rapid killing agent of the
beetles. The inference has been drawn by some experimenters that

64

THE GEAPE ROOT-WORM.

the beneficial effects of poison sprays are due rather to a distaste on
the part of the beetles for poisoned foliage, and their consequent
abandonment of sprayed foliage and migration to unsprayed areas,
than to the direct killing effect of the poison. This view is supported
to some extent by cage experiments which showed that in many
cases when confined in cages the beetles fed but slightly upon sprayed
foliage and the death rate was not as rapid as might be wished. In
addition to this, beetles thus confined with poisoned vines have in
feeding indicated a preference lor unsprayed areas, all of which left
reasonable cause for doubt as to the direct efficiency of arsenicals as
a killing agent.

During our investigation of this pest, covering the seasons of 1907,

1908, and 1909, we have observed this tendency of the beetles to feed
more freely upon the unpoisoned than upon poisoned foliage, both
in the open vineyard and in cages, yet we have no direct evidence of
wholesale migration of the beetles from sprayed areas.

CAGE EXPERIMENTS WITH POISON SPRAYS AGAINST THE

BEETLES.

On July 13, 1907, 100 beetles recently emerged from the soil were
divided into two lots of 50 each and placed in cages; one cage con-
tained sprayed foliage collected from a vineyard recently sprayed, the
other unsprayed foliage. The beetles in the cage containing the
unsprayed foliage fed freely upon the leaves soon after they were
placed in the cage, whereas those placed in the cage containing the
sprayed foliage did but little feeding during the first 3 days. During
the next 3 days there was evidence of an increased amount of feeding.
At the end of the 6 days, 25 of the beetles feeding on the sprayed
foliage had died as against 6 dead beetles out of the 50 feeding on the
unsprayed foliage. At this date (July 19) the experiment terminated
on account of the withering of the sprayed foliage, and the impossi-
bility of obtaining additional recently sprayed foliage.

Another cage experiment to observe the feeding of beetles upon
poisoned and unpoisoned foliage was undertaken during the summer of

1909. This experiment was made upon young grapevines growing in
large flower pots and covered with a wire screen (see fig. 22). Thus
the freshness of foliage was assured throughout the experiment and
the limited area of the plant permitted close observation of what took
place. Three plants growing in pots were used in this experiment.
The plants in two of the pots were sprayed very thoroughly, care being
taken to cover the entire upper surface of all of the leaves with a poi-
soned spray, which consisted of Bordeaux mixture with 3 pounds
arsenate of lead to 50 gallons of the mixture, the proportions used in
field experiments. The plant in the third pot was unsprayed. An

REMEDIAL MEASURES.

65

additional object of this experiment was to observe the readiness with
which beetles that had just emerged from the soil and had not had a
previous opportunity of feeding on unsprayed foliage would feed on
poisoned foliage as compared with beetles which were taken from
vineyards and which had fed to some extent upon unsprayed vines.
Accordingly 30 beetles, on emerging July 8, from soil inclosed with
wire screens, were placed on a sprayed plant in pot I. Thirty more
beetles collected in a vineyard, June 30, and fed on unsprayed leaves
until July 8, were placed (July 8) in pot II, also containing a sprayed
plant. At the same date 15 beetles which had just emerged were
placed on an unsprayed plant in pot III.

Table XXIV shows the death rate of the beetles in these three
cages.

Table XXIV. — Experiments v:ith -poison sprays against grape root-worm beetles feeding
on vines in confinement at North East, Pa., in 1909.

Pot I.

Pot II.

Pot III.

30 beetles emerged
from soil July 8,
and at once re-
moved to
sprayed vine.

30 beetles taken on
vines in the field
June 30 and
placed on
spraved vine
July 8.

15 beetles emerged
from soil July 8,
and removed at
once to un-
sprayed vine.

Number
of dead
beetles.

Date.

Number
of dead
beetles.

Date.

Number
of dead
beetles.

Date.

16
12

2

Julv 9
July 10
July 11

3
10
13
2
1
1

Julv 9
July 10
Julv 11
Julv 12
July 13
July 17

1
1
1
1

3
1

Julv 15
July 27
Julv 29
Julv 31
Aug. 14
Aug. 15
Aug. 28

30

30

15

Total.

It was observed that the beetles just emerged from the soil and
which had been placed in pot I without having had an opportunity
to come in contact with unsprayed foliage fed as readily and indis-
criminately on the poisoned leaves as did those placed on the unsprayed
plant in pot III. The beetles placed on the other sprayed plant in
pot II, which had had 8 or 10 days of feeding on unsprayed leaves,
fed less upon the sprayed foliage, especially for the first 24 hours. A
glance at the table will show that 50 per cent of the beetles in pot J
died in 24 hours as against 10 per cent in pot II. On the fourth day
all beetles in pot I had died and also 85 per cent of those in pot II,
whereas it was not until the eighth day of the experiment that the
first dead beetle was found in pot 111, and 73 per cent of the beetles
remained alive on this plant for more than a month.
51282°— Bull. 89—10 5

66

THE GEAPE ROOT-WOEM.

FIELD EXPERIMENTS WITH POISON SPRAYS AGAINST THE

BEETLES.

The most striking evidence of the value of a poison spray as a
direct killing agent of the beetles, however, was obtained by us in a
field experiment conducted at North East, Pa., June 30, 1909. At
this date our attention was called by Mr. Frank Pierce to the presence
of large numbers of grape root-worm beetles feeding upon a block
of several acres of vines planted that spring. These vines had been
planted on land from which the vines of the greater portion of an
unproductive vineyard had been removed early the same spring.
The owner, not being aware at the time that these vines had been

Fig. 29.— Young grapevine, unsprayed, showing extensive feeding by beetles of the grape root-
worm. North East, Pa., 1909. (Compare with fig, 30.) (Original.)

rendered unproductive by infestation by the grape root-worm,
decided to replant the area immediately with young vines. After
removing the old vines the ground was plowed and planted to the
young vines and the space between these vines was sown to peas.
Thus the soil was left uncultivated during the period between early
May, when the peas were sown, and July 1. Consequently the root-
worm larvae which had infested the roots of the old vines were per-
mitted to perform their transformations undisturbed. On June 28,
when Mr. Pierce harvested the peas growing between the rows of
grapevines; he observed some grape root-worm beetles feeding upon

REMEDIAL MEASURES.

07

foliage of t He young vines. By June 30, when our attention was called
to the infestation, the leaves of many of the plants were badly riddled
by the beetles (see fig. 29). At our suggestion Mr. Pierce sprayed part
of these young vines quite thoroughly, using Bordeaux mixture and
3 pounds arsenate of lead to 50 gallons of the mixture. This applica-
tion was made with a hand spray pump mounted on a grape wagon,
and the spray was directed at the plants by a man following behind
the wagon and carrying an extension rod with two nozzles at the end
and connected with the spray pump by a long lead of hose. In this
way 4 rows of vines could be treated from the wagon. The vines
were sprayed on the afternoon of June 30. It should also be stated
that the portion of the old vineyard not removed in the spring and
adjoining the young vines was treated at the same time. On the
afternoon of July 1 an examination was made of the effect of the
treatment of the previous day. Only a few beetles were found on the
young vines as compared with the large numbers present previous to
the application of the poison spray. Close examination of the soil
beneath the vines disclosed the presence of a large number of dead
beetles. Eighteen dead beetles were found beneath one vine, and
under a number of others from 3 to 10 dead beetles were found. In
addition to this we observed that a small brown ant was very actively
removing evidence of the direct effect of the poison by tearing to
pieces the dead beetles and often dragging away the whole body of
the beetle. Wing-covers, heads, and legs of several beetles were to be
seen beneath a single vine, and in several cases ants were observed to
attack the beetles before the}' were quite dead.

A visit was also made to the old trellised vines adjoining them,
anticipating evidence of a wholesale migration of beetles from the
young vines to the denser foliage of the old vines. Such, however,
was not the case; although there was evidence of considerable feed-
ing at an earlier date, few beetles were now observed on the vines.
Several dead beetles were found beneath these old vines, and frag-
ments of beetles and their wing-covers were also observed. A few
days later a second application of Bordeaux mixture and arsenate
of lead was made on these vines to take care of later emerging beetles.
On a visit to these young vines July 10 not more than 4 live beetles
were observed, although more than an hour was spent in the block,
and not a single dead beetle was found on the ground beneath the
vines, although fragments of their bodies were in evidence. It' this
timely application of a poison spray had not been made, the young
vines would have been seriously injured by the feeding of the bee-
tles; for it not infrequently happens that the beetles, where they
are numerous and the foliage limited, as in this case, riddle the
foliage and tear it into shreds until it has the appearance of being
singed by fire.

68

THE GRAPE ROOT-WORM.

In view of the results described above, there can be no doubt as
to the value of a poison as a direct and effective killing agent of the
beetles in the open field. It is quite possible, moreover, that the
rapid removal of dead bodies by ants and other agencies and the
close search required to find them on account of the fact that their
color is the same as that of the soil, and also by the fact that they
were distributed over a large area on the foliage of full-grown vines,
have resulted in the failure of other workers to find a sufficient num-
ber of dead bodies of beetles in sprayed vineyards to warrant them
in feeling that this method of control is as effective as might be
desired.

COMPARATIVE EFFECTIVENESS OF ARSENATE OF LEAD AND
ARSENITE OF LIME.

In our field work with arsenical sprays, planned for a period of
two or three seasons, arsenate of lead was the insecticide used
throughout the experiments. Since, however, many vineyardists
were using arsenite of lime when this investigation commenced, it
was deemed advisable to make a test of its efficiency as an insecti-
cide against the grape root-worm beetle as compared with arsenate
of lead.

In the summer of 1907 a test of these two insecticides was made
in two vineyards in different parts of the township of North East.
One vineyard of about 8 acres belonging to Mr. W. S. Wheeler was
divided into three plats. Two plats of about 3 acres each were
sprayed, one with Bordeaux mixture and arsenate of lead and the
other with Bordeaux mixture and arsenite of lime. The third plat
of about 2 acres running through the middle of the block was left
unsprayed. Two spray applications were made on these plats at
the same dates, July 9 and July 27, with a gasoline-engine power
sprayer (PI. X, fig. 2). The spray was applied at a pressure of about
100 pounds, and about 100 gallons of the liquid were used per acre.
The formula used on the plat sprayed with arsenite of lime was,
copper sulphate, 5 pounds; lime, 6 pounds; resin-fishoil soap, 2
pounds, and 1 quart arsenite of lime made according to Kedzie's
formula (containing 4 ounces of white arsenic) to 50 gallons of water.
The resin-fishoil soap was added to increase the mixture's property
of adhering to the foliage. The formula used on the plat sprayed
with arsenate of lead was, copper sulphate, 5 pounds; lime, 5 pounds;
arsenate of lead, 3 pounds; and water, 50 gallons. The effect of these
treatments in preventing egg deposition is shown by a count of the
egg clusters on 25 vines in each of the three plats. It should be
stated in addition that at the time of making the count of egg depo-
sition there was evidence of a great deal more feeding by beetles on
the foliage on the plat treated with arsenite of lime than upon the

H KM EDIAL MEASURES.

foliage of the plat sprayed with arsenate of lead. 'For results, see
Table XXV.)

Table XXV. — Relative value of arsenite of lime and arsenate of lead oh insecticides, as
shown by egg depositions at North East. Pa., 1907.

VINEYARD OF W. S. WHEELER.

Date of

Size of clusters.

Total

Esti-
mated

Num-

Num-

Eggs

Date

appli-
cation.

Formula.

Large.

Me-
dium.

Small.

clus-
ters.

num-
ljer of

B683-

lx?r of

vines.

ber of

canes.

per

vine.

per

cane.

exam-
ined.

1907.

Unspraved

37

102

98

151

290

6,420

5,610
1,040

25

.50

256.8

128.4

Aug. 14
Do.

