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Bulletin 23

November, 1894

NEW HAMPSHIRE COLLEGE

AGRICULTURAL EXPERIMENT STATION

SOME DANGEROUS FRUIT INSECTS

BY CLARENCE M. WEED

NEW HAMPSHIRE COLLEGE

OF

AGRICULTURE AND THE MECHANIC ARTS

DURHAM, N. H.

NEW HAMPSHIRE COLLEGE

OF

AGRICULTURE AND THE MECHANIC ARTS

AGRICULTURAL EXPERIMENT STATION

Durham, N. H.

BOARD OF CONTROL

Hon. Geo. A. Wason, Chair?nan, New Boston.
Pres. Chas. S. Murkland, ex-officio, Durham.
Charles W. Stone, A. M., Secretary, East Concord.
Hon. John G. Tallant, Pembroke.
Henry W. Keyes, A. M., Haverhill.

THE STATION COUNCIL
President Chas. S. Murkland, Acting Director.
Henry E. Alvord, C. E., Agriculturist.
Chas. H. Pettee, A. M., C. E., Meteorologist.
Fred W. Morse, B. S., Chemist.
Herbert H. Lamson, M. D., Bacteriologist.
Clarence M. Weed, D. Sc, Efitomotogist.

assistants

Edward P. Stone, B. S., Assistant Chemist.*

Fred D. Fuller, B. S., Assistant Chemist.

Frederick W. Howe, B. S., Assistant in Chemistry.

RuEL S. Alden, /''arm Siiperijitetuient.

Richard Fitzgerald, Clerk.

The Bulletins of this Station are sent to any resident of New Hampshire
upon application.

* Absent on leave.

SOME DANGEROUS FRUIT INSECTS

BY CLARENCE M, WEED

None of the evil effects of the changes which modern civiliza-
tion has made upon the earth is more evident to the American
farmer than the increased difficulty of saving his crops from the
ravages of noxious insects and parasitic fungi. Many of us
have heard from our fathers and grandfathers of the apples
which once grew in abundance in yards and along highways,
strangers alike to the codling moth, maggot, or scab, the
luscious peaches free from worms and rot, the plums unmarked
by the curculio, and the pears that had yet to learn the secret
of becoming dwarfed, gnarly, and cracked ; of the grapes th^t
knew not how to rot, and the potatoes which had neither been
blighted nor bitten by the Colorado beetle. Now all is changed :
every crop has foes that often gather the lion's share of the har-
vest. The enemies have come from the north and the south,
the east and the west, from Europe and the islands of the sea,
and in our own midst they have flocked from the forest to the
field, deserting a wild plant for its cultivated congener, or chang-
ing their habits to conform to a new environment.

This increase of noxious insects, however, is the natural
result of the changed conditions of things. Among the principal
factors tending toward it, may be mentioned : (i) the massing
of crops in limited areas ; (2) the facilities for transporting
insects long distances by vessels and railways carrying agricuL
tural products ; (3) the abandoned farms and orchards that
serve as breeding grounds ; and (4) the destruction of forests
and the cultivation of prairies.

Considering each of these factors briefly, we find that the
tendency of the first — that of the massing of crops in limited

areas — toward increasing our insect pests rests upon the bio-
logical law that the increase of any animal is limited by its
food-supply. Under the natural conditions existing on this con-
tinent before the advent of the white man, those insects which
fed on wild plants had, as a rule, only a limited food-supply.
The apple maggot, or railroad worm, for example, is supposed
to have bred originally in the wild haws of the woods. The
parent flies had then usually to find here and there an isolated
tree bearing the fruit in which it deposited its eggs. Its
chances of being caught by a bird or entrapped in a spider's
web while on this search were very good, so that the scarcity of
the food-supply not only directly limited the number of individ-
uals that could be produced, but by being scattered it increased
the chances of the adult insects falling a prey to enemies. But
in a modern apple orchard all this is changed : the food-supply
is almost unlimited, and is so massed together that the insect
runs little risk in passing from fruit to fruit, or from tree to tree.
Hence it can multiply indefinitely, unless there is some means
of checking it. The same line of reasoning applies to a large
proportion of our injurious insects.

We are indebted to our commerce on sea and land for many
of the most noxious insects. Brought to our shores from Europe,
Asia, or Australia by ships, many of these pests have found a
land which for them was flowing with milk and honey, and in
which their hereditary enemies had not yet gained a foothold.
Consequently they have multiplied without let or hindrance ;
and by natural and artificial means— notably the railroad trains
— they have rapidly overrun the country of their adoption.

