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Digitized by the Internet Archive
in 2010 with funding from
University of Toronto

http://www.archive.org/details/bulletin276main

MAY 19 1919

University of Maine

Wt
i

no,276

Biological
& Medical

se Maine Seriuttural Eyer.

V\BRAR

JAN 19
ORONO,
el CRSIT) y OF a 7
BULLETIN 276 MARCH, 1919
eee,
THE MEADOW PLANT BUG.
yi
CONTENTS

PAGE
TEL 0 Cri eC eae i Se I
RGN ss Ios. a 3
TR ot cere a <a eras ie Te 3
MTG RSs 5 cece cs Achieve cw ss sk wale a is Sale 4
mend to be am Introduced Species.........,..... 006% 4
Seemmmition in Maine............c...t.. BAN AI st on chrome a etait 5
MIE. LINIPOTCANCE «pet ke ele ee eee 6
AES I Res a a 7
EE. SG Oy Soi aH eo 8
RS SS, ee” ace 8
II IEG 5 cc lack oes hn we secs We ee RS II

SO ee er re 14

. MAINE
AGRICULTURAL EXPERIMENT STATION
ORONO, MAINE

ov
THE STATION COUNCIL
PRESIDENT ROBERT J. ALEY, President
DIRECTOR CHARLES D. WOODS, Secretary

THOMAS V. DOHERTY, Houlton,
FRANK E. GUERNSEY, Dover,
CHARLES S. BICKFORD, Belfast,

Committee of
Board of Trustees

JOHN A. ROBERTS, Commissioner of Agriculture
EUGENE H. LIBBY, Auburn, State Grange
WILSON W. CONANT, Buckfeld, State Pomological Society
FRANK S. ADAMS, Bowdoinham, State Dairymen’s Association

LEONARD C. HOLSTON, Cornish, Maine Livestock Breeders’ Ass'n.
WILLIAM G. HUNTON, Portland, Maine Seed Improvement Ass'n.

Anp THE HEADS AND ASSOCIATES OF STATION DEPARTMENTS, AND THE
DEAN OF THE COLLEGE OF AGRICULTURE

THE STATION STAFF

CHARLES D. WOODS, Sc D. Director

ADMINIS- ESTELLE M. GOGGIN, Clerk
TRATION CHARLES C. INMAN, Clerk
MARY L. NORTON, Clerk

FRANK M. SURFACE, Pu. D., Biologist*

JOHN W. GOWEN, Pu. D., Assistant

BIOLOGY RAYMOND PEARL, Pu. D., Collaborator
MILDRED R. COVELL, Clerk

HELEN A. RING, Laboratory Assistant

“JAMES M. BARTLETT, M. S., Chemist

; HERMAN H. HANSON, M. S., Chemist*
CHEMISTRY % EIMER R. TOBEY, B. S., Assistant
Cc. HARRY WHILE: Assistant

ENTOMOL- ( EDITH M. PATCH, Pu. De Entomologist
OGY | ALICE W. AVERILL, Laboratory Assistant
PLANT WARNER J. MORSE, Px. D., Pathologist
ah _’ DONALD FOESOM Paap: Assistant
PATHOLOGY. | ViOiA ORE nS) Laboratory Assistant
| ( JACOB ZINN, Ken D, Assistant Biologia
pee NES \ i: RAYMOND RING, A. B, Scientific Aid
FARM | WALTER E:; CURTIS, Scientific Aid
HIGHMOOR ({( WELLINGTON SINCLAIR, Superintendent
FARM ), . Sateen ee eee Scientific Aid
ROYDON L. HAMMOND, Seed Analyst and Photographer

* Absent on leave during period of war.

BULLETIN 276

THE MEADOW PLANT BUG *

HERBERT OSBORN

Research Professor of Zoology and Entomology, Ohio State University,
and Consulting Entomologist, Maine Agricultural Experiment
Station

SUMMARY

1. Miris dolabratus has been a conspicuous insect in tim-
othy meadows in portions of the eastern United States during

the past 40 years and now has a distribution as far west as
Illinois and Minnesota and south in the Mississippi valley into

Kentucky.

2. It is believed to be an introduced species coming from
Europe with timothy hay or other large stemmed grass shipped
for forage or packing sometime between 1800 and 1825.

3. It feeds upon cultivated grasses especially timothy, or-
chard grass and meadow fescue and when abundant must seri-
ously affect the value of the crop.

4. It is a dimorphic species, there being two forms of
females, a long-winged and a short-winged form, the latter be-
ing far more plentiful, something like 90 per cent of all fe-
males.