July 8

0-6-2-00+ 1 quart
Kedzie

132

257

25

65

224. 4

86.3

July 27

5-5-3-50

%

14

47

64

25

51

41.6

20.39

Do.

VINEYARD OF W. E. GRAY.

Julv i-i
Julv 2.".

July fi
Julv 25

Unsprayed

Prepared Bor-
deaux: 1 qt.
arsenite lime,
2 qts. fishoil
soap, .50 gals,
water

Prepared Bor-
deaux: 3 lbs.
arsenate of
lead, 50 gals,
water

28

119

139

286

6,360

25

75

254.4

21

107

155

283

5,810

25

63

232.4

11

49

78

136

2,800

25

5,

112.0

Do.

The vines on all these plats were quite thrifty and were carrying
a heavy foliage.

The second experiment for comparing the value of these two poi-
sons against the grape root-worm beetle was made on a 12-acre vine-
yard belonging to Mr. W. E. Gray. North East, Pa. The vineyard
was divided into three plats, 5 acres on the east side, 2 acres
through the middle of the block, and 5 acres on the west side. In
this experiment a commercial brand of prepared Bordeaux mixture
was used. The poison ingredients of the spray, however, were the
same as in the experiments on the vineyard of Mr. Wheeler. The
plat on the east side of the vineyard was sprayed with a mixture of
2 gallons prepared Bordeaux mixture, 1 quart of arsenite of lime.
Kedzie formula, 2 quails of fishoil soap, and .">() gallons of water.
The plat on the east side of the vineyard was sprayed with a mixture
of 2 gallons of prepared Bordeaux mixture. 3 pounds of arsenate of
lead, and 50 gallons of water. The 2 acres through the middle of
the vineyard were left unsprayed. As in all of our other spray exper-
iments, the foliage in the untreated plat showed much more feed-
ing by the beetles at the time of taking the records of egg deposition.
A greater amount of feeding by the beetles was also apparent on the
foliage treated with arsenite of lime than upon that treated with
arsenate of lead. The results of these experiments are set forth in

70

THE GRAPE ROOT-WORM.

Table XXV and indicate a much greater efficiency from the arsenate
of lead application than from the application of arsenite of lime.

Vineyardists throughout Erie County have practically abandoned
the use of arsenite of lime as a poison spray against the grape root-
worm beetle, and arsenate of lead is now used almost exclusively.

RESULTS OF VINEYARD EXPERIMENTS WITH POISON SPRAYS.

The field experiments of this investigation were carried on during
the three consecutive seasons of 1907, 1908, and 1909, and in view
of results obtained by spraying by the senior author during his single
season of cooperative work with the late Prof. M. V. Slingerland
the remedial measures tried out were almost entirely along the line
of spray applications, it being his belief that the j^ost effective results
could be obtained by this method of combat. Some of the principal
points upon which information was desired were the effect of poison
sprays in ridding the vines of the grape root-worm beetles, the effect
of this application in preventing egg deposition by beetles, the rela-
tive effect of this treatment on vines of different ages and different
stages of infestation, the determination of the immediate seasonal
benefit to the vines by prevention of egg deposition, and the cumu-
lative benefit both in vigor of vines and crop yield obtained by
following up a line of treatment for several consecutive seasons.

A brief survey of vineyard conditions in the townships of North
East, Pa., during the late summer of 1906 enabled us to make a
selection of vineyard areas in the various stages of infestation and
decline best suited to the working out of these problems. A block
of vineyard owned by Mr. Roscoe Davidson, of North East, was
selected for the experiment to determine the effect of poison appli-
cations. The conditions existing in this vineyard were well suited
to the plan of experiment. The area was about 12 acres, thus mak-
ing it possible to secure results of commercial value. The vineyard
(PI. VI) is situated on a northern slope and is divided into four
blocks or sections. The soil is of a loose gravelly texture. The
lower northern section consists of young Concord vines about 7
years planted, the two sections immediately above are made up of
vines about 20 years planted and are referred to as old Concords, and
the south section consists of a block of 7-year-old Niagara vines
referred to in these experiments as young Niagaras. At the time
the experiment was undertaken the whole block showed a uniformly
heavy infestation of larvae on the roots of the vines. With the excep-
tion of the section of young Concords, however, the vines had not
yet reached the stage of serious decline and were still producing
fairly profitable crops. With the young Concords the case was
different. Our attention had been called to these vines late in the
summer of 1906 at the time when the fruit was commencing to color.

Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture.

Plate VI.

1

REMEDIAL MEASURES.

71

So serious was the injury of the larvae to the roots at this date that
the large crop of fruit which some of these vines were carrying was
actually shriveling up and dropping to the ground. By the fol-
lowing spring many of these vines had either died outright or were
in a very weakened condition. Plate IV, figure 2, gives an example
>f the manner in which the fibers had been removed from the roots
of many of these young vines by the larvae of the root-worm, and
shows the limited growth of new canes as a result of the infestation
which rendered the vine incapable of producing a crop of fruit during
the coming season. Thus the variety of conditions existing in this
vineyard was such as to enable us to work out several features of
the problem on the same block, namely, the effect of a poison-spray
application on vines of different varieties, of different ages, and in
different stages of injury, all growing side by side under practically
the same conditions. All of the vineyard was subjected to the
same treatment in regard to cultivating, fertilizing, and spraying,
with the exception of six rows running through the center of the
block (PI. VI) which cut through all four of the sections mentioned
above. These six rows were reserved as a check and from these
the spraying alone was withheld.

Below are given all of the data relating to the experiment conducted
on this vineyard during the seasons of 1907, 1908, and 1909, together
with the results obtained.

As the time for the emergence of the beetles from the soil drew
near daily visits were made to this vineyard during the latter end
of June and early July, 1907. On July 15 an occasional beetle was
found feeding on foliage near the ground. All preparations had
been made for spraying as soon as the first beetles appeared, and
the first application was made at this date. The sprayer used was
a gasoline-engine power outfit constructed especially for vineyard
work (PL X, fig. 2). The regular Bordeaux formula, 5-5-50, was
used, and to this 3 pounds of arsenate of lead were added, this latter
ingredient being the active poison agent of the spray. A pressure
of about 100 pounds was maintained throughout the application,
and about 100 gallons of spray mixture were applied per acre. Fixed
nozzles were used of the eddy chamber type.

On July 23 a second application was made, the same formula
being used and the same pressure maintained.

During the season of 1908-9 the same spray formula, machinery,
and nozzle arrangement were used ami the same pressure main-
tained. The only varying factor was the dates of application, which
varied each season with the date of emergence of the beetles. To
facilitate comparison, the dates of application, effect of spray on
egg deposition, prevalence of larvae at roots, and crop yield as com-
pared with the unspraved check are tabulated for the three seasons.
(Tables XXVI. XXVII. and XXVIII.)

72

THE GRAPE ROOT-WORM.

Table XXVI. — Effect of poison spray against the grape root-worm as shown by relative
occurrence of eggs in sprayed and unsprayed plats in Davidson vineyard for 1907, 1908,
and 1909, North East, Pa.

CHECK (UNSPRAYED) PLAT-YOUNG CONCORD VINES.

Date of
applica-
tion.

When
examined.

Number of egg

clusters found.

Estimated
number
of eggs.

Num-
ber of
vines.

Num-
ber of
canes.

Average num-
ber of eggs.

Large.

Me-
dium.

Small.

Total.

Per
vine.

Per
cane.

Aug. 2, 1907

92

163

246

501

11,950

25

55

478

217.2

July 13,1908

31

109

190

330

6,720

25

29

268.8

231,7

July 19,1909

41

41

74

156

4,020

25

35

160.8

114.8

SPRAYED PLAT— YOUNG CONCORD VINES.
Formula: 5 lbs. blue vitriol (copper sulphate), 5 lbs. lime, 3 lbs. arsenate of lead, 50 gallons water.

July 15
July 23

}Aug.

2, 1907

7

10

22

39

870

25

66

34.8

13.8

June 22
June 30

jjuly

13, 1908

0

5

16

21

310

25

41

12.4

7.5

July 2
July 14

}july

19, 1909

1

7

12

20

380

25

47

15.2

8.8

CHECK (UNSPRAYED) PLAT-OLD CONCORD VINES.

Aug.
July
July

2, 1907
13, 1908
19, 1909

52
47
35

136
139
57

213
146
91

401

332
183

8,810
7,980
4,370

25
25
25

71
68

352.4
319.2
174.8

127.6
112.3
64.2

SPRAYED PLAT— OLD CONCORD VINES.
Formula same as above (5-5-3-50).

July 15
July 23

}Aug. 2,1907

4

13

13

30

720

25

72

28.8

10.0

June 22
June 30

jjuly 13,1908

2

13

10

25

590

25

64

23.6

9.2

July 2
July 14

Jjuly 19,1909

0

7

14

280

25

81

11.2

3.4

CHECK (UNSPRAYED) PLAT— YOUNG NIAGARA VINES.

Aug. 6, 1907
July 15,1908
July 19,1909

32
11

3

74
18
9

77
31
15

183
60
27

4,590
1,400
570

25
25
25

49
34
51

183.6
56.0
9.6

93.6
41.4
4.7

SPRAYED PLAT— YOUNG NIAGARA VINES.
Formula same as above (5-5-3-50).

J Aug. 6, 1907
}july 15,1908
jjulv 19,1909

0

2

1

3

70

25

35

2.8

0

1

0

1

30

25

36

1.2

1

4

7

12

240

25

51

9.6

REMEDIAL MEASURES.

73

Table XXVII. — Effect of poison spray against the grape root-worm as shown by occur-
rence of larvie at roots of vines in sprayed and uns prayed plats in I)ai idson < ineyard
in 1907, 1908, and 1909, at North East '. Pa.

DIGGINGS MADE IN SUMMER OF 1907.

Number of larva?.

Date of examination.

Number
of vines.

Variety and age of
vines.

u„.

sprayed
plat.

Sprayed
plat.

September 5, 1907

1

Young Concord. . .
Old Concord

92

G

Do

1

91

H

1

Do

1

Young Niagara

0

DIGGINGS MADE IN SUMMER OF 1908.

August 26, 1908
August 25, 1908
Do

Young Concord. .

Old Concord

Young Niagara...

214

40

86

4

58

5

DIGGINGS MADE IN SUMMER OF 1909.

September 8-9, 1909 ...
September 10-15, 1909 .
September 11-15, 1909.

Young Concord. . .

Old Concord

Young Niagara....

39

0

13

0

17

0

Table XXVIII. — Davidson vineyard. Effect of spray applications on the crop yield
for the seasons 1908 and 1909 at North East, Pa.

FOR SEASON OF 1908.

Year.

Variety and age of
vines.

Treatment.

Plat

Plat
yield.

/alue per Value per SmSt
basket. acre.

1908
1908
1908
1908
1908

Young Concord Sprayed '.

.do Unsprayed..

Acre.

Old Concord.

do

Young Niagara .

Sprayed.
Unsprayed...
Sprayed.

.do Unsprayed.

Lb.baskets
101.8
81.8
502.0
455.0
231. 4
150.4

Cents.
13
13
13
13
9
9

$26.26
21.06
80. 97
78.91
62. 37
40. 50

FOR SEASON OF 1909.

1909
1909
1909
1909
1909
1909

Young Concord
do

Old Concord...
do

Young Niagara
do

Sprayed...
Unsprayed
Sprayed...
Unsprayed
Sprayed...
Unsprayed

1
I

435.8

11

$95. 70

$47. 9*1

i

217.0

11

47. 74

■

1.039.0

11

152. 35

39. 70

3

836. 0

11

112. 65

|

158.2

28

132. 72

61.32

J

85.0

28

71.40

The effect of the spray on egg deposition was obtained by stripping
all of the loose bark from 25 consecutive vines in the sprayed portion
and also in the check rows, making an actual count of the number of
egg clusters deposited on an equal number of consecutive vines in the
sprayed and unsprayed plats. This has proved to be one of the best
wTays to determine the immediate direct effect of spray applications.
These examinations were made at a time, determined by careful

74

THE GRAPE ROOT-WORM.

observation, when the maximum number of eggs had been deposited,
and before but few larvae had hatched from the earliest deposited

eggs.

