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Sectional Volume No. 2.

K3G75

listry of Agriculture and Fisheries.

UC-NRLF

B 3 flMM Sll

COLLECTED LEAFLETS

INSECT PESTS

FRUIT TEEES.

PRINTED FOR

LONDON :

MINI!

10, Wlii'
Agents f of Aducrtisements : C. VERNON & SONS, Ltd., 38, Holborn Viaduct, London, E.C.I.

Price iOd. net, Post Free.

Sectional Votviciq 5fp; 2.

Ministry of Agriculture and Fisheries.

COLLECTED LEAFLETS

ON

INSECT PESTS

OF

FRUIT TREES.

LONDON :

FEINTED FOE HIS MAJESTY'S STATIONERY OFFICE.

To be obtained at the Office of the
MINISTEY OF AGEICULTUEE AND FISHEEIE*.

10, Whitehall Place, London, S.W.I.
Agents for Advertisements: C, VERNON A SONS, Ltd., 33, Holborn Viaduct, London. E.C.I.

1921.
Price lOd. net, Post Free.

.

LIST OP CONTENTS.

PAGE.

Introduction

LEAFLET No. TITLE.

15. The Apple Blossom Weevil (Anthonomus

poniorum, L.) ... ... ... , ... ... 14

16. The Apple Sucker (Psylla mali, Sehmidb.) ... 17
319. Apple Capsids (Plesiocoris rugicollis, Fall.) .. 20
330. Apple Aphides (Aphis maiifolia, Fitch., &c.) 23

34. The Woolly Aphis (Schizoneura lanigera, Haus-

mann) ... ... ... ... ... ... 27

107. The Mussel Scale (Mytilaspis pomoruui,

Bouche) ............... 31

69. The Lackey Moth (Clisiocampa neustria, Linn.) 34

4. Winter Moths (Cheimatobia brumata, L., &c.) 37

30. The Codling Moth (Cydia pomonella, L.) ... 43

65. The'Small Ermine Moths (Genus Hyponomeuta} 47

205. The Apple Sawfly (Hoplocampa testudinea.

Klug.) ............... ... 50

49. Bark Beetles (Scolytus ruyulosus, Ra-tz.) and
Shot Borers (Xyleborus dispar, Fab., and
X. saxeseni, Ratz.) ... ... ... ... 52

308. Plum Aphides (Aphis pruni, Reaumur, &c.) ... 58
210. The Oyster-shell Scale (Aspidiotus ostreaiormk,

Curtis) ................... 62

239. The Pear Leaf Blister Mite (Eriophyes pyri,

Nalepa) ......... ^ ......... 64

53. The Pear Midge (Diplosis (Contarinia) pyrivora,

Riley) ................... 66

62. The Pear and Cherry Sawfly (Eriocampa lima-

citia, Cameron) ... ... ... ... 68

1. The Black Currant Mite (Eriophyes ribis,

, Nalepa) ... ... ...... 70

41. Red Spiders (Bryobia and Tetranychus) ... 74

68. Currant and Gooseberry Aphides (Genus Ribes) 77
223. The Brown Scale (Lecanium persicae, Geoffroy) 79
20. The Magpie Moth (Abraxas grossulariata, Linn.) 82
12. The Gooseberry Sawfly (Ne mains ribem, CurtisT 85
14. The Raspberry Moth (Laniprouia rubiella

Bjerk.) ... ............... 88

2. Wingless Weevils (Otiorrhyncus piciptx,

Fab., Ac.) ... ............ 91

161. The Vapourer Moth (Oryyia antiqua, Linn.) ... 94
60. The Goat Moth (Cossus ligniperda, Fab.) and the

Wood Leopard Moth (Zeuzera asculi, Zinn.) 96

Vlll

SPRAYING

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Efficiently and Economically

BY

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"Ready for use" Spraying Mixture.
Full particulars and Catalogues from :—

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London, E.C.2.

INTRODUCTION.

Contents of the Book. — The number of insect pests
attacking fruit trees is large — so large that only a com-
paratively small proportion of them can be dealt with
individually in this collection of leaflets. On* the other
hand the control measures which it is possible to take are
few, and as the majority are illustrated by one or other
leaflet, hints may be obtained not only as to how to deal
with the particular pests described in this volume but with
many others which do similar damage.

Contents of the Leaflets. — Most leaflets are divided into
certain sub-sections: — ''Plants Attacked and Nature of
Damage," 'Description and Life-History," and "Measures
of Control." It is sometimes complained that these sub-
sections contain too much *' technical matter " and that
all that is required is " how to recognise the pest " and
" how to control it." Now recognition and control are
exactly the objects at which each leaflet aims, but the
necessary information cannot be given without the introduc-
tion of some so-called " technical matter," particularly in
relation to the habits and life of the pest. The following
consideration will make this clear. Insects, though very
small, are creatures with their own habits and ways, living
in a perfectly wild state just like birds, fish, or any wild
animal. In order to fish successfully, whether for minnows
or sharks, the first essential is to understand the habits of
the fish. This applies also to shooting, no matter whether
the game is a tiger or a rabbit. A man, for instance, who
realised that his crops were being eaten by rabbits but knew
nothing whatever about them — even whether they ran or
burrowed underground — would not make much of a bag, or
protect his crops successfully !

The same considerations apply to insect pests — to hunt or
control them successfully it is essential to know as much as
possible of their habits, and in dealing with insects it is as
unreasonable to object to the use of certain special — so-
called " technical " — terms as it would be to object to the
use of such terms as warren in the case of rabbits, leveret
in the case of a young hare, or brush in the case of a fox's
tail!

A useful leaflet, therefore, must contain some technical1
matter, but it is hoped that in spite of this the whole will be
read, for only material is put in which may have a definite
bearing on the control of pests, while the technical terms
are reduced to a very few which may easily be learnt.

(39204) P.1149/R.206. 3,000 11/21. M. & S. Gp. 95.

The sections in a leaflet follow on naturally. The first
thing which attracts attention to a pest is the damage.
Under " Plants Attacked and Nature of Damage " is given
.a list of the crops likely to be attacked and the characteristic
signs of injury. Under the next section, " Description and
Life-History/' are described, the appearance of the pest in its
various forms, and its life-history or habits, showing where
it lives at each season of the year and which are its vulner-
able stages. With this information it is then possible to
follow the suggestions given under " Measures of Control,"
carrying out each operation with discretion and not by rule
of thumb — a most important point, for success is often
dependent on adapting a measure to meet special local
conditions.

Notes on Insects in General. — As it is impossible to
deal separately with many insects in the leaflets themselves,
a few general notes may be found useful.

Description. — Insects belong to a group of creatures char-
acterised (1) by the possession of a jointed body which is
supported not by bones inside but by a hard horny skin, and
(2) by the possession on one or more segments of the body
of jointed " appendages " which may be modified to act as
legs, jaws, antennae (feelers), &c. Strictly speaking, the term
Insects should be confined to the creatures in the group with
only three pairs of legs (in addition to other characteristics),
such, for instance, as moths, beetles or bugs, but for
practical purposes the name usually includes the groups
containing mites (red spiders) and spiders with four pairs
of legs, and the millipedes and centipedes with many pairs
of legs. From the practical point of view no detailed know-
ledge of the various organs of the body is necessary but it
is helpful to know a little of the features which characterise
an insect as a living creature.

The body consists of three parts — the head, the thorax and
the abdomen.

(a) The head bears the antennae (or " feelers "). which
are not only organs of touch but are probably connected
with other senses, possibly in some forms with smell.
(Little, however, is known about the senses of insects except
that by some means they smell and probably hear also.)
There are also on the head the eyes which when well
developed enable them to see the shape of things, or in
other cases may be only sufficient to detect light or dark-
ness. The mouth, on the underside of the head, is
surrounded by " appendages " which vary in the different
groups, in some taking the form of biting jaws and finger-
like organs to push food between them, while in others the
same organs may be modified so as to form a " trunk
enabling the insect to bore holes and suck up juices. From

the practical aspect it is very important to recognise the
difference in feeding habits which must correspond with the
difference in the mouth parts, since species with jaws can
eat solid matter, while those with trunks merely suck up
juices through a minute hole.

(b) The second section of the body, the thorax, is essentially
the part connected with movement. It usually carries three
pairs of legs and it may also be provided with one or two pairs.
of wings.

(c) The third section of the body, the abdomen (often called
the " tail "), corresponds more or less with the lower part
of the body in man, and contains the organs of reproduction
and the gut, in passing through which food is digested.
Extending down the whole length of the insect, just under
the upper surface, is a long tube which pumps the blood,
beating like the heart, to which it may be compared.

It will be noticed that no reference has yet been made as
to how insects breathe. This is because they have
entirely different " machinery " from that in man. In
the latter case the air is taken into the lungs and
the oxygen is absorbed by the blood and carried to wherever
it is needed. In insects the same result is obtained but by
a " short cut " since they have a series of holes (spiracles)
along the sides of the body (usually thorax and abdomen)
which lead into tubes passing to every part, so enabling air
to flow freely in and out. Every organ has therefore a
direct air supply and there is no need for lungs. In con-
trolling insect pests the special method of breathing is an
important point to remember.

Finally, as regards the structure, the statement may be
recalled that insects have no bones, but depend for their
support on their " skin," which in consequence may be
regarded as .their skeleton, being either hard or tough and in
many cases forming almost an armour plate. This armoured
character of the skin makes many insects difficult to kill.

Life History. — In addition to a knowledge of the structure of
insects, it is helpful, or even necessary, to have some idea
of their life history — their methods of breeding and develop-
ment. The usual method of starting life is from an egg
laid by the mother, but the young which are hatched from
these eggs often at first have little likeness to their
parents. In course of time they grow to resemble the latter,
but in so doing pass through stages so unlike in shape or
form that it seems hardly credible they can be the same
creature. This great change of form is perhaps explained
by the fact that insects at the different stages of their lives
concentrate strictly on " the business in hand," definite
periods of their existence being devoted very largely to one
object. This is clearly shown in the case of the White
Butterfly, the egg of which gives rise to a caterpillar

6

with one main object and that is to eat. The caterpillar
having eaten all it requires at that period of its life, turns to
a chrysalis, a stage in which the insect neither feeds nor
travels but undergoes great changes internally. From the
chrysalis comes the butterfly which, though it may sip a
little nectar, concentrates on breeding and spreading the
species. In each stage the foim of the insect is such as to
adapt it to one object at a time — the caterpillar with its
jaws and absence of wings is fitted to do little else but feed,
the chrysalis must remain outwardly immovable, and the
butterfly with wings, with a trunk which does not allow of
its taking solid food, and with breeding organs well
developed, is clearly adapted to propagating the species.

The bearing of all this on insect control is that it is very
necessary to be on the lookout for the different stages, which
though not in all cases as strongly marked as in the butterfly,
nevertheless always occur to a greater or less extent.
Obviously the stage when damage is likely to be done is
that adapted to feeding, but it serves equally well if the
pests are destroyed in one of the other stages. The great
thing therefore is to look for the condition in which the
insect is most vulnerable and to tackle it then, even though
at the time it may be doing no actual damage. Finally, in
connection with breeding, it may be pointed out that some
groups of insects such as Aphides (Green Fly) have found
it possible to do without males for many generations, the
females producing young without pairing, while in a few
cases (certain sawflies) males appear to have been nearly
lost altogether. This power of dispensing with males
naturally causes such insects to prove dangerous enemies,
for instead of about half the total population being able to
produce young, all can. Indeed throughout the insect world
it is possible to see how every development has been
regulated by the supreme necessity for rapid reproduction,
and it is this perpetual increase which so threatens the fruit-
grower.

Nature's Control of Pests. — The conditions under which
fruit trees are grown render them peculiarly liable to the
attacks of insect pests, for in the first place the fruit tree
is an artificial product which through cultivation has lost many
of the good constitutional features of wild trees, and
secondly the planting of large districts with the same kinds
of fruit enables a pest to penetrate throughout the area without
ever being at a loss for food. The reasons why, under con-
ditions so favourable to pests, fruit trees are not completely
overwhelmed is that the insects are to a considerable extent
kept in check by natural agencies. Thus, while for a year or
several years the destruction wrought by a pest may rise in a
wave which seems to threaten the very existence of a certain

crop, natural agencies sooner or later step in and again reduce
the numbers of the pest — and in consequence the damage done
by it — to more reasonable proportions. Thus over a term of
years a balance is more or less preserved. In times gone by
this natural control was perhaps sufficient to meet commercial
needs, but now with keen competition and the call for high
quality and high yield, the average damage due to pests is
more than the industry can bear. It is therefore necessary
to add artificial measures to the natural agencies already at
work. Any consideration of such measures would, however,
be incomplete without some further reference to the chief
agencies of natural control — i.e., weather conditions, the
attacks of other insects, and of birds.

Of these agencies, the weather admits of no interference
on behalf of fruit-growing, but there is some hope that in years
to come a greater knowledge of the effects of weather on insects
may make it possible to predict the appearance or absence of
serious epidemic pests, and so enable measures against them
to be taken in time. Work to this end is going forward.

As regards birds, the pros and cons of protection, legal and
voluntary, are gradually being placed upon more sure and
sensible foundations, and there is no doubt that insectivorous
species are among the very best friends of the fruit-grower
and therefore to be encouraged whenever possible. At the
same time the conditions of modern fruit-growing and agricul:
ture, with the necessity for destroying weeds and clearing up
overgrown hedgerows, limit to some extent the chief means
of encouraging the more useful birds (by the provision of suit-
able breeding places). It seems clear therefore that useful as
birds are as allies, it will never be possible to rely upon them
alone for winning the fight against insect pests.

The remaining great natural factor in regulating the number
of pests is found in beneficial insects — that is to say, those
insects which prey upon others. Such insects are always of
great value and are sometimes of overwhelming importance in
saving fruit trees from their enemies, and of all natural means
of control they perhaps offer the most scope for human inter-
ference. It is, however, not yet possible to increase beneficial
insects sufficiently to render the use of purely artificial methods
of control unnecessary, and in the case of practically every
pest some such measure as spraying is required. In this con-
nection it cannot be too strongly emphasised that artificial
control not seldom results in the destruction of both friend and
foe together, and that, tEerefore, having once taken over a
responsibility from Nature, the work must in future be
thorough or epidemics may be even more frequent than they
were in 'former times, when matters were left to take an
entirely natural course.

.8

Methods of Controlling Insect Pests. — Measures for
keeping insect pests in check may be divided roughly into
Indirect, which tend to make conditions unfavourable to
pests in general, and Direct, which are designed to destroy a
certain definite pest.

Indirect Measures. — From what has been said above it is
clear that insects in their various stages are adapted to certain
special conditions — the caterpillar to living and feeding on a
leaf, the butterfly to breeding, and so on. The object of all
indirect measures is to make the conditions unsuitable to pests
in one or more of their stages and so cut the cycle. An
instance or two will show what is meant. Certain beetles
(Scolytus rugulosus, S. pruni, &c.) which burrow into the
twigs and branches of plum and other fruit trees, find a
difficulty in beginning an attack on a tree of which all the
branches are in vigorous health, probably because the sap flow
blocks up the tunnels and hinders the beetles from working.
A branch dying, however, or recently dead, suits them exactly
and enables them to begin their attack. If an orchard is well
pruned so that all dead and weakly branches are removed, and
if the soil is kept reasonably fertile, the trees will never be in
the condition to suit boring beetles and a serious infestation
is rendered most unlikely.

Again, certain pests spend the winter in one of the active
stages and so are compelled to find protection of some sort —
.as, for instance, in heaps of rubbish, in moss and lichen on
tree trunks, or in rough growth in ditches. If trees are kept
clear of moss and lich'ens, heaps of rubbish are burnt, and
hedgerows and ditches are cleaned out, the winter shelter is
at once much reduced with the result that, however favourable
to pests the orchard may be at other seasons, they will always
be kept in check by the lack of suitable winter quarters.

These instances show the possibility of influencing the
numbers of insect pests by making conditions unfavourable
during a period of their life-history.

Finally, reference may be made to the temptation to defer
too long the removal of worn-out pest attacked trees or
bushes. It is true that they can often be cleaned up to some
extent and their productive life in this way prolonged, but
from the commercial point of view it is better policy to grub
or burn them — substituting young stock in their place. In
this way possible centres of infestation are got rid of and the
productive capacity of the whole plantation will be kept at a
high level.

Direct Measures. — Chief among direct measures for the
control of fruit pests is spraying — which is very efficient when
done thoroughly and with understanding. Haphazard work
carried out witli no clear idea as .to what is required is usually
waste of money. Sprays may be divided into (a) Cleansing

9

Washes, (b) Cover Washes, (c) Internal Poison Insecticides,
(d) Contact Insecticides.

(a.) Cleansing Washes, such as a solution of caustic soda,
might equally have been dealt with under Indirect Measures
as they are used primarily with the idea of killing moss,
lichen, &c., which serve as winter quarters for pests. They
are only applied in winter as they would burn foliage, and
except in badly neglected orchards can generally be replaced
by cover washes which also help to destroy moss, lichen, &c.

(b) Cover Washes, of which plain lime-wash is a typical
example, are applied in spring — early or late according to
the season and kind of fruit tree. They act by covering or
sealing up the eggs of pests just at the time they should be
hatching, and also by smothering any young insects which
may already have hatched. This being the case it is obvious
that the more complete the coat of wash applied, the more
pests will be killed, and since insect eggs occur more abun-
dantly on the twigs than on the larger branches, the sprayers
should specially endeavour to cover the twigs properly.
Further, in the case of lime, as the wash should dry on
and resist rain for some weeks, as thick a fluid as can be
forced through the spraying machine should be used.

(c) Internal Poison Insecticides are insecticides which
when eaten cause death but otherwise may be quite harmless,
having no effect on the skin or external parts of an insect.
In using internal poisons therefore the object is to spray
not the pest but the leaves of the tree, whicn under favour-
able conditions remain poisonous to pests for a considerable
period.

As it is necessary to cover every leaf and bud with a
uniform coating of poison, a nozzle giving the finest spray
should be used, and further, the nozzle must be moved
from one direction to another fairly rapidly for if leaves
receive too much spray, the minute drops run together and
collect at the tip of the leaf, with the result that there is
too much poison at the tip and too little elsewhere. A"
further point is that the liquid should stick to the leaves
and not merely collect in globules. Just as plain water will
not thoroughly wet a greasy plate, some leaves are so
formed that they are not easily wetted. In such cases it
is necessary to add to the insecticide some substance such as
saponin which enables the liquid to wet the leaf — just as
the addition of soap to water allows it to wet the greasy
plate.

Finally, in connection with internal poisons, attention
should be drawn to the necessity for spraying soon enough.
It should be noted (1) that young insects are more easily
poisoned than old, and (2) that insects such as caterpillars
cause damage very rapidly — an orchard green and seemingly
not much injured may be completely stripped of leaves n

10

week or ten days later. The great thing is to know the
habits of tne pest and to apply the spray just at the right
time so as to catch the young insects as soon as possible
after they have hatched.

(d) Contact Insecticides destroy insects by actual contact
with them. It has been shown that while some insects
have jaws and eat solid matter, others have " trunks "
with which they suck the sap or juice of plants through *
minute hole. These sucking insects cannot be forced to eat
a poison spread on the surface of the leaves, since they
bore through the poisoned layer and only feed when they
have reached the inside of the leaf. In spraying against
such pests, a poison which kills by contact — on touching the
insect — must be used. Insects having hard or tough skins
are fairly well protected against poisons applied to them,
but their defences have a weak spot — the breathing hole or
spiracle through which poisons can reach the interior. As
the spiracles are very small and few in number it is evident
that to poison an insect through them the body must be
thoroughly wetted, while further, the fluid must be of such
a nature that it will run well into minute holes. These two
needs give the clue to all contact insecticide spraying. The
necessity for the fluid to touch the insect involves a spray
applied with force through a coarse nozzle — passed up and
down each bough in order to reach both sides of every leaf
and every hole and corner between buds and in flower
trusses, where the pests may be hiding.

The need for a fluid which runs well involves the use of
some substance such as soap which enables the liquid
to penetrate the breathing holes (spiracles) of the insect,
carrying with it the poison (e.g., nicotine) which may be
used. If these two needs are met, good results may con-
fidently be expected. This also applies to certain contact
insecticides which do not act by poisoning the insect but
by smothering it with some sticky substance. Thus red
spiders (mites) can be killed by a thin paste made of flour
and water which is not poisonous but sticks the pests to
the leaves.

Finally, as in the case of internal poisons, it is most im-
portant to time the application of contact insecticides pro-
perly, especially not to spray too late. Many insects such
as Aphides (Green Fly) cause the leaves they feed upon to
curl round and inside these curled leaves the pests are
naturally protected against any contact insecticide. To
avoid the difficulty it is necessary to spray soon after the
pests have appeared and before they have had time to induce
the leaves to curl. In judging the period during which
useful spraying is possible, some knowledge of the life-
history of the pest is clearly invaluable, and such knowledge
is pqually necessary to ensure that those spraying are placing

11

the insecticide where it will do good. " Rule of thumb '

spraying is likely to be wasteful and inefficient.

In concluding these notes on spraying, reference should be
made to dusting, in which the insecticide is applied as .a dust
instead of as a fluid, and also to the application of insecticides
by hand. As regards dusting, this treatment has made some
progress in the United States of America, but it has not clearly
shown its superiority over liquid spraying. In certain cases
(e.g., Black Currant Mite and Pear Slug Worm) good results
have been claimed in Britain, and where a grower has a dusting
machine for use in connection with fungus pests, the possibility
of attacking insects with the same methods should be kept in
mind.