5. The species hibernates in the egg form, hatching oc-

curs about May 25th to June 10th in Maine, and the nymphs
pass through 5 instars of about 6 or 7 days each, adults oc-
curring from early July, mating and laying eggs from July
10th to August ist for the short-winged forms necessarily in
the fields where the females have developed.

*Papers from the Maine Agricultural Experiment Station: En-
tomology No. 101. This bulletin is based on a more detailed paper by
the same author, published under the title “The Meadow Plant Bug,
Miris dolabratus;” Journal of Agricultural Research, Vol. XV, No. 3.

2 MAINE AGRICULTURAL EXPERIMENT STATION. 1919.

6. The eggs are laid in stems of grass or clover in fields
where females have grown, being thrust through the wall of

the stem and held by an expanded cap which is firmly held by
the walls of the stem, the egg being protected in the hollow of
the stem and in this position remain for at least 8 or 9 monthsi
before hatching.

7. Measures for control so far evident and based on
habits determined will consist especially of rotation, with prob-
ably some advantage from burning, early cutting, pasturing
heavily in fall, and possibly by mechanical devices for captur-
ing the nymphs or adults.

8. The spread of the insect should be prevented by care
in the disposition of timothy hay moved to a distance. No hay
from an infested district should be allowed to be scattered in
or near meadows in localities where the insect is not already
present.

9. Natural enemies consist so far as at present known
of spiders, the predaceous damsel bugs Reduviolus sps. a Tach-
inid fly Phorantha occidentis and an undetermined species and
a species of fungus Entomophthora sp.

Tue Meapow PLant Buc. 3

INTRODUCTION

This species presents a number of interesting problems,
biologic as well as economic, and considering its great abun-
dance over a large area of the eastern United States and Can-
ada during the past forty years it seems strange that it has
not received more careful investigation.

My own attention was attracted by its appearance in im-
mense numbers in northern Ohio at about the time of my re-
moval to that state in 1898. It was entirely unknown to me
from previous field collecting and specimens I had seen were
collected in western New York by Mr. E. P. Van Duzee about
the year 1888.

My attention was again forcibly attracted to the species by
the great abundance in Maine in 1914 when they were encoun-
tered in my studies of the meadow leafhoppers. A reference
to the literature indicated almost total neglect of the species
in this country and almost nothing concerning its economic
importance was found. It seemed therefore well worth a spec-
ial study and I was gratified to be able to arrange with the
Maine Agricultural Experiment Station to undertake a sum-
mer’s study of the species at Orono.

As an old-world species the insect has evidently been fam-
iliar since it was described by Linne (1758) and has had fre-
quent mention by later writers who have treated it simply from
the systematic standpoint. Wolff (1802) indeed gives a recog-
nizable figure of the nymph in one of the later instars also a
rough sketch of the egg but so far as noted no detailed study
of life-history, habits or economic status has been made even
in the regions where it has been longest known.

DESCRIPTION

No very satisfactory description of the species is available
in the accessible text books or manuals. The adults are about
two-fifths of an inch long, (9g mm.) rather slender, with long
black antennae which are thickest at the base, the head rounded,
set fairly close to the thorax which widens behind and the wings
lie nearly flat on the back are narrow and have nearly parallel
sides, extend to or slightly beyond the tip of the abdomen in
the males and long-winged females and to the fifth abdominal

4 MAINE AGRICULTURAL EXPERIMENT STATION. 1919.

segment in the short-winged females. The color is yellow or
yellowish gray with dark markings which form two rather in-
definite stripes on the pronotum and elytra. The antennae and
legs are black with yellowish bases or yellow with black hairs
and spots.

The nymphs are yellow marked with black, the general
color being quite dark in the early instars and becoming lighter
with the successive moults.

DISTRIBUTION

The range of the species is evidently throughout a large
part of Northern Europe and North America but in this coun-
try it has been especially noticeable in Eastern Canada, New
England, New York and West into Ohio. Reports from a
number of states establish its occurrence in large numbers and
the records given support the view that it is an old world
species which has gained introduction within the past century.

BELIEVED TO BE AN INTRODUCED SPECIES

With the evidence available there seems to be good reason
to believe the species to have been introduced from Europe at
some time not later than the early part of the last century,
probably not earlier at best than about 1800 and, if we may
give weight to the first records by Uhler and Provancher we
may suppose an introduction in New England or at Quebec
or some of the maritime provinces of Canada, perhaps equally
probable for Nova Scotia, New Brunswick or Quebec. From
any of these localities the dispersal might easily reach the other
localities concerned in the course of a few decades though
without artificial assistance its progress must be slow.