All of the bark was carefully stripped from the vine and a count
made of the egg clusters found. The number of eggs in these clusters
may vary from 3 or 4 to 75 or even 100. Since it was impossible to
make an actual count of the individual eggs, the clusters were classi-
fied, as the count was made during the examination of the vines, as
large when they contained approximately 50 eggs or more, medium
when they contained about 30 eggs, and small when they contained
about 10 eggs. In this manner we obtained the estimated number of
eggs per vine given in the Table XXVI dealing with egg deposition.
A simple enumeration of the number of egg clusters deposited per
vine regardless of the number of eggs which they contained would
have given but an inadequate idea of the total number of larvae which
might infest the roots of these vines. The number of canes per vine
is also given to indicate the size of the vine, since the limit of the area
upon which the beetles could deposit eggs would have some influence
on the number of clusters deposited.

The prevalence of larvae at the roots of vines in sprayed and
unsprayed plats was determined by making careful diggings at the
roots of a given number of vines in both the sprayed and the
unsprayed plats (Table XXVII). During these diggings the differ-
ence in the number of root fibers thrown out by vines in the sprayed
and unsprayed plats was very noticeable. On May 13, 1908, after
the vineyard had received the protection of one season's treatment
with poison spray the root systems of several vines were examined
in the block of young Concords. It was found that the roots of
many of the vines in the unsprayed plat were almost entirely devoid
of new root fibers, and that the large roots were badly channeled and
pitted by the feeding of the larvae of the grape root-worm, whereas
the roots of vines examined in the sprayed portion of this vineyard
showed that they had thrown out large masses of new fibrous roots
during the growing season as a result of the protection the spraying
had afforded them in the prevention of the deposition of eggs by the
beetles. Plate IV, figure 1, will illustrate this luxuriant growth of
new root fibers on roots of sprayed treated vines, practically all of
which were produced during the growing season of 1907, as compared
with the lack of them on the unsprayed vines (PI. IV, fig. 2). These
illustrations also indicate the recuperative power of badly injured
grape vines when protection from the larvae is afforded; for in the
spring of 1907, previous to the protection of the vines by the poison
spray, the roots of the vines in the sprayed plat were as devoid of
root fibers as were those in the unsprayed plat, as was shown by dig-
gings made in the spring of 1907.

Bui. 89, Bureau of Entomology U. S. Dept. of Agriculture.

Plate VII.

Fig. 1.— Retarded growth of vines in the unsprayed r lat. (Original.)

Fig. 2.— Vigorous growth of vines in the sprayed plat. (Original.}

Views of Experimental Flats in Mr. Roscoe Davidsons Vineyard at North

East, Pa.

REMEDIAL MEASURES.

75

In addition to the above-described methods of comparing the effect
of the treatment of this vineyard with a poison spray, an accurate
count of the number of baskets of grapes picked from equal areas in
the sprayed and unsprayed plats was made and their cash value for
each season recorded. This data, covering the seasons 1907, 1908,
and 1909, is presented in Table XXVIII.

Plate VII, figure 1, shows the light growth of the vines in the
unsprayed plat as compared with Plate VII, figure 2, showing the
heavy growth in the sprayed plat after three years' treatment.

RESULTS OF VINEYARD RENOVATION EXPERIMENTS.

At the time this investigation was commenced the feeling was
quite common among vineyardists of North East, Pa., that it would
be useless to attempt to restore to their former productivity some of
the vineyards very badly injured by the root-worm, and that it would
be cheaper to tear out these old vines and replant the ground to
new vines. In view of the fact that our survey had shown that
many young vineyards just coming into bearing were also declining
very rapidly under attacks of the pest, and that a run-down condition
of old vines was very common throughout the entire grape belt, it
was deemed desirable to investigate as to what could be done in the
way of renovating a badly run-down vineyard.

RENOVATION EXPERIMENT ON AN OLD VINEYARD.

During the fall of 1906 our attention had been called to the condi-
tion of 10 acres of old vineyard which in previous years had possessed
the reputation of being very productive but had suddenly shown a
rapid decrease in yield and also in growth of vine. The yield of this
vineyard, which in 1905 was 6,597.5 pounds of fruit per acre, declined
in 1906 to 1,697 pounds per acre, showing a decrease of 4,900.5
pounds and barely covering operating expenses. When visited by us
in the fall of 1906 the foliage of these vines was found to be riddled
by the beetles of the grape root-worm, the cane growth was stunted,
and many vines simply threw out tufts of puny shoots near the lower
wire of the trellis. The roots were almost devoid of fibers and badly
scarred by the feeding of grape root- worm larvae, and the fruit hung
in scraggy clusters of undersized berries — in short, this vineyard had
all the appearance of being in the last stages of production as a result
of grape root-worm injury. In the spring of 1907 it was decided to
undertake an experiment in this vineyard to determine if by ridding
the vines of this pest, the vineyard could be restored to its former
condition of profitable production. At this point it should be stated
that the vineyard had received in previous years only indifferent
cultivation and practically no fertilizing or spraying. The import ance

76

THE GEAPE ROOT-WORM.

of these operations was recognized at the outset of the experiment and
arrangements were made to give the vines thorough cultivation and
liberal fertilizing in addition to thorough spraying with a poison and
a fungicide; in fact, to treat the vineyard according to the most
approved methods of vineyard management.

That spring when the vineyard was pruned many of the badly
weakened vines were cut back to the ground and others to the lower
wire of the trellis. Even on the most vigorous vines, not more than
one to three fruit-bearing canes were left, it being thought desirable
to concentrate the remaining energies of the weakened vines and
force the vegetative growth rather than attempt to produce fruit of
an inferior quality such as was borne by the vines during the season
of 1906. In order that some light might be thrown on the effect of
different kinds and amounts of fertilizer used in restoring these
injured vines it was decided to divide the vineyard into seven plats
of one acre each and the following kinds and amounts of fertilizer
were applied :

Plat I. Barnyard manure, 7 wagon loads.

Plat II. Complete high grade commercial fertilizer, 1,000 pounds.
Plat III. Complete high grade commercial fertilizer, 1,000 pounds plus 100 pounds
sodium nitrate.

Plat IV. Sodium nitrate, 400 pounds.
Plat V. High grade commercial fertilizer, 1,000 pounds.
Plat VI. High grade commercial fertilizer, 500 pounds.
Plat VII. No fertilizer; no spraying.

The brand of fertilizer used in 1907-8 analyzed available phos-
phoric acid, 11.28 per cent; potash, 5.89 per cent; nitrogen, 3.41
per cent. In 1909 a brand of fertilizer was used analyzing phos-
phoric acid, 8 per cent; potash, 8 per cent; nitrogen, 5 per cent.
The plats commenced on the west side of the vineyard and ran east-
ward. Plats I, V, VI, and VII included seven rows measuring
approximately one acre in area. Plats II, III, and IV contained 14
rows each, but all the data here given are reduced to a 7-row or 1-acre
basis for convenience in comparison. The ground on which this
vineyard is planted is quite level and is of a stony loam on the west
side grading to an almost stoneless clay on the east side where it
has been somewhat enriched by wash from a slight elevation lying
immediately south, which doubtless is responsible for the greater
productivity of plats 5, 6, and 7, at the beginning of the experiment.

The barnyard manure was spread broadcast over the rows of Plat
I during the month of April. The commercial fertilizer was dis-
tributed on the other plats in two equal applications, the first being
made May 21, when active growth of the vines commenced. The
second application was made June 18, about one month later.

All of the fertilizer was applied with a broadcast fertilizer dis-
tributor and immediately followed by a spring-tooth cultivator.

REMEDIAL MEASURES.

77

The ground was plowed early in May and received three thorough
cultivations during the summer. It should be observed at this
point that this is by no means an attempt to solve the problem of
vineyard fertilization, which belongs to the province of the horticul-
turist, and that the results obtained on these plats are presented
without comment upon this feature of the experiment, leaving the
reader to draw his own conclusions.

With the appearance of the first beetles all of the plats except the
check plat received a thorough spraying with Bordeaux mixture and
arsenate of lead, using the following formula: Copper sulphate, 4
pounds; quicklime, 4 pounds: arsenate of lead, 3 pounds. A
second spraying with the same ingredients was made ten days to
two weeks later. (See exact dates on Table XXIX, showing egg
deposition.)

Table XXIX. — Effect of poison spray against the grape root-n orm as shown by relative
occurrence of eggs on sprayed and unsprayed plats of the Porter vineyard during 1907,
1908, and 1909, at North East, Pa.

UN'S PRAYED PLAT.

Year

When exam-
ined.

Number of egg clusters found.

Esti-
mated
num-
ber
of eggs.

Num-
ber
of

vines.

Num-
ber
of

canes.

Average num-
ber of eggs.

Date of
spray

applica-
tion.

Large.

Medi-
um.

Small.

Total.

Per
vine.

Per
cane.

1907. .

Aug. 12,1907

97

1.50

238

485

11.730

2.5

76

469.2

154. 37

1908. .

Julv 22.1908

45

91

78

214

5, 7G0

25

76

230. 4

78.9

1909. .

Jufv 21.1909

37

56

94

187

4,470

25

97

178. 8

46.08

SPRAYED PLAT.

Formula: 4 lbs. blue vitriol (copper sulphate), 4 lbs. lime, 3 lbs. arsenate of lead, 50 gallons water.

1907. .

Aug. 13,1907

1

21

34

50

1,440

25

56

57. 6

.,. - fJuly
\Julv

13
_>_>

1908. .

July 22,1908

0

10

4

14

340

25

58

13. 6

r. s J June

24

2

1909. .

July 21,1908

3

8

18

400

25

117

18.4

q (July
" |\July

5
16

The spray applications were made with a gasoline-engine spraying
outfit specially mounted for vineyard work (PI. X, fig. 2) haying an
arrangement of fixed nozzles, three on each side, the two lower of
which throw the spray on the side of the vines as the machine passes
through the rows. The upper nozzle reaches out over the top of the
row throwing the spray downward so that it covers the new growth
at the top of the trellis. This downward direction of the spray to
cover the new growth at the top of the trellis is highly desirable since'
the beetles exhibit a tendency to feed more freely on this new growth,
especially after the lower leaves have been coated with a poison spray.
A pressure of from 100 to 125 pounds was maintained throughout

78

THE GEAPE ROOT-WORM.

the operation, using about 100 gallons of spray liquid per acre. With
this spraying outfit it is possible to cover from 8 to 10 acres of vine-
yard per day.

METHODS OF OBTAINING AND RECORDING RESULTS.

As in the preceding field experiment, the results of the spray appli-
cation were determined by counting the number of egg clusters
deposited on the vines by the grape root-worm beetles at a time when
the maximum number of eggs were to be found upon the vines. All
of the bark was removed from 25 consecutive vines in the unsprayed
plat and also in the adjoining sprayed plat. The results of these
examinations are given in Table XXIX for the three seasons 1907,
1908, and 1909. Table XXX indicates the effect on the larvae of
spraying as shown by the number of larvae found at the roots of the
vines by carefully removing the soil from the base of the vine for a
distance of 3 or 4 feet from the trunk of the vine and to a depth of a
foot or 16 inches, going several inches below the second whorl of roots.

Table XXX. — Effect of poison spray against the grape root-worm as shown by relative
occurrence of larvae at roots of vines in sprayed and unsprayed plats of Porter vineyard,
at North East, Pa., in 1907, 1908, and 1909.

Date of examination.

Number
of vines.

Variety and age of
vines.

Number of larva?.

Un-
sprayed
plat.

Sprayed
plat.

April and May

September 25, 1907
Mav 27-28, 1908....