Hand application of insecticides (except in greenhouses and
very small gardens) is practically limited to the destruction of
Woolly Aphis on apples (Leaflet No. 34), where the insecticide
is painted on to the colonies of the pest, but it may also be
useful where " bendable " twigs attacked at the growing point
can be bent over and dipped in a vessel of insecticide. Goose-
berries attacked by Aphides are sometimes treated in this way.

Oilier Direct Measures. — In addition to spraying there are
certain other direct measures for pest control, (a) In small
gardens, and sometimes even in commercial orchards, " hand
picking " may be of great use if the owner is sharp enough
to detect the pest when it is just beginning to obtain a foot-
hold. Hand-picking may consist in the removal by hand of
the insects or their eggs — as for instance the nests of the
Lackey Moth caterpillars — or more usually it takes the form of
collecting attacked leaves and fruit in or on which the pest
as still living. Instances of these are Apple Sawfiy in the
fruits, Pear Leaf Blister Mite in the leaves, or Apple Blossom
Weevil in the closed " capped " blossom. In the case of single
trees attacked by a pest not controllable by spraying hand-
picking is always worth a trial as it may save the whole
orchard.

(b) Next to hand-picking may be mentioned the running
of poultry in orchards (chiefly of course those containing
standard or half -standard trees). Fowls are extraordinarily
efficient insect hunters, and if not too few in number can be
relied upon to destroy any pest which passes a part of its
life in the soil.

(c) Where a pest has to crawl up or down a tree trunk,
banding may be employed. This consists in placing round the
trunk a band of sticky material to catch any insects which try
to pass over it (Leaflet No. 4, Winter Moths), while another
form of banding consists in placing round the trunks bands
of hay or sacking, &c., in which the pests find suitable quarters
to spend the winter or the chrysalis stage (Leaflet No. 30,
Codling Moth).

(d) \Yhere pests are attacking roots, the use of soil fumi-
gants or insecticides— e.g., the injection of carbon bi-sulphide
— is sometimes advised, but the results obtainable are un-
certain, sometimes hopeful but more often unsatisfactory and
it is advised that at present all soil insecticides should oe
treated as experimental only.

Against insects other than those in the soil, fumigation h-is
a few special applications — e.g., in cleaning stock from pests
prior to planting. This, however, requires certain facilities
and is better left to the nurseryman. The grower can, how-
ever, use fumigants in the case of certain large insects (Leo-
pard Moth) which burrow into fruit trees, and it is then no-
difficult matter to insert the necessary chemical in the burrow
and block up the hole. Further particulars are given in
Leaflet No. 60.

Conclusion. — The preceding notes relate solely to insect
pests but readers should be warned that the different aspects
of fruit-growing cannot be shut off into water-tight compart-
ments. To show the bearing of this, brief reference may be
made to three points.

(1) Just as separate varieties of a crop differ in regard to
flavour of fruit, character of growth, &c., so they also differ 11
their susceptibility to damage by pests. This point has not
perhaps been sufficiently realised in the past, but plant
breeders are now fully alive to the importance of immunity,
and h#ve already achieved some notable successes. Unfor-
tunately new varieties of fruit take so long to raise and have
to combine such a number of qualities, that progress in pro-
ducing resistant varieties must necessarily be slow. Neverthe-
less this aspect of pest control should always be remembered
and even if new resistant varieties are not forthcoming, much
may yet be done by observing the difference in susceptibility
already shown by well-known commercial fruits so that kinds
may be selected which show themselves more . resistant to
the pests prevalent in the district.

(2) Insects are not the only organisms which attack fruit
trees. Fungus pests are often quite as important, and it is
thus necessary to control both simultaneously. Fortunately,
it is often possible to mix insecticides and fungicides and apply
them together, though unless such mixing has been definitely
advised it is better to get expert- advice before trying experi-
ments, since some mixtures would prove most injurious. In-
direct measures for pest control, notably pruning out weak and
dead wood, are usually equally valuable in the case of insects
and fungi.

(3) Good cultivation generally has a considerable bearing
on pest control. Just as a man when in good health is less
likely to contract an illness, so a flourishing plant is much
better able to resist the attacks of its enemies, and an addi-

13

tional freedom from losses so caused may well be credited to
the expense of proper cultivation under modern conditions.
Even in the best -cultivated orchard, however, the " doctor "
is sometimes required and it may again be emphasised that
if he cannot visit the orchard, a good large piece of his patient
(the affected tree) should be sent him, as his trouble is
enormously increased if he has to base his opinion on the
examination of a few scraps.

J. C. F. FRYER.
London, S.W.I.

October, 1921.

H

THE APPLE BLOSSOM WEEVIL.

(Anthonomus pomorum, L.)

a, Weevil, nat. size; b, magnified, c, Larva, nat. size; d, magnified.
e, Pupa, nat. size; /, magnified, g, Larva in blossom bud.

The Apple Blossom Weevil occurs in most counties in
England and Wales, and is recorded from Scotland and Ire-
land. It is specially prevalent from the midlands southward,
being a serious pest in the Evesham district, in Cambridge-
shire, Kent, and in the southern and south-western counties.
Abroad the insect is well known in most European countries,
in some of which — as, for instance, France — it has proved
even more -destructive than in the British Isles, and indeed
has caused such damage that growers have been forced to take
co-operative action for its destruction.

The Apple Blossom Weevil is notoriously difficult to con-
trol owing to the fact that it is little amenable to treatment
by spraying, but there are certain general measures which
serve to check its numbers to some extent.

Nature of Injury. — If an apple orchard be examined at
the close of the blooming period it will often be noticed that
certain of the blossoms have failed to expand, the petals hav-
ing died and become brown in colour without falling off. Such
blossoms are usually known as " capped blossom," and a
further examination will show that underneath the brown
petals is a small yellowish grub (or later a pupa), which has
eaten away the base of the flower and so prevented all further
growth. Blossoms so attacked ultimately die and fall off. In
bad cases a high proportion of the flowers in an orchard may

15

be damaged in this manner, with the result that the crop is
almost entirely lost. Pear blossoms are also occasionally
attacked by the weevil, but the losses are seldom serious.

Description and Life-History. — The adult beetle is a
small insect about £ in. in length with a long rostrum or
" trunk." In colour it is black or brownish, dotted with fine
grey hair, and across the wing-cases (elytra), which appear
to form the " back " of the insect, is a light-coloured, greyish
or yellowish mark. This mark is more or less in the form of
a V, and is very characteristic of the insect (Fig. b). The
adult weevils appear in spring and crawl or fly to the apple
trees, on which they may often be found in numbers during
the period preceding the opening of the blossom. Eggs are
laid as follows : — The female weevil bores a hole into the un-
opened bud, lays an egg in the hole and then pushes it down
with her trunk, afterwards sealing up the hole with saliva.
Only one egg is laid in each blossom, and a single female can
probably lay 50 eggs or more. If the weather happens to be
such that the apple blossom expands very rapidly, the flowers
may open before or about the time when the egg hatches,
in which case the insect dies. As a rule, however, the grub
appears first and prevents the petals from expanding. The
larva grows rapidly, and in a fortnight is full grown. It is
then a pale yellowish grub with a brown head (Fig. d) and lies
in the cavity of the capped blossom in the curved position
usual to weevil larvae. The bloom by then is practically dead
and the. larva* turns to a pupa (Fig. /). About a week or ten
days afterwards the pupa casts its skin and becomes an adult
weevil, the insect remaining a short time within the blossom
and then eating its way out through a hole in the side. These
weevils may be found upon the apple trees for 3 .or 4 weeks
after their emergence, but they gradually disappear- and long
before the autumn they have all found their way to winter
quarters — as, for instance, under rough bark on the trees,
beneath stones or rubbish on the ground, or in dead J eaves,
hedge cuttings, &c. They remain there during the winter,
and in the following spring come out again and return to the
apple trees, when a fresh generation is produced.

Natural Enemies. — The Apple Blossom Weevil is eaten
by birds such as tits, and is also destroyed by insect parasites.
The larva of the ichneumon Pimpla pomorum feeds on the
larva and pupa of the weevil in the capped blossom, and in
this way very many are destroyed. Dr. Imms, of the Rotham-
sted Experimental Station, has shown that in an orchard in
Cambridgeshire over 25 per cent, of the weevils were killed by
this ichneumon.

16

Methods of Control. — From the above account of the life-
history it will be clear that the Apple Blossom Weevil is at
no time really susceptible to those measures usually employed
against orchard pests. The insect when young is protected
within the " capped blossom "; when adult it appears to feed
little — or at all events, not in such a manner as to make a
lead arsenate spray of much use. It spends the winter in
various places, always well concealed, and winter treatment
cannot be wholly effective.

(1) Nevertheless, in most orchards something, and in many,
much, can be done in winter. In the first place, if the trees
are mossy and the trunks encrusted with loose bark many
weevils will hibernate on the trees and a winter wash, or later
a lime wash, will destroy many of them; recent reports tend
to show that late lime-washing is fairly successful against the
weevil. The burning of all rubbish and the cleaning of hedge
bottoms and ditches will also be helpful, as will the cultivation
of the ground underneath the trees.

(2) In Prance it has been found practicable to reduce the
numbers of the beetles by shaking them off the trees just be-
fore they lay their eggs. A large sheet is spread under the
tree which is shaken or tapped with a stick, and the beetles
which fall down are tipped into a pail containing a little
paraffin.

(3) In small orchards or where the trees are young it is
worth collecting the capped blossom by hand before the beetles
emerge.

(4) In connection with this hand picking, the possibility
of increasing the number of ichneumon parasites is worth
consideration. If the collected " capped blossom " be placed
in the orchard in a box with a muslin cover of a certain mesh
(about 1/32 inch) the weevils will be1 imprisoned while the
ichneumons will be able to escape. It has already been pointed
out that the ichneumon is an efficient enemy of the weevil,
destroying 25 per cent, and if capped blossoms could be col-
lected over a wide area and the ichneumons released, this
percentage might be considerably increased. In France results
obtained by this method are said to have been distinctly hopeful.

(5) The weevils seek winter quarters fairly early in the
summer and they may then be trapped by means of bands of
sacking tied round the trunks of the trees — as for Codling
Moths. The band should be in a position by the beginning
of June and should be removed and be burned in the autumn.
This method of control may prove of more value than has
hitherto been supposed.

(6) Apart from winter washing, no spray has yet been
proved to be of much use and spraying should only be tried
experimentally.

17-

THE APPLE SUCKER.

(Psylla mail, Schmidb.)

The Apple Sucker is a widespread and abundant insect
and is usually regarded as one of the most harmful pests of
the apple, both in the British Isles and on the continent
of Europe. It has hot, however, been recorded from America,
Australia, New Zealand, or South Africa.

Nature of Injury. — Apple Suckers belong to the same
Order of insects as Aphides and Capsid bugs, which obtain
their food by sucking up the sap of plants through minute
holes, or punctures, so causing the injury or death of the
parts attacked — especially when the latter are in a young
growing state.

In the case of the Apple Sucker, the most serious damage
is done to the flower buds and flowers. The insects' when
quite young attack the flower buds and later the stems of the
blossoms, draining away the sap, with the result that the buds
may die unopened, or if they expand, fail to set fruit. In
the latter case the trusses of bloom often remain on the tree,
dead and brown as if damaged by frost. This is the most
characteristic sign of attack. Damage is also done to the
developing leaf buds and leaves,; the latter being sometimes
deformed, stunted, and rendered light in colour. After the
blooming period and when the leavers have reached their full
development, further injury is not obvious; but, nevertheless,
it seems likely that the trees may be weakened by the attacks
of the sucker to the prejudice of the succeeding crop. Certain
varieties of apple, such as Bramley's Seedling, appear to
suffer less than others, and, in fact, in most varieties there
is considerable variation in the precise amount of injury,
trusses of bloom noted as being infested sometimes developing
a full crop.

Description and Life-History. — The eggs (Fig. ]) of the
Apple Sucker are minute, oval, and creamy white in colour, with
a small projection at one end and a longer projection, at the
other, the latter passing into the bark and holding the egg in
position. They are laid mainly on the fruit spurs (Fig. 2), and
to a. less extent at the base of the leaf buds and on the twigs
generally. The eggs hatch from the end of March to the
end of April, varying with the season and also with the
variety of apple on which they are laid, those on parly leafing
varieties hatching first. The newly-hatched suckers, small
rather flat, yellow insects, crawl in between the leaf folds
and later into the trusses, puncturing them and feeding on
the sap. The young suckers grow rapidly, and before long
excrete from the hind end of their bodies a small whitish
globule or drop, and later long waxy threads which are usually

18

THE APPLE SUCKER.

1. Egg. 2. Position of eggs on fruit spur (represented by dots)

3. Sucker (larval form). 4. Adult Sucker. 5. Condition of

Apple buds for spraying.

19

very conspicuous, being sometimes white, sometimes blue,
and iridescent. By this time the suckers have become bright
green in colour, and rudiments of wings can be seen
(Fig. 3). In the succeeding moults the wing rudiments be-
come more conspicuous, and finally, four to six weeks from
the date of hatching, the adult winged suckers appear
(Fig. 4).

The adult suckers live on the apple trees throughout the
summer, but do not lay eggs until the autumn. In
September, egg-laying begins, and may continue until
November, when the adults die. The eggs then remain
until the following spring, when they give rise to a further
generation.

Methods of Control. — There are three methods of dealing
with the Apple Sucker, the first two being those usually
employed.

(1) The trees are sprayed with lime-wash about the time
when the buds begin to swell; if necessary the spraying may
be continued until within about a week of the bursting of the
blossom. It is sometimes thought that late lime- washing
may injure the young leaves and blossom buds, but the
injury, if it occurs, is unimportant, and the results as regards
insects are more satisfactory than when the work is done
too early. The lime-wash forms a coating over the twigs,
which tends to seal up the eggs just when they are about to
hatch, and also to kill any young suckers which may already
have appeared. The work must therefore be done thoroughly,
so that the twigs and branches are well coated with lime.
The following is a formula for making lime-wash: —

Best Quick Lime (in lumps) . . . 10-15 Ib.
Water 10 gal.

Only the best stone quick lime should be used, ordinary
builder's lime is often impure and partially air slacked. In
making the wash a small quantity of water should first be
poured into the lime to slake it; the remainder of the water
should then be added, and after a thorough stirring, the wash
should be carefully strained into the machine.

(2) The trees are sprayed with a contact insecticide shortly
before the blossoms open (Fig. 5), a nozzle with a rather coarse
jet being used for the purpose, so as to get a driving spray.
Occasionally, the newly-hatched suckers may be found some-
what earlier in large numbers on the unexpanded leaf buds,
and in this case they are specially amenable to treatment
by spraying. The best contact insecticide is nicotine and

20

soap, which also deals with Aphides, Caps id bugs and young
caterpillars. The following formula has proved satisfactory: —

Nicotine (98-99 per cent.) ..:. ... -?- oz.

Soft Soap ... ... Jlb.-llb.

Water ... ... 10 gal.

The soft soap is first dissolved in. a little hot water, and the
solution is added to the remainder of the water. Finally,
the nicotine* is poured in, and after stirring the wash is ready
for use. Sufficient soap is needed to make the mixture lather
well. With soft water ^ Ib. will be, sufficient. An emulsion
containing creosote oil has been recommended as an efficient
insecticide for the control of sucker. In practice, however,
it has at times caused such severe injury to the foliage that
its use cannot be advised without further investigation.

(3) It has been pointed out that the suckers do not lay
eggs until the autumn. It may therefore be possible, in the
case of early varieties of Apple, to kill the great majority
after the apples have been picked, and before eggs have been
laid. At this date injury to the leaves is not of great impor-
tance and any contact insecticide, as for instance a paraffin
or creosote emulsion, will answer the purpose.

References.

Theobald. — " Insect Pests of Fruit/' p. 153.
Petherbridge. — Journal of the Board of Agriculture, 1915,

Vol. XXI, p. 915, " Spraying for Apple Sucker and

Plum Aphis."

Awati. — Annals of Applied "Biology, 1915, Vol. I., p. 247.
Petherbridge. — Annals of Applied Biology, 1916, Vol. II,

p. 230, " Spraying for Apple Sucker. "
Lees.— Annah of Applied Biology. 1916, Vol. II, p. 251,

" Some Observations on the fcgg of Psylla Mali."

APPLE CAPSIDS.

(Plesiocoris rugicollis^ Fall.)

Capsid bugs have only recently attracted much attention
among fruit growers, but they must now be reckoned among
the most dangerous insect pests of the apple, while their
attacks on currants, though less serious, must also be regarded
with some alarm, f

The most harmful species (possibly the only harmful
species), "is the Green Apple Capsid, Plesiocoris rugicollis, an

* Nicotine, especially when undiluted is very poisonous, and must,
therefore, be used with care.

f Articles giving further information as to Capsid Bugs appeared in
the Ministry's .loaMal. Vol. XXII, No. 10, Vol. .XXIV, NOB. 1 and 12,
and Vol. XX V, No. 1.

21

insect which is almost always to be found on willows and
sallows, and is widely distributed throughout the country,
though its occurrence in apple orchards is still somewhat
irregular. Abroad the insect is known to attack apples in
Norway, while allied species cause a similar form of injury
to apples in Canada and the United States.

Capsid bugs feed on the sap of plants, sucking it up
through, a trunk (or proboscis), and in order to reach the sap,
they drill small holes or punctures, which in the case of the
apple form the centres ol more or less extensive injuries.
The first signs of attack are shown by the appearance, early
in the season, of small brown spots on the young growing
leaves, each spot marking the position of a puncture. As
the leaves become larger, the parts round each puncture either
die and fall out or fail to develop properly, with the result
that attacked leaves are deformed, ragged and under-sized.
The bugs also attack the shoots which are checked or even
killed, thus encouraging the formation of an excessive number
of side shoots, and in consequence a badly-shaped, stunted
tree.

Of all injuries, however, the most obvious is that to the
fruit. Attacked apples are usually deformed; the skin shows
rough russetted patches with scattered pits and pimples in-
dicating the position of the original punctures. Really bad
specimens are shapeless, often with cracks extending deeply
into the interior, and the whole surface so discoloured, rough
and corky, that the fruit has little resemblance to an apple.
The crop of course is much reduced, since many fruits fall
off before they reach maturity, while a large percentage of the
remainder are always so scarred as to be of little value for
the market. There appears to be some variation in the extent
of the injury to different varieties of apple, certain varieties as,
for instance, Bramley's Seedling, sometimes suffering less
than others, but nothing definite can yet be stated with regard
to this point. In addition to apple, black and red currants
are also attacked, the leaves showing the characteristic
spotting. It seems likely that the bugs have only recently
transferred their attentions to apple and currant.

Description and Life-History. — The eggs of the Green
Apple Capsid are oval, white in colour, and are laid under
the bark of the apple twigs, being therefore practically in-
visible unless the twig is peeled. Towards the end of April
— earlier or later, according to the season — the eggs produce
small green insects which if it were not for their great activity
might possibly be confused with aphides (green fly). The
young Capsids, as soon as hatched, creep in between the de-
veloping leaves and flower buds, puncturing them and
sucking up the sap. Feeding on the leaves, shoots and fruit-
lets, the young bugs grow rapidly, and from the end of May

22

to the middle of June become, full grown. They are then
winged, are bright green in colour, and have the general form
shown in Fig. 4. The full-grown bugs — as in the previous
stages— are very active, running or falling off the branch
when disturbed, and using their wings to get back to a tree.
They do not appear to fly long distances or to migrate from
one orchard to another. From the middle of *June to the
middle of July, sometimes later, the bugs lay their eggs in
the apple twigs, and by the middle of August are no longer
to be found in the orchards. The eggs remain through the
autumn and winter, and give rise to bugs in the following
spring.

Methods of Control. — Apple Capsids are difficult insects
to control, but the damage can be greatly reduced by careful
spraying. The work, however, must be well done, tor it is
necessary to wet each bug with the spray fluid — -not an easy
matter when they are sheltering between the flower buds in
the trusses or among the developing leaves. Further, a very
few bugs are capable of doing great injury, and therefore the
majority of the insects must be killed if real benefit is to be
gained. A fairly coarse nozzle should be used so as to get a
driving spray, which should be directed first downwards into
the trusses and leaves of a branch passing from the tip to
the trunk, and then back again to the tip after turning the
nozzle upwards so as to catch bugs sheltering underneath
the leaves.

The best time to spray varies with the season, but it is
generally during the. week or ten days immediately preceding
the bursting of the blossom. A watch should be kept for the
first signs of spotting of the leaves — then after an interval
of ten days to allow the majority of the bugs to hatch, the
spray should be applied. Much good can be done by one
spraying, but in a badly affected orchard, especially if a good
crop is anticipated, it is. better to spray again immediately
after the petals have fallen.

The best insecticide to use is nicotine, which should always
be combined with soap or paraffin emulsion to assist it to run
freely in the trusses and between the young leaves. The
following formula has proved satisfactory : —

Nicotine (98-99 per cent.) ... 3 oz.

Soft soap ... 4 Ib.

Water ... ... 40 gal.

This wash is, of course, expensive, but it is waste of labour
and time to spray against Capsids with a wash which is not
highly efficient. Further, nicotine and soap will kill aphides,
apple suckers, and a good proportion of any winter moth
caterpillars which may be present, and it is therefore a good
" general purpose " spray.

23
APPLE APHIDES.*

The so-called " Aphis " or '• Blue Bug " Blight, which
attacks apples, and to a minor extent pears, is in some years
one of the worst pests fruit growers and gardeners have to
contend with in this country. The terms Aphis, Dolphin
or Blue Bug " Blight " are common names in all fruit-grow-
ing districts. They apply to damage done by several species
of plant lice or aphides.