The abandoned or neglected fields and orchards all over the
United States have proven a prolific breeding ground for many
insect pests. Too often the efforts of painstaking farmers have
been rendered unavailing by the proximity of such sources of
infection. An orchard that has outlived its usefulness had bet-
ter be converted into firewood than left to die uncared for.

The destruction of forests has compelled certain insects to
resort to cultivated crops for subsistence ; and in some cases a
decided change in feeding habits has resulted. So, also, the
bringing of the prairies into cultivation has caused many insects

which originally fed on wild grasses, to resort to pastures and
meadow lands.

The operation of these various causes, together with the enor-
mous powers of multiplication possessed by the insects them-
selves, has led to a constantly increasing injury to cultivated
crops, until to-day these tiny foes exact a tribute of ten per cent,
of the crop products of American agriculture. They form an
omnipresent host of taxgatherers, taking possession of the far-
mer's crops and enforcing their onerous demands without pro-
cess of law, unless preventive measures are vigorously prosecuted.
They are no respecters of persons ; like the rain, they fall upon
the fields of both the just and the unjust.

"The authorities best able to judge have estimated the annual
loss in the United States due to these little pests at nearly half
a billion dollars. Noxious insects, according to Dr. C. V. Riley,
recently the distinguished entomologist of our National Depart-
ment of Agriculture, occasion losses in the United States which
are ' in the aggregate enormous, and have been variously esti-
mated at from $300,000,000 to $400,000,000 annually.' In
single states and single seasons the loss is often frightful in
extent. During some of the great chinch-bug epidemics the
loss in Illinois occasioned by this one insect has amounted to
over $73,000,000 a year; and in seasons not marked by an out-
break of such a great crop pest the injury is much more severe
than is ordinarily supposed. The official entomologist of the
state just named. Professor S. A. Forbes — after years of careful
field observation and statistical study — has recently expressed
his belief that ' the insects of the state of Illinois derive as
large a profit from the agriculture of this great agricultural state
as do the farmers themselves.' " *

Fortunately, however, there is an extended silver lining to this
dark cloud of insect injury. If these creatures have increased
on every hand, our knowledge of methods of controlling them
has also augmented with the passing years. Many of the
remedies proposed ten or twenty years ago, seem now foolish
and impracticable. Within the last decade especially, the
progress has been phenomenal. It has been shown that many

*C. M. Weed, Popular Science Monthl}', March, 1S93.

6

insects can be checkmated by a proper crop rotation ; that the
natural enemies of others can be used to destroy them ; and
that others are easily killed by improved insecticides. But the
most important advance has been the introduction of the spray-
ing machine, an apparatus by means of which insect killing sub-
stances may be easily and rapidly distributed over the surfaces
of trees, shrubs, vines, and herbaceous plants. As I have else-
where said, its introduction into American horticulture marks
an advance almost as important as was marked by the advent
of the improved cultivators into our agriculture. Before the
latter were introduced the weeds that infest the soil were fought
by the hand hoe, but now a single team does the work of many
men. In the same way until recently various laborious and
partially effective methods were used in fighting noxious insects
and destructive fungi ; but now many foes of both these classes
are fought on a large scale by the force-pump and spray nozzle,
and every season adds others to the list of those against which
this method may be successfully used. With a large class of
farmers and fruit growers, spraying has become a recognized
part of the season's operations, and therein lies the chief promise
of the method. When the belief becomes general that it is as
important to save a crop from destruction by its foes as it is to
produce it ; that fighting noxious worms must take its place as
a farm process by the side of that of fighting noxious weeds:
that the parasitic plants which absorb the vitality of leaf and
fruit are as dangerous to the crop as the plants which dispute
with it the possession of the soil — and when along with this
recognition there is placed before the farming community a
cheap and wholesale method of preventing the injuries of these
organisms, then the vast annual loss now suffered because of
insects and fungi will be very greatly lessened.