June 19, 1909

September 25, 1909

20-vear Concord

....do

....do

....do

....do

76
92

100
67

115

When the crop was ready to harvest, the final effect of the season's
treatment was obtained for each plat. Table XXXI indicates the
plat number, area, fertilizer applied, number of crates or baskets of
grapes, net weight of fruit, value per pound or basket, cash value per
acre, cost of spraying and fertilizing, and value of crop less cost of
treatment.

The data in Table XXXI, giving the results of the treatment from
1907 to 1909, inclusive, show a great increase in crop yield of this
vineyard as a result of thorough spraying and heavy fertilization.
This experiment proves conclusively that if energetic measures are
taken with vineyards rendered practically unprofitable as a result of
grape root-worm injury they may be made to yield very profitable
crops.

REMEDIAL MEASURES.

79

Table XXXI.— Crop yield of plats in renovation experiments for 1907, 19<)H, and

1909, at North East, Pa.

FOR SEASON OF 1907.

Plat
num-
ber.

Plat
area.

Rind of fertilizer used.

Num-
ber of
K-pound
baskets
per
acre.

Net
weight
of fruit

in
pounds
per
acre.

Aver-
age
value

of fruit
per

8-pound
basket

for 1907,
1908,
1909.

Value
of fruit
per
acre.

Cost
of two
spray-
ing ap-
plica-
tions
per
acre.

Cost
of fer-
tilizer

and
appli-
cation
per

acre.

v 1

.

Oi fruit

less
cost of
spray-
ing and
fertiliz-
ing per
acre.

Acre.

Cents.

I

1

Barnyard manure

129

968

12*

116.11

$4.00

$22.00

II

1

Commercial fertilizer, 1,000

198

1,485

12*

24.75

4.00

18.50

2.25

pounds.

III

Commercial fertilizer, 1,000

211

1,590

26.37

4.00

21.00

1.37

pounds; sodium nitrate, 100

pounds.

IV

1

Sodium nitrate, 400 pounds. . .

194

1.460

12*

24. 25

4.00

10.50

9. 75

V

1

Commercial fertilizer, 1,000

308

2,310

12*

38.50

4.00

18.50

16.00

pounds.

VI

Commercial fertilizer, 500

255

1,917

12*

31.87

4.00

9.50

18.37

pounds.

VII

1

No fertilizer; no spraying

263

1,975

12*

32. 87

32.87

FOR SEASON OF 1908.

Acre.

Cents.

I

1

Barnvard manure

427

2,606

12*

$.53. 37

$4.00

$22.00

$27. 37

II

1

Commercial fertilizer, 1,000

482

2,921

:

60.25

4.00

18.50

37. 75

pounds.

III

1

Commercial fertilizer, 1,000

590

3,542

73. 75

4.00

21.00

48. 75

pounds; sodium nitrate, 100

pounds.

IV

1

Sodium nitrate, 400 pounds. . .

649

3.912

»

81.12

4.00

10.50

66.62

V

Commercial fertilizer, 1,000

681

4,153

...

85.12

4.00

18.50

62.62

pounds.

VI

1

Commercial fertilizer, 500

630

4,022

12*

78. 75

4.00

9.50

65. 25

pounds.

VII

1

No fertilizer; no spraying

535

3,369

12*

66.87

66.86

FOR SEASON OF 1909.

Acre.

Cents.

I

1

Barnvard manure

1.188

9.049

121 S14V 50

$4.00

$22.00

$122. 50

II

1

Commercial fertilizer, 1,000

1,282

9,898

12*

160. 26

4.00

18.50

137. 76

pounds.

III

1

Commercial fertilizer, 1,000

1,184

9,146

12*

148.00

4.00

21.00

123.00

pounds; sodium nitrate, 100

pounds.

IV

1

Sodium nitrate, 400 pounds. . .

1,037

8,372

12*

129. 62

4.00

10.50

115.12

V

1

Commercial fertilizer, 1,000

1,171

9.090

12*

146. 37

4.00

IS. 50

123.87

pounds.

VI

1

Commercial fertilizer, 500

1,260

9.580

12*

157.50

4.00

9.50

144.00

pounds.

VII

1

No fertilizer; no spraying

855

6.412

12*

106. 87

106.87

80

THE GRAPE ROOT-WORM.

In examining the yields for the various plats it will be observed
that in the first year of the experiment plats I, II, III, and IV fell con-
siderably below the unsprayed and unfertilized plat. This condition
is due in a great measure to the fact that vines in plats V, VI, and VII
were in a somewhat more thrifty condition at the outset of the experi-
ment. The soil in these plats grades to a clay loam and has been
enriched somewhat by the wash from an elevation immediately south
of them. While the untreated plat shows great improvement in
yield simply as a result of thorough cultivation, yet the annual
increase in yield on this plat was much less than that upon the
treated plats in the same soil.

In addition to this increase in crop yield there was noted a great
improvement in the quality of the fruit both in size of berries and of
clusters. Plate IX, figure 2, gives a comparison of the size and com-
pactness of fruit on a vine in the sprayed portion as compared with
fruit on a vine in the unsprayed portion shown in Plate IX, figure 1.

It was also found that the fruit in the sprayed plats remained firm
and that there was practically no loss from shelling of the berries,
whereas the fruit and stems in the unsprayed plat were badly mildewed
and there was a great deal of shelling of berries. This benefit is
derived from the fungicidal effect of the Bordeaux mixture. This
increase in crop yield has also been accompanied by a marked improve-
ment in the vigor of the vines throughout this vineyard. Practically
all of the vines are now in a condition to produce a full crop of fruit,
and there is no reason why this vineyard should not continue to
produce as profitable crops as it did previous to its infestation, pro-
vided it is subjected to treatment similar to that which it has received
during this investigation.

Plate VIII affords a comparison of the growth of vine at the
beginning and at the end of the experiment, the upper figure show-
ing the vineyard at the beginning of the experiment, and the lower
figure after three years' treatment.

RENOVATION EXPERIMENT ON A YOUNG VINEYARD.

About the year 1900 there was a heavy planting of new vineyards
throughout the Lake Erie grape belt. Scarcely had these young
vines come into bearing when the owners noticed a rapid decline
both in their crop yield and in vigor of vines. Close observation
indicated that this decline was due largely to injury by the grape
root-worm, and that the decline of these young vines was even more
rapid than in the case of older, well-established vines. In many
vineyards it was found that young vines had been killed outright in
a single season.

Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture.

Plate VIII.

Views of the Porter Experimental Vineyard, Showing Comparative Growth of
the Vines in 1907 at the Beginning of the Experiment Upper Figure1,

AND IN 1909 AT THE END OF THE EXPERIMENT I LOWER FIGURE . NORTH EAST, Pa.

(Original.)

Bui. 89, Bureau of Entomology, U. S. Dept. of Agriculture.

Plate IX.

Pig 2— Average condition of berries in the treated plats. North Kast. Pa.. 1909. (Original.)
Condition of Fruit on Vines in Plats of the Porter Experimental Vineyard.

REMEDIAL MEASURES.

81

During the summer of 1907 our attention was called to the condi-
tion of a young vineyard near North East, Pa., belonging to Mr. H. K.
Mosher, which for the first three years of bearing had maintained a
very thrifty condition. The soil of this vineyard had been well
cultivated and heavily fertilized with barnyard manure, yet in spite
of this favorable treatment the crop yield in 1907 decreased to an
alarming extent, amounting only to about one-eighth of the value of
the yield for the previous season.

This vineyard is about 5 acres in extent. The crop value in 1904,
first year bearing, was $127.51; in 1905 it was $410.77; in 1906 it
was $435.72, but in 1907 it was only $55.92

There is every reason to believe that the grape root-worm was
directly responsible for the sudden decline of these vines, for when
the roots of many of the vines, which were practically dead, were
examined by us they were found to be entirely devoid of fibrous
roots, and the whiplike larger roots and the crowns of the vines were
badly furrowed and scarred as a result of feeding by the full-grown
larvae (PI. III). From one section of this vineyard, about 2\ acres
in area, containing 1,584 vines, 563 dead vines were removed in the
spring of 1908. In addition to this, about 50 per cent of the remain-
ing vines were cut back either to the ground or to the lower wire of
the trellis, thus greatly limiting their fruit production for the coming
season. So discouraged was the owner with the condition of this
vineyard that he was at the point of pulling out all of the vines and
replanting it anew. At our request, however, he permitted us to
plan a renovation experiment on this section to determine if the vines
could be restored to a thrifty condition and again produce profitable
crops. This experiment was commenced in the spring of 1908. The
remaining vines were severely cut back, as mentioned above, and new
vines planted in the place of those which had been removed. The
vines were heavily fertilized with a high-grade fertilizer. In this
case, owing to the limited root area, as a result of the feeding by the
larvae, it was deemed desirable to sprinkle the fertilizer by hand
about the base of the vines instead of scattering it broadcast over the
whole area between the rows. Twelve rows received an application
of 400 pounds of nitrate of soda and 24 rows received an application
of high-grade commercial fertilizer at the rate of 2,000 pounds per
acre. This fertilizer was distributed in two applications; the first on
May 21, when active growth was well started, and the second about a
month later.

With the appearance of the first beetles, June 23, 190S. the vines
were sprayed thoroughly with Bordeaux mixture and arsenate of
lead, using 4 pounds of copper sulphate, 4 pounds of stone lime, and 3
51282°— Bull. 89—10 (5

82

THE GRAPE ROOT-WORM.

pounds of arsenate of lead to 50 gallons of water. On July 2, 1908, a
second application was made, using the same formula as for the first
application. The spray was applied with a traction sprayer at a
pressure of about 100 pounds, and about 100 gallons of fluid were
used per acre, covering the vines quite thoroughly with a fine spray.
The whole 5 acres were included in each of these two spray applications.
As a result of this treatment most of the vines made quite a vigorous
growth of wood, which gave a good supply of bearing canes for next
season. Owing to the severity with which these vines were cut back
in the spring, the cash value of the crop from the 5 acres was $31 .02.

The treatment given this section of vineyard in 1908 was duplicated
during the summer of 1909. The same amount of fertilizer was
applied, and two applications of spray were made, the first applica-
tion June 29, the second July 8. As a result of the second season's
treatment the vines have taken on a healthy appearance and made a
vigorous growth of new canes. The number of grape root-worm
beetles has been reduced to a minimum, as shown by the small amount
of feeding on the foliage and by the number of egg clusters deposited.
An examination made on July 24 showed but nine egg clusters on 25
sprayed vines as against 73 egg clusters on the same number of un-
sprayed vines. Diggings made in search of larvae showed a similar
condition. Only three larvae were found about the roots of five
sprayed vines as against 55 larva? found about the roots of five un-
treated vines. The crop value for the season of 1909 for the 5 acres
was $213.92 as against $31.02 for the season of 1908. The vineyard
has made sufficient growth of vines during the season to enable the
owner to put up enough bearing canes to produce a full crop for 1910.

The additional cost of the operations of spraying and fertilizing for
the seasons of 1908 and 1909, over and above ordinary vineyard
management, amounted to $135, itemized as follows:

Nitrate of soda, 1,000 pounds $25.00

Complete fertilizer, 2 tons 70. 00

Spray material and labor, $4 per acre 40. 00

The success of this attempt to restore this 5 acres of vineyard to
its former state of productivity can not be better summarized than
by presenting the following figures showing net weight of fruit and
the crop value for the years 1904 to 1909, inclusive:

Pounds. Value.

1904 11,630 $127.51

1905 23,705 410.77

1906 21,130 435.72

1907 3,195 55.92

1908 4,390 31.02

1909 19,935 213.92

REMEDIAL MEASURES.

83

The owner of this vineyard is greatly pleased with the results
obtained by the treatment described above and is satisfied that a con-
tinuation of these methods will in another season restore his vine-
yard to its full bearing capacity of 1905. It might be added that
previous to this experiment Mr. Mosher was very skeptical regarding
the possibility that this pest could work such havoc in vineyards
and also as to the value or necessity of a spray treatment. During
this experiment, however, he has become a thorough convert, and
is satisfied that the intelligent use of a poison spray has been the
chief factor in the restoration of his vines.

s: RAYS.