Of the eight species of aphides recorded as attacking the
apple in Great Britain only four are of general importance.
These are: (i) the Blue Bug or Eosy Apple Aphis (Aphis
malifolia, Fitch); (ii) the Green Apple Aphis (Aphis pomi,
De Geer); (iii) the Oat Apple Aphis (Siphocoryne avena
Fabr.), and the Woolly Aphis or American Blight (Schizoneura
lanigera, Hausmann).

This leaflet deals only with the first three, which are
leaf, blossom, shoot or fruit feeders. In this respect they
are unlike the Woolly Aphis, which usually feeds on the
wood and roots, although in very bad attacks it may spread
to the leaves and fruit. This latter insect is dealt with in
Leaflet No. 34. By far the greatest amount of harm is done
by the Eosy Apple Aphis (Aphis maltfolia). but in some years
and in certain localities the Green Apple Aphis (Aphis pomi)
and the Oat Apple Aphis (Siphocoryne avena) are of
considerable importance.

Nature of Damage. — The damage by the- three species
of apple pests mentioned above is mainly to the foliage and
young wood, but also to some extent to the fruit, which is
stunted and deformed. The Oat Apple Aphis (Siphocoryne
avence) may damage the blossom as well as the leaves, and
in some seasons similar damage is done by the Blue Bug or
Eosy Apple Aphis (A. malifolice). The Green Apple Aphis
(A. pomi) mainly attacks the young shoots, and so densely
do the insects cluster on them that they check the growth.
They do not, however, produce such distortion as is caused
by A. malijolia.

The Blue Bug or Eosy Apple Aphis (A. malifolia) causes
the leaves to curl up, and beneath this shelter the lice repro-
duce, in certain seasons, at a great rate. The foliage becomes
smothered and poisoned by their honey-dew and other
secretions and turns brown. In some cases they produce,
earlier in the year, yellow or rosy-red, galled masses on the
leaves. Later they may swarm on the leaf -stalks, shoots and
fruitlets, and by their punctures deform them. The leaves
may fall and only a few stunted and galled apples remain.

* ATI abridged edition of an article, by Mr. F. V. Theobald, published
in the Journal of the Board of Agriculture, for April, 1919, pp. 63-71.

The crop is now and then completely ruined by this pest, and
the trees have a serious set-back for the next season and
probably for a longer time.

The Green Apple Aphis (A. pomi) may on occasions
produce a' certain amount of leaf-curl, but never to the same
disastrous extent as A. malifolice. Moreover, it never occurs
in such vast numbers. It mainly feeds upon the young top
growths, and although producing but little deformed growth,
it nevertheless checks the health of the tree, especially when
on young stock.

The Oat Apple Aphis (S. avence) does little harm as a rule,
except where it invades the blossom trusses, in which case
appreciable damage may be done. It produces little or no
leaf curling, appears earlier, matures and flies away much
sooner than the other two kinds.

Description. — The general appearance of the aphides
found on apple is familiar to most people, while the
blue-black or reddish colour of the Eosy Aphis usually
enables this species to be distinguished from either of the"
other two. Accurate distinctions, however, cannot be given
without entering into greater detail than the average reader
desires. The following descriptions, therefore, are printed
in small type and may be passed over except by those who
require some guide as to the identification of the species.

(1) Apterous or Wingless Viviparous Females : —

1. A . malifolice. — Blue-black, slatey-grey or pink. Cornicles

long, black; fat, rounded and more or less mealy.

2. A. pomi. — Green, not mealy. Cornicles long and black.

3. S. avence. — Green, not mealy. Cornicles rather short, con-

stricted at base and apex, brown and green.

(2) Alate or Winged Viviparous Females: —

1. A. malifolice. — Cornicles black, rather long. Abdomen red

and black.

2. A. pomi. — Cornicles black, rather long. Abdomen green,

with black lateral spots.

3. S. avence. — Cornicles pale brown to green, rather short, con-

stricted at base and apex. Abdomen green, with black
lateral spots.

Life-Histories. — All three species pass the winter in the
egg stage on apples and pears. The small oval eggs are
pale at first, but soon become black and shining. They are
placed on the shoots and buds, those of the Rosy Aphis
and the Oat Aphis mostly singly, but those of the Green
Aphis in masses all over the wood. These eggs hatch during
April into wingless females, usually known as " Mother
Queens," which are viviparous (capable of giving rise to
living wingless females in every respect resembling them-
selves), their progeny quickly reaching enormous numbers.
These wingless females act somewhat differently in the
different species; those of the Eosy Aphis cause the leaves

to curl up and afford them protection to a much greater
extent than those of the Green Aphis, while those of the Oat
Aphis cause no curling whatever. By June or July a change
in the life-history of all three species takes place, and winged
forms are produced, which nevertheless are all females and
all viviparous. These winged forms in the case of the Eosy
and Green Apple Aphides now fly off to other food plants
for the rest of the summer. In the case of the Eosy Aphis
the alternate food-plant is said, in America and Canada, to
be different kinds of plantain (Plantago spp.), but this does
not appear to be the case in Britain. Where they really fly
to has not yet been traced; but they have been found on the
guelder rose (Viburnum opulus). The Green Aphis is not
normally a migrant. It can and does alternate between the
apple and the thistle (Carduus), but such a migration is un-
usual, and it normally continues its activities upon the apple.
The third species, the Oat Aphis, migrates regularly during
the first half of June to such plants as cultivated and wild
oats, barley, wheat, and different grasses. Late in September
and during October the migrants return to the apple and pear
nnd produce a generation of oviparous or egg-laying wingless
females, and in the case of the Green Aphis wingless males.
In the Eosy and Oat Aphides winged males are normally
produced before the return migration takes place, and fly
back to the apple later than the migrating females. The
generation of wingless females produced on the return of
the migrants to the apple are fertilised By the males, and
before the winter arrives lay their eggs, thus completing the
cycle.

Natural Enemies. — Aphides have several natural enemies.
None appear, however, to check them much until most of
the damage has been done. These natural enemies are (1)
parasitic insects, (2) predaceous insects, and (3) fungoid
enemies. The parasitic enemies are small Hymenopterous
insects, called C-halcid Flies; the predaceous are Lady Bird
Beetles and their larvae or Coccinellida; the Aphis Lions or
larvae of the Lace Wing Flies (Chrysopidtz) ; the Slug or
Leech-like larvae of the Hover Flies (Syrphidce) ; and the
maggots of certain Gall Midges (Cecidomyiida). The latter
seem to be most abundant in North Britain. None of these,
however, appear to be of any practical help on a large scale,
and no reliance can be placed on them as a means of check-
ing " Aphis Blights."

The fungoid enemies, of which there appear to be many,
also appear too late to stop any epidemic, and when they
attack late colonies, that is, after all the damage has been
done, a few Plant Lice escape, enough to produce under
favourable circumstances a blight in the following seasons.

26

Methods of Control. — Apple Aphides can be controlled
by spraying, but too frequently this treatment proves in-
effective owing to the fact that it has been carried out too
late. The most injurious species — the Rosy Aphis — causes
such curling of the leaves that the pests are quite protected,
and spraying under these conditions is to all intents and
purposes a waste of insecticide. Effective spraying can, how-
ever, be carried out: —

(1) By using lime-wash early in the season when the eggs
are about to hatch. The normal time to apply this wash is
when the leaf -buds are swelling and about to burst, but
many growers continue the treatment with good results to
within a week or so of the opening of the blossom. The
effect of the wash is to prevent some of the eggs from hatch-
ing and to kill newly hatched aphides or so hamper their
movements that they are unable to establish themselves. In
lime- washing, the whole tree must be covered, and specially
the twigs and smaller branches.

(2) By using a contact insecticide (such as nicotine and
soap or pyridene and soap) during the period between the
opening of the leaf -buds and the bursting of the bloom.
Where there is no curling of the leaves, this spray may also
be applied soon after the petals have fallen from the blossom.
In using all contact insecticides, the application must be very
thorough, so that the insecticide penetrates into the half-
expanded buds and reaches every insect. The nozzle used
should give a rather coarse and powerful spray.

(3.) By using a contact insecticide such as paraffin emul-
sion from the middle to the end of October when the leaves
are falling. The aphides are then laying the winter eggs
and can be killed by a thorough application of the cheapest
aphis wash available. At that period there is no danger to
be anticipated from "burning"" the foliage, and a strong
paraffin emulsion is probably as good as anything.

Apart from spraying, the only precaution to be taken is the
reduction of ants in the orchard, since it appears that these
insects are most active in spreading the Rosy Aphis. "When
nests are found powdered naphthalene may be dug into-
them.

FOEMUL^E. —

I. Lime Wash.

Best Quicklime 10-15 Ib.

Water 10 gallons.

Obtain only the best stone quicklime and store carefully to
prevent it from air-slaking. Builders' lime, which is often
partially air-slaked, should not be used.

Slake the lime with a little water and then add the
remainder of the water, stirring vigorously the whole time.
Strain carefully before filling the spraying machine. Keep
well agitated throughout the application.

pTG- i. — APPLE CAPSIDS (Plesiocoris rugicollfe').

(Three times natural size.)

Reproduced from the Annals of Applied Biology, Vol. 1, by kind permis-
sion of the Cambridge University Press.

FIG. 2.— Apples attacked by Capsid Bugs.

2—26

r

WOOLLY APHIS.

Fio. 4— Apple twig showire canker-like galls produced by Woolly Aphi
rttacks (slightly less than natural size).

2-27

27

Theobald strongly advises the addition of J Ib. of common
salt to each 10 gallons of the above wash.

II. Nicotine and Soap Wash.

Nicotine (95-99 per cent.) £ oz.

Soap (soft) £ Ib.

Water (soft) 10 gallons.

If the water is hard, 1 Ib. of soap should be used. Dissolve
the soap in hot water, dilute to the required strength, add the
nicotine and stir well. If soft soap is unobtainable, hard
soap should be used instead. This is the best contact
insecticide. It will also kill Apple Sucker, Capsid Bugs and
young caterpillars.

III. Pyridene and Soap Wash.

Pyridene 4 oz.

Soap (soft) I Ib.

Water (soft) ' 10 gallons.

Pyridene may be use.d as a substitute for nicotine to reduce
the cost of the wash. It is slightly less effective against
Capsids and is of little use against caterpillars.

THE WOOLLY APHIS.

(Schizoneura lanigera, Hausmann.)

X.

1. Winged female, magnified ; and line showing natural size. 2. Wing-
less viviparous female, magnified.* 3. Apple twig, covered by woolly
aphides.

* Figure 2 is reproduced, with permission, from Mr. G-. B. Buckton':*
" British Aphides."

28

Distribution.— This insect is always more or less abun-
dant in old and neglected orchards and apple plantations
where no attention is given to pruning or to keeping the trees
free from moss, lichens, &c. Unfortunately it is also some-
times seen in orchards recently planted owing to nursery stock
being frequently sent out with aphis on the plants. Indeed,
although dispersal by the agency of wind is not unimportant,
by far the most common way for the pest to be distributed
is on infested nursery stock. Not only has the woolly aphis
been carried from orchard to orchard in Britain in this way.
but also from country to country, until it is now found in every
part of the world where apples are grown. It has been stated
that this aphis, although termed the American Blight, was
originally a European insect, but it is doubtful whether its
country of origin has yet been conclusively settled.

Injury Caused. — All varieties of apple in this country are
subject to the ravages of woolly aphis, but perhaps the old
Eibston Pippin suffers most of all. The Blenheim Orange,
Cox's Orange Pippin, and Lord Sufiield also suffer severely.
Varieties having a soft bark are most affected. Certain experi-
ments conducted in Victoria and elsewhere show that in the
case of apples grafted on Majetin and Northern Spy stocks
the roots are free from attack.

Infestation may be on the main trunk, on the branches, on
the fruit, or on the roots; in very bad attacks the leaves are
also infested. The fact that the woolly aphis lives below
ground on the roots should be carefully noted, as the above-
ground parts, though cleared of the insect, may receive
a new infection as a result of migration from below.
That this migration from the roots actually takes place may
easily be proved by grease banding the trees, when the aphides
may be caught in large numbers as they ascend the trunks.

The woolly aphis feeds, like all aphides, by puncturing the
epidermal tissue and then draining away the sap by means
of its proboscis. Not only is the tree weakened, but swellings
or galls result which later on crack, an appearance being pro-
duced (Fig. 4) resembling the lesions caused by the canker-
fungus. Sheltered in the canker- like cracks, the aphides are
more difficult to reach by treatment. The wounds produced
by the aphis ,are also said to serve as points of entry for the
true canker fungus (Nectria galligend.) (See Leaflet No. 56.*)

Description and Life-History. — The woolly aphis may
readily be recognised in an orchard by the masses of white
woolly substance formed by the larvae and females which are
sheltering in the crevices of the bark. The woolly substance
arises as an excretion from glands in the backs of both the
young and mature females. It may often be seen hanging

* To be obtained from the Ministry, also included in Sectional Volume
No. 1, price 8d.

29

in festoons from the trees. Parts of this " wool " get blown
off and are carried by the wind, often for some little distance,
and in this material young Schizoneurce may be earned.

Various forms of the woolly aphis are found in the course
of the year's cycle :- — wingless females that produce live young;
winged females that are also viviparous ; and males without
wings, which pair with wingless egg-laying females.

The wingless viviparous females are oval in shape and
purplish-brown in colour. Numerous white threads pass from
their backs. Their antennas and legs are very short, and in
colour are dark reddish-brown to black. Such wingless vivi-
parous females may be found all the year round. They give
rise to great numbers of young (so-called lice) which are at •
first of a dull yellowish colour but later become purple brown.
It is the woolly material secreted by these that gives rise to
the festoons mentioned above. These lice on becoming adult
produce live young in turn, and a number of such generations
can be produced in the summer.

The wingless viviparous females may, however, give rise,
between June and late October, to winged viviparous
females, the exact function of which has not yet been
discovered. Patch* appears to have shown conclusively
that in America these winged females, which there occur
commonly, migrate to elm trees, where they give rise to
wingless males and wingless egg-laying females. The eggs
laid by the latter in the crevices of the bark of the elm
remain over the winter, and in the spring produce wingless
forms from which arise aphides which attack and curl the
elm leaves. Subsequently the elm leaf form produces winged
individuals which migrate back to the apple.

In this country there is as yet no direct evidence that the
woolly aphis of the apple migrates to elm, but it is of
interest to note that Theobald! has discovered a woolly aphis
which curls elm leaves and which produces a winged form
indistinguishable from the winged form found on apple. No
males or egg-laying females of this aphid have yet been;
discovered in this country and its relation — if any — to the
apple woolly aphis is still unknown. It is, of course, quite
distinct from the usual species of Scliizoneura (S. nlmi or
fodiens) which attacks elm and currant in Britain.

On the apple in this country the woolly aphis produces
winged forms only occasionally, while wingless males and
females, which lay winter .eggs, are known on apple trees,
but are exceedingly rare. The usual method of passing the

*Bull> 203. Agric. Exp. Station, Maine, U.S.A.

f An account of this observation has not yet been published, but
Mr. Theobald kindly allows a reference to be made to it. He finds the
Elm form common all over Britain — the top of the young shoots being
extensively curled. Winged forms appear in -Tune and July and fly
away from the Elms

30

winter is as a wingless viviparous form which hides in.
cracks in the bark, in the canker-like wounds, or in the galls
on roots. There appears to be a migration of individuals
from the portions of the tree above ground to the roots at
the approach of winter and a return migration from below
to the branches in the spring.

Natural Enemies. — There are not many natural enemies
that do much good in checking the increase of this pest.
Possibly the woolly excretions and oily globules that surround
the . insect protect it from the various foes which attack
unprotected plant lice.

The larvae of Lady Birds (Coccinellida) devour them, as
•also do the adult Lady Birds. Larvaa of several species of
Hover Flies (Syrphida) also feed upon them, but not to the
same extent as upon other plant lice. Lace Wing Flies and
Ichneumon Flies are seldom found attacking them. Small
dipterous larvae of the genus Pipiza feed on the subterranean
form. Perhaps the Tits (Parid-a) (See Leaflet No. 43*) do
most good in keeping down this pest. These little birds,
especially the Blue Tit, do inestimable good by devouring
woolly aphis and other pests all the year round, and should
be protected in every orchard.

Methods of Prevention and Remedies. — (1) Woolly
aphis is especially prevalent in neglected orchards where
the trees are close together and where their trunks are
covered with lichens and moss. To clean the trees and
destroy the hibernating females a winter wash should be used.
This may be the simple alkaline wash composed of caustic
soda, 2-2£ lb., and water, 10 gallons, or it may be one of the
more efficient Woburn washes (See Leaflet No. 70*). Lime
or lime sulphur winter washes have also been found useful,
but they are naturally less effective than the more caustic
fluids.

(2) Any portion of a tree which has been wounded, as
for instance, by pruning, is specially liable to an attack by
woolly aphis. If large branches have been removed the cut
surface should always be dressed, Stockholm tar being an
excellent dressing for this purpose.

(3) Methylated spirit brushed well into the affected
portions of trunk or branches is the most successful
treatment for young trees or when an attack first manifests
itself in an orchard. Owing to the rapidity with which
methylated spirit evaporates and its consequent expense,
paraffin or petrol is sometimes substituted for the spirit,
but where the trees are young and the bark thin, this may
lead to injury. A wide range of compounds containing'
linseed oil, Stockholm tar, shellac and other substances have*
also been invented for brushing on to the affected portions

* Obtainable from the Ministry.

31

of the trees. In all cases, however, success depends on the
thoroughness with which the treatment is carried out.

(4) For a summer spray nicotine and soft soap, dilute
paraffin emulsion, or quassia and soft soap have all been
recommended. If used they must be applied with force and
the affected parts thoroughly drenched owing to the necessity
of penetrating the woolly material before the insects them-
selves are reached.

(5) To prevent the introduction of the aphis, great care
should be taken to see that all young stock is clean before
planting. If any traces of either the root or the aerial forms
are seen, the trees should be returned to the nurseryman
to be disinfected before being planted. All nursery stock can
be fumigated with hydrocyanic-acid gas (see Leaflet No. 188*),
and thus thoroughly cleared of woolly aphis before planting.

THE MUSSEL SCALE.

(Mytilaspis pomorum, Bouch6.) •

The Mussel Scale is one of the most abundant scale insects
in the British Isles ; it also occurs on the Continent of Europe,
in North America, South Africa, Australia and New Zealand,
having been introduced into the three last countries on
infested nursery stock. As a pest the insect is most con-
spicuous in neglected apple orchards, but it is always present
on apple and certain other trees in all the fruit-growing
districts in the kingdom, and wherever it is allowed to increase
unchecked is likely to cause serious damage. In America it
is regarded ais an insect of considerable importance to apple
growers and is there known as the Oyster- Shell Scale from
its resemblance in shape to American oysters.

Description and Life-History. — The Mussel Scale lives on
the stem and branches, and occasionally on the leaves and
fruit of the plants, such as the apple, which it attacks. If a
branch infested by this insect be examined, it will be found
that the surface of the bark is more or less covered by small
brown objects (Fig. 1) about J inch in length, which are shaped
somewhat like a mussel shell. Each mussel-like scale forms a
roof or covering over the living insect during the summer, and
over its eggs in winter.

The winter is spent in the egg stage, the eggs — exceedingly
minute and like a whitish dust — lying underneath the scales.
At the end of May or early in June very small wingless, louse-
like insects (larvae) are hatched from the eggs and crawl from

* Obtainable from the Ministry.

32

under the scale on to the bark of the tree, where they wander
about for three or four days, and may during this period be

c.

Q.

FIG. 2.

a. Female Mussel Scale, dorsal view; 6. The same, ventral view:
c. Male scale.

carried to other trees by means of the wind or by clinging to
birds and insects. When one of these " lice " (larvae) reaches
a suitable spot, it drives its " trunk " (or proboscis) into the
bark and begins to feed by sucking up the sap — just like a
Green Fly or a Capsid Bug. Unlike either of the latter pests,
however, it soon loses all ' power of movement and remains
fixed to the bark in which its trunk is buried. As it grows
it forms the scale under which it lives, building up the scale
in such a way that the insect itself is always completely covered
(Fig. 2).

In the case of the Mussel Scale, the insects are practically
all females, and when they become adult towards the end of
summer they lay eggs (as a rule without the intervention of
a male) under the scale, continuing until there may be as many
as 80 eggs under one scale. The female then dies and the
eggs remain in safety under the scale during the winter.
Mussel Scale insects of the male sex do occur, but they are
very rare on fruit trees. When young, the males, like the
females, live under scales, but the male scales are somewhat
different, being straighter and not so large (Fig. 2c). Under
the scale the young male passes through a pupal (chrysalis)
stage, and on becoming adult emerges as a minute fly-like
insect with two wings. The males pair with the females and
soon die, having no mouth parts for feeding.

Plants attacked and Nature of Injury. — Mussel Scales are
injurious to apples, and less frequently to pears and currants
(both black and red). The insects also attack sallow, haw-
thorn, broom and other plants.. Trees gro'vi'ig against walls

33

suffer more than others, as the pests flourish most in warm,
sheltered situations.