The introduction of destructive insects still continues and is
likely to continue for many years to come. At present there
are two recently introduced insects that have not yet appeared
in New Hampshire so far as known, but which are liable to
reach us at any time and to become very destructive. I refer
to the Gypsy Moth and the San Jose Scale. There are three
other insects — the Pear Midge, Pear Tree Psylla, and Bud

Worm — which are probably present in some parts of the state,
but which have not yet become so injurious as they have in
neighboring states. The purpose of these pages is to warn the
fruit-growers of the state of the threatened danger, and to give
them the information necessary for recognizing and combating
the pests when they do appear. For the facts I am especially
indebted to the publications of the Department of Agriculture,
the State Entomologist of New York, and the experiment sta-
tions of New Jersey and the Cornell University. The illustra-
tions have come from the same sources, and should be specifi-
cally credited as follows : After Slingerland, Figs. 3-8 ; after
Howard, Figs. 10-14; after Taschenburg, Figs. 15-18; after
Lintner, Fig. i ; after Riley, Fig. 2.

Fig. I. Pear Midge Injury: a, uninjured young pear; />, infested pear cut
open to show midge larvae ; tr, d, e, f, outlines of infested fruits.

The Pear Midge

Diplosis pyrivora

This insect appears to have been introduced into America
about 1877, being first noticed in Connecticut. It has
since spread into a number of neighboring states, and has
become in many localities the most destructive enemy of the
pear. The adult is a small mosquito-like grayish fly (Fig. 2, c)
having a slender body, long legs, and a long ovipositor project-

ing from the end of the abdomen. These flies appear in the
pear orchard in early spring, even before the blossoms open,
and continue present about ten days. As soon as the blossoms
open sufficiently for the insect to insert its ovipositor, the eggs
— often nearly a dozen in number^are deposited inside the
blossom envelopes. Three or four days later the eggs hatch
into little maggots which enter the open ovary of the embryo
fruit, where they feed upon the growing tissues, gnawing and
rasping it in such a manner as to destroy the core and seeds,
and cause the fruits to become dwarfed and deformed. Such
pears are illshapen in outer appearance, as shown in the series
represented in Fig. i. The midge maggots at first are whitish
in color, but they soon become orange or reddish. They
become full-grown early in summer: they are then "about one-

Fig. 2. Pear Midge: a, larva; /', pupa; c, parent fly. Magnified.

sixth of an inch in length, pointed towards each extremity, yel-
low in color, with a brown, horny breast bone on the under side
just behind the head. The segments of the body are well-
marked, and when removed from the infested fruit they move
about quite rapidly, bending themselves quite double by draw-
ing the tail forward until it touches the head, and then jerking
or springing upward and outward several inches at a time.

9

When they are full grown they remain in the fruit until there
comes a rain, which causes a rapid decay and a cracking open
of the infested fruit. Through the openings so made they
emerge and drop to the ground." * They then enter the soil
an inch or two where somewhat later they make oval cocoons
of silk mixed with particles of earth or sand : in these cocoons
they apparently remain unchanged until the following spring
when they become pupae and shortly afterwards again change
to adult flies.

These midges appear to have decided preferences among va-
rieties of pears, the Lawrence being the favorite.

Remedies. — The only stage at which this insect is liable to
injury without detriment to the trees is when the larvae are in
the ground. Professor J. B. Smith of New Jersey has found
that they then can be destroyed to advantage by the application
of kainit applied about the middle of June to the ground
beneath the trees at the rate of i,ooo pounds to the acre. This
is dissolved by the soil moisture and causes the death of the
naked midge larvae. In case an orchard is generally infested
Professor Smith recommends the following practice : " Cultivate
as usual, or, if the orchard is in grass or clover, plow under
after June 15th, as soon as maybe. Top-dress with kainit,
1,000 pounds to the acre, to benefit trees as well as to kill in-
sects. As soon as proper, say early in August, sow crimson
clover. This will use up the potash not required by the fruit
trees, and will store nitrogen, as well as occupy the ground.
Early in the following spring turn this sod under as deeply as
may be proper. It should be done before the pear buds are
developed, in order to head off and destroy any midges then in
the pupa state near the surface of the soil."

The Pear-tree Psylla

Psylla pyricola

This is an extremely minute insect, which during recent years
has done great damage to pear orchards in several eastern

* J. B. Smith.

10

states. It was apparently introduced into Connecticut early in
the present century; since then it has spread west to Ohio,
Michigan, and Illinois, south to New York and New Jersey,
and probably over much of New England, though here it has
been reported as destructive only in Massachusetts and Con-
necticut.

The adult pear psylla is a small, jumping
louse about one tenth of an inch long, resem-
bling, when magnified. Fig. 3. It has four
nearly transparent wings, and is reddish with
n transverse dark stripes on the abdomen.
There are two distinct forms. The summer
broods are much lighter in color than the
brood which passes through the winter. This
difference is so great that the two forms were

„ ^ „ considered distinct species until the life his-
T^iG. 3. Pear Psylla.