ARSENICAL POISONS.

Arsenic in some form or other is usually the active killing agent
used against insects which secure their food by chewing upon the
foliage or fruit of plants, and since the grape root-worm beetles belong
to the category of chewing insects the direct killing agent (or stomach
poison) applied to grapevines is the arsenical poison which the spray
mixture contains.

There are several forms of arsenicals used as insecticides. Those
that have been most commonly used in the past are Paris green and
arsenite of lime. Arsenite of lime is a common home-prepared
insecticide made by boiling together, for about 20 minutes, 1 pound
of white arsenic with 4 pounds of sal-soda crystals in 1 gallon of
water. This is known as the Kedzie formula; and when used with
water, milk of lime made by slaking 2 or 3 pounds of good stone lime
must always be added to 50 gallons of the mixture; for the boiling
of the sal-soda with the arsenic is simply to put all of the arsenic
into solution in order that all of it may unite with the lime to form
arsenite of lime. When used with Bordeaux mixture this addition of
lime is not necessary.

Another arsenical poison and the one which has largely displaced
both Paris green and arsenite of lime as a stomach poison for use on
foliage is arsenate of lead. In properly made arsenate of lead less
than 1 per cent soluble arsenic is present, whereas in Paris green and
arsenite of lime a much higher percentage of arsenic may be soluble
or exist in a weakly combined state, and since it is this soluble arsenic
which is injurious to foliage a much higher strength of the arsenate
of lead can be used without danger of injuring the foliage. In
addition to having this advantage the lead base makes the arsenate
of lead much more adhesive to the foliage than either Paris green
or arsenite of lime. The chief element in favor of the two latter
arsenicals is that they are somewhat cheaper than arsenate of lead.
However, within the past few years the increased consumption of

84

THE GEAPE ROOT-WORM.

arsenate of lead for spraying purposes and the sharper competition
among manufacturers to secure the trade have been the means of
considerably lowering its cost to the consumer and the matter of
price should no longer be a bar to its use.

COMBINING INSECTICIDES WITH FUNGICIDES.

Since the use of a fungicidal spray for grapevines is highly desirable
and frequently absolutely necessary to hold in check fungous dis-
eases such as mildew and black-rot, and since some of the applica-
tions for these fungous diseases and the insect pest may be made
at the same date, it has become customary to combine the two
treatments by adding poison in the form of arsenate of lead to Bor-
deaux mixture, the fungicide used against the fungous diseases.

The formula recommended for this combined treatment is asf ollows :

Pounds.

Copper sulphate (blue vitriol) 5

Fresh stone lime 5

Arsenate of lead 3

Water 50

When Paris green or arsenite of lime are the arsenicals used, 4
ounces of the former, or 1 quart of the latter prepared according to
Kedzie's formula, may be added to 50 gallons of Bordeaux mixture.
For reasons given above the use of arsenate of lead in preference to
either of these other arsenicals is strongly urged. We here include
detailed directions for making Bordeaux mixture which are given
by Mr. C. L. Shear, of the Bureau of Plant Industry, in Farmers'
Bulletin 284, treating of fungous diseases of the grape.

PREPARATION OF BORDEAUX MIXTURE.

Failure to secure satisfactory results from the use of Bordeaux
mixture is frequently due to lack of proper care and thoroughness in
its preparation, or to the use of poor material. All ready-made
preparations of Bordeaux mixture in the form of a paste or a dust
should be avoided, as the chemical constitutents do not properly
combine in these conditions. A definite chemical compound is desired,
and this can only be produced in proper form and condition by care-
fully following the directions given below:

Stock solution. — In order to carry on the work with the greatest convenience and
economy, a considerable quantity of copper sulphate and of lime should be ready for
immediate use. The copper and the lime may be prepared and kept most conven-
iently in the following manner:

Copper sulphate solution. — Take 100 pounds of copper sulphate (bluestone), place
it in a gunny sack, and suspend it in a 50-gallon barrel of water. Kerosene or whisky
barrels will be found very convenient. The copper sulphate will all dissolve in from
12 to 18 hours if suspended in a loosely-woven sack, but if it is thrown loose in the bot-
tom of the barrel it will take several days and considerable stirring to dissolve it. Thia

REMEDIAL MEASURES.

85

makes a solution containing 2 pounds of copper sulphate to each gallon of water. This
may be kept as long as desired without deterioration, if covered so as to prevent
evaporation.

Lime solution. — The various kinds of ground and prepared lime can not always be
relied upon; stone lime is therefore to be preferred, and is more likely to give uni-
formly satisfactory results. Slake 100 pounds of stone lime in a 50-gallon barrel, add-
ing the lime in small quantities with sufficient water and mixing thoroughly. When
the lime is all slaked fill the remainder of the barrel with water. You will now have a
stock preparation of lime which when thoroughly mixed will be thin enough to dip,
and pour readily. Each gallon of this preparation will contain 2 pounds of stone lime.
This may be kept under cover and used as needed. Where large quantities of mate-
rial are being used it is desirable to have two or more barrels each of stock lime and
bluestone instead of one, so that the bluestone in one barrel may be dissolving while
that in the other is being used.

Mixing copper sulphate solution and lime solution. — To prepare a 100-gallon spray
tank of Bordeaux mixture, take two 50-gallon barrels and fill them nearly full of water;
to one barrel add 5 gallons of the bluestone stock solution, which will be equivalent
to 10 pounds of bluestone. To the other barrel add 5 gallons from the barrel of the
stock lime preparation, which will be equal to 10 pounds of stone lime. Mix the lime
thoroughly and allow the contents of the two barrels to run together in a trough, or
through hose attached at the bottom of the barrels into the tank of the sprayer.

If an insecticide is to be used, it may now be added to the mixture.

After the mixture is prepared it should be used very soon, and not be allowed in any
case to stand more than a few hours before using.

The quantities mentioned in this account of the preparation of Bordeaux mixture
will give 100 gallons of the 5-5-50 formula. For the other formulas, the manner of
preparation is precisely the same, and the necessary changes in quantities of blue-
stone and lime are easily calculated.

PLANTS FOR PREPARATION OF THE SPRAY MIXTURE.

Plate X, figure 1, shows a mixing plant erected beside a creek in
a vineyard, using a hydraulic ram to elevate the water to the tank,
the lime being slaked and the copper sulphate dissolved in the bar-
rels standing upon the ground. An abundant water supply which
can be delivered to the sprayer tank either by pressure or by gravity
greatly minimizes both the cost and labor of preparing spray mix-
tures and in addition saves a great deal of time at a season when the
vineyardist is almost overwhelmed with the routine work of vine-
yard operations.

Lack of preparation for spraying operations and failure to utilize
to the greatest advantage the flow of water down creeks or from
springs adjoining vineyards, either by gravity or by the use of hydrau-
lic rams, to elevated mixing stations frequently cause the vineyard-
ist who is rushed with work either to neglect spraying entirely or
to be so delayed in making the application that it is only partly
effective; whereas if plans are made in advance to simplify the mixing
and loading of the spray mixture, the apparent magnitude of the task
is greatly lessened. The thing of prime importance is for the vine-
yardist to become thoroughly convinced that spraying is one of the
absolutely necessary operations in successful vineyard management.

86

THE GRAPE ROOT-WORM.

TIME OF APPLICATION OF SPRAYS.

Much time and labor is actually wasted in making spray applica-
tions after beetles have done considerable feeding and deposited
many of their eggs. The necessity of having all equipment and mate-
rial in readiness to make the first application as soon as the first
beetles appear can not be too strongly emphasized. There is no
doubt that the indifferent results secured from spraying by many
vineyardists is largely due to failure to make the first application as
soon as the first beetles appear upon the vines.

Unfortunately no definite date can be set for the making of this
first application on account of the wide range in the date of emergence
of beetles from the soil from year to year, due to variations in sea-
sonal temperature conditions, especially during the spring months.
Our records show that the beetles emerged fully three weeks later in
1907 than in 1908 and spraying operations had to be planned
accordingly.

Normally the first beetles may be expected to appear between the
20th and 25th of June. It should not be inferred, however, that the
insect does not exist in the vineyards in serious numbers if the
beetles are not in evidence at the latter date, for it happens that
even experts have been led astray, as occurred in Chautauqua County,
N. Y., in the spring of 1907, when experts visited the grape belt dur-
ing the first week in July and, finding no beetles at this date, inferred
that the pest no longer existed in very injurious numbers. Yet late
in July it was found that beetles had emerged in enormous numbers
in many vineyards throughout the area visited. This emphasizes
the fact that only by the closest observation can the vineyardist
determine the damage which this insect may inflict upon his vines
and he must be fully prepared every season to combat the pest on its
first appearance. A more detailed discussion of the changes in time
of emergence of the beetles from year to year is given under the head
of seasonal history of the insect.

NUMBER OF SPRAY APPLICATIONS.

During this investigation it has been learned that two thorough
spray applications will reduce this pest to numbers which will not
materially affect the health of the vine or the production of profitable
crops. The second application should be made about a week or ten
days after the first to cover the growth of new foliage which has
developed, and also to destroy those beetles which may not have
emerged from the soil at the time the first application was made.
Since rearing records indicate that the maximum number of beetles
emerge within the period of ten to fifteen days after the first beetles
appear (see fig. 23) the small percentage of late emerging beetles will
not be likely to effect very great injury. The fact that there is some

Bui. 89, Bureau of Entomology, (J. S. Dept. of Agriculture.

Plate X.

REMEDIAL MEASURES.

87

danger of staining the fruit with spray applications made much later
than the middle of July is an additional reason for making the second
application not later than that date.

Nearly every season since spraying grapevines with a poison lias
become a practice there has been more or less rumor concerning ill-
ness of persons by poisoning resulting from the eating of sprayed
grapes. We have given considerable attention to looking up reports
of this nature but have never been aide to secure direct evidence of
poisoning of persons in this manner. From our observations and

Fig. 30.— Young grapevine sprayed with arsenate of lead against the beetles of the grape root-worm.
North East, Pa., 1909. (Original.)

experiments with poison sprays against the grape root-worm beetle
and all other insect pests known to us at present in vineyards in the
Lake Erie Valley, all applications should be made4 in normal seasons
not later than the middle of July, and in exceptionally late seasons
like that of 1907 not later than July 25. If vineyardists will en-
deavor to make their last poison application before that date they
need have no fear of either staining their fruit or creating cause
for rumor of poisoning by persons consuming the same and also
may feel assured that they have made the applications at a period
when they will prove most efYective in the control of this pest.

88

THE GRAPE ROOT-WORM.

PRESSURE TO BE MAINTAINED IN SPRAY APPLICATIONS.

In order that effective results may be obtained with poison sprays
it is very desirable that, as nearly as possible, all of the foliage be
covered with a mistlike spray. (See fig. 30.) Since in many vine-
yards having thrifty growing vines the foliage is quite dense during
the latter part of June and early July it is necessary that this finely
divided spray be thrown into the vines with considerable force. For
effective work a steady pressure of not less than 100 pounds should
be maintained and if this can be increased to 125 or 150 pounds still
better work may be accomplished.

SPRAYING APPARATUS.

In order to cover vineyard areas of several acres in this manner it
has become necessary to use power sprayers and during the past few
years several types of power vineyard sprayers have come into use.

Horsepower sprayers. — Geared sprayers operated by horsepower (PI. X, figs. 4, 5)
are in general use in many vineyard sections. There are a number of sprayers of
this type upon the market. With many of them, however, it is difficult to maintain
a sufficiently high pressure to cover thoroughly all of the foliage without driving
through the vineyard at too rapid a rate. In addition to this the nozzle arrangement
is not adjusted so as to cover the foliage on the top of the trellis. A very unpleasant
feature in the operation of many of these machines is that the driver is seated directly
between the nozzles which are attached to the sides of the machine and consequently
is drenched with the spray. It would seem however, that with a little ingenuity on
the part of the manufacturers this unpleasant seating position and ineffective nozzle
arrangement could be satisfactorily adjusted.