The injury to the tree is caused by the loss of sap which
is sucked up and devoured by the pests. In a bad case, where
the branches are completely encrusted with scales, the tree
suffers so severely that it may die in part if not altogether.
Old trees are more often infested than young trees, but at the
same time they are able to withstand the attack better, and
when by bad management, a young plantation is allowed to
become badly infested, the damage sustained may be irrepar-
able. Since Mussel Scales are to be found in small numbers
in practically every apple orchard, a careful watch should
always be kept so that if any increase in the numbers of the
pest is noted, control measures may be taken before serious
harm has resulted. .

Natural Enemies. — Mussel Scales are devoured by Tits
and probably also by the Tree Creeper and Wryneck. They
are attacked by certain minute parasitic insects (Chalcids)
which, however, are not a sufficient check on the pest to
render artificial measures of control unnecessary.

Control Measures. — (1) In the case of a bad attack, the
trees or bushes should be sprayed when dormant (November
to February) either with an oil emulsion or with Woburn wash
(see Leaflet No. 70). There are now on the market several
makes of oil which mix (or form an emulsion) with water,
and if used they should be diluted in the proportions recom-
mended by the makers for a winter .wash. A home-made*
emulsion for winter use may be mixed as follows: —

Paraffin oil ... ... ... ... 1 gall.

Soft soap l£-2 Ib.

Water 10 gall.

The soap is first dissolved in' about a gallon of boiling
water. The soap solution is then removed from the fire, and
the paraffin is at once added, the whole being emulsified by
squirting the liquid back into itself with a hand syringe.
The strong emulsion may be kept until required for use, when
the remaining nine gallons of water should be added and the
whole thoroughly stirred — or better, emulsified again with
the hand 'syringe.

Oil emulsions, whether bought or home-made, must be
applied carefully so as to wet every portion of the tree, not
forgetting the undersides of the large branches. The eggs
under the scales will be killed only where the scales them-
selves are thoroughly wetted, and if a few escape the trees
will be re-infested.

(2) In America' good results have been obtained .by the
use 'of lime-sulphur washes, and although in England lime-
sulphur has proved rather disappointing in the case of bad

34

infestations, il, will probably be found satisfactory in keeping
moderate or slight attacks in check. Lime-sulphur should
be bought ready made, and be diluted when required for use
(not before) with water in the proportions recommended by
the makers to form a winter wash (usually 3 quarts of lime-
sulphur to 10 gallons of water). The wash should be applied
in late winter or early spring up to the period when the buds
begin to open.

(3) If the pest has not been dealt with in winter — the
best time — it may be greatly reduced by spraying wTieu the
eggs are hatching, about the end of May or early June. At
this period a weak paraffin emulsion has proved satisfactory,
and probably any other contact insecticide, such as nicotine
and soap, would do as well. A suitable paraffin emulsion
may be made as recommended in paragraph (1) above, but
using the ingredients in the following proportions: —

Paraffin 2 pints.

Soft soap 1 Ib.

Water 1.0 gall.

(4) Growers, when buying fruit trees, especially apple,
should examine them for Mussel Scale (and also such pests
as Woolly Aphis) before making a purchase.

(5) It is better to prevent attacks by occasional winter
washing than to wait until it has become necessary to deal
with a serious infestation, and in this connection it is worth
noting that trees which are regularly sprayed and kept free
from moss, lichen, &c., seldom suffer from Mussel Scale,
even though the washes used have not been specially directed
against Scale.

THE LACKEY MOTH.

(Clisiocampa, neustria, Linn.)

The Lackey Moth is an insect which is always present in
orchards throughout the southern half of the country but
which is rare and seldom harmful north of the Midlands. The
chief characteristic of the Lackey from the fruit-grower's point
of view, is that it will remain for years in a district without
to all appearance increasing in numbers or causing much harm.
Then, suddenly, with little warning, the insects become sb
abundant that the caterpillars are a veritable plague, stripping
trees of their foliage and almost defying efforts to exterminate
them. After a season, or perhaps two, the Lackey popula-
tion resumes its normal proportions and again several years
may elapse before another epidemic breaks cxut.

Photo.']

MUSSEL SCALE.

[R. A. Malby.

FIG. 1. — Piece of infected Branch.
(Twice natural size.)

2-34

THE LACKEY MOTH.

FIG. 1.— Eggs on twig. FIG. 2.— Web on apple branch, showing cater-
pillars and cast skins. FIG. 3. — Full grown caterpillar. FIG. 4. —
Cocoon. FIG. 5.— Chrysalis. FIG. 6.— Male Lackey Moth. FIG. 7.—
Female Lackey Moth.

So

Plants Attacked and Nature of Damage. — Lackey Moth
caterpillars feed on the foliage of many kinds of trees and
shrubs including apple, cherry, plum, and pear among fruits,
and oak, hawthorn, willow, alder, elm and rose among forest
trees and shrubs. As the caterpillars live and feed together for
the greater part of their lives their work of destruction is very
thorough and every leaf on the branches attacked is often
completely devoured. Naturally, if there are several colonies
on one tree the foliage is wiped out, the fruit in consequence
cannot mature, and in addition to the loss of the current
year's crop the health oi the tree is so prejudiced that a crop
the following season is also unlikely.

Description and Life-History. — Lackey Moths come out
of their chrysalides at the end of July arid may be found from
August to September. They are brown moths one-and-a-
quarter to one-and-a-half inches in spread of wings, and of
the general shape shown in Figs. 6 and 7. The exact shade of
brown varies greatly, some moths being quite light- — almost
yellow-brown — and others a rusty red-brown, with all inter-
mediate shades. On each of the front pair of wings are two
light bars and the space between them is usually darker than
the general ground colour. As regards habits, the moths
fly only at night and the males (Fig. 6) are strongly attracted
by light, sometimes coming in numbers to lighted rooms or
to street lamps. The females (Fig. 7) are more sluggish.
After pairing, they lay their eggs on the twigs of the various
trees on which the caterpillars feed. TRe eggs (Fig. 1) are laid
together in a ring, a quarter to half an inch wide, which com-
pletely encircles the twig, the whole comprising a hundred to
two hundred eggs. These eggs are grey-brown in colour and
the mass is sufficiently large to be seen easily. The moths
die in September or earlier and the eggs remain throughout
the winter and hatch about the end of April.

The little caterpillars when first hatched are tiny, dark-
coloured, hairy creatures, but they soon develop a colora-
tion which becomes more brilliant as they grow. Their
.general appearance is shown in Figs. 2 and 3, and their colora-
tion is roughly as follows: — The ground colour is blue-grey:
down the middle of the back is a white line, on each side of
which are two broad orange-red stripes divided by a black line.
Then, lower down the sides is a blue stripe, followed again by
a third orange-red stripe (or a series of orange-red spots),
while the whole insect, except the head, is clothed in reddish
brown hairs. All markings are narrowly outlined in black.

In habits Lackey caterpillars are gregarious and live in
company for the greater part of their lives. When newly
hatched they spin between two or throe loaves a small silken
web a.nd as they grow they build larger nests by spinning to-
gether twigs and branches in a thick web of silk (Fig. 2). A

36

numerous colony may require a nest 1 ft. long and 6 inches
wide, a conspicuous object on the tree, especially when most
of its foliage has been devoured. The caterpillars shelter in-
side these nests buti they may often be found sunning
themselves on the outside, where they also cast their skins (as
they must from time to time when growing). Their fondness
for sunning themselves is also shown by their habit of lying,
many together, along any exposed branch.

Throughout their existence the pests feed voraciously, de-
vouring leaf by leaf, so that in some cases the tree is stripped
bare- of foliage and almost smothered in web. When full-fed
in the latter half of June or early July each caterpillar spins
a silk cocoon (Fig. 4), yellow or white in colour, between
leaves on the tree, on the trunk, on a neighbouring fence, or
among grass and other herbage. Inside the cocoon the cater-
pillar turns to a blackish-brown chrysalis (Fig. 5) from which
the moth emerges some three weeks later.

Natural Enemies. — Lackeys, in the egg or caterpillar
stages, are attacked by numerous enemies which consist chiefly
of such other insects as Ichneumonid, Braconid or Tachinid
flies. Sixteen or more kinds of Ichneumon fly have been found
to destroy them and at least two kinds of Braconids related
to those which parasitise White Butterflies (making the small
yellow cocoons so often found beside the dead or dying butter-
fly caterpillars). Lackey caterpillars do not seem to be readily
eaten by birds, but of course are subject to disease. It is
not yet known whether the sudden epidemics are due to a
temporary lack of natural enemies or to favournble weather
conditions, but it is clear at present the pest is riot always
kept in check by these means.

Control Measures.— 1. Spraying is effective if carried out
early enough, and also at any time if there are not many cater-
pillars on the tree. When, however, the whole tree is enveloped
in webbing it is impossible to get enough poison on to the
leaves to do any good. The best time to spray is within three
weeks after the dropping of the petals from the flowers. Lead
arsenate (1 Ib. paste to 20 gallons water) is the best insecticide
to use and the wash should be applied through a fine nozzle,
giving a light dressing to every leaf on the tree.

2. Nest Destruction. — In gardens with only a few trees
affected, the nests can be destroyed by hand, taking care that
caterpillars which fall do not escape. Nest destruction is also
necessary in orchard epidemics where spraying could not be
carried out sufficiently early. Sometimes the trees are first
banded with sticky material to prevent fallen larvae from
crawling up again, and in cases where the trees- are very high
shot-guns have been used to destroy the nests. Naturally
nest destruction is ruinously expensive in commercial orchards
but it has on several occasions beeri necessary to resort to it.

37

3, Egg Collection, — As the. egg-bands are not difficult to see
in winter they can be collected and destroyed. This has been
done systematically in times of epidemics but it is not a
measure which can be given much attention in normal years,
though workers should be instructed to look out for and destroy
every egg-band they detect when pruning trees. In small
gardens and on small trees it is quite possible to deal with the
Lackey wholly by this means.

WINTER MOTHS,

FIG. 1.— Winter Moth (Cheimatobia brumata). FIG. 2. — Mottled Umber
Moth and Caterpillar (Hybernia defoliaria) . Male Moth, winged;
Female Moth, wingless. All natural size.

The caterpillars of three species of moth do great damage to
fruit trees in the spring and -are among the most serious pests
with which the fruit grower has to contend. These moths
are the Winter Moth (Cheitnatobia brumaia, L.), the Mottled
Umber (Hybernia defoliaria, 01.) and the March Moth (Anisop-
teryx cescularia, Schiff). All three are sometimes known col-
lectively as Winter Moths.

Plants attacked and Nature of Damage. — Practically

every form of ''standard a>nd 'bush fruit is .attacked by these
pests as well as most forest trees and bushes'; indeed it would
be easier- to mention the kind? of plant not" attacked, (e.<j.,
•Conifers) than to list every tree or b,ush upon which one or
other of the caterpillars ca-cfclive. . -The nature of the injury
is also rather extensive-. Tin caterpillars appear early in spring
and feed during the entire period in which fruit trees are
making thrir' foliage,' :produ(liirig blossom or setting fruit, and
all may be injufM or in a seTJe'jre attack be practically destroyed.
The characteristic method ojj .feeding of the Winter Moth and
the March Moth is to spin together very loosely two leaves —
or a leaf to the side of a bl^om truss — and then to eat holes
in the leaf, attacking more |txr less indiscriminately the edges

38

and the centre of the leaf. In the case of the blossom truss
they may eat out the buds before these have opened and later
bite holes in the young fruit-let. If the leaves are not out when
the eggs hatch the young caterpillars burrow into the unopened
lea.f and fruit buds and do much harm in this way. In bad
attacks practically everything green on the tree has been de-
voured by the end of May and the orchards are as lea Hess as
they were in winter. Fresh leaves are produced later but the?
orchard is crippled for the year and possibly a.s regards crop
poduction for the year after us well.

The caterpillars of the Mottled Umber feed on the foliage
in much the same way as the above-mentioned species but
they do not so often spin leaves together rior are they so
inclined to feed upon the trusses of f nutlets or blossom.

Tog-ether with the Winter Moth caterpillars may usually be
found those of the Tortrix or Leaf-Boiler Moths which also
are very harmful. As these Tortrix pests cannot be controlled
by " banding " (one of the methods of dealing with Winter
Moths) it is well to know the difference between the two
groups, specially as both spin leaves together. The simplest
differences to observe are as follows. Winter Moth cater-
pillars in walking progress with a looping movement, clinging
to the leaf only by legs at the " head " end and claspers at
the " tail " end. Tortrix caterpillars crawl in the ordinary
way, lying flat on the leaf, while in addition they have the
very characteristic habit of wriggling rapidly backward if
touched in front.

FIG. 3.— Apple Shoot oeing eaten by Winter Moth caterpillars.

39

Description and Life-History of Winter Moths.

WINTER MOTH (Clieinmtobia brumata). — The Moths. — The
•male of the Winter Moth measures 1-l-fc inches in spread of
i'orewings, which in colour are grey-brown with numerous
darker wavy lines, the hindwirigs being grey without- markings.
From the middle of October to the end of December it emerges
from its chrysalis in the soil and may frequently be seen flitting
about orchards and hedges at dusk, later in the evening coming
to street lamps and other artificial lights. The female Winter
Moil; is very different in appearance from the male, having
finy shrivelled- up looking wings, so small that flight is not
possible. The body is large, the legs appearing long, thus
giving the insect a superficial resemblance to a spider, quite
unlike the popular conception of a moth. From the second
week in October onwards to December these female Winter
Moths emerge from chrysalides buried in the ground at the
Uist- of a tree (the result of infestation the previous spring),
crawl up the trunk to the small terminal shoots, and deposit
eggs upon them.

77? f Eyg. — The eggs are small, cylindrical, at first light
green in colour, but later becoming reddish, and are placed
singly or in small groups at the base of buds and on pruned
surfaces. From 100 to 200 are laid by one female.

77f.<> Caterpillar. — From the eggs laid by the moth in winter
the devastating caterpillars hatch in early spring, usually
about the middle oj March just before the bursting of the
buds. When first hatched they are grey with black heads
and are extremely small. As they grow and change their
skins they become green with white stripes and greenish
heads. As already mentioned they progress by " looping/'
having, like all members of the group to which they belong,
six true legs in front and but two pairs of claspers behind,
instead of the five pairs possessed by caterpillars of most other
groups of moths and butterflies.

They eat bud. leaf, blossom and young fruit, spinning leaves
and blossom heads together and living under the protective
covering thus formed. In May and June they become fully
fed. let themselves down to the ground by silken threads and
form chrysalides in the soil. Moths emerge from these chry-
salides in the following autumn and winter to begin the cycle
again.

THE MARCH MOTH AND THK MOTTLED UMBER. — For all prac-
tical purposes the life histories of these species resemble suffi-
ciently that of the Winter Moth to render separate treatment
unnecessary.

The March Moth- appears in the month bearing its name or
sometimes earlier. The male measures about 1| inches in
spread of the rather narrowish fore wings, which are grey-brown

40

with transverse bands, the hindwings being pale greyish white
with a darker zig-zag line running across them. The female is
quite wingless and brown in colour with a pencil or tuft of
hairs at the hind end of the body. The eg^s tire laid round
•the twigs in bands or rows and embedded in the clown or hairs
from the hind tuft of the female. The egg bands somewhat
resemble those of the Lackey, but are, of course, visiblv
smaller.

The caterpillar is yellowish green with a darker green line
down the back, edged with yellow, and there arc pale yellowish
lines at the sides. It is more slender than the caterpillar of
the Winter Moth, but is difficult to distinguish from it. The
pupal or chrysalis stage is spent in the ground in a similar
way to that of the Winter Moth.

. The Mottled Umber Moth is about twice the size of the
Winter Moth. The male has the forewiugs pale brown or
brownish yellow banded and mottled with dark brown as is
shown in Fig. 2, the hindwings being paler with a brown spot
near their middle. The female is wingless, the yellow brown
body having two dark spots on every segment.

The moths normally appear from the first week in October
to the middle of December, but occasionally are seen in
January or even February. The eggs are rather larger than
those of the two foregoing species, somewhat longer in shape
and rusty coloured. As many as 400 are deposited by one
female.

The caterpillar when full grown is much larger than those
of the Winter and March Moths and quite distinct in coloura-
tion, being chestnut brown (sometimes yellow brown) above
and yellow on the sides and underneath, with a wavy dark
stripe on each side of the brown. When full grown it descends
to the ground in a similar way to the other two species to form
a chrysalis. It is the caterpillar of the Mottled Umber which
contributes largely to the serious defoliation of oaks and other
forest trees which in some years is so noticeable.

Natural Enemies — The insects just described are subject
to the attacks of numerous insect parasites, and birds also
devour them in large numbers. It is possible that the fluc-
tuations in numbers which are so characteristic of Winter
Moths may in. part be due to the presence or absence of their
natural enemies, but in any case it is clear that the fruit-
grower, cannot depend on their aid for keeping the pesfs
sufficiently in check.

Methods of Control.— Winter Moths may be controlled
either by banding the trees in autumn to catch the
\vinglfss females as they ascend the trunks or by .spraying the
foliage in spring to kill the larvae. The former method, is
most in use and will be found effective in the case of standard

41

trees where the bands can be placed from 3 to 5 feet above the
ground. When the bands are placed low down, which is
inevitable in the case of bush trees, a number of the moths
usually find their way over the bands. How they do so is
not altogether clear, but there seems no doubt that the male
moths are able to carry the females for a short distance when
pairing. Moreover in the case of bush trees the process of
banding is somewhat troublesome and spraying is usually the
better method to employ.

Where trees are often attacked by larvae of the" Bud Moth "
(Hedya ocellana) or of other moths with winged females,
banding is not essential since it is then necessary to apply an
arsenical spray in spring which controls moth caterpillars of
all kinds including those of the Winter Moth.

(1) Banding. — The bands should be placed on the trees
at the beginning of October and should be kept in a " tacky '•
condition until April. Winter Moths appear between October
and January, but the majority are caught in November and
early December. March Moths emerge in February and
March, while during the latter month and in April the eggs
of the Winter Moth hatch. Since some of the latter are
likely to have been laid on the trunk of the tree below the
band, the young larvae must be prevented from ascending.

Various compositions for use in banding are on the
market and growers will learn by experience which
are best suited to their requirement. In general they
fall into two classes, (1) those of an oily nature, (2) those
which are sticky, like bird lime. The former are usually
cheaper to buy but must be renewed about three times
during the season, while the latter are more expensive, but
one application should be sufficient. Greasy compositions
must never be applied directly to the bark of the tree or
serious injury may ''• be caused. This warning also applies to
ma.ny of the " sticky" compounds, though it is said that
some of the latter are harmless. Unless the grower has
definite information as regards the particular compound he is
about to use, it is wise to protect the bark by means of a paper
band. Exceptions to this -rule are old trees with a very uneven
surface, since in these cases the paper band would not fit suffi-
ciently closely to prevent the moths from crawling underneath'.

A stout, grease-proof paper is usually used for banding
purposes and it should be noted that good paper, though more
expensive than bad paper, is the more economical in the end.
since it will retain the grease in good condition much longer.

The paper band should be .from 7 to 9 in. wide and should
be firmly tied round the tree 3 to 5 ft. from the ground, by
two pieces of string, each string being an inch or two from
the edge of the paper. The best methods of applying the
composition to the band naturally vary with the class of
substance used, but, in general, it should cover from 3 to 6

42

in. of the band and should be so applied as to form hori-
zontal ridges rather than a uniform smooth surface, since it-
will then remain sticky for ;\ longer period. Compounds which
are thin and liable to run should be applied mainly to the upper
part of the band so as to prevent the drops from running "off
on to the bark.

It is not always easy to make a neat job of applying the
adhesive to the paper bands. If the selected substance be of a
birdlime-like consistency the operator's hand is quite the best-
implement. The method is to " slap " the substance on to
the band and draw the hand round the circle. If using the
hands in this way be objected to, shaped pieces of wood may
be obtained for the purpose.

A good material will retain its sticky qualities for many
months, though it may be necessary to scrape the bands
occasionally to expose a fresh surface to the air. The bands
should be examined periodically to find whether they are still
sufficiently " tacky " to fulfil their object, and a fresh coating
of composition must be put on if necessary.

(2) Spraying. — Lead arsenate has been found most satis-
factory for this purpose. It is usually obtained in the paste
form. 4-5 lb. of paste being added to 100 gallons of water.
The spray should be applied as soon as the leaves begin to
appear (before the blossom opens) and, if necessary, a second
application may be made after the petals have fallen, but in HO
case should lead arsenate be used on open blossom, owing to
the danger of poisoning bees.

A nozzle giving a fine, misty spray is most suitable, and the
folia-ge should not be drenched so that the liquid drops off the
tips of the leaves. Lead arsenate may be used in conjunction
with either Bordeaux mixture or lime sulphur if it is necessary
io deal also witTi fungus diseases — as for instance Apple Scab •
(SPP Leaflet No. 131) or Brown Rot (see Leaflet No. 86).*

(3) Forest trees such as oaks should never be allowed to
overhang the margins of fruit plantations for Winter Moth
caterpillars will fall off the oaks and crawl up into the fruit
trees. As these caterpillars also feed on hawthorn and nut
bushes in hedges, the hedges should be kept well trimmed,
and it is a good plan to instruct workers when spraying with
lead arsenic to give also a light dressing to the hedges when-
ever they reach the end of a row.

* Obtainable from the Ministry and also included in Sectional Volume
No. 1, price 8d.

THE CODLING MOTH.

(C'ydia pomonella, L.)

FIG. 1. — Codling Moth, enlarged. Lines showing natural size.
„ 2.— Larva of ditto

,, 3.— Pupa of ditto „ .„ „ ,,

,, 4. — Section of apple showing work of larva, which has entered
at the eye, passed up the core by the burrow a, and is
leaving the fruit at side at the point shown by letter 6.