Evidence in favor of the species being an introduced one
may be summed up briefly as follows:

First: It has been a common insect in Europe for an indefi-
nite period, covering a large area and doubtless as-
sociated with the cultivated grasses to which it seems
so closely restricted here.

Second: The species was not known in America until about
1830 when it was collected by Harris as noted by Uhler
and later recorded by Provancher altho a number of

Tue Merapow PLant Bua. 5

careful students such as Say, Uhler and Walsh had given
no little attention to the insects of the group to which it
belongs and would almost certainly have encountered it
in their work, if it had been present in any abundance,
in different parts of the country where it now occurs.

Third: It has shown a gradual westward and southward dis-
persal as indicated by the available records of occur-
rence. This shows occurrence in New England in 1832,
Maryland 1868, Quebec 1872, New York 1887, Ohio
1888 (?), Ill. 1906, Kentucky 1908.

Fourth: It is adapted to certain cultivated grasses which were
introduced from Europe and its close restriction to these
and apparent inability to adapt itself to native grasses
even of as large forms as the cultivated ones is very
significant.

Fifth: In the plan of hibernation of eggs in stems, there is
evidently furnished abundant opportunity for the trans-
portation of eggs to distant points in hay shipped for
forage or packing.

DISTRIBUTION “IN MAINE

The species has certainly been present and abundant in
Maine for many years but except for the notes by Prof. H.
T. Fernald there does noi appear to have been any record that
assists in determining the time of its appearance or the extent
of distribution. The Experiment Station collection contains
several specimens those bearing dates for Orono being July
14th and 18th 1905 and July 11th 1907, all being adults and Dr.
Patch published a record of its abundance in 1908. As men-
tioned elsewhere the writer noted it as abundant ir 1914 at
Orono. Prof. C.L. Metcalf took specimens and noticed the
species as abundant in late instars and adult males at Fort Kent
July 5th and 6th, at Presque Isle mostly adults on July 8th
and at Houlton as adults with few nymphs of late instars on
July oth for the summer of 1916. The writer found them
abundant at Phillips and other points where timothy meadows
were examined between Farmington and Dallas on July 18th
1916 and also very plentiful in some old meadow land in the
vicinity of Saddleback Lake on July 19th and 20th. None oc-

6 MAINE AGRICULTURAL EXPERIMENT STATION. 1919.

curred on Saddleback Mt. at any point above the level of the
meadow land or the growth of the timothy and other grasses
commonly occupied by the species.

It is evidently safe to assign its distribution in the state
to all parts where suitable grasses occur and it may confidently
be expected to occur in all old meadow land where timothy
forms a part of the combination during the months of June,
July and August and search in the stems will be pretty sure
to disclose them as eggs during other months of the year.

Economic IMPORTANCE

While, from the great numbers appearing in meadows and
the evident attack on the plants, it must be inferred that there
is serious injury to the crop there appears to be little to es-
tablish the amount of loss or to separate it from that due to
other species. In fact but few of the Capsidae have been given
much attention from the economic standpoint. The familiar
and cosmopolitan tarnished plant bug, Lygus pratensis, has been
known for years as a pest to many plants. In 1892 Dr. L.O.
Howard called attention to Oncognathus binotatus as “A New
Enemy to Timothy Grass.” Dr. M.V. Slingerland has treated
the common four-lined plant-bug (Poecilocapsus lineatus) as a
pest of currants, Professor Popenoe the little Haltica bractatus
or uhleri as a garden pest of beans and the common Calocoris
rapidus has been known for many years to affect the clover
crop.

Some idea of the effects produced by the meadow plant
bug may be secured by noting the enormous numbers that are
hanging to the plants and especially to the heads during the
time the timothy is in bloom. Often a number may be seen
clinging to a single head, from three to five being not unusual.
The fact that they suck the bloom doubtless means a heavy
loss in seed or in weight and nutritive value of hay, although
there is little external evidence of injury.

Evidence of injury based on the amount of hay per acre
where these insects are plenty as compared with fields where
they are absent suffers from the fact that_so many different
insects are present and it is almost impossible to determine the
proportion to be charged to each. Judged merely by the num-

THE MEADOW PLantT Bue. 7

bers present and also by the size and feeding capacity of these
insects they may easily be counted among the most destructive
to the crop though they do not kill the plant by attacks at or
near the root.