Gasoline-engine sprayers. — Many vineyardists prefer to have the power for pro-
viding pressure independent of the rate at which the machine travels through the
vineyard and more directly under the control of the operator than it is with the geared
sprayers. Since, however, the regulation gasoline-engine outfit used for spraying
orchards is too heavy and cumbersome to use in the narrow rows of vineyards it has
become necessary to mount the tank and machinery on a specially constructed shortened
truck having low front wheels to admit of easy turning into the narrow vineyard rows.
Plate X, figure 2, is an illustration of this type of gasoline-engine vineyard outfit and
is the sprayer used for the past three seasons in making the application of poison
sprays in the field experiments conducted during this investigation. An outfit of
this kind has the additional advantage of being adaptable for use as an orchard outfit
by simply disconnecting the fixed nozzles at the pump and connecting a lead of hose
and rod when wishing to spray trees. It was for the purpose of tree spraying that the
derrick or platform was erected above the tank. When used for vineyard work the
derrick proved useful as an elevated seat where the driver would be clear of the spray.
(See PI. X, fig. 2.)

Compressed-air outfits. — Compressed-air outfits are a type of sprayer which find
favor with a number of vineyardists and perform excellent work. The air is com-
pressed by means of a stationary engine at the loading station and one of the cylin-
drical tanks is charged with air and the other filled with the spray liquid. The two
tanks are connected so that the air may pass into the tank containing the liquid and
force it out through the nozzles in the form of a fine spray. Since there is no machin-
ery connected with this sprayer except at the loading station there is practically
no danger of delay from machinery getting out of order while working in the field.

BEOOMM KN DATTONS.

89

Carbonic-acid-gas sprayers. — Carbonic aeid is employed as power in a .similar manner
to compressed air. It is, however, somewhat more expensive than either horsepower
engines, gasoline engines, or compressed air. More or less difficulty sometimes occurs
in procuring the drums of gas, which have to be obtained from large cities where this
gas is manufactured. Yet there are many of these outfits in use and giving good
satisfaction.

Hand pumps. — Where but limited areas of vineyard are to be treated quite effect-
ive work may be done with a pump operated by hand to treat vines, and in gardens
or places where it is impossible to drive a cart a knapsack sprayer may be used. For
larger areas, however, it will be found more economical to use power outfits.

The care of spraying apparatus. — For the successful operation of spray pumps it is
highly desirable that the working parts be made of brass, since iron is acted upon
by Bordeaux mixture. It is also important that the pump be so constructed that
packing can be conveniently removed and replaced. Each time after the pump is
used a few pailfuls of water should be run through the pump, hose, and nozzles to
remove all of the spray mixture so that sediment in the mixture may not dry up and
clog the valves and nozzles while the machine is not in use. If this precaution is
taken much annoyance may be avoided when the machine is next put in operation.

Nozzle adjustment. — Practically all of the power sprayers are equipped with adjust-
able nozzles attached to a vertical rod firmly fastened to the sides of the tank, usually
at the rear end of the machine. There are usually two or three of these nozzles set
horizontally to throw the spray into the side of the vines. In addition to these hori-
zontally directed nozzles, the uppermost nozzle
should be carried out over the top of the trellis and
directed downward to insure the covering of all the
foliage on the top of the trellis (PI. X, figs. 2, 3),
since it is upon the new growth developing at the top
of the trellis that the beetles are likely to do much
feeding, especially after the lower foliage has been
thoroughly covered with a spray mixture.

Nozzles. — Nozzles of the Vermorel type are the
kind in general use for vineyard spraying and pro-
duce a fine mistlike spray which is so necessary for FlG- 31.-A large nozzle of the cy-
effective work, and for this reason they are more

desirable than nozzles of the Bordeaux type, which throw a heavier, fan-shaped
spray. The chief drawback with the ordinary Vermorel nozzles lies in the rapid
wearing out and enlarging of the opening of the cap, resulting in a coarse spray if
allowed to become too much worn. More recently larger nozzles of the Cyclone type
(fig. 31) have come into general use, especially where high pressure with power
machinery is used. These nozzles throw a larger cone of spray, have steel disks for
caps, which can be removed when the opening becomes much worn, and possess
the added advantage of not clogging so readily as the smaller Vermorel nozzles.

RECOMMENDATIONS.
DESTRUCTION OF THE ADULTS OR BEETLES.

The beetles of the grape root-worm feed upon the upper surface
of the leaves of the grapevine, and may he poisoned by thoroughlv
spraying the foliage of the vines with an arsenical. The first poison-
spray application should be made as soon as the fust beetles are
found upon the vines. Our observations indicate that the beetles
feed much more freely immediately alter emergence from the soil

90

THE GRAPE ROOT-WORM.

than they do several days later, during the period of egg deposition,
and since the object of this application is to prevent egg deposition,
it is very desirable that the poison application be made early, so
that the first meal of the beetle will consist of poisoned foliage.

The beetles may be expected to appear on the foliage during the
last week or ten days in June or the first few days in July, depending
on the earliness of the season. After June 20 vineyardists should
keep a sharp watch for their appearance and have their spray equip-
ment in readiness to make the first spray application.

The development of the pupa in the soil will also indicate approxi-
mately the appearance of the beetles, for they may be expected to
appear within a week or ten days after the pupae can be found in the
soil in considerable numbers. Since a large majority of the beetles
emerge from the soil from ten to fifteen days after the appearance
of the first beetles, it is necessary to make a second spray applica-
tion within a week or ten days after the appearance of the first
beetles. In this way it will be possible to keep the foliage well
covered with poison spray during the emergence of a maximum
number of the beetles.

Observations and experiments indicate that, if these two appli-
cations are made promptly and thoroughly, this pest can be reduced
to such small numbers that it will not materially affect the vigor of
the vines.

The spray formula recommended is as follows:

Arsenate of lead pounds. . 3

Water gallons.. 50

Copper sulphate (blue vitriol) pounds . . 5

Lime (fresh lump lime) do 5

The first ingredient of the formula, arsenate of lead, is the arsenical
poison and the active killing agent or insecticide. The two last
ingredients, copper sulphate and lime, with the water, form Bordeaux
mixture, which is a fungicide used to control black rot, mildew, and
other fungous diseases of the grape. Fortunately this insecticide
and this fungicide can be mixed without changing the quality of
either, and for this reason their use in combination is recommended.

DESTRUCTION OF THE TVTM.

In the vineyards throughout the Lake Erie grape belt pupation of
the grape root-worm may be expected to commence about June 10,
reaching the maximum about June 15 to 18. These dates can not
be fixed, however, on account of variation in weather conditions.
The exact time of pupation of the insect can best be determined by
the person operating the infested vineyard by carefully removing the
soil around the base of infested vines to a depth of from 2 to 4 inches.

RECOMMENDATIONS.

91

When pupae are discovered, the soil beneath the trellis should be
removed by the horse hoe and the soil directly around the base of
the vine carefully and thoroughly stirred with a hand hoe. The
efficiency of this method of destroying the pupae may be increased
by throwing up a ridge of earth beneath the trellis during the last
cultivation of the preceding summer. This will tend to encourage
the insects to form their pupal cells above the roots of the vine and
thus admit of their destruction by cultivation without serious injury
to the roots of the vine by the horse hoe.

It is in these two stages — namely, the pupa and the beetle — that
the insect appears to be most readily overcome; in fact, no effective
measures have yet been developed for the destruction of the larvae
or of the eggs. Experiments conducted against the larvae in the
soil with oils, carbon bisulphid, fertilizers, salt, etc., have proved
ineffective, and in some cases injurious to the grapevine; and since
the eggs are deposited beneath the bark of the canes when the vines
are in full foliage, it is practically impossible to reach them with a
spray application.

GENERAL TREATMENT OF INFESTED VINEYARDS.

In addition to these recommendations dealing with direct means
of controlling the insect in producing vineyards, a few suggestions
are offered concerning the care and treatment of newly planted
vines, and also of old, run-down vineyards in relation to this insect
problem.

Serious injury is most likely to occur to young vines planted in
soil on which infested vines were growing during the preceding
season, for this soil is likely to be heavily infested with grape root-
worm larvae which will transform to beetles. These emerging
beetles readily discover the newly planted vines and soon riddle the
leaves of these small plants. For this reason it is very desirable,
when the replanting of an old vineyard area is found necessary, that
some annual crop be grown for at least one season, in order that the
soil may be free of the insect when the new vines are planted.

In order that newly planted vines may bo maintained in a thrifty
condition during the period between planting and the bearing of the
first crop of fruit, the vineyardist should keep a sharp watch during
the month of July for the appearance of the grape root-worm beetles
upon his young vines. When the beetles are numerous, they skele-
tonize many of the leaves, and this greatly retards the growth of the
plant. If the infested vines are thoroughly sprayed with arsenate of
lead at a strength of 3 pounds to 50 gallons of water, the injury by the
beetles may be in a great measure prevented.

92

THE GRAPE ROOT-WORM.

There is little danger that young vines will become reinfested dur-
ing the first season, since there is a very limited amount of cane or
stem upon which the beetle can deposit its eggs. By the second sum-
mer, however, the area upon which eggs may be deposited is somewhat
increased, and we have discovered occasional egg clusters of this insect
under the loose bark of the short stem of 1 -year-planted vines and
have also found a few larvae at their roots late in summer, indicating
that permanent infestation may take place early in the life of the vine-
yard. Hence it may be necessary to spray some vineyards from the
time of planting.

Generally it is during the third season's growth of the vines, when
the cane is trained to the trellis, that serious permanent infestation,
by means of egg deposition by the beetle, takes place. The larvae
hatching from these eggs are especially injurious to these young vines,
which possess but a limited root system compared with that of an old-
established producing vine. It is the opinion of the writers that the
first year or two of fruit production of young vines exposed to infesta-
tion is the most critical period of their existence, and especial care
should be taken during that period to prevent infestation by the
beetles. This can be accomplished by following the suggestions made
on pages 89-90, giving directions for the destruction of the beetles.

When vines in a producing vineyard have been badly injured by
this pest, such vines may frequently be renovated by cutting them
back to the ground, so that the limited vitality of the injured vine
may be devoted entirely to the making of vegetative growth. A
heavy application of fertilizer should be made, consisting either of
barnyard manure or a commercial fertilizer containing a high per-
centage of nitrogen. The vines should be thoroughly sprayed at the
time the beetles make their appearance and thorough cultivation of
the soil should be maintained throughout the season. The grapevine
possesses remarkable recuperative power and, as the results tabulated
in this paper, under the heading of field experiments, indicate,
responds bounteously to careful and generous treatment.

BIBLIOGRAPHY.

1826. Sturm, J. — Catalog meiner Insecten-Sammlung, Kiifer, pis. 4 col., pp. 1-207.

1837. Dejean, P. F. M. A.— Catalogue des Coleopteres, Third Edition, Paris.

1843. Sturm, J.— Catalog der Kafersammlung von J. Sturm, p. 295.

Fidia lurida Dej., synonym flavescens Sturm Cat. 1826.

1847. Melsheimer, F. E. — Description of new species of Coleoptera of the United
States. <Proc. Acad. Nat. Sci. Phila., vol. 3, pp. 158-181.

1863. Baly, J. S. — An attempt at a classification of the Eumolpida3.<Journ. Ent.,
vol. 9, pp. 143-163.

Original description of the genus Fidia.

1866. Walsh, B. D. — Answers to correspondents. An undescribed species of

Fidia. <Pract. Ent., vol. 1, No. 10, pp. 99-100.
This insect later proved to be F. viticida Walsh.

1867. Walsh, B. D.— The grapevine Fidia (Fidia viticida Walsh ).<Praet. Ent.,

vol. 2, pp. 87-88, fig.

Original description of the species.