The Codling Moth is probably the most notorious of all
apple pests and is to be found in almost every country in
which apples are grown. The damage is caused by the larva
which burrows into the fruit and so produces the worm-eaten
or maggoty apple which must be familiar to everybody.

It must be noted, however, that there is a further pest, the
Apple Sawfly (Hoploc&mpa testudinea), the larvae of which
damage the apples in much the same way as those of the
Codling Moth, and it is very necessary to distinguish between
the two, since the methods of control in the case of the Codling
Moth are quite useless when employed against the Sawfly.
An account of the Sawfly will be found in Leaflet No. 205.
but the chief distinguishing features are also given below in
the sections " Description and Life History of Insect " and
' ' Nature of Damage. ' '

Description and Life History of Insect.. — The Codling
Moth measures from ^-f inch in spread of wings and ^ inch
from head to tail (tip of abdomen). The fore-wings are dark
grey with numerous waved brown lines giving the appearance
of watered silk. Near the end (outer margin) of the wings
is a brown patch which in certain lights has a coppery
metallic lustre, the most characteristic feature of the moth.
The hind wings are greyish brown often with a coppery tinge.

Codling Moths emerge from the pupae towards the end of
May and may be found for a period of about three weeks.
They fly at dusk and spend the day at rest on the trunk,
branches or leaves of the apple- trees, but are very difficult to
detect.

The female after pairing, .lays her. .eggs singly on the young
fruit and OLI the leaves, or twigs. The eggs are small — *fa jnch
in diameter- — aval and .very flat, appearing in fact more like
small shilling scales 'than the eggs of an insect. After a period
of 1U days or longer, according to the weather, the young-
larva ; leaves the .egg and crawls away until it reaches the
" eye " (or calyx) of the apple, through which, in the great
majority of eases, it gnaws a hole into the interior. As
an exception the larva may enter the apple at some other
point, but in this case it is usually when- two apples press
together or where one is in ' contact with a leaf. Having
penetrated into the apple, the larv,a attacks chiefly the core
and the neighbouring flesh, burrowing down the centre to the
pips, which are also.eaten.

After a period of three weeks to one month the larva is full
fed. It then measures from -|-f inch in length and is pinkish
or creamy white in colour with a brown head. It lias three
pairs of true legs and five pairs of " sucker " legs including
the clasper-like pair at the. "tail." There are therefore 8
pairs in all, and this feature will serve to distinguish it from
the Apple ' Sa'wfly larva, which has ten pairs altogether. In
general appearance the two larvae are different, Sawfly larvae
being often dead white and rather plump, while the Codling
lame are to some extent coloured and more slender, but these
features are not constant and cannot be relied on.

On becoming full fed the Codling larva burrows its way out
through the side of the apple, which may still be hanging on
the tree or may have dropped to the ground. In either case
the larva crawls away in search of some shelter in which to
spend the winter, and for this purpose it often chooses a crack
or crevice in the bark of the apple tree, though it may conceal
itself in a dead leaf or in any other rubbish near by. Having
ohosen its position it spins a silk cocoon in which it remains
as a larva until the following spring, when it changes into a
yellowish brown pupa. Very occasionally the larva pupates
m the summer and emerges as a moth in August, but this
second brood is rare in Britain, though it becomes normal in
the wanner climates of America. \Yhrn moths of a second
brood -are produced they give rise to larv;n which attack the
apples 'in the same wav as the first brood, though they often
enter thr> fruit through the side instead of through tho eye.
As in the case of the first brood they spin cocoons in which
to pass -the winter, pupating the following spring and
ing moths in duo course.

45

Plants attacked and Nature of Injury.— The attacks of

the Codling Moth are not confined to> the apple. Pears at times
suffer rather severely and the fruits of the quince, walnut, and
of various wild species of Pyrus may also be damaged, though
as regards these plants the pest is of little importance.

In the case of the apple. Codling Moth injury may usually
be distinguished from that due to Apple Sawfly by the fact
that the larva has entered through the eye and has confined
itself mainly to the neighbourhood of the core, finally passing
out by a burrow to the side. The Sawfly larva, on the other
hand, usually both enters and leaves the apples by holes at
the side (as opposed to the eye), while instead of attacking
mainly, the core region, it eats out a large irregular cavity in
the flesh. In the case of Sawfly attack the decay produced
is more rapid and the apple seldom attains any size, usually
falling in June or July.

Distribution and Economic Importance. — The Codling

Moth is an insect which has been able to adapt itself to prac-
tically every climate in which its chief host plant, the apple,
can be grown, and since it is easily carried in infected fruit, it
has now spread throughout the apple-growing regions of the
world. It appears to have been known to the ancient Komans,
and has certainly been long resident in Europe.

In Great Britain the insect is abundant in England and
Wales, and occurs in Scotland and Ireland. Descriptions of
its life history were made in the 18th century, and it is
probably an old inhabitant of these islands, though its numbers
have perhaps been reinforced by the introduction of larvae in
infested consignments of apples from abroad.

In Europe — that is to say, in countries in which it has long
been resident — it is always a troublesome pest, but its attacks
seldom attain the proportions which have marked its spread
through America, and Australia.

In the latter country, the moth has been made the subject
of special legislation with apparently good results. It is
impossible to give any estimate of damage done in Britain by
the. Codling Moth, since confusion so frequently occurs between
the" Moth and the Sawfly. Further, the Codling Moth is most
numerous in old orchards and gardens attached to houses,
where little attention is paid to its ravages. In large com-
mercial orchards it does not seem to be such a serious pest
as is sometimes supposed, and this is explained by the facts,
(1) that trees in modern orchards are kept very clean, (2) that
spraying is carried out if necessary, (3) that there is usually
qrily one brood in the year. In America, where the annual loss
from the Codling Moth has been estimated at no less than
£4.000,000, it is the occurrence of more than one brood in the
season which makes it such a dangerous enemy.

There are several insect parasites of the C.odling Moth, and
birds also devour great numbers of the hibernating larvae, '.but

46

it does not appear that these natural enemies are alone capable
of keeping the pest in check and recourse must therefore be
had to artificial measures of control.

Methods of Control.

A. — In Orchards where Spraying can be practised — (1) It
the trees are covered with moss and loose bark they should be
cleaned by means of an alkaline winter wash (see Leaflet
No. 7U,* The Renovation of Xt'-ylectrd Orchards). This will

the number of cracks and crevices in which they can spin
.their cocoons.

(2) The trees should be sprayed with lead arseiiate just
after the petals have fallen. It will be found that there is
a period of from 7-14 days during which the calyx cup,
subsequently the eye of the apple, is open, while later it
closes. The object in spraying is to force the arsenate into
the calyx cup, where it is retained after the calyx closes,
with the result that any Codling larva which attempts to
'burrow through the " eye " of the apple is poisoned. It is
useless therefore to spray too late, when the calyx cup is
closed, for then the poison cannot reach the point at which
ic will be needed, but it is also necessary to wait until the
blossom has completely fallen to avoid poisoning the bees.
A nozzle giving a fine spray is usually used! and the spray
should be directed as much as possible on to the young
fruitlets. 1 Ib. of lead arsenate paste should be allowed to
every 20-25 gallons of water, or the water may be replaced
by a similar quantity of Bordeaux Mixture if it is desired to
-control fungus diseases as well. The lead arsenate spray in
addition to checking the Codling Moth will also destroy any
'leaf -eating caterpillars, such as those of Winter Moths, which
may be present.

B. — In Orchards where Spraying is impossible. — (1) The
trees may be banded in Junef with old frayed sacking,
-folded paper or ropes of hay, If possible, two bands
4-6 inches wide should be used on each tree, one just below
the junction of the branches with the trunk and the other a
/few inches from the surface of the ground. The upper band
will catch those larvae which crawl down the branches, while
the lower will arrest those which fall from the tree and
crawl back to the trunk. A single band is fairly effective
and may be placed at any convenient height on the trunk,
which must be cleaned as far as possible (see Section 3 below).
The bands must not be made "sticky." The larvae on
leaving the fruit are likely to make their cocoons in the folds
of the sacking or in the hay, and the bands must therefore be
burnt in the autumn after the apples have been gathered.

* Obtainable from the Ministry.

I If bands are applied at the end of May or very early in June, they
will also trap Blossom Weevil.

1. SMALL ERMINE MOTH (Hyponomeuta padellus). 2. Egg mass.
3. Caterpillar. 4. Cocoons. 5. Apple ehoot with web.

2—47

47

(2) All fallen fruit should be picked up and disposed of
.in such a way as to kill any larvse inside. Attacked apples
should be separated from the others when they are picked
and if unfit for cooking should be given to the pigs or other-
wise dealt with so as to destroy any larvae which they may
.contain.

(M) All rubbish near the trees should be cleared away and
burnt. Without spraying it is often possible to clean the
trt-fs somewhat by pruning out all dead wood and scraping
•off loose bark and moss.

THE SMALL ERMINE MOTHS.

(Genus Hyponomeuta.)

The name " Small Ermine Moths " is given to a group of
little moths which are often of considerable importance to
the fruit grower. They are present in almost every orchard
or garden throughout the country, and where no steps are
taken to keep their numbers in check they are capable of
doing very serious damage. Outside the British Isles Small
Ermines are known as pests in practically every European
•country and also in Japan. Recently one of the more harmful
species has been introduced into the United States of America,
where efforts are being made to stamp it out.

Technical Note. — There are several species of Small Ermine
.Moth in the British Isles, but this leaflet is chiefly concerned
with one or more, which for the present may be dealt with
under the name Hyponomeuta padella L. and will include
forms often referred to in literature as H. malinella Z. and
H. ra-riabilis Z. It is doubtful whether the true H. malinella
has proved injurious in this country, though it is said to occur
on crab apple. A further species, H. evonymella (cogr.atelhi
Hb.), may also receive brief mention as it is sometimes most
injurious to spindle (Euonynms) hedges.

Plants attacked and Nature of Injury. — The Small
Ermine (H. padella) is most harmful to apple trees and haw-
thorn hedges, but it also attacks pear, plum, cherry, mountain
ash and other allied plants. The injury consists in the
destruction of the leaves by the Ermine caterpillars, which in
a bad attack completely defoliate the tree, leaving only bare
twigs and a few shrivellel brown leaves spun together by a
•dense web of silk. As a result, apples usually fall from the.
-trees when still young, and, although new leaves are produced
-before the end of the season, the trees are seriously weakened
and the chances of obtaining a crop the following year are
much reduced. The injury to hawthorn hedges (and also to
Euonymus hedges by H. evonymella) is similar, and while
"there is no loss of fruit, the leafless hedges in summer are
Tery unsightly; if the attack occurs for two or more years

48

in succession portions of the hedge are likely to die out. In
the, case of both apple and hawthorn the injury is at its worst
in' 'July.

Description and Life-History.— Small Ermine Moths are
about one-third of an inch in length and about three-quarters
of an inch in spread of wings. In colour the fore wings are
white or grey with a number of black dots* and the hind wings
are of a uniform grey. The moths appear at the end of
July and in August and lay their eggs on the twigs or small
branches of the apple or hawthorn. The eggs are flat and
are laid many together in .small scale-like masses, each egg
being firmly cemented to the next. These egg-masses are
so slightly raised above the surface of the twig and are so
nearly of the same colour that they are not easily detected.
In September minute caterpillars are hatched from the eggs,
but during the winter remain under the egg shells which
form a protection over them. In the early spring they crawl
out and bore into the buds and later mine into the growing
•leaves. As the foliage develops they feed on the surface of
.the leaves, spinning two or three together to form a nest.

Towards the end of May and in June the work of the
caterpillars becomes more evident, and colonies may be found
living in large webs spun between the leaves and twigs, the
leaves being eaten and fresh leaves drawn in to serve as food.
Gradually the whole branch or even the whole tree may
become enveloped in a dirty ragged web, and practically every
leaf may be devoured. Each -web appears to be full of little
black caterpillars which wriggle vapidly backwards and for-
wards., and if disturbed often fall down suspended by a silken
thread.

When nearly full grown the caterpillars measure about half
an inch in length and are dusky grey in colour with black
spots.

In July the caterpillars are full grown and spin cocoons,
often many together, in which they turn into chrysalides. The
motihs appear some three weeks after, and the life-cycle begins
-again.

1 The above account of the life-history refers in the main to
• tihfe Ermines on apple, hawthorn, plum, &c., but there are one
6r"'twb curious points which are worthy of mention. In the-
firist place the cocoons of the apple-fed caterpillars are formed
of dense white silk, and are often spun together in definite
rowW." On the other hand the chrysalides of the hawthorn-
f6eders are suspended almost at random in the webs and are
enclosed in very slight and flimsy cocoons which hardly serve
fo bide: the chrysalides. Secondly, the apple-feeders produce
hr higli proportion of moths with white fore wings, while those
•front1 hawthorn are either white or grey — more often, perhaps,,
the latter colour.

49

The facts are somewhat suggestive of the presence of two
distinct forms, and it is important from the practical point of
view that the matter should be decided. If there is only u
single species, then the grower who wishes to clear his orchard
should treat any surrounding hawthorn hedges a.s well as hit?
apples. If, on the other hand, there are two species, a severe
infestation on the hedges need not necessarily be regarded us
a danger to the apples.

The Euonymus-feeder in its life-history does not differ widely
from that just described, but the insect is quit-e distinct, and
indeed never feeds on either apple or hawthorn. The moths
always have pure white fore wings with very conspicuous
black spots, and are somewhat larger than those of the apple-
feeding species.

Natural Enemies. — Ermine Moths are attacked by a
number of species of Ichneumon Fly, such as Angitia majalis
Grav., and Herpestomus brunneicornis Grav., the larvae of
which feed inside the Ermine caterpillars. They are also
devoured by starlings and probably by other birds.

Methods of Control. — 1. The most satisfactory treatment
is to spray the affected trees or hedges with lead arsenate (1 Ib.
lead arsenate paste in 20 gallons of water) soon after the
blossom is over. The object is to cover the leaves with a fine
spray of lead arsenate which will sooner or later be eaten
by the caterpillars, and will poison them. It is useless to
wait until serious damage is apparent, for then not only has
considerable loss of fruit and foliage already occurred, but
also the dense web prevents the spray from reaching those
leaves which are left. Provided the webs are small, however,
and there is much clean foliage, it is still worth applying the.
spray, in order to prevent further injury. It is not certain
how early the spraying can be done, but it is probable thai/
many of the caterpillars will be destroyed even if the lead
arsenate is put on just before the blossom opens. In no
circumstances should the spray be applied to open blossoms.

Lead arsenate is poisonous to man, and must therefore.be
used with care.

2. It is possible — though it does not appear to have been
proved — that a winter wash would destroy the young larvae
under the egg scales. In addition to the caustic washes given
in the Ministry's Leaflet No. 70 (The Renovation of Neglected
Orchards), paraffin emulsions and miscible oils are worth a
trial. Miscible oils must be bought from a manufacturer, and
be diluted in accordance with his instructions.

A paraffin emulsion for winter use may be made as
follows : —

Paraffin 1 gallon.

Soft soap H-21b.

Water 10 gallons.

50

Dissolve the soap in boiling water, using up to 2 Ib. if the
.water is at all hard. Remove from the fire, and, while still
very hot, add the paraffin and mix thoroughly by syringing
the liquid back into itself with a hand syringe. Thorough
mixing is important if a good emulsion is to be obtained.
... Any .of the above winter washes should be sprayed on to
the trees so as to wet thoroughly the twigs and branches.

THE APPLE SAWFLY.

(Hoplocampa testudinea, Klug.)

1

The Apple Sawfly, though a serious pest in many parts of
the country, frequently passes unrecognised since the injury
it causes resembles in many ways that of the better known
Codling Moth (Cydia pomonella). (See Leaflet 30.) It is
necessary, however, to distinguish between the two insects
since some of the measures of service in the control of the
{Codling Moth are useless in the case of an attack by the Apple
Sawfly. The essential differences are, given under the headings
.'.' Description " and " Nature of Damage."

The Apple Sawfly is widely distributed in England and it
has been reported as injurious in parts of Scotland and Ireland.
In Continental Europe it has been recorded from Sweden,
Germany', Holland and France.

61

Description.— A dull Saw fly. —The general shape and
appearance of the adult may be seen from Fig 2. In colour
it is reddish yellow, with the top of the head, the thorax be-
tween the wings and the upper side of the abdomen, black.
It measures about £ inch in length and about g inch in spread
of wings.

Larva. — The form of the larva is shown in Fig. 3. In
colour it is usually white or cream, but, according to Theobald,
pink specimens sometimes occur. When first hatched the
head is black and there is also a black plate over the anal
(or " tail ") segment, but later the head becomes light brown
and the tail plate greyish. There are ten pairs of legs and
this character may be used to distinguish the Sawfly larva,
from that of the Codling Moth. In Sawfly larvae it will be
found that there are three pairs of true legs directly behind the
head, which are followed by seven pairs of " sucker" legs
including the- clasper-like pair at the tail. The Codling Moth
larva also possesses the three pairs of true legs but there are
only five pairs of sucker legs. The general appearance also
of the Sawfly larva differs from that of the Codling Moth and!
when the two larvae have once been definitely identified by the
character given above they will afterwards be known at a
glance.

Cocoon. — The larva pupates in the ground in a yellowish
silken cocoon to which grains of earth are attached.

Life-History. — The adult Sawflies leave the cocoons at
the end of April and in May, appearing during the period in
which the apple is in flower. They may then be found on
bright days sitting on the blossoms. The eggs are laid on the
iipwer bel6w the calyx, one egg only being placed on each
blossom. After a period varying from a week to a fortnight
the egg hatches and the young larva burrows into the develop-
ing fruitlet and eats out a large cavity in the interior (Fig. la).
This cavity communicates with the exterior by means of a
small hole through which wet frass exudes, thus indicating the
attacked fruitlets (Fig. 1). The larva may require more than
one fruit for its support and it may, therefore, leave the
original fruit on which the egg was laid and crawl away to
attack others. After from four to six weeks the larva is full
fed and it then leaves the tree and spins a cocoon in the soil
at a depth varying f rom 1 to 4 inches. The attacked fruits seldom
grow to any size, and the majority usually fall off in July.
Some of the larvae remain in the fruits until they fall, but most
have become full fed and have left before then. The pupae
normally remain until the following spring before the adults
emerge, though occasionally there is said to be a small second
brood in July.

Nature of Damage. — The actual loss in fruit is too
obvious to need further remark, but a note may be given as to

52

the distinguishing features between the injuries caused by
Sawfly and those due to Codling Moth. The Sawfiy ]arva
enters through the side of the apple and eats out a large
irregular cavity. The Codling Moth larva enters through the
*' eye " and tunnels down through the core, feeding mainly
on that portion of the apple ; it then mines a hole to the exterior
through the side of the fruit. The large irregular cavity is,
therefore, characteristic of the Sawfly, while the tunnel down
the core is usually the work of the Codling Moth. A further
form of injury attributed to the Sawfly consists in curious
ribbon-like scars sometimes found on the skin of the apple.
These scars are said to be made by the Sawfly larvae in their
efforts to bite a way in through the skin.

Methods of Control. — No practical measures for the

control of this insect have yet been discovered. Spraying with
lead arsenate or Paris green have been tried without success,
the failure being probably due to the fact that the larva enters
through the side of the fruitlet and not through the " eye."
In the case of the Codling Moth sufficient poison is retained in
the eye to poison the young larva. Deterrent sprays against
the adult Sawfly have not proved of much use. The measures
which have been found of service are as follows, but they
are suited to small gardens rather than to fruit-growing on a
commercial scale: —

(1) All attacked fruits should be picked off the tree and
destroyed before the larvae have left them.

J2) Poultry allowed to run under the trees during June
1 destroy the larvae as they go to the soil to pupate.
(3) By thoroughly working the soil under attacked trees
some of the pupae may be exposed to the attacks of birds while
others may be injured in the process or prevented from
emerging.

BARK BEETLES AND SHOT BORERS.

Fruit trees such as apples and plums frequently suffer from
the attacks of beetles which bore into their trunks, branches
and twigs, causing in the case of serious infestations the death
of part of or even the whole of the tree. The most common
species is the Bark Beetle (Scolytus rugulosus), but the Shot
Borer Beetles (Xyleborns dispar and X. saxeseni), though less
common, cause a more serious form of injury.

I. BARK BEETLES (Scolytus rugulosus, Eatz.),

Trees Attacked and Nature of Damage.— The fruit tree

most often damn^ed is the plum, but the beetles are also found

on apple, pear, cherry, apricot, peach and quince, and among

wild plants on Imwthoni, bird cherry and mountain ash. In

53

t-lie case of an infested plum tree it will usually be noticed
that some of the twigs or smaller branches -are dead and that
numerous holes — about the size of a No. 8 shot — have been
bored through the bark which peels off disclosing little
tunnels that have Been made between the bark and the wood
(Fig. 6). Further search will probably reveal twigs not yet
dead and with a few holes only. On peeling the bark off
such a twig fresh borings containing beetles or grubs according
to the season will be found. Twigs damaged in this way
usually die and the infestation, if it becomes serious, no
longer remains confined to the twigs but extends to the larger
branches and even to the trunk itself, channels being driven
between the wood and the bark, or in the latter only if very
thick. The entire tree may thus be killed. The nature of the
attack on apple and the other trees is substantially the same
as that on plum, though it more seldom assumes serious
proportions.