Magnified. tory was carefully worked out by Mr. M. V.

Slingerland.

The dark form passes through the winter in some sheltered
situation about the tree, such as beneath loose bark, or in the
crevices between the branches. In early spring they come forth
from their hiding places and deposit their eggs about the buds
and on rough bark. These eggs are very small, and of the
extraordinary form represented in Fig. 4. When first deposited
they are yellowish, but turn dark soon afterwards. The eggs
hatch in three or four weeks, the time depending largely on
weather conditions. The young psyllas, which during their
immature stages are called nymphs, crawl to the stalks of the
unfolding leaves, in which they insert their tiny beaks to suck
out the sap. They grow rapidly, occasionally moulting or shed-
ding their skins to provide for their increase in size, and in the
course of a month become mature.

The first summer brood thus developed deposits eggs on the
under sides of the leaves. These eggs hatch
ten days later, and mature in about three
weeks. The insects of the second brood
suck the sap from the leaves. There are ^"^- 4- Kgg. Magnified,
several of these summer broods, the number varying with the

11

locality and length of season. In early autumn the dark, hiber-
nating winter form is developed.

The sap which passes through the bodies of these little creat-
ures is ejected on the foliage, and forms the so-called "honey
dew." Where the insects are very numerous this becomes very
abundant, falling in showers when the branches are disturbed.
After the honey dew has been present for some time a peculiar
black fungus develops upon it, and gives the tree a sooty ap-
pearance.

Mr. Slingerland makes the following statement concerning
the indications of the presence of the pest: "Among the first
indications that pear growers, who suffered from this pest in
1891, had of its presence, was the noticeably lessened vitality of
their trees early in the season. Old trees, especially, put forth
but little new growth. Where new growth started, in many
cases the shoots began to droop and wither in May, as if from
a loss of sap. A little later, whole trees put on a sickly
appearance ; the leaves turned yellow and the fruit grew but
little. By midsummer nearly all the leaves and half-formed
fruit fell from many trees."

Remedies. — This insect can be destroyed by spraying in spring
after the eggs hatch out and before the first brood matures,
with kerosene emulsion diluted with twenty-five parts of water.
This is a simple and satisfactory remedy; if applied soon after
a shower has washed off much of the honey dew it is more
effective.

The Bud-worm

Tmetocera ocellana

There is evidence to show that this insect was introduced to
America from Europe early in the present century. It now
occurs over a large portion of Canada and the United States,
and sometimes is very destructive over wide areas, occasionally
becoming the most serious orchard pest of the season. As
soon in spring as the buds begin to open, the little caterpillars
may commence work upon them, gnawing the miniature leaves
and blossoms, but the attack is more likely to begin after the

12

buds about half open. The larvre then eat out the centres of
the buds, where the leaves and flowers are least developed.
The caterpillar forms for itself a protecting case by using silken
threads to bind together the leaves. As the season advances
some of the leaves are killed, become detached at the base, and
turn brown ; the blossoms also are more or less webbed, so that
the smaller branches present an appearance similar to the
accompanying illustration. (Fig. 6.)

The life-history of this insect may be summarized as follows :
The moths appear in the orchard early in summer ; during day-
light they rest upon the bark of trees or other shelter; at night
they fly about and de-
posit their eggs, one in
a place on the under
side of the leaves. About
ten days later these eggs
hatch into small green
larvae, which feed upon
the epidermis of the
leaves, each making for
itself a silken tube and

a thin layer of silk for protection and concealment,
or two the green color changes to brown.

"As the larva increases in size and the area over which it
feeds becomes larger, the tube is enlarged and lengthened along
the midrib, sometimes becoming nearly one inch in length.
The silken web under which the larva feeds covers the entire
field of operations, but is so thin near the edges where the
larva has last fed as to be scarcely visible. The excrement of
the larva being retained by the web appears as little black pel-
lets scattered here and there over the feeding ground." *

The green portion of only one side of the leaf is eaten, the
veins and veinlets being left untouched : these and the green
of the opposite side die and turn brown, and thus become con-
spicuous,

* M. V. Slingerland.

Fig. 5.

Apple leaf showing work of young
bud-worm.

In a day

13

Fig. 6. Work of bud-worm among opening leaves.