1867. Walsh, B. D.— Grapevine beetles. <Pract. Ent., vol. 2, p. 118.

1868. Riley, C. V. — First Annual Report Insects of Missouri, p. 132.

1870. Riley, C. V.— Grapevine Fidia.<Amer. Ent. and Bot., Sept., vol. 2, p. 307.
Answer to correspondent.

1872. Kridelbaugh, S. H.— Injurious insects. <Ann. Rep. Iowa State Hort. Soc.

for 1871, pp. 153-167.

1873. Crotch, G. R. — Materials for the study of the Phytophaga of the United

States.<Proc. Acad. Nat. Sci. Phila., vol. 3, pp. 158-181.
Original description of Fidia longipes Melsh.

1874. Chapuis, F. — Ilistoire naturelle des insectes. Genera des Coleopteres, vol.

10, p. 275.

1877. Lefevre, E. — Descriptions de Coleopteres nouveaux on peu connus de la
famille des Eumolpides.<Ann. Soc. Ent. France, ser. 5, vol. 7, pp. 115-166.

1880. Stout, O. E. — Insects injurious and beneficial. <Rep. Kans. State Hort. Soc.
f. 1879, vol. 9, pp. 86-91.

Mention of Fidia viticida Walsh.

1880-1892. Jacoby, M.— Biol. Centr.-Amer., Insect a, Coleoptera, vol. 6. Pt. I. p. L66.
1885. Lefevre, E. — Catalogus Eumolpidarum.<Mem. Soc. Roy. Sci. Liege, Ber. 2,
vol. 2, separ., pp. 1-172.

1891. Riley, C. V., and Howard, L. O.— Insect Life, vol. 3. p. 219.

Refers to investigation in Europe of Adoius vitis 1.., and mentions Fidia. the Amer-
ican rrlated beetle.

1892. Horn, G. H. — The Eumolpini of Boreal America. <Tran Amor. Ent. Soc.,

vol. 19. pp. 195-234.

Three species of Fidia in Boreal America. Mentions synonyms of F. viticida Walsh.

1893. Riley, C. V. Insect Lite. vol. 5, p. IS.

Injury by F. viticida at Yineland, Ark.

93

94 THE GRAPE ROOT-WORM.

1894. Ashmead, W. H. — A new genus and species of Proctotrypidae and a new
species of Brachystichia, bred by Prof. F. M. Webster. <Journ. Cine. Soc.
Nat. Hist., vol. 17, pp. 170-172.

Egg parasites of the grape root- worm.

1894. Howard, L. O. — The grapevine root- worm. <Insect Life, vol. 7, p. 48.
1894. Webster, F. M. — Studies of the development of Fidia viticida Walsh. <Journ.
Cine. Soc. Nat, Hist,, vol. 17, pp. 159-169, pi. 9.

The first account of the underground habit of the grape root-worm larvae; this con-
stitutes the more technical features of the publication in Ohio Exp. Sta. Bui. 62, 1895.

1894. Webster, F. M. — Questions and answers. <The Ohio Farmer, January 18,
p. 57.

1894. Webster, F. M. — Entomology. <The Ohio Farmer, May 3, p. 357, 5 figs.
Answers to correspondents.

1894. Webster, F. M.— Entomology. <The Ohio Farmer, June 28, p. 509.

1894. Webster, F. M. — Inquiries and answers. <The Ohio Farmer, September 27,

p. 257.

Grape root-worm injury at Lawrence, Kans.

1895. Dille, N. W.— Entomology. <The Ohio Farmer, July 11, p. 37; continued

June 20, p. 497.

Popular account of the grape root-worm.

1896. Marlatt, C. L. — The principal insect enemies of the grape. <Yearb. U. S.

Dept. Agr., 1895, pp. 391-393, fig. 98; (abstract in Amer. Nat., 1896, p. 759).

A general account of the grape root-wrorm; recommends carbon bisulphid and also
kerosene emulsion to be applied to the roots.

1895. Webster, F. M. — The grape root-worm. <Bul. 62, Ohio Agr. Exp. Sta., Octo-
ber, pp. 77-95, 1 pi. (Abstract in Ent, News, 1896, pp. 82-83.)

A more detailed account of studies first published in Journ. Cine. Soc. Nat. Hist.,
1897, vol. 17, pp. 159-109; includes Ashmead's paper on egg parasites.

1895. Webster, F. M. — Grape root- worm. <The Ohio Farmer, August 22, p. 147.

Answers to correspondent.

1896. Murtfeldt, Mary E. — Grapevine pest,<Colman's Rural World, St. Louis,

Mo., March 26, pp. 75,97.
1896. Stimson, J. T. — Report of the horticulturist, <Bul. 43, Ark. Agr. Exp. Sta.,
p. 114, fig.

Injury caused by F. viticida Walsh in Arkansas.

1896. Webster, F. M. — Insects affecting the roots of the grapes. <Ann. Rep. Ohio

State Hort, Soc, p. 31.

Egg parasites of the grape root-worm occurring in increased numbers.

1897. Webster, F. M., and Mally, C. W. — Insects of the year in Ohio.<Bul. 9, n. s.,

Div. Ent., U. S. Dept. Agr., pp. 40-45.

Experiments with tobacco and kainit applied to the soil to kill larvse of the grape
root-worm.

1899. Lugger, O. — Beetles injurious to fruit-producing plants. <Bul. 66, Minn.
Agr. Exp. Sta., p. 223.

Adoxus obscurus L. common on cultivated grapes in 1898.

1899. Webster, F. M., and Mally, C. W.— Insects of the year in Ohio.<Bul. 20,

n. s., Div. Ent., U. S. Dept. Agr., pp. 68-73.
Grape root-worm abundant in 1897 in Ohio.

1900. Slingerland, M. V. — The grape root-worm, a new grape pest in New York.

<Bul. 184, Cornell Agr. Exp. Sta., pp. 21-32, 11 figs.

An account of the grape root-wrorm condition in the Chautauqua grape belt; with
compilations from Webster's papers of 1894 and 1895.

1900. Smith, J. B. — Catalogue of the insects of New Jersey, p. 303.

Both the European and the native grape root-worms found throughout the State.

BIBLIOGRAPHY.

95

1901. Howard, L. O. — Notes from correspondence. <Bul. 30, Div. Ent., U. S.
Dept. Agr., pp. 97-98.

Serious injury to vineyards at Bloomington, 111.

1901. Slingerland, If. V.— Entomology. <Proc. West. X. Y. Hort. Soc. f. 1901,

pp. 68-73.

Mention of grape root-worm.

1902. Doty, S. X. — Destructive grape-worms.<Journ. of Agr., St. Louis, June 26.

General comments on the grape root-worm.

1902. Felt, E. P. — Seventh report of the state entomologist on injurious and other
insects of the State of New York for 1901. <Bul. 53, N. Y. State Mus.,
pp. 699-925, 6 pis., 29 figs.

Mention of Fidia viticida Walsh.

1902. Felt, E. P. — Grape root-worm. <Country Gentleman, May 15; June 26.
Value of cultural methods.

1902. Felt, E. P. — Report of the committee on insects. <6th Ann. Rep. Eastern

X. Y. Hort. Soc, pp. 210-218.
1902. Felt, E. P.— Grapevine root-worm. <Bul. 59, X. Y. State Mus., pp. 49-84,

6 pis.

Results of studies in the Chautauqua grape belt, 1902; use of beetle catcher recom-
mended.

1902. Felt, E. P. — Report of the committee on insects. <6th Ann. Rep. Eastern
N. Y. Hort. Soc, pp. 210-218. (Published by New York Fruit Growers'
Association, 1902.)

1902. Felt, E. P. — Grapevine root-worm. <Country Gentleman, July 10, pp.
574-575.

Effectiveness of cultivation in the control of the grape root-worm.
1902. Felt, E. P. — The grape root- worm. <Country Gentleman, May 15, 1902, p.
413, 2 figs.

Comprehensive account of the grape root-worm condition.
1902. Felt. E. P.— Insects in Xew York, III.<Country Gentleman, April 10, p.
308.

1902. Johnson, W. G. — Remedies for the grape root-worm. <Amer. Agr. (Xew
York), June 7, 1902, p. 750, 2 figs.

Summary account of the life history of the grape root-worm; refers to Slingerland's
work.

1902. Slingerland, M. V., and Craig, J. — The grape root-worm. <Bul. 208,
Cornell Agr. Exp. Sta., pp. 177-200, 16 figs.

Account of infestation in Chautauqua grape bolt; successful results from poison
spray experiments.

1902. Webster, F. M., and Newell, W. — Insects of the year in Ohio. <Bul. 31,

n. s., Div. Ent., IT. S. Dept. Agr.. pp. 84-90.

Grape root-worm, less destructive in 1901, again taking on a new vigor.

1903. Burgess, A. F. — Remarks on the grape root-worm. <Bul. 40, Div. Ent.,

U. S. Dept. Agr., p. 34.

Arsenate of lead spray showing good results.
1903. Chittenden, F. H. — The principal injurious insects in 1902. <Yearl>. i\ S.

Dept. Agr., 1902, p. 729.
1903. Felt, E. P. — Grapevine root-worm. <Bul. 72, X. Y. State Mus.. pp. 55.

pis. 13.

Replaces Bui. 59, 1. c, and contains records of further experiments with beetle
catcher.

1903. Slingerland, M. V. — A big fight against grape pests. v^Proo. Western X. Y.
Hort. Soe. f. 1903, pp. 75-78.

Effectiveness of an arsenical spray.

96 THE GEAPE ROOT- WORM.

1903. Felt, E. P. — Insecticides and notes. <Country Gentleman, January 15, p. 47.

1903. Felt, E. P. — Summary of root- worm situation and experiments. <Country

Gentleman, September 24, p. 828.

Results of experiments with beetle catcher.

1904. Burgess, A. F. — Notes on economic insects for the year 1903. <Bul. 46,

Div. Ent., U. S. Dept. Agr., pp. 62-65.

Grape root-worm continues to appear in injurious numbers.

1904. Chittenden, F. H. — The principal injurious insects of 1903. <Yearb. U. S.

Dept. Agr., 1903, p. 564.
1904. Felt, E. P. — Recent work upon the grapevine root- worm. <Proc. Western

N. Y. Hort. Soc. f. 1904, pp. 48-51.
1904. Felt, E. P. — Report of the committee on entomology. <N. Y. State Fruit

Growers Ass'n, 1904, pp. 28-29.
1904. Felt, E. P. — Insect pests of the year. <N. Y. State Fruit Growers Ass'n,

1904, pp. 136-139.

1904. Felt, E. P. — Contribution for the destruction of the grape root-worm. <Grape
Belt, June 14, p. 7.

1904. Felt, E. P. — In the Chautauqua grape belt. <Country Gentleman, June 9,
pp. 544-545.

1904. Felt, E. P. — Time to get out the beetle catchers. <Grape Belt, June 28, p. 7.
1904. Felt, E. P.— Grape-vine root-worm. <Grape Belt, Feb 9, 23; Mar. 8, 15;
Apr. 5, 12; May 6, 17.

Republished from Bui. 72, N. Y. State Mus., 1903; also republished in part in James-
town Journ., Feb. 10, 1904, p. 5.

1904. Pettit, R. H. — Insects injurious to fruits in Michigan. <Spec. Bui. 24,

Mich. Agr. Exp. Sta., pp. 79.
1904. Sceleffer, C. — New genera and species of Coleoptera. <Journ. N. Y. Ent.

Soc, vol. 12, p. 227.

Includes a key to the species of Fidia of Boreal America.

1904. Slingerland, M. V., and Johnson, F. — Two grape pests. <Bul. 224, Cornell
Agr. Exp. Sta., pp. 65-73, figs. 4.

Good results from spraying experiments.

1904. Slingerland, M. V. — Notes and new facts about some New York grape pests.
<Bul. 46, Div. Ent., U. S. Dept. Agr., pp. 73-78, 1 fig.

Failure of experiments with "catchers"; spraying shows encouraging results.