Fig. 1. Miris dolabratus: A, adult on timothy head in resting or
feeding position; B, female ovipositing ; C, eggs from oviduct, nearly
or quite mature; D, mature egg ready for deposition; E, mature egg
greatly enlarged showing membranous operculum. From drawings by
the author. (Jour. Agr. Research).

Foop PLANTS

Timothy has been most commonly mentioned as the food
plant of the species and this is quite evidently the grass with
which it is most commonly associated as even where it may
be found on other grasses it is usually where timothy forms a
large part of the combination of species growing together.

I have found it commonly attached on timothy heads, very
evidently feeding, and individuals have been carried along for
several instars with no other food, so this is- clearly, a normal
food supply (fig. 1). I have also found it commonly on
orchard grass, meadow fescue and witch grass and the nymphs
seem to thrive on these plants about as well as on the timothy.
It has not been observed commonly on blue grass or other
small grasses or grasses with small seed heads except as these
are mixed with the coarser forms and while it occurs where
clover is mixed with timothy and lays eggs in clover stems it
has not been observed ever to feed either on stems, leaves or

8 MAINE AGRICULTURAL EXPERIMENT STATION. 1919.

heads of clover. I believe it is quite strictly a grass feeding
species and primarily adapted to timothy.

Before the grasses head out they occur on the stems and
leaves but the larger part of the growth occurs after timothy
begins to head and the heads seem to be the favorite point of
attack. The insects cluster on the heads sometimes in numbers
to a single head and thrust their beaks down into the flowerets
evidently drawing their food from the tender parts of the blos-
som or from the forming seed. I have seen a female thrust
the beak down in the flower of a witch grass pierce the glumes
or insert the beak between and down into the anthers penetrat-
ing the anthers and causing them to burst and probably sucking
juices from the ovules. Mrs. Slosson’s (1894) record for Mt.
Washington above 5500 feet is for adults and Mr. C. W. John-
son informs me that many insects capable of flight are carried
up by air currents and found at altitudes much above their
food plants.

DIMORPHISM

The species occurs in two distinct forms of females a
long-winged and a short-winged form but only one form of
male, the long-winged, has been observed. The short-winged
form of female is by far the most abundant and as this form is
entirely unable to fly and therefore is very definitely restricted
in its migration it is of special interest to note that it must be
the form which produces practically all of the eggs.

Lire History

The eggs hatch in May or early June the time being deter-
mined in part by latitude and season. The exact date of hatch-
ing at Orono was not observed as nymphs were already abun-
dant at the time of my arrival June 12th and as the season of
I916 was exceptionally late it is probable that the average date
of hatching would be the last week in May. Young nymphs
continued to appear until about June 25th and none after July
Ist while the first adults appeared June 16th and were abun-
dant by June 26th.

Tue Meapow Prant Buse. 9

Evidently the adults feed for some time before mating as
the first matings observed were July 8th and 1oth. The eggs
however develop rapidly when the insects reach the adult stage
as fully developed eggs in large numbers, 50 to 60 to the
individual, were dissected from the females, the first one dis-
sected, June 30, containing 30 fully formed and others im-
mature. Another, dissected on July 8, contained 69 developed
and a few immature eggs.

These dissected eggs were of special interest as they might
furnish the clue to later determination of place and method of
Oviposition and the peculiar strongly curved neck and large
membranous expansion over the head naturally suggested some
rather unusual mode of placement.

|

2

ESS

Fig. 2. Miris dolabratus: Nymphs showing relative size of body
and development of wing pads. A, first instar; B, second instar; C,
third instar; D, fourth instar; E, fifth instar. Note also position of
dorsal gland orifice between segments 3 and 4. From drawings by the
author. (Jour. Agr. Research).

The nymphs cling closely to the plants and while they pass
readily up and down the stems and doubtless shift from one
plant to another there is no extended migration, probably no
movement providing for any dispersal. When molting they

10 MAINE AGRICULTURAL EXPERIMENT STATION. 1919.

cling to the plant and, as with other insects generally, the skin
splits along the middle line of the back and the body and legs
are gradually withdrawn and the increase in size and resump-
tion of color takes place in a short time.

Five distinct stages of the nymphs are recognized and this
seems to be the genenal rule for the Hemiptera, being the num-
ber noted in a large number of the species which have been
reared through the nymphal stages (fig. 2).