Description and Life-History.— The adult beetles are
brownish-black insects of the form shown in the illustration
(Fig. 5b). In size they vary considerably but are usually
about one-sixteenth of an inch' in length. During warm
weather in spring the beetles leave their burrows, flying away
in search of fresh trees to attack. On discovering a suitable
tree the female selects a twig or branch and bores a hole
vertically through the bark. It then turns and bites out a
tunnel or brood chamber ^-% in. in length along the branch
between the bark and wood, laying eggs on each side as it goes.
From the egg a small white legless grub is hatched (Fig. 5a,
much enlarged), which at once begins to burrow a channel of
its own, passing first at right-angles to the brood chamber and
then, when clear of the latter, turning to right or left up or
down the branch. The grub feeds on the inner bark jusfc
next to the sap wood and goes burrowing on until full-grown
when it bites a small chamber, usually just in the sap wood,
and changes to a pupa. After spending a period as a pupa,
it turns to an adult beetle and bores its way out through the
bark to the outside fc each beetle making its own flight hole.
The presence of many holes therefore shows that a brood has
already hatched out. Fig. 6 shows a piece of a small plum
branch of which most of the bark has been peeled away.
The very black tunnels are the brood chambers from which
smaller channels pass to right and left getting gradually larger
and ending at a hole underneath which is the pupal chamber
and through which the adult beetles reached the outside of
the branch. It is difficult to say how many generations there
are in the year, but there are probably two main broods,
the first appearing in spring and the second in summer. The
descendants (larvae) of the second brood may in hot summers
feed up rapidly and give rise to yet a third generation of adult

54

beetles, but most of them p rob ably feed more slowly spending
the winter in the twigs and producing the first brood of the
following year.

Other Species of Bark Beetle. — A slightly larger kind of
Bark Beetle (Scolytus pruni, Eatz.), though rare, is occasion-
ally found in old apple and pear plantations, working in much
the same manner as the one above ($. rugulosus), though
preferring the larger branches and trunk. It seldom seems
sufficiently numerous to be injurious. A further kind of Bark
Beetle (Scolytus destructor, Oliv.) is found on elms, to which
it may be most harmful. It is only mentioned here as the
question is sometimes asked as to whether infested elms are
a danger to fruit 'trees. So far as is known this is not the
case as the Elm Bark Beetle does not live in any kind of
fruit tree.

II. SHOT BORER BEETLES.
(Xyleborus di&par, Fab and X. saxeseni, Eatz.)

Trees Attacked and Nature of Damage. — Both species of
Shot Borer attack a great variety of trees including plum,
apple, pear, oak, sycamore, chestnut and (abroad) conifers,
but in this country the plum appears to suffer most injury.
In contrast to the Bark Beetles, Shot Borers work in the hard
wood, leaving the bark untouched except for an occasional
small circular hole showing where the beetles first entered.
In further contrast to the Bark Beetles is the remarkable fact
that both Shot Borers and their grubs feed primarily, not on
the wood itself but on a form of fungus which grows on the
walls of their tunnels (possibly also on the sap which oozes
into them). As the colonies of beetles are large in number
they naturally require extensive burrows and the damage is
correspondingly great, the wood being so tunnelled as to
weaken or even kill the tree.

The two species of Shot Borer may. be known. by the shape
of their borings. The common Shot Borer (X. dispar) always
makes circular Burrows such as might have been drilled with
a tool. The first hole is bored in through the bark and from
I to \ in. into the wood. It then turns to right or left round
the branch following a growth ring and from this burrow still
more are made passing up or down the branch parallel with
its length. The holes throughout are circular and of approxi-
mately the diameter of the beetles themselves. Fig 4 shows
a section of a branch cutting through Both vertical and
horizontal channels. In the other species — sometimes called
the Flat-Celled Shot Borer (X. saxeseni)--ihe .first tunnel
passing in through the bark into the wood is also round, but
once into the hard wood the burrows 'are extended up and down
so as to make large flat cavities or slits about one-sixteenth
of :an inch in depth and £-1 in. in length and breadth. Fig. 2

55

shows a section of a branch cut to show these cavities both'
from the side and from the top. Possibly on account of the'
size of these burrows, this species seems to prefer larger'
branches (or trunks) than the ordinary Shot Borer.

In both species the walls of the burrows are stained by the
fungus — black in the case of the ordinary Shot Borer, brown
or partly brown in the Flat-Celled Borer. In each case the
stains extend in the wood for some distance from the burrows
so that a branch cut off even at a point where it appears t<y
be sound may show a characteristic brown stain.

Description and Life-History.— (a) Shot Borer Beetle.
(Xyleborus dispar). The adult beetles are small black-brown.'
insects, the female (Fig. 3a) about J in. in length and the
male (Fig. 3b) much shorter. In spring the female bores
into the tree and lays eggs in the burrows. White legless
grubs are hatched from the eggs and feed on the fungus on
the walls of the borings, and also perhaps on the exuding sap.
On becoming full-fed these grubs turn to pupae and then tci
adult beetles, which may be found packed so tight in the

talleries (just like shot) that it is incredible how each beetle
nds enough to feed upon. These beetles again carry on the
work of lengthening the burrows in which the winter is spent.
It seems uncertain whether there is more than one generation
in the year. On the Continent two have been recorded, but
in England there is possibly only one main brood. Males are
very rare in the burrows except in winter when they may
outnumber the females. Unless therefore the females can lay
eggs without pairing, most of them would be forced to wait
until late autumn or winter before breeding.

(b) The life-history and appearance of the Flat-Celled
Borer (Xyleborus saxes eni)' is substantially the. same as that
of the Shot Borer but the beetles themselves (Fig. 1) ar^
much smaller and there is not the marked difference in size
and shape between the sexes. Again there is some doubt as
to the number of generations in the year, but as a rule beetles
of both sexes and grubs of different ages may all be found
together in the large flat brood chambers, and there may
well Be two broods each year.

III. METHODS OF CONTROL.

In the case of both Bark and Shot Borer Beetles, control
measures are preventive rather than remedial, and the same
remarks apply more or less to all.

1. There is no doubt that trees in an unhealthy state, either
because of the attacks of other pests or because of unsuitable
conditions, are preferred by the beetles, probably because they
are not hindered in their burrow-making By too free a flow
of sap. THus a Bad attack by Aphides or Brown Hot oh
plums, with the resulting weakening or death of twigs, is "very
likely to cause ah increased infestation by Bark Beetles. In

56

the same way trees planted under conditions which cause
them to suffer during a spring drought may fall victims to the
bhot Borers, which can obtain a foothold during the • time
when the trees are in a temporarily unhealthy state. It is
obvious, therefore, that the first line of defence is to keep up
* high standard of health by generally recognised measures.

a. Although the dying tree is in an ideal condition for the
beetles, it becomes unsuitable when it has died and the wood
has dried up, with the result that first the Borer Beetles and
then the Bark Beetles are compelled to desert it. The insects
must then seek other quarters, and if very numerous they may
be compelled to attack not only sickly but also healthy trees
which fall victims solely because their enemies are in such
overwhelming numbers. It is therefore most important to
cut down and clear away all dying and badly damaged trees
or branches, burning them even if it is necessary to use other
dry wood to avoid delay in destruction. Tf they cannot
possibly be burned they should be carted far away Irom the
orchard. The beetles will come out freely for some time from
trunks and branches left lying about, for such wood does
not dry sufficiently rapidly to kill the brood inside. The best
cime to fell is during the first 'half of autumn for the insects
will not leave during the winter and there is thus time to get
the wood burned. All infested wood should have been disposed
oi by March at latest.

3. In certain cases trapping may be useful against Shot
Borer Beetles. For instance after all badly affected trees or
branches have been burned, there may be left a number'
slightly attacked which it is desirable to save. In order to
give such trees as good a chance as possible beetles which
come out in the spring and are in search of fresh quarters may
be trapped. This should be done by providing them with wood
in an attractive condition — as for instance, freshly cut oak
posts or plum trunks (unaffected by beetles) which may be
available owing to thinning or replanting, with better varieties.
The use of the stumps from which affected trees have been
c-ut has also been advised for trapping purposes. Whatever
may be used the traps should be in position by March, and
should be removed and burned about midsummer.

4. Various preparations have been advised for brushing on
to the trunks and branches of trees attacked by Shot Borers.
They may either be of such a nature as to deter beetles from
beginning an attack or they may be intended to kill the fungus
in the burrows (upon which they feed). As the application of
these preparations is a difficult business in commercial orchards
and as the preparations themselves are more or less experi-
mental, no formulae are given here but thev can be supplied
if desired. It is suggested, however, that lime-wash properly
applied would have a considerable deterrent effect on beetles
in search of trees in which to start a burrow, and as such

57

reatment is valuable against several other pests, a trial wilk
ot in any case be wasted.

X

BARK BEETLES & SHOT BORERS.
[For Description of Plate, see next page.]

58
DESCRIPTION OF PLATE.

FIG. 1. — Flat-celled Borer (Xyleborus saxeseni, Batz.).

FIG. 2.— Wood showing flat cavities of the Flat-celled Borer in vertical
and horizontal section.

FIG. 3a.— Female and FIG. 3b. male of Shot Borer Beetle (Xyleborus
dispar, Fab.).

FIG. 4. — Wood showing circular burrows of Shot Borer Beetle in vertical
and horizontal section.

FIG. 5a. — Larva — much enlarged (after Ormerod)— of the Bark Beetle
(Scolytus rugulosus, Batz.).

FIG. 5b. — Bark Beetle (Scolytus rugulosus, Batz.).

FIG. 6.— Twig with portion of bark removed showing workings of the
Bark Beetle (Scolytus rugulosus, Batz.). The dark channels are
brood chambers made by the parent beetle. The smaller channels
are made by the larvas or young. (Fig. 5a.)

PLUM APHIDES.

I. LEAF-CUBLING PLUM APHIS.
(Aphis pruni, Keaumur.)

Nature of Damage. — The presence of this aphis is easih
recognised by the characteristic curling of the leaves (see
Fig. 1) which are often covered with sticky honey-dew. In
a bad attack the leaves die, the new growth is checked, and
the fruit is either undersized or falls off before it is ready to
pull. The aphides themselves live in the curled leaves.

Plants Attacked. — All varieties of plum and damson are
attacked, and also blackthorn, peach, apricot, and apple,
though to the last three little damage is done.

Life-History. — In the autumn small, shining black egg*
are laid on the twigs and at the base of the buds. Early in
spring — either in March or April, according to the district —
these eggs produce young, which grow into large purplish or
brownish " mother queen " aphides. The queens give rise
to living young, which at first are green, but when full grown
are often dark in colour. These aphides, which are also jof
the female .sex and are wingless, produce young in their tui'n,
and reproduction in this manner continues until late June or
July, when winged forms appear. The winged forms desert
the plums, but the plants to which they fly are not known,
with certainty, though Theobald has now traced them 'to
" Forget-me-not " both wild and cultivated. Winged forjns
again appear on the plums in autumn, and these give rise '10
males and females, the latter producing the .winter eggs.

Natural Enemies. — The plum aphis is attacked by lady-
birds, lacewing and syrphid flies, as well as by minute

Photo] [R. A. Malby.

LEAF CURLING PLUM APHIS.
FIG. 1.— Pluin twigs attacked by aphides. The upper leaves have been

curled by the Leaf-curling Plum Aphis ; the lower leaves show the

presence of a few Mealy Plum Aphides.

2—58

Photo'] [R. A. Malby.

MEALY PLUM APHIS.
FIG. 2. — Plum leaf (greatly magnified) attacked by the Mealy Plum

Aphis, showing winged and wingless forms and also cast skins. It

will be noticed that the leaf has not been curled.

2—59

59

hymenopterous parasites, but these natural enemies, do not
as a rule become very numerous until the aphis attack is at
its height. It must not be thought, however, that they do
no good, since by killing off vast numbers of the -aphides they
tend to prevent a severe attack the following year.

Measures of Control. — This aphis can be controlled by
spraying, but it is of the utmost importance to spray early in
the season. When the leaves have once been curled little
can be done. Lime- washes applied in late February or March,
have been found effective, the later applications giving the
best results. The aphides may also be controlled by means
of contact insecticides, such as nicotine and soft soap, quassia,
and soft soap, or paraffin emulsion, the spray being applied
just before the blossom opens or ; after the petals h,ave fallen,
but, in the latter case, before the leaves have been curled. A
close watch is required in order to discover the attack in its
early stages.

II. MEALY PLUM APHIS.
(Hyalopteru's pruni, Fab.) !> •

Nature of Damage. — Although serious damage is some-
times reported as being due to this aphis, it is, as a rule, far
less harmful than the Leaf -curling Plum Aphis. It is seldom
abundant on the plums before midsummer, and is found on
the underside of the leaves, on the leaf stalks and young
growth, but it produces no curling of the leaves (see Fig. 2).
It secretes abundant honey-dew, however, which, falling on
the leaves and fruit, may do considerable damage.

The insect may be recognised by its light green colour, by
the waxy or mealy secretion with which it is covered, and by
the fact that it occurs late in the season and does not curl the
leaves.

Plants Attacked. — This aphis attacks plurns of various
kinds, greengages, damsons, peach, nectarine, apricot, and
other species of Prunus. It is very probable that it also lives
on reeds and grasses.

Life-History. — The eggs of the Mealy Plum Aphis are laid
on the plum twigs in the autumn and do' not hatch until the
end of April or the Beginning of May in the following year.
" Mother queen " aphides hatch out from these/," eggs and
commence to give birth to 'wingless females which in their
turn give rise to additional wingless females. It is not until
the middle or end of June that winged forms are produced,
and while some of these probably migrate to grasses or reeds,
others only fly from one tree to another, ,, or .from one twig to

60

another. Those remaining on the plum are presumably re-
inforced in the early autumn by a return migration of the
descendants of those from grasses or reeds and these produce
egg-laying females which lay their eggs at the base of the
leaf buds and complete the life cycle. From the above it
will be seen that this species appears at a much later date than
the Leaf -curling Aphis, not usually being present in abundance
until after midsummer.

Natural Enemies. — The remarks under this heading on
the Leaf -curling Plum Aphis apply also to the present species.

Measures of Control.*— The best wash for use against the
aphis is said to be a paraffin emulsion containing liver of
sulphur.

Some washes fail owing to the fact that they cannot pene-
trate the mealy secretion by which the insects are covered.

III. HOP DAMSON APHIS.
(Phorodon humuli, Schrank.)

This aphis is treated fully in Leaflet No. 88f, and need only
be dealt with briefly here. It is found in injurious numbers
chiefly on the damson, but it occasionally occurs on other
plums. The life-history is briefly as follows : Eggs are land
on the damsons in autumn, and, on hatching in early spring,
produce aphides which live for 3 to 5 generations on the
damsons. Towards the end of May winged forms appear
which desert the damsons and fly to hops. There is a return
migration to the damsons in autumn. By sucking the juices
of the damson trees these aphides may do considerable damage,
while they are also the cause of the notorious hop blight. In
hop-growing districts, therefore, it is very necessary that the
aphis should not be allowed to multiply when on the damson.
The same measures of control may be employed as were sug-
gested in the case of the Leaf-curfing Plum Aphis-.

Spray Formulae.

I. — Lime Wash-l

Quick-lime 10-15 Ib.

Water 10 gal.

The best stone quick-lime is to be preferred, and the pro-
portion of lime to water should be as high as possible, having
regard to the nature of the spraying apparatus available. In
making up the wash sufficient water should be poured on to
the lime to keep it covered until it is slaked. After slaking,
the remainder of the water should be added, the whole well

*• Theobald, Insect Pests of Fruit, p. 385.
| Obtainable from the Ministry.

* Lees, Annals of Applied Biology, I, p. 351. Pether bridge, Jour. Bd.
A uric., Vol. XXI, pi 916.

61

mixed, and strained into the spraying machine. Lees advises
that the lime should be allowed to slake for from 6 to 12 hours,
before it is used.

If a lime-sulphur wash is required instead of plain lime
wash it is suggested that the concentrated solution should be
obtained from the manufacturers, unless it is to be used on a
large scale, when it may prove economical to make it locally.

II. — Nicotine Wash.

Nicotine, 98 per cent f-1 oz:

Soft soap ... ^-1 lb.

Water 10 gal.

The nicotine and soap are dissolved in the water. The
soap may be first mixed with a little hot water in order to
dissolve it more quickly. If the 'water used is at all " hard
1 lb. of soap will probably be needed to every 10 gallons of
the wash ; with rain water J- lb. will be sufficient.

Ill . — Paraffin Emulsion.*

Paraffin 1 pint.

Soft Soap. ... 1 lb.

Liver of sulphur (if needed) ..: 2 oz.

Water ..: 10 gal.

The soap should be dissolved in about 1 gallon of boiling
water and the paraffin added while the liquid is still hot.
The mixture should be thoroughly churned, preferably by
spraying it back into itself with a hand syringe. The
remainder of the water, in which, if necessary, the liver -of
sulphur is dissolved, should then be added, and after it has
once more been thoroughly churned the fluid is ready for use.
Unless the mixture is completely emulsified the paraffin is
liable to burn delicate foliage, and it should, therefore, be
prepared and used with care. It has, however, the very
marked advantage that the necessary ingredients are always
easily obtainable.

Formuke for making other " contact insecticides," such us
resin wash or quassia, may be obtained on application to the
Ministry. In certain circumstances it is convenient to use
a proprietary contact insecticide to avoid the trouble of pre-
paring the home-made washes.

* Lees (Annual Keport of the Long Ashton Kesearch Station, 1913,
p. 71) suggests this formula", but without the liver of sulphur.

THE OYSTER-SHELL SCALE.

(Aspidiotus ostreceformis, Curtis.)

FIG. 1.— Oyster- Shell Scale (female), 12£ times natural size. FIG. 2.—
Oyster-Shell Scale insect (male), 25 times natural size. FIG. 3. —
Oyster-Shell Scales in position on bark, 12$ times natural size. (All
after Newatead, Monograph of the British Coccidse, Bay Society,
1900.)

This, scale insect, which lives under a shield or covering
somewhat like a minute oyster-shell (Fig. 1), is widely dis-
tributed in Britain and is a pest which should be known to
all fruit growers.

Plants Attacked and Nature of Damage. — The Oyster-
Shell Scale attacks plum, cherry, apple, pear, peach, apricot,
and nectarine. It has also been found on currant and many
other plants, among which heather may be mentioned. The
scale insects live on the trunk, branches and twigs of the
tree, sucking up the sap, in consequence the tree is weakened
and in exceptional cases where the pests are very numerous,
twigs, branches, and even whole trees may be killed. This,
however, is unusual in commercial plantations, and as a rule
the Oy slier- Shell Scale is one of the many pests which do not
cause obvious injury and in consequence are overlooked.
Nevertheless, such insects are worthy of attention, for they
never cease their attacks, and by draining away the sap impair
the vitality and fruitfulness of the tree.

Description and Life-History. — The most obvious feature
to be observed in the case of trees attacked by the Oyster Scale
is that the bark appears to be dotted here and there with small
white spots or scars slightly larger than a pin's head. Each
of these spots shows the position formerly occupied by a scale
insect which has died and from which the scale or covering has
fallen off. Close observation will then show that on the

surface of the bark — trunk, branches, or twigs — :are numerous
minute greenish-grey scales like oyster shells about the same
size as the scars just mentioned (Fig. 3). The life-history
01 the insect which makes these scales is as follows : — In its
youngest stage when just hatched from the egg, the pest is a
minute and active louse-like creature which runs about on the
bark seeking for a place to settle down. In this stage it may
also be carried from tree to tree by clinging to other insects or
to the feathers of birds. On finding a suitable spot it drives in
its trunk and begins to suck the sap, at the same time losing its
power of moving about, and forming on its " back " a little
scale as a protection. It is in this stage that the winter is
:>assed. Once fixed, scales of the female sex, though growing
in size, never move away again. In the case of the male, the
full-grown or adult form is a winged insect (Fig. 2) which
comes out from under its scale in early summer and flies away.
The adult female scale, after pairing with a winged male, lays
eggs from which hatch the young " lice " mentioned above,
the life-history being thus completed. There appears to be
but one generation in the year.

Natural Enemies. — The Oyster- Shell Scale is much
reduced in numbers by the attacks of its natural enemies.
One specially valuable enemy is a jet-black " ladybird " with
two red spots on its wing-cases (Chilo corns). This ladybird
beetle which feeds on the scale may usually be seen crawling
about on the trunks of affected trees and it is often very
conspicuous on warm days in March and April.

Methods of Control. — (1) When buying young stock all
trees bearing scales or showing the characteristic littlfe white
^cars should be rejected unless the seller can guarantee that
the stock has been fumigated with hydrocyanic acid gas or
otherwise cleared of scales.

(2) The scale insects can be killed by thoroughly washing
the trees in winter with lime-sulphur at winter strength made
according to the following formula: —

Lime-sulphur (1.3 Sp. Gr.) 3 quarts.
Water ... 10 gallons.

The concentrated lime-sulphur (1.3 Sp. Gr.) solution may
oe bought ready-made. A strong paraffin emulsion or miscible
oil is also effective.

(3) In orchards which are well sprayed against other pests
Oyster-Shell Scale seldom develops sufficiently to become
troublesome. Any of the washes used for clearing the trees
in winter at the same time check the scale, while summer
Tvashes tend to destroy the young scales when settling down.
The freedom from injury by the Oyster- Shell Scale is one of
the benefits which the progressive grower can credit against
his spraying accpunt.

64

THE PEAR LEAF BLISTER MITE.

(Eriophyes pyri, Nalepa.)

The Pear Leal 'Blister Mite is a troublesome pest of the
pear tree and may do much damage, though the injury it
causes often seems to pass unrecognised. This is regrettable
since, as in the case of most pests, an attack in its early stage
is far easier to deal with than later when the infestation >s
bad.