1904. Slingerland, M. V. — Our insect enemies in 1903. <Proc. Western N. Y.
Hort. Soc. f. 1904, pp. 72-77.

1904. Washburn, F. L— Ninth Ann. Rep. State Ent. Minn. f. 1904. St. Anthony

Park, Minn.

Grape root-worm listed, without specific instance of its occurrence in Minnesota.

1905. Burgess, A. F. — Some economic insects for the year 1904 in Ohio. <Bul. 52,

Div. Ent., U. S. Dept. Agr., p. 54.

The root-worm is reported less injurious in Ohio in 1904.

1905. Burgess, A. F. — Some destructive grape pests in Ohio. <Bul. 5, Ohio Dept.
Agr., Div. Nursery and Orchard Inspection, pp. 17.
Spraying most advisable method for its control.

1905. Chittenden, F. H. — The principal injurious insects of 1904. <Yearb. U. S.
Dept. Agr. for 1904, p. 603.

1905. Felt, E. P. — Twentieth report of the state entomologist on injurious and other
insects of the State of New York for 1904. <Bul. N. Y. State Mus., pp. 35,
95-97. (In part reprinted in the Grape Belt, June 27, 1905, p. 7.)
Further contributions to the grape root-worm investigations.

BIBLIOGRAPHY.

97

]905. Felt, E. P.— Notes for the year. <Bul. 52, n. b., Bur. Ent., U. S. Dept.
Agr., pp. 51-52.

Spraying may reduce the pest 60 per cent.

1905. Felt, E. P. — New York State Fruit Growers Ass'n, Rep. Committee on Ento-
mology. <Proc. Fourth Ann. Meet., 1905, pp. 27-30.

1905. Felt, E. P. — Grape root-worm. <Country Gentleman, February 2, 1905, pp.

70, 106.

1906. Burgess, A. F. — Some economic insects of the year in Ohio. <Bul. 60,

Bur. Ent., U. S. Dept. Agr., pp. 71-74.

Injury to the grape root-worm in 1905 slight.

1906. Felt, E. P. — Twenty-first report of the state entomologist on injurious and
other insects of the State of New York for 1905. <Bul. 104, N. Y. State
Mus., pp. 45-186.

Further grape root-worm experiments.

1906. Felt, E. P.— Notes for 1905 from New York. <Bul. 60, Bur. Ent., U. S.
Dept. Agr., pp. 89-90.

1906. Felt, E. P.— Grape root- worm. <Grape Belt, July 24, p. 5.
Condition of infested vineyards.

1906. Felt, E. P.— Grape root- worm. <Grape Belt, May 29, p. 1.
1906. Felt, E. P.— Injurious Insects of 1905. <Proc. N. Y. Fruit Growers Ass'n,
pp. 120-124.

1906. Slingerland, M. V. — Final demonstration of the efficiency of a poison spray

for the control of the grape root- worm. <Bul. 235, Cornell Agr. Exp. Sta.,
pp. 91-93.

Effectiveness of a poison spray; egg parasites.

1907. Atwood, G. G. — Some items of information for orchardists and fruit growers.

<Bul. 1, N. Y. Dept. Agr., Bur. Hort. Insp., pp. 20.
1907. Felt, E. P. — Twenty-second report of the state entomologist on injurious and
other insects of the State of New York for 1906. <Bul. 110, N. Y. State
Mus., pp. 39-186.

1907. Quaintance, A. L.— The grape root-worm . <Farmers' Bui. 284, U. S. Dept.

Agr., pp. 6-12, fig.

1908. Felt, E. P.— Entomological Notes for 1907. <Journ. Econ. Ent., vol. 1. pp.

148-150.

1908. Felt, E. P. — Twenty-third report of the state entomologist on injurious and
other insects of the State of New York for 1907. <Bul. 124, N. Y. State
Mus.

1908. Johnson, F. — Grape root-worm investigations in 1907. <Bul. 68, Pt. VI,
Bur. Ent., U. S. Dept. Agr., pp. 61-68.

History of the root-worm condition in the Lake Erie grape belt: results of experi-
ments of 1907.

1908. Quayle, H. J. — A new root pest of the vine in California. <Journ. Econ.
Ent., vol. 1, pp. 175-176.

The European grape root-worm (Admits osscurus L.).

1908. Quayle, H. J. — The California grape root-worm (Adonis obscurus L.). <Bul.
195, Cal. Agr. Exp. Sta., pp. 26, figs.
51282°— Bull. 89—10 7

INDEX.

Page.

Adoxus obscurus, bibliographic references 94,97

related to Fidia viticida, distribution and habits 15-16

vitis, bicolored form of Adoius obscurus 15

vitis, bibliographic reference 93

Ampelopsis quinqucfolia, food plant of grape root-worm 13

Arsenate of lead against red-headed Systena 18

and arsenite of lime, comparative effectiveness against grape root-worm beetle 68-70

Bordeaux mixture against grape root-worm beetle 64-68,71-75,77-78,81-82,84,90

comparison with arsenite of lime and Paris green as insecticide 83-84

Arsenite of lime and arsenate of lead, comparative effectiveness against grape root-worm beetle 68-70

Bordeaux mixture against grape root-worm beetle 84

comparison with arsenate of lead and Paris green as insecticide 83-84

Bordeaux mixture and arsenate of lead against grape root-worm beetle 64-68,71-75,77-78,81-82,84,90

arsenite of lime against grape root-worm beetle S4

Paris green against grape root- worm beetle 84

directions for preparation 84-85

Brachysticha fidix, parasite of grape root-worm 51,56-57

Carabid beetles and their larvpp, enemies of grape root-worm 50

Cercis canadensis, food plant of grape root-worm 13

Chrysopa sp. , enemy of grape root-worm 51

Colaspis brunnea, mistaken for grape root-worm beetle, description and habits 18

Craponius inazqualis, mention as enemy of grape „ 18

Cremastogoster lineolata, enemy of grape root-worm 51

Cultural methods for destruction of pups of grape root-worm 61-63

Dipterous parasite of grape root-worm 55-£6

Elm leaf-beetle. (See Galcrucella lutcola.)

Fertilizers used in renovation experiment on old vineyard injured by grape root- worm 76

young vineyard injured by grape root-worm 82

Fidia flavescens, bibliographic reference 93

known species 16

longipes, bibliographic reference 93

injurious to cultivated grape, distribution 16

lurida, bibliographic reference 93

= Fidia viticida 11

murina= Fidia viticida 11

viticida (see also Grape root-worm).

bibliographic references 93-97

copy of original description 21

validity of name 11

Fidiobia flavipes, copy of original description 51

parasite of grape root- worm, life history 51-55

Fungicides, combination with insecticides 84

Grapeberry moth. (See Polychrosis viteana.)

Grape, cultivated varieties, food plants of grape root-worm 13-14

curculio. (See Craponius insequalis.)

food plant of Colaspis brunnea 18

Craponius insequalis 18

Haltica chalybea 17

Macrodactylus subspinosus 17

Polychrosis viteana 18

Systena frontalis 17-18

Typhlocyba comes 18

leafhopper. (See Typhlocyba comes.)

production in Lake Erie Valley, 1900 to 1909 fi8

root-worm (see also Fidia viticida).

98

INDEX. 99

, Page.

Grape root, worm as affecting vineyards in Lake Erie Valley 57-39

beetle, beetles mistaken therefor 16-19

related thereto 15-16

description 21

destruction 83-90

seasonal history 22-33

bibliography 93-97

California. (See Adoius obscurus.)

control measures 59-83

cultural method for destruction of pupae 61-C3

description of stages 19-21

destructiveness 14-15

development and feeding of larva before wintering 35-C6

distribution 12-13

egg deposition, feeding before and after it 25-28

mating and its bearing upon it 28

period for season of 1909 Zl-i2

process 28

variation in number of eggs per cluster 29

depositions, numbers by individual females 29

description 19

incubation period 33-C5

eggs, number per cluster, variation 29

female beetle CO

emergence of beetle 22-25

experimental and rearing methods <4-C0

feeding and development of larva before wintering 35-.' 6

of beetle before and after egg deposition 25-28

larva in spring 37

food plants 13-14

history 10-12

injury, character 14-15

insect enemies, parasitic 51-57

predaceous 50-51

introduction 9-10

larva, description 19-20

seasonal history 35-39

life cycle as determined by rearing 40-41

history, seasonal variations 41-44

studies, summary 50

longevity of male and femals beetles 32-33

mating and its bearing on egg deposition 28

natural enemies 50-57

occurrence of larva? in different soils 36

origin 12

parasitism, double 56-57

poison sprays against beetle in cages, experiments 64-435

field, effect 63-64.70-75

experiments 66-68

position of pupa in cell 39

post-larval stage 38-39

preface 3-4

preventive measures, evolution 53-61

pupa, description 20-21

destruction 61-63, 90-91

seasonal history 33— 10

pupal cell, time and making 37-38

period, duration 40

pupation in field and in breeding cages, time 33— 10

process 39

rearing and experimental methods 44-50

recommendations for destruction of beetles 89

pupa? 90-91

remedial measures for control 53-89

renovation experiment on old vineyard 75-SO

young vineyard S0-S3

100 THE GRAPE ROOT-WORM.

Page.

Grape root-worm, seasonal history 22-50

variation in life history 41-44

sprays in control 83-88

summary of life-history studies 50

temperature records during breeding period of 1909, North East, Pa 43

treatment of injured vineyards 91-92

vineyard renovation experiments, results 75-83

vitality of newly hatched larva 35

wintering of larva in earthen cell 36-37

Grapes, wild, food plants of grape root- worm 13-14

Grapevine Colaspis. (See Colaspis brunnea.)
Fidia. (See Fidia longipes.)
flea-beetle. (See Haltica chalybea.)

Haltica chalybea, mistaken for grape root- worm beetle, description and habits 17

IJeteropus [Pediculoides] ventricosus, enemy of grape root-worm 51

Hippodamia convergens, enemy of grape root- worm 51

Hoplophora [Phthiracarus] arctata, enemy of grape root- worm 51

Insecticides and fungicides, combination 84

Lachnosterna sp., enemy of grape root-worm 51

Lasius brunneus var. alienus, enemy of grape root-worm 51

Lathromeris (Brachysticha) fidix, parasite of grape root-worm 51,56-57

Macrodactylus subspinosus, mistaken for grape root- worm beetle, description and habits 17

Nozzle adjustment for spraying vineyards 89

Nozzles for spraying vineyards 89

Paris green and Bordeaux mixture against grape root- worm beetle 84

comparison with arsenate of lead and arsenite of lime as insecticide 83-84

Pediculoides ventricosus, enemy of grape root- worm 51

Phthiracarus arctatus, enemy of grape root- worm 51

Polychrosis vitcana, mention as enemy of grape 18

Redbud. (See Cercis canadensis.)
Red-headed Systena. (See Systena frontalis.)

Renovation experiment on old vineyard injured by grape root- worm 75-80

young vineyard injured by grape root-worm 80-83

Rhizoglyphus phylloxerse, enemy of grape root-worm 51

Rose-chafer. (See Macrodactylus subspinosus.)

Spraying apparatus, care 89

for vineyard use 88-89

Spray formula recommended against grape root- worm beetle 90

mixture, plants for preparation 85

Sprays against grape root- worm beetle 83-88

number of applications 86-87

pressure in applications 88

time of application ' 86

Staphylinus vulpinus, probable enemy of grape root- worm , 51

Systena frontalis, mistaken for grape root-worm beetle, description and habits, remedy 17-18

Telephorid enemy of grape root- worm 51

Temperature records during breeding period of grape root-worm during 1909 at North East, Pa 43

Typhlocyba comes, mention as enemy of grape 18

Tyroglyphus [Rhizoglyphus] phylloxerx, enemy of grape root-worm 51

Vineyard conditions in Lake Erie Valley 57-59

experiments with poison sprays against grape root- worm beetle, results 70-75

renovation experiments against grape root- worm, results 75-83

Vineyards, recommended treatment of those injured by grape root-worm 91-92

Virginia creeper. (See Ampelopsis quinque folia.)

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