No single individual has been carried from the first instar
through to the adult stage but numbers have been carried from
two to four of the instars-in confinement and under observa-
tion so that it is possible to give a connected series of stages
from the smallest found to the adult form. The time occupied:
in the different stages has run from 5 to 8 days, averaging 6
to 7 days, and the total period of development from hatching
to adult stage must be about 30 to 35 days.

The principal changes are in the increase in size and in
the growth of the wing pads which are entirely wanting in the
first, appear as faint enlargements of the meso-thorax in the
second instar, are fairly distinct on both meso- and meta-thorax
in the third, extend to the second abdominal segment in the
fourth and on to the middle of the fourth segment in the fifth
for the female and to the base of the fifth segment for the
male. There is considerable irregularity in development as in-
stars 1-4 and probably 5 with adults were taken June 23.

Fig. 3. Miris dolabratus: genital segments: A, female; B, male of
fifth instar nymph; C, female; D, male of adult. From drawings by
the author. (Jour. Agr. Research).

In the fourth and fifth instars the sexes are easily distin-
guished, males being slightly narrower, the abdomen with more

Tue Meapow PLant Bua. 11

parallel sides, and the genitalia being seen in outline through
the semitransparent walls (fig. 3 a & b).

With the final molt the wings expand rapidly and the
distinction between males and females and the dimorphic forms
of females become clearly marked.

The adults. remain quite constantly on the grass heads and
evidently feed for a number of days before mating or egg lay-
ing begins.

On the grass heads they are more commonly found with
the heads directed upward and they show some tendency to
mount to the highest point but they often stand head down-
ward and pass up and down the heads and stem freely. The
position with the head upward appears to give them an excel-
lent position for probing into the florets with their beaks. It
was noted that in egg laying the females selected small stems
of grass I mm. to 114 mm. in diameter while in clover stems as
much as 244 mm. diameter were used. Probably the rough or
softer stem of clover serves as a good foothold though the tarsi
are too small to clasp around it.

Fig. 4. Miris dolabratus: A-E, antennae of nymphs; F, antenna of
adult drawn to same scale and showing relative lengths of segments.
From drawings by the author. (Jour. Agr. Research).

NATURAL ENEMIES

Among the natural enemies or checks of the species may
be counted the gray damsel bug, Reduviolus ferus, (fig. 5)
which is a very common and widely distributed species through-
out the northern part, at least, of North America and in fact
the holarctic region. Webster and Mally (1897) say Corsicus
ferus was observed to attack Leptoterna dolobrata Linn. which
was feeding quite abundantly on timothy heads about East
-Cleveland, June 28, 1896.

12 MAINE AGRICULTURAL EXPERIMENT STATION. 1919.

This species has been found in Maine associated with
Miris dolabratus as well as with the leafhoppers and it is prob-
able that it may feed on either with equal avidity. While not
seen feeding on the mature Miris it is pretty certain that it
will feed upon the larvae and its fondness for leafhoppers in
both the nymph and adult stages has been proven by repeated
observation. Direct observation on the insects attacked is dif-
ficult as it is almost impossible to follow them in their move-
ments in the field and even when offered a variety of food in
confinement it is difficult to determine as to their selection in
the species offered as they very seldom make their attacks on
the insects while under observation and it is left to infer from
the numbers killed how ready they are to prey upon different
kinds of insects. We have had them live and thrive in con-
finement and progress to the adult stage on a diet of Miris and
also on a food supply of leafhoppers and it is probable that
they will eat a variety of small insects the particular kinds be-
ing determined rather by the available supply than by any defi-
nite choice on the part of the bug. They are able to survive
considerable periods without food, and their development is
doubtless affected by abundance or scarcity.

Reference has been made to the record of Leonard of
rearing Phorantha occidentis from Miris dolabratus in New
York. A larva apparently a Tachinid was secured issuing
from a nymph of Miris at Orono June 17, 1916, but it failed
to mature. On July 18, 1916 a nymph which issued from Miris ©
buried itself promptly in earth and from this an adult emerged
July 29th. This larva issued from the anterior part of the
abdomen under the wings while the host was still alive. The
species has not been determined but is evidently closely related
to the species bred by Leonard.

Spiders are undoubtedly quite efficient enemies of the
plant bugs but they dispose of their prey so completely that
little is left as evidence of their work. Mr. Fletcher found a
Miris encircled by a spider’s web in which it had evidently been
captured and enmeshed. In some unpublished records made
by Mr. Sherman Bilsing in Ohio a number of different species
of spiders are credited with feeding on this species along with
many other capsids.