The Pear Leaf Blister Mite occurs everywhere, but judging
by the records would seem to be more troublesome in the
southern half of the country than in the northern. The mite
is also a pest on the Continent of Europe and in America.

Plants Attacked and Nature of Damage. — The chief
damage is done to pear, but the apple is also occasionally
attacked, while among wild and garden plants, Mountain Ash
or Eowan, White Beam, Wild Service Tree and Cotoneaster
all suffer at times from the Mite.

The nature of the damage is much the same in each case,
but the following description refers to pear. When the leaves
(Fig. 2) of an infested tree have expanded in spring it wlil be
noticed that the upper surface of an attacked leaf is dotted
with small yellowish- green pimples, the underside showing
•corresponding impressions. These pimples or blisters are
usually more numerous on the half of the leaf on each side of
the midrib than towards the margins. In some cases the
blisters, while starting green in colour, scon turn pink or red.
Later the blisters become brownish, and the whole leaf often
turns black and dies in the latter half of summer. In the
cose of, trees badly infested the young fruitlets and their stalks
are also attacked, causing either malformation of the fruit
or — more usually — its death, and fall from the tree when
quite young.

Description of Pest and Life-History. — The damage is
•caused by a very minute mite — so small (less than 1/100 inch)
as to be invisible without the aid of a microscope. The
general appearance of the mite is shown by Fig. 1, and further
description is unnecessary as the pest will be identified^ by
the damage it causes and not by its structural characteristics.

The mites spend the winter under the outer bud-scales of
the buds. In spring they pass on to the leaves and burrow
into the under-surface, setting up the irritation which results
in the blister-like pimples on the leaves. In these^ blisters
tbe female mites lay eggs and the young feed within for a
period and then pass out through a minute hole on the
underside of the blister and burrow in at another spot, so
forming fresh blisters. Reproduction goes on throughout
the summer season, but before the leaf falls the mites move
again to the shelter of the young buds in which to spend
ihe winter.

PEAR LEAF BLISTER MITE.

1. — The Mite (Eriophyes pyri, Nalepa) (greatly magnified).
2. — An infested pear leaf, showing hlisters caused by the Mites.

2—64

65

Methods of Control. — (a) A look-out should be kept for
the first signs of the pest in an orchard or garden, ;vnd treat-
ment given at once before serious damage is done. Buyers of
young stock will find it worth their while to inspect prospec-
tive purchases before the leaves have fallen, and if mite is
discovered to go to another nurseryman. If this precaution
has not been taken, special care should be taken to destroy
Blister Mite at once in a young plantation as, if left for two
or three years, the chance of obtaining successful growth ia
greatly prejudiced.

(b) Spraying during the dormant season is satisfactory In
destroying the mites which are then under the bud-scales and
not so well protected as when in the leaves. The spraying
should be earned out either directly after the leaves have fallen
(about November) or just before the buds begin to open in
spring (about February). Either lime-sulphur or oil emulsions
may be used. Lime-sulphur should be obtained from the
makers and be mixed with water according to the makers'
directions for winter use. In experiments at Wye, Theobald
found that a lime-sulphur-caustic-soda wash applied in
November and February was more effective than either lime-
sulphur alone or paraffin emulsion. His formula for such a
wash, in addition to lime-sulphur, contains 1 Ib. of caustic
soda and 1 Ib. of soft soap to each 10 gallons. Oil emulsions
may be bought in the form of a miscible oil* which merely
requires dilution with water according to the maker's instruc-
tions. A home-made emulsion may be obtained as follows: —

Paraffin oil 1 gall.

Soft soap l£-2 Ib.

Water 10 gall.

The soap is first dissolved in about a gallon of boiling water.
The soap solution is then removed from the fire and the
paraffin at once added, the whole being well mixed by squirting
the liquid back into itself with a hand syringe. The strong
emulsion may be kept until required for use, when the remain-
ing nine gallons of water should be added and the whole
thoroughly stirred — or better, mixed as before with a hand
syringe.

(c) It is said that attacks may be checked by spraying in
summer with a weak oil emulsion, but in view of the success
obtainable by winter spraying a partial remedy is hardly worth
troubling about.

* Miscible oils may be taken as comparable to paraffin emulsions in
their action. They are so prepared as to emulsify at onco in water
without the addition of soap, but are not usually designed for summer
washes — only for winter use. The makers' instructions for mixing should
be taken.

66

(d) In the case of single trees in gardens, an attack may be
kept under control by picking off and burning attacked leaves
as soon as they can be recognised. This remedy is, of course,
only applicable where an infestation is noticed at once, and
not after two or three years, when the mites have become well
established throughout the tree.

THE PEAR MIDGE.

(Diplosis (Contarinia) pyrivora, Eiley.)

<HHOIi>

1. Pear stunted and malformed by the larvsB within it. 2. Section of
pear with larvae. 3. Larva, much magnified. 4. Female fly, much
magnified. Lines show natural length of fly and larva.

The Pear Midge is a most serious pest, for by attacking the
fruit itself, it directly reduces the profit, whereas many other
pests may be present in some numbers without seriously or
immediately affecting the yield of the crop. Fortunately it
does not attack all varieties of pears equally, and the later
flowering varieties may escape while early flowering varieties
of the William's " Bon Chretien " type are completely cleared
of fruit.

The insect was recorded as a pest in Continental orchards
by Kollar as long ago as 1837,* and it is supposed to have
Seen introduced into America about 1877 though there is
reason to believe that it was known in that country many
years before. Attention was first called to its occurrence in
England by Miss Ormerod in 1883, but the absence of earlier
records may well be accounted for by the lack of trained
observers, and the fact that the damage is very similar in its
effects to that due to weather and other natural causes. Of
late years it appears to have been steadily on the increase.

Nature of Damage. — The presence of this pest usually
first becomes evident from the rapid falling of the young fruit,
when about the size of marbles. In bad cases the whole of

67

the crop of a tree will quickly drop in this way. Upon exami-
nation the freshly fallen fruit will usually be found to be
deformed and much distorted, and often will be disfigured with
black patches of decayed tissue which may or may not havet
broken into cracks. Upon cutting open such an attacked
fruitlet, a blackened mass of pulp and excreta with a number
of the small whitish-yellow maggots (see Figs. 1 and 2) will
be found. Later the dead fruitlets become quite black,
shrivelled, and more or less hollow inside : even if the maggots
are absent these signs will show at once the presence of the
pest. It has been noted that an attacked fruitlet always grows
much more rapidly than a sound one and becomes deformed,
sometimes rounded, at other times bulged out at the side or
otherwise distorted. Consequently an attack may be noted
soon after the fruit has set. An internal examination should
always be made, as pears may become deformed from other
causes.

Description and Life-History. — The adult midge appears
in April, about the time the blossoms on early pears commence
to show signs of the white petals — usually about the middle
of April. It is, however, seldom noticed, being barely one-
tenth of an inch long and lives but a short time. Its general
appearance may be gathered from Fig. 4. The male is
blackish-grey to black in colour, clothed with pale yellowish
or white hairs and has long antennae. The female is dusky-
grey always paler in colour than the male, and its antennas
are shorter. It has a long ovipositor (when fully extended,
as long as or longer than the body) for the purpose of de-
positing eggs inside the pear blossom.

The eggs are laid by the female in batches of from ten to
thirty within the flowers, the unopened buds being pierced
by the ovipositor for this purpose. They are white, rather
long, pointed at one end and semi-transparent, and they hatch
in from four to six days.

The larvae maggots are footless, yellowish -white in colour
(Fig. 3). They make their way into the developing fruit
and in about five to six weeks are full grown and ready to
leave. By this time the decay in the interior of the fruitlet
caused by the presence of the maggots has usually reached
the outside at one or more spots, and on these spots the skin
soon cracks, allowing the maggots within to escape. Upon
reaching the soil the maggots burrow therein to a depth of
l|-2^ inches and spin a delicate silken cocoon about one-tenth
of an inch long, in which they remain for some considerable
time (in some cases apparently until the following spring)
before pupation. Should a young fruitlet remain intact ex-
iernally, the maggots are imprisoned, but sooner or later it
falls to the ground and subsequently decays, when the maggots
are able to escape and burrow into the ground. When mature

68

the larVae measure from one-seventh to one-sixth of an inch
in length. They are able, in common with other maggots
of the genus, to make a jumping movement which assists them
in escaping from the fruit.

Methods of Control. — 1. In small gardens, where only
bush fruit are grown, the best remedy is the hand-picking
and destruction of all infested fruit, with repeated shallow
cultivation of the ground beneath the trees in June and July.

2. In larger orchards great benefit has been derived from
stocking heavily with poultry in April, May and June, i.e.,
when the flies are appearing from the ground, and while the
maggots are leaving the fruit.

THE PEAK AND CHERRY SAWFLY.

(Eriocampa limacina, Cameron.)

Pear Slugworms are neither slugs nor worms but are the
young (or larvae) of a species of sawfly which is found
throughout most of the country, though complaints are more
frequent from the South than from the North, and relate more
often to gardens than to commercial plantations.

Plants Attacked and Nature of Damage. — Fears and
cherries are the fruits most often injured, but there are records
of the pests being found on apples, while hawthorns and
similar shrubs suffer from the attacks of the Pear Slugwonn or
allied species. The damage is done to the foliage and its nature
is characteristic, the leaf being eaten in sucH a way that only
the veins and the lower epidermis (or skin) are left. In bad
cases every leaf is treated in this way, and in place of green
foliage the tree is left only with shrivelled brown skeleton
leaves. Naturally under such circumstances the crop is unable
to develop, or if the attack does not occur till late in the
summer, the maturing of the fruit-buds for next season is
prevented.

Description and Life-History. — If leaves attacked as de-
scribed above are examined while there are still green areas
left, small, slimy, slug- like grubs, black or dark olive-green in
colour, will be found on the surface of the leaves. In shape
these slugworms are broad at the head-end and pointed towards
the tail, rather like young tadpoles, but underneath are the
legs and sucker feet of the typical sawfly caterpillar. The
origin of the slugworms is as follows : — At the end of May or in
June the adult, sawflies, blackish, four-winged insects of the
usual sawfly appearance, come out of their cocoons in the soil

2 -68

2—69

and the females lay their eggs in slits in the undersides of the
leaves of pears or cherries (like other sawflies, the Pear Slug
Sawfly has a saw-like apparatus at the end of the abdomen for
cutting slits in which to lay eggs). In rather less than a
fortnight the eggs give rise to young larvae, at first whitish in
colour, which force their way out from the upper surface of
the leaf and begin feeding, soon assuming the typical slug-
worm appearance. When full-fed the slugworms change to
orange-yellow caterpillars, in shape not unlike those of the
gooseberry sawfly. In this stage they do not feed but crawl
down to the soil and spin a cocoon within it, the outside of the
cocoon being stuck all over with particles of soil. In summer
the insect turns to a pupa within the cocoon and a fresh brood
of sawflies comes out in about a fortnight. There may be
two and possibly three broods during the summer, and the
larvae of the last brood, which feed in early autumn, remain
for the winter as larvae within their cocoons in the soil, turning
to pupae the following spring. Prom these pupae the -first
brood of adults appears in May or June.

Methods of Control. — (1) Slugworms are easily destroyed
by spraying. In the case of the earlier broods of larvae lead
arsenate is effective and can safely be used so long as the fruit
is not to be picked for six weeks after spraying. Later,
hellebore or nicotine wash can be applied up to fourteen days
before picking. The slugworms are not difficult to kill and
even soap and water applied with force is fairly effective.

Formula : —

(a) Lead Arsenate.

Lead arsenate paste J Ib.

Water 10 gallons.

(b) Hellebore.

Hellebore powder ... 4 oz. up to 1 Ib.

Water ... 10 gallons.

The powder is thoroughly mixed with the water and the liquid used
without straining.

(c) Nicotine.

Nicotine, 98 per cent. f oz. (fluid measure).

Soft soap 1£ Ib.

Soft water 10 gallons.

(2) Freshly slaked lime dusted on to the larvae is efficient
in gardens where only a few trees have to be dealt with and
the application can be made thoroughly. Some recommend
a mixture of soot and lime, but the latter alone is sufficient.

(3) Various measures, such as the removal of the surface
soil in winter from around trees which have been attacked,
have been suggested, also hoeing, digging, &c., but apart from
the questionable success of these measures, they do not seem
worth considering in opposition to such proved treatments as
spraying and dusting.

70

THE BLACK CURRANT MITE.

(Eriophyes ribis, Nalepa.)

The disease known as " big bud " in Black Currants caused
by the Black Currant Mite, was first recorded in these islands
in the year 1869, but according to Miss Orinerod it had been
responsible for losses in the district of Blantyre, N.B., for 20
years previously. Similarly Theobald* states that about the
same period it was known to the Maidstone growers. * The
original home of the mite, however, is uncertain. It has now
spread throughout Great Britain and Ireland, and occurs in
most of the countries of Western Europe. It has also been
introduced into Canada.

It has been scheduled as a destructive pest by the Depart-
ment of Agriculture for Ireland, where attempts are being
made to stamp it out, but this end does not yet appear to have
been attained.

The Black Currant Mite is undoubtedly the most serious
animal pest of the Black Currant, and its attacks have caused
a marked reduction in the area devoted to this fruit. In spite
of much careful research by numerous investigators, no really
satisfactory methods of control have yet been discovered, and
there is need for still further investigation. It is only necessary
here to describe the nature of the attack and to indicate the
lines of the treatment which have given the more hopeful
results.

Plants Attacked — Nature of Injury. — The plant which
suffers most seriously from the mite is the Black Currant,
but Red and White Currants and the Gooseberry are also
attacked. Owing to the difficulty in carrying out the necessary
experiments, it does not appear to have been proved that the
mites can pass from one species of host plant to another, but
it is highly probable that they can do so. The point is
obviously one of great practical importance.

The nature of the injury in the case of the chief host plants
is briefly as follows: —

Black Currant. — The developing buds are attacked and swell
until they are almost globular in shape and are about twice
the size of the normal buds — thus giving rise to the term
" big bud." Buds, if slightly attacked, may produce small
stunted and crumpled leaves, but as a rule they dry up and
die in early summer.

The natural result of this loss of buds is a progressive
decrease in the crop which may ultimately fail altogether.
In the case of certain old bushes, however, it has been noticed
that the number of " big buds " produced each year has

* Theobald, " Ingect Pests of Fruit," p. 232.

71

increased up to a certain point, bat subsequently has remained
stationary, and in spite of the attack a small crop is always
obtained. Notes on the resistance to the disease shown by
some varieties or individual bushes of black currants will
be found in the section on Methods of Control. Owing to
the fact that the extent of this resistance is so variable, no
list of resistant varieties is given. Young bushes frequently
appear to resist attack for 4 or 5 years but subsequently break
down, and a variety should not be judged until it has been
tried for a considerable period.

Red Currant. — Theobald* states that " the mites produced
a dense growth of buds, every here and there, which were
found to be teeming with them. At the same time the shoots
bearing the attacked buds were abnormally swollen, many
twice the thickness of normal ones.*'

Gooseberry. — In the case of the Gooseberry the noticeable
features of the attack concern the young shoot, soft tender
leaves, and to some extent the fruit blossom. The mites
cause a marked blistering and, according to Miss Taylor,!
" after a bad attack the whole leaf surface, the veins and
the petiole become covered witn succulent outgrowths."
" Leaves so attacked are considerably under the normal size
and the main stem itself is reduced in length. The leaf colour
is yellow green and the tree has a generally unhealthy colour."
Obvious injury only occurs early in the season — later, when
the leaves and shoots harden, no further damage is done and
the later- formed leaves are normal in size.

The reason for the difference in the form of attack on the
three plants would seem to lie in the nature of the buds.
The black currant bud is somewhat loosely made, and hence
the mites can penetrate to the centre. In the red currant
and gooseberry the buds are tightly compressed and the mites
cannot work their way in.J

Description and Life-History. — The general appearance of
the mite when highly magnified is shown by Fig. 2, but the
animal is only about T^F inch in length, and if a big bud is
cut open, the mites are hardly discernible to the naked eye ;
even through a pocket lens they appear only as minute white
specks.

From July throughout autumn and winter and until
March the mites live mainly inside the buds, where eggs are
laid and fresh generations are produced. During a period
covering roughly the months of March, April, May and June
the diseased buds either dry up and die, or produce distorted
foliage, and the mites are forced to migrate to fresh quar-
ters. When weather conditions are favourable — that is to say,

* Theobald, *' Insect Pests of Fruit,1' p. 241.

•f- Taylor, Journal of Agricultural Science, VI, p. 131.

+ Taylor, loc. cit., p. 133.

on sunny days with some wind*— the mites crawl out of the
buds and stand erect on the outside of the bud. They then
either "jump " or are blown off by the wind, which is capable
•.i-r' carrying them, probably, for a considerable distance. The
mites may also migrate by clinging on to insects which settle
on the affected bushes, and may travel for short distances on
the twigs by crawling. Naturally in this process of migration,
in which chance plays so large a part, very many of the mites
can never reach an appropriate food plant, but so enormous is
the number of mites produced — Miss Taylor calculates that
under favourable conditions 1,000 mites may leave one bud
in an hour — that sufficient reach fresh currants to carry on
the attack in spite of all losses. After migration, but before
the new buds are large enough to enter, the mites live at the
bases of the leaf stalks, between the developing buds and the
stem and among the young leaves at the growing points of the
shoots. When the buds are sufficiently large, that is to say
about July, the mites enter into them and reproduce, causing
the well-known " big buds."

Natural Enemies.— Black Currant Mites are attacked by
the larva of a minute parasitic insect (Tetrastichus eriophyes)
and by a parasitic fungus (Botrytis eriophyes). They are
also preyed on by other mites and insects. The reproductive
powers of the mite, however, appear more than sufficient to
counterbalance all losses in this manner.

Methods of Control.— 1. As has already been stated there
are no entirely successful measures for combating the Black
Currant Mite, and badly affected bushes should be grubbed,
up and burnt. In replanting it should be remembered that
•adjacent red currants and gooseberries may be attacked; and
it is, therefore, better to choose a fresh site for the young
bushes. It should hardly be necessary to point out that stock
showing big buds should never, in any circumstances, be
purchased or planted, but experience shows that this error
is still sometimes committed. Similarly, cuttings should never
be taken from diseased bushes, unless they are required for
some special purpose, in which case they should be dipped
for ten minutes in water heated to a temperature of 115° F.,
M treatment which appears to kill the mite in all its stages.!

In order to obtain cuttings entirely free from mite, GoudeJ
recommends that soft cuttings should be taken in April — May,
and after being dipped for one hour in a nicotine insecticide
(nicotine 98 per cent. •!• oz., soft soap 4 oz., water 5 gallons)
and then rinsed in clear water, they should be stuck in a cold
frame.

* Taylor, loc. cit., p. 121, et seq.

I Spencer Pickering and F. V. Theobald. " Fruit Trees and their
Enemies, with a Snraying Calendar," p. 81.

\ Goude, Jour. Mm. Agric.. p. 460, August. 1921.

73

With reference to the different varieties of Black Currant,
certain forms have been claimed to be immune, but further
evidence is required as to this supposed immunity, which
too often breaks down. It is often observed, however, that
in a plantation where several varieties are grown some are
more subject to attack than others, while occasionally almost
free bushes are found in close proximity to plants badly
diseased. There is, undoubtedly, much variation in the
[lowers of resistance shown both by different varieties and by
different individuals in each variety, and the establishment of
a- highly resistant race does not seem impossible.

2. In gardens, attacked buds should be destroyed as soon
as they can be detected so 'as to kill the mites before the period
of migration. In commercial orchards, if many of the bushes
are affected, it may prove impracticable to collect " big buds,''
but when the mite first appears in a previously clean plantation
the twigs carrying diseased buds should be removed and burnt.
If only one or two bushes show signs of attack it is better
to remove and burn the whole bush. It might be thought
that in the case of a bad attack cutting the bushes to the
ground would prove a complete cure, but this has not proved
to be the case, though it is not known how the fresh shoots
become infested. Success has been claimed, however, for
certain systems which are based on drastic pruning of thi?
nature. The bushes are planted much more closely than usual,
and then either (1) every alternate bush is annually cut to the
ground or (2) the whole of the old wood is removed immediately
after the fruit has been gathered.

3. Some growers appear to have obtained considerable suc-
cess by applying dry or wet " sprays," while others have
reported a complete failure. Treatments of this nature are
open to the objection that the mites are only affected by them
when on migration, and, as the migratory period extends over
three months, it is necessary to spray or dust several times.

The dry spray treatment, originally suggested by Collinge,*
is, perhaps, in more general use than the wet spray. It con-
sists in dusting the bushes four times with ground quick lime
and sulphur, at intervals of a fortnight, beginning at the
end of March. The first dressing should contain only 1 part
of quick lime and 4 parts of sulphur, the second!, 1 part of quick
lime and 8 parts of sulphur, and the last two dressings, sulphur
alone. Eisk of burning is lessened by using slaked lime
instead of quick lime, about equal quantities of lime and
sulphur being allowed. The powder should be applied when
the bushes are damp, and it is best distributed by means of
one of the machines made for the purpose.

* Collinge, " A Marraal of Injurious Insects, pf . 240, 241.

74

4. Xo suggestions are made for the control of the Black
Currant- Mite on other host plants. The attacks either appear
to be rare or, more probably, are overlooked.

RED SPIDERS.

BED SPIDER (greatly magnified).