Late in summer or early in autumn the half-grown caterpillars
desert the leaves and crawl upon the twigs, where they form
little silken cases, generally near the buds or in creases in the
bark. (Fig. 7.) In these they remain throughout the winter. The
following spring they emerge to feed upon the opening leaves.
They again make tubes, which serve as protective cases. After
feeding six or seven weeks they become full-grown : then they
form silken cocoons, generally in a rolled leaf or between two
leaves, in which they change to pupae, to emerge a short time
later as moths.

The full-grown larvae are cinnamon brown in color with the
head, legs, and shield behind dead black. They are about
half an inch long and of the general form shown in Fig. 8, c.

14

The moth Fig. 9, has
a general resemblance to
the common codling
moth. It is dark ashen
,. gray with creamy white
blotches on the front
wings, which expand a

Fig. 7 Twig showing the position of th^ win- little more than half an
ter homes of the larvae at a, a, and b, natural .
size. inch.

Fig. 8. Bud-worm: a, pupa, front view; /', pupa, baclc view; c, larva.

Magnified.

Remedies. — These little pests can most successfully be
destroyed by spraying with the
arsenites early in spring when
the buds are opening and the
larvje just beginning the season's
work. It is advisable to use the
Bordeaux mixture and Paris Fig. 9. Bud Worm Moth.

green combination in order to prevent injury by apple scab or
other fungous maladies as well as insects.

The San Jose Scale

Aspidiotus perniciosus

This insect is related to the common oyster-shell bark-louse,
but can at once be distinguished from the latter by the charac-
teristic round scale — as shown at b. Fig. 10.

15

It infests practically all kinds of deciduous fruit trees and
if unmolested is liable to kill them. It was introduced into
California from Chili about 1870, since when it has spread over
a large portion of the Pacific slope ; and has lately appeared in
the eastern states, where it threatens to do much damage.

Mr. L. O. Howard describes the San Jose Scale as " per-
fectly round, or at most very slightly elongated or irregular. It
is flat, pressed close to the bark, resembles the bark of the

Fig. 10. San Jose Scale: a. pear, moderately infested — natural size; b,

female scale — enlarged.

twigs in color, and when fully grown is about one-eighth of an
inch in diameter. At or near the middle of each scale is a
small, round, slightly elongated black point ; or this point may
sometimes appear yellowish. When occurring upon the bark
of the twigs or leaves and in large numbers, the scales lie close
to each other, frequently overlapping, and are at such times

16

difficult to distinguish without a magnifying glass. The gen-
eral appearance which they present is of a grayish, very
slightly roughened scurfy deposit. (Fig. ii.) The natural rich
reddish color of the limbs of the peach and apple is quite
obscured when these trees
are thickly infested, and they
have then every appearance
of being coated with lime or
ashes. When the scales are
crushed by scraping, a yel-
lowish oily liquid will appear,
resulting from the crushing
of the soft yellow insects be-
neath the scales, and this
will at once indicate to one
who is not familiar with their
appearance the existence of
healthy living scales on the
trees."

The young scale lice hatch Fig. n. San Jose Scale : Apple Branch,

with scales in situ — natural size ; en-

from eggs beneath the female larged scales above, at left.
scales, in spring, soon after the unfolding of the leaves. They
are minute yellowish creatures, resembling Fig. 12 when highly
magnified ; they crawl about over the bark a short time, and
finally fasten themselves to it, generally on the new growth,
where they secrete a scale and there develop. Some of them
mature into little two-winged creatures, resembling, when mag-
nified, Fig. 14 ; these are the males : others develop into females,
which do not become winged but remain on the bark in a fixed
position. In the bodies of these the young are produced, as
shown in Fig. 13.

When the San Jos^ scale occurs upon older trees, it is most
likely to be found on the twigs and smaller limbs, but upon
young trees it may occur over the whole surface. But it does
not confine its attacks to the bark, for the leaves and fruit are
often infested : upon the latter there is a very characteristic
purplish ring around each scale. These rings are well illus-
trated in Fig. 10. " Upon the leaves the insects have a tendency

17

to collect along the midrib, on the upper side of the leaf, in one
or more quite regular rows, and also to some extent along the
side ribs. The infested leaves turn brown, but do not have a
tendency to fall as a result of the damage."

Fig. 12. San Jose Scale : a, young larva — greatly enlarged ; b, antenna of

same — still more enlarged.

This pest is most likely to be introduced into new localities
upon nursery stock imported from infested regions. This is
belie,ved to be the way in which it was first brought to the
Eastern states. It is also likely to be carried upon fruit sent
to market. In a given locality the insects are most likely to be
carried from tree to tree and orchard to orchard by the young
lice crawling upon insects and birds and then crawling off after
they have lit upon other trees. They may also be blown about
by the wind.