Tue Meapow PLant Bua. 13

Fig. 5. Reduviolus ferus: A, first instar; B, second instar; C,
third instar; D, genital segments of female; E, fifth instar; F, adult
male; G, genitalia of male. From drawings by the author. (Jour-
Agr. Research).

14 MAINE AGRICULTURAL EXPERIMENT STATION. 1919.

The extent to which birds, toads and other animals may
serve to reduce their numbers is open to study.

Certain fungi which attack insects may also be considered
as possible checks on this species. While no extended effort
has been possible we have found one form at least which is
probably nearly related if not identical with a form occurring
on aphids. (Entomophthora aphidis.)

MEASURES FOR CONTROL

While the main efforts during this summer’s studies have
been directed toward solving a number of puzzling questions
as to the development and habits of the species and while some
definite experiments are needed with certain measures that may
be suggested on the strength of the facts learned there is cer-
tainly a very definite basis established for certain kinds of
treatment that should do much to reduce the numbers of the
insect.

The most fundamental point determined with reference to
the insect in connection with control is doubtless the fact that
the eggs are deposited in the stems of plants in the fields where
the insect has been present. This, in connection with the fact
that the great majority, probably ninety per cent of the females,
are wingless, means that we know that practically all the eggs
deposited in mid-summer are in the old timothy meadows and
that any measure which will destroy them in this location will
have immediate effect in preventing further loss from this
source.

It is very evident that plowing under and planting of the
field to a different crop will absolutely prevent further injury
from the stock of insects established in any old meadow and
therefore rotation where this is practicable may be counted a
certain remedy for the field concerned. However, for the pro-
tection of adjacent fields or in order to exterminate the insect
as completely as possible the borders of the fields and the fence
rows usually supporting a considerable growth of grass should
be remembered and, for the disposal of this insect, should be
plowed as closely to the border as possible or burned over when
the grass is dry so as to destroy the eggs as completely as pos-
sible.

Tue MeEApow PLant Bue. 15

Where rotation is impracticable or undesirable it will be
more difficult to secure complete eradication and careful tests
of treatment based on the habits of the insect are necessary
to determine the most successful methods.

It is clear that burning over of meadows if sufficiently dry
in autumn or early spring so as to destroy the eggs would be
very effective but there are of course many objections to this
treatment so that it can not be urged as sufficient. In some
seasons probably there would be no time when the grass would
burn sufficiently close to the ground to destroy any large part
of the eggs and there is the danger if burned too deeply that
the stand of grass will be injured. This method especially for
the conditions prevailing in Maine does not seem to promise
much. Where burning is practiced, it should assist. It would
be worth while to compare results in fields so treated.

Early or late cutting of the crop may have some effect
on the number of eggs laid in a field, an early cutting before
the insects are mature for example depriving them of their
usual form of food, the heads of grass, may reduce egg de-
position but whether to such an extent as to warrant any spec-
ial change in the usual practice as to time of cutting can only
be determined by further study.

The application of any form of insecticide or of special
kinds of fertilizers does not seem to offer any very practical
relief and the use of hopper-dozers or mechanical devices for
their capture have not been tested; nor do they have much
promise.

Finally there is the important consideration of the spread
of the insect into adjacent fields or farms or to more distant
points and for this the facts secured furnish a very sure foun-
dation for effective control. Knowing that practically the only
opportunity for such wider distribution is by carriage of hay,
attention to the disposal of any such material introduced where
the insect is not present, in some way to avoid scattering of
eggs where they can hatch where suitable food plants will be
available for their subsistence, will serve to exclude them.

16 MAINE AGRICULTURAL EXPERIMENT STATION. 1919,

ACKNOWLEDGMENT

I am indebted to a number of persons for assistance in the
preparation of this report, especially to Dr. Edith M. Patch for
facilities to carry forward the study and to Mr. R. K. Fletcher
for careful attention to field observations and to the entomolo-
gists of various states who have kindly taken the trouble to
send records for their territory.

DESCRIPTION OF PLATES

Fig. 6. Miris dolabratus: A.—a, Eggs in grass stem, all hanging
in one direction; b, eggs in grass stem placed in opposite directions;
c, Same as upper part of b, more enlarged; d and e, eggs in clover
stems. Photographed by Mr. Hammond. (Jour. Agr. Research).

Fig. 7. Miris dolabratus: B.—b, Eggs at left; 1, first instar; 2,
second instar; 3, third instar; 3+, third instar more mature; 4, fourth
instar; 5, fifth instar; 6, adult male above, female below. Photographed
by Mr. C. J. Drake. (Jour. Agr. Research).

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