The young lice are easily destroyed by spraying with kero-
sene emulsion. But in cases where the insect is first intro-
duced to a new locality, the infested trees should be burned to
check the outbreak.

18

PREVENTING THE SPREAD OF THE SCALE.

Concerning this Mr. L. O. Howard, entomologist to the
U. S. Department of Agriculture, says: "The principal mode
of spread is by commerce in nursery stock, cuttings, and fruit.
The time will come in the immediate future when some kind of
quarantine regulations will have to be established by states, or
by large fruit-growing districts. Should this species already

©

Fig. 13.

San Jose Scale : c, adult female containing young — greatly en-
larged ; d, anal fringe of same — still more enlarged.

have obtained the firm foothold in the East which we suspect.
New York, Michigan, and other states, in which the pomologi-
cal interests are great, should immediately, by act of legislature,
establish quarantine regulations similar to those in force at the
present time in the state of California. In the meantime no
orchardist should admit a single young fruit tree, or a single cut-
ting, or a single bud, from a distance into his orchard, without
first carefully examining it, and satisfying himself absolutely that

19

it does not carry a single specimen of the San Jos^ scale. If
this plan is adopted by every one interested, and without excep-
tion, the rate of spread of the species can be limited to the nat-
ural spread by crawling, by winds, and by the aid of other
insects and birds.

Fig. 14. San Jose Scale: male adult — greatly enlarged.

" We wish particularly to impress upon the minds of fruit-
growers that as soon as this insect is found to occur in an
orchard the most strenuous measures must be taken to stamp it
out. No halfway measures will suffice. The individual must
remember that not only are his own interests vitally at stake,
but those of the entire community in which he resides. Trees
badly infested should be instantly burned, as previously stated.
The individual may think that he cannot bear the loss, but the
loss in consequence of the slightest neglect will be much greater.
The fact, too, that there is a community of interests among fruit-
growers in this matter must not be lost sight of. Fruit-growers
must be mutually helpful in an emergency like this."

20

The Gypsy Moth
Ocneria dispar

Fortunately this notorious insect, which our Massachusetts
neighbors are striving hard to subdue, has not yet been found
in New Hampshire. It is sincerely to be hoped that it may
never be found here ; but as we are so near the infested terri-
tory it seems' worth while to include in this connection a brief
notice of the pest.

The Gypsy moth is one of the most troublesome insects in

Europe. It feeds on an extraor-
dinary variety of plants, attacking
almost everything, and is difficult
to destroy by natural or artificial
means. As is well known it was
introduced into the vicinity of
\ Boston twenty-five years ago, and
Fig. 15. Gypsy Moth. Male, has since become very destructive
in that region. In 1891 the legislature of Massachusetts estab-
lished a commission for the extermination of the insect, and
has since appropriated a large amount of money to carry on
the work, which has already checked the outbreak to a remark-
able degree. It is much to be hoped that the work will be con-
tinued unabated for several years.

There is an idea somewhat prevalent that this insect could be
exterminated by
importing para-
sites, but this is
fallacious. In my
opinion it would
be a great mis-
take to abandon
the work of ex-
termination and
leave it to be

done by para-

TT 1 ^1 Fig. 16. Gypsy Moth. Female.

Sites. Under the ^^ •'

most favorable conditions there could only result a long series

21

of oscillations in the numbers of the moths, in which periods of
destruction would alternate with periods of immunity.

The later stages of the Gypsy moth are illustrated in ''the
accompanying figures. The male moths are much smaller than

Fig. 17. Gypsy Moth Cg,terpillar.

Fig. 18. Chrysalis of Gypsy Moth.

the females. " The full grown caterpillar is about an inch and
three fourths in length, very dark brown or black, finely retic-
ulated with pale yellow. There is a pale yellow line along the
middle of the back and a similar one along each side. On the
first six segments following the head there is a bluish tubercle,
armed with several black spines on each side of the dorsal line,
and on the remaining segments these tubercles are dark crimson
red. In the middle of the tenth and eleventh segments there is
a smaller red tubercle notched at the top. The whole surface

22

of the body is somewhat hairy, Init along each side the hairs are
long and form quite dense clusters."*

Should any one in New Hampshire find an insect answering
to this description they would confer a favor by sendino- it,
securely packed, to the writer. Information concerning the
presence of any of the pests described in these pages would
also be appreciated.

* Fernald.

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