The pests so well known to horticulturists as " Red
Spiders " are in reality mites and belong to the group which
includes the Cheese Mites, Gall Mites, and similar pests.
They comprise a number of different kinds, all very much alike
but fortunately the precise differences between them are not
of vital importance from the practical point of view. It will
therefore be sufficient to note that there are two sections of
which one, characterised by the Gooseberry Red Spider
(Bryobia), spins little or no web, while the other, of which the
Greenhouse Red Spider (Tetranychus) is typical, usually spins
a fairly thick silken web. Naturally the kinds which make a
thick web are more difficult to kill by spraying than those
not so protected and the difference is therefore worth observing.

Plants Attacked and Nature of Damage. — The injury to

^onsob'MTies and hops arid to plants under glass such as vines or
cucumbers, is perhaps of most importance, but Red Spiders
are also found on most fruit trees, many flowering plants
(e.g., violets), and a number of trees and shrubs such as
the lime, gorse and ivy.

The injury in all cases is done by the feeding of the Red
Spiders, both young and old, which bite into the leaf, usually

75

on the underside, and suck the sap. The leaves in consequence
become sickly and show a more or less marked change of
colour, turning first yellow and then — in a bad attack —
greyish white. In the latter case the leaves die and the fruit is
unable to mature. Gooseberries suffer chiefly in the spring
and early summer, but attacks on plums and apples occur
later, often towards the end of the growing season, when pre-
mature leaf-fall may be caused. In these cases the leaves
sometimes take on a rusty colour instead of yellow. Green-
house plants may suffer at any time when in leaf. Dry condi-
tions are likely to cause attack both under glass and outside.

Description and Life-History.-— Bed Spiders themselves
are little red creatures, considerably smaller than the head
of the average pin. When adult they have four pairs of legs,
a short rounded body and a mouth formed for biting and
sucking. The Eed Spiders of apples and other " top " fruit
spend the winter in the egg stage, the eggs — brilliant crimson
in colour — being often crowded together on the twigs. These
eggs hatch in early spring and the mites feed and breed
throughout the summer in the leaves, eggs again being laid
on the twigs in or before autumn.

The Gooseberry Eed Spider seems to be less definite in its
mode of spending the winter. Doubtless a number pass
through in the egg stage but others hatch earlier, and both
eggs and mites may be found on the bushes in winter. In any
case the mites have left the eggs by the time the buds unfold
and they feed and breed in the foliage. As a rule their activity
does not extend beyond midsummer.

The Greenhouse Eed Spiders and the Hop Eed Spiders,
differ from those mentioned above in that they spin — chiefly
on the undersides of the leaves — fairly thick silken webs
among which they live and lay their eggs. They spend the
winter partly in the egg stage but also largely as young mites
which shelter in crevices of the bark of vines and other fruit
trees, in cracks in woodwork, or in the case of hops on the
poles, on trees, or under stones and clods.

Methods of Control. — (I) Spraying. — lied Spiders on fruit
trees are controllable by spraying, but as in the case of almost
every pest the work must not be put off too long or the damage
will already be past repair. Never should the foliage be
allowed to turn to the silvery-grey colour before the work
is put in hand. In the case of gooseberries a tendency in
spring to lose a healthy green colour should be regarded with
suspicion and leaves should be examined with a magnifying
glass in order to see if Eed Spiders are present. An in-
expensive glass is quite good enough for the purpose and
will have many other uses in the control of pests. Spraying
when necessary must be thorough so that the leaves are
thoroughly wetted.

76

Of spray fluids for the destruction of Eed Spiders, sulphur
compounds or paraffin emulsion are those usually recom-
mended. From the former class, potassium sulphide is the
standard insecticide but in the case of gooseberries lime-
sulphur would seem to answer the same purpose, and can
be used simultaneously against Red Spider and American
Gooseberry Mildew. Paraffin emulsion compounds have fallen
to some extent out of favour, probably owing to occasional
foliage injury. Paraffin jelly has, however, been found very
effective by Theobald* (Wye Agricultural College).

In the case of the Greenhouse Red Spiders which make
thick webs, special precautions have to be taken to ensure
proper wetting and Lloydf (Waltham Cross Experiment Station)
states that he finds flour paste very effective for the purpose,
having the advantage of causing no hardening of the foliage
in cucumbers, a marked defect in the case of solutions con-
taining soap. Flour paste has also been used for the control
of Red Spider in the U.S.A. even without the addition of a
sulphur compound, and it is probable that the addition of it
to all sulphur washes would be beneficial, even when they are
required for outdoor use. Formulae for preparing the various
washes are given below with the exception of lime-sulphur
which is fullv described in Leaflet No. 195 J on American
Gooseberry Mildew.

FORMULA.

fa) Potassium Sulphide (Liver of Sulphur) Wash. (Original
Formula.)

Potassium sulphide ... ... 5 oz. -

Soft soap ... ... ... $• lb.

Water 10 gall.

In preparation the soap and potassium sulphide are dissolved
in the water.

(b) Potassium Sulphide (Liver of Sulphur) Wash. (Lloyd's
Formula.)

Potassium sulphide ... ..» 1 oz.

Flour ' H oz-

Water 2 gall.

" Place 14 pints of water in a bucket and add 1 oz. liver
of sulphur which will completely dissolve while the flour paste
is being prepared. Make 1£ oz. ordinary wheat flour into *
smooth paste with a very little water. Add water to 2 pints

* Insect Pests of Fruit. F. V. Theobald.

f Circular (Vol. 1. No. 6) Lea Valley and Bist. Nurserymen &

Obtainable from the Ministry and also included in Sectional Volume
No. 1, price 8d.

77

till the mixture is as thin as milk and as free from lumps
Boil this until it froths up, stirring it all the time. Add it tu
the solution of liver of sulphur and mix thoroughly. Apply
with a hand or knapsack sprayer and wet the plants all over.
The flour paste must be used the day it is prepared, and any
mixed spray remaining at night must be thrown away."

(c) Flour spray (U.S.A. formula).

One pound of flour is made into a " batter " with a little
water, and is then mixed with 1 gallon of water. The mixture
is heated until a clear paste is formed. For spraying, 8 gallons
of flour paste are used in 100 gallons of water.

(d) Paraffin Jelly (Theobald's formula).

Paraffin 5 ga!L

Soft soap g Ib.

Boil the soft soap and paraffin together and, when boiling,
add 1 pint of water and stir well. This becomes a jelly on
cooling; add 10 Ib. of this jelly to every 40 gallons
of water.

CAUTION. — Owing to possible danger from fire the boiling
should take place out of doors and away from buildings.

(II) Moisture. — Apart from spraying, which will deal with
all fruit crops, the chief means of controlling Red Spider is by
keeping the plants sufficiently moist. Red Spider attacks are
specially likely when plants have even temporarily become too
dry. Cold water sprayed on alone has been found of great
assistance.

CURRANT AND GOOSEBERRY APHIDES.

Currant and gooseberry bushes are often considerably
damaged by Aphides or Plant Lice. In some districts bushes
may be quite ruined; the leaves turn brown and shrivel up
and the fruit falls off. Long spells of dry, warm weather are
very favourable to the development of the insects. As Aphides
are usually more or less prevalent on the bushes, and as
favouring natural conditions may result in their increase to
overwhelming numbers, attempts should be made, especially
in autumn and in spring, to destroy them.

An interesting feature in the life-history of these Aphides
is that only part of their life is passed on the currant and
gooseberry bushes. At certain times of the year they migrate
to other kinds of plants, returning as winged individuals in
autumn or the next spring. All the species affecting the
currant and gooseberry feed above ground except one found
on the currant which feeds on the roots.

The bushes are affected in various ways. The leaves may
show marked blisters, green, yellow, and red in colour, under
cover of which the insects feed. The leaves curl up and hang
down and form rosettes and the attacked shoots remain short

78

and become bent and hidden by rolled up curled leaves. The
fruit fails or falls away owing to the destruction of the leaves.

Theobald writes of nine species found on the genus Ribes ;
of these four may be mentioned here.

Aphis grossulariae, Kalt. — Is found on the currant and
gooseberry from May onwards. Later it leaves these plants
to fly to other species, but the complete year's round of life
is still in doubt. On the currant and gooseberry this Aphis
attacks the leaves and the young wood. The leaves get
crowded together and overlap and the Aphides are thus
sheltered from any spray applied too late.

Winter is passed on the currant and gooseberry in the egg
stage. The eggs hatch and from April onwards the wingless
females are found on the under surface of the leaves which
show green, yellow, and red blisters. The winged individuals
appear in summer and fly to the lettuce; they have also been
found on nipplewort, sow-thistle, and guelder-rose. The return
to the currant and gooseberry takes place in autumn.

Myzus ribis, Linn. — This species is found on the currant
and gooseberry from May to July. It gives rise to blisters
on the leaf, as with the previous species, and it often causes
the leaves at the apex of the shoots to curl. Winged females
migrate in late summer but details are lacking.

Macrosiphum lactucw, Schrank. — This species found on
red and black currants migrates to the lettuce and other
composites at midsummer and returns to the currant in the
autumn.

Methods of Control. — Aphid attacks on gooseberry or
currant are not easy to deal with, for until the injury becomes
apparent the presence of the pest is seldom realised. Early
spraying, before leaves have become curled or shoots distorted,
is effective and any good contact insecticide, such as nicotine
and soap or paraffin emulsion, may be used (for formulae see
Leaflet No. 308, Plum Aphides). • When (in small gardens)
young growth is attacked at the tip, it is often better to bend
over the shoot and dip the tip into a vessel of insecticide
instead of spraying, as by the latter means it is difficult to wet
aphides in a "rosette." Primings should always be burned.

THE CURRANT BOOT AND ELM LEAF APHIS.

Schizoneura ulmi, Linn. — This species, in summer, is
found on the elm where it causes a very marked curling of the
leaves. Winged individuals in late summer and autumn leave
the elm and distribute themselves over a number of different
species of plants, amongst which are the currant and goose-
berry. The insects infest the roots and are then covered by a
woolly material like that of the WToolly Aphis of the apple. A

79

migration back to the elm takes place sometimes in the same
autumn, but more commonly in the next spring. It is probable
that this insect is more prevalent than is generally supposed
and that its presence is associated with a reduction in the
growth of the bushes. In the present state of our knowledge
it is impossible to speak definitely on the subject, to which,
however, attention should be given as it may prove of consider-
able importance to currant growers.

In the present unsatisfactory position as regards soil fumi-
gants, little can be said as to methods of control. When a
consignment of young stock for planting is found to be
infected, dipping the roots in an insecticide should be tried.

THE BROWN SCALE.

(Lecanium persicae, Geoff roy.)

.... — . _ . . .__ i

Photo'] [R. A. Malby.

FIG. 1. — Brown Scale on Peach Twig (slightly magnified).

This insect or its variety L. ribis Fitch is found in great
abundance on the gooseberry, currant, peach and nectarine,
and also on a number of other cultivated and wild plants. It
has a decided preference for the older branches, the young
shoots being attacked only when the insects become over-
crowded. As a rule it is much more prolific on plants grown
in sheltered spots, especially on wall-trained trees in a fairly
sunny aspect, and peaches and nectarines in houses often suffer
severely.

The Brown Scale is very generally distributed throughout
England, but is less known in Wales, Scotland and Ireland.

Description and Nature of Damage. — The mature female
and old dead females are easily recognised as brown " scales,"
a little longer than broad, flat beneath and highly^ convex
above (Fig. 1). At first these " scales " are dusky yellow
with darker transverse bands, but become darker with age
until they may be light reddish-brown to dark chestnut-

80

coloured- There is usually a clearly defined central ridge
with many grooves running therefrom to the sides. (The
var. ribis is rather more circular in form, has the transverse
bands more distinct in the early stage, and is of a rather
brighter reddish-brown when mature.) The insects leave a
distinct pale scar when removed from a twig. Bushes or
trees infested with these pests seldom bear much fruit, and
the leaves ripen and fall much earlier than on clean bushes,
both results being due to the drain on the vitality of the plant
by the persistent sucking up of the sap.

FIG. 2. — Larva magnified about FIG. 3. — Underside of young

50 diameters, (m), mouthparts.

female magnified about 15 dia-
meters, (c), channels leading
to respiratory tubes (stigmata).
Cm), mouthparts.

Larva. — The young larvae (Fig. 2) are quite minute, about
the size of a large cheese mite, which they somewhat resemble,
except that they possess but three pairs of legs, have rather
long antennae, and two bristles at the end of the abdomen. The
mouthparts (Fig. 2m) form a sucking tube with which the
insect pierces the bark, and through which it sucks up the
juices of the plant.

Male. — The male of this insect has not yet been discovered,
and there can be no doubt that the females are able to repro-
duce their species without the intervention of the opposite sex.

Life-History. — The female begins to lay her eggs (usually
during: the latter half of summer), while the body is yet soft,
and distended; and as the process develops the under surface

81.

of the insect shrinks, so that a relatively large cavity is
formed beneath the insect which is filled with hundreds of
whitish translucent eggs. At this stage the insect dies and her
dead body, the so-called "scale," forms a protection for) the
eggs, and for a short period also for the young larvsB or " lice. "
in autumn the young escape from beneath the dead parent
chiefly through the little slit or cleft at the posterior extremity,
leaving behind them the white egg shells and a little white
mealy secretion.

The larvae usually fix themselves under the partly detached
or curled- up portions of the bark, so that they are often com-
pletely hidden, and in this way pass the winter without any
material change. They are then of a reddish-brown colour,
and so small that they are not easily seen. In spring they
cast their skins, and may become active for a short period";
in June they become adults and the cycle commences again.
The old " scales " or dead females may, if undisturbed, re-
main attached to the host plant for a very long period — two
or three years in some instances; it often happens, therefore,
that the representatives of two or three generations may occur
on the plant at the same time.

In the open in this country the Brown Scale is usually
single-brooded, but under exceptional circumstances two or
even three broods have been noted within a year.

Remedies and Methods of Control. — This scale can be
best controlled by winter and by spring washing. It should
be borne in mind that it is the lame or young insects which
are found living during the winter months ; and as they are
very minute aiid often protected by the semi-detached bark, the
spraying must be thorough or the result will not be satisfactory.
Care must also be taken to ensure that the under sides of
the branches are well sprayed, as the insects are usually more
abundant in such situations than on the exposed and more
accessible portions of the bushes.

It is advisable to complete pruning before spraying opera
tions are commenced ; and in the case of old and badly infested
plants it is desirable to remove as much of the old wood as is
practicable.

The spraying apparatus should have the nozzle fitted at
an angle of about 45 degrees so that the spray may be con-
veniently directed to the under sides of the branches. •

In the case of the gooseberry, " brushing " is practically
impossible owing to the thorns, but peaches can be cleaned
by scrubbing in the winter.

(1) The best winter wash is lime-sulphur. The concen-
trated lime-sulphur solution can be bought ready made and
should be diluted to winter strength — 3 quarts of lime-sulphur
(1.3 specific gravity) to 10 gallons water, or according to the
ma-ker's directions.

-82

(2) If preferred, instead of lime-sulphur a caustic wash
G>r a strong paraffin emulsion may be used. Directions for
making these washes are given in Leaflet No. 70.

(3) Summer washing is less effective than spraying n
winter, which should be considered the standard treatment,
but some good may be done by a thorough application of
lime-sulphur diluted to summer strength (3 pints of lime-
sulphur, 1.3 specific gravity, to 10 gallons of water), or paraffin
emulsion. For gooseberries of the varieties Berry's Early,
Freedom, Lancashire Lad, and Crown Bob, the concentrated
lime-sulphur (1.3 specific gravity) should be used at the
rate of 1| pints to 10 gallons of water. The advantage of
using lime-sulphur on gooseberries lies specially in the fact
that it will also control American Gooseberry Mildew, but it
should not be used on peaches or nectarines, or gooseberries
of the variety Yellow Eough and Valentine's Seedling when
in leaf.

THE MAGPIE MOTH.

(Abraxas grossulariata, Linn.)

S.C.K.

1. Moth; 2. Caterpillar; 3. Chrysalis. All natural size.

The Magpie Moth, also known as the Currant Moth, is a
well-known enemy of gooseberries and currants to which it
may do considerable damage if allowed to breed unchecked.
Fortunately, it is not really difficult to control and, therefore,
with reasonable care, it need never cause a serious loss of crop.
As in the case of another abundant gooseberry pest — the
Gooseberry Sawfly — the great thing is to deal with the attack
in its early stages, before, and not after, the damage has been
done. The Magpie Moth occurs— and attacks may therefore
be expected — throughout the British Isles, in town and
industrial areas as well as in the open country. Abroad, the
moth is recorded as a pest in Central and Northern Europe,
and its range extends across Asia to Japan.

83

Plants Attacked and Nature of Damage.— The caterpillars
of the Magpie Moth feed on currant and gooseberry, plum,
sloe, apricot, nut, laurel (Prunus laurocerasus), spindle
(Euonymus), and probably other plants, but damage of import-
ance is usually confined to currants, gooseberries, and occa-
sionally apricots. The pest is perhaps more often harmful in
confined gardens than in large orchards. The injury, which
consists in the destruction of foliage by the caterpillars, begins
as soon as the leaves appear and continues until June, the
bushes in a bad attack being completely stripped. This
naturally weakens the trees, and may cause a loss of crop for
one or two years.

Description and Life-History.— The Magpie Moth is the
well-known black, white and yellow insect shown in Pig. 1.
It appears in July and August and lays eggs, singly or in small
groups, on the leaves of gooseberries, currants, &c. In about
a fortnight minute blackish caterpillars are hatched from the
eggs and feed on the foliage, growing slowly, until the autumn,
when, while still small, they go into winter quarters sheltered
among the dead leaves of their food-plant, in moss and lichen
growing on the bushes, or in any cranny where they may get
some protection during winter. As soon as foliage appears in
spring the caterpillars leave their winter quarters and again
begin to feed, growing in size until the end of May or early
June, when the bushes may have been almost stripped of
foliage, with the natural result that the fruit cannot develop.
The caterpillar, shown in Fig. 2, is then black and white in
colour, with a yellow stripe down each side. When full-fed :t
turns into a shining black chrysalis, with narrow yellow bands
round the " tail " (abdominal) segments, arid is suspended
in a slight cocoon among the leaves or twigs of the food-
plant, on fences, walls, or other places. The moth emerges
in about a month and the life-cycle begins again. Barely
there is a partial second brood, a few caterpillars feeding up
rapidly and producing moths in autumn, but this second brood
is never sufficiently numerous to do any damage.

It is important to distinguish between true Magpie Moth
caterpillars and those of the Gooseberry Sawfly, since after
an attack of the former no damage will again occur until the
following season, while in the case of the latter damage must
be expected at intervals throughout the summer unless preven-
tive measures are taken. Gooseberry Sawfly caterpillars
(Leaflet No. 12) may be recognised by the fact tKat they are
qreen, more or less speckled iritli black, and so are very
different from the black, white andt yellow Magpie caterpillars.

Methods of Control. — (1) In gardens with only a com-
paratively few bushes, the caterpillars can best be dealt with

84

by hand-picking in spring as soon as signs of damage are
apparent.

(2) In Commercial Plantations : Spraying. — Magpie cater-
pillars are easily killed b'y means of lead arsenate, but a
difficulty arises from the fact that this insecticide is very
poisonous and cannot be used when the gooseberries are fruit-
ing. Lead arsenate spray should, therefore, be applied either
(1) just before the flowering period, or (2) at the end of August
to kill the young caterpillars. The time available for the work
during the first period is very short, as it is necessary to wait
until as much foliage as possible has been produced, while, on
the other hand, spraying must cease before bees have begun
to visit the flowers. It is possible that a second application of
lead arsenate might be given directly after the flowers have set,
but the berries swell so rapidly tHat there would be a risk of
poisoning the fruit unless the work was carried out rapidly and
with discrimination.

If spraying be deferred until the end of summer, the nozzle
should be directed as much as possible on to the undersides
of the leaves.

When an attack has not become apparent until it is too late
to use lead arsenate, then hellebore (which loses its poisonous
properties rapidly) may be used within three weeks of the
time when the fruit is to be gathered. Pyrethrum, which must
be fresh, is non-poisonous, and may be applied at any time.
There axe also various non-poisonous proprietary compounds
to be bought from most horticultural firms.

(3) Formula.

A. Lead arsenate paste* ... ... \ Ib.

Water 10 gallons.

B. Hellebore powder* 2 Ib.

Water 10 gallons.

C. Pyrethrum powder ... ... 2 Ib.

Water 10 gallons.

In mixing lead arsenate it is best to work up the paste into
a thin cream with a little water, subsequently adding the
remainder.

Sprays B and G are improved by the addition of \ Ib.-l Ib.
of soft soap to each 10 gallons, and when being used, they
should be kept well shaken up. Half-a-pound of soap will
be enough unless the water is hard, when the full quantity
may be allowed.

* Load arsenate and Hellebore are poisonous to man and animals
•,ud should be kept under lock and key. Spocial tubs should be
reserved for mixing the ?pray fluid.

85

THE GOOSEBERRY SAWFLY.

(Nematus ribesii, Curtis.)

The Gooseberry Sawfly is a common and destructive pest
in most parts of the British Isles. It also occurs in many
European countries, in the United States and in Canada,
being thought to have reached the two latter countries in
soil adhering to the roots of imported gooseberry or currant
bushes.

Plants Attacked and Nature of Damage.— The Gooseberry
Sawfly occurs most frequently on the gooseberry, but it also
attacks red currants, and (more rarely) black currants. The
injury is due to the sawfly caterpillars, which devour the
leaves (Fig. 1), and in a bad attack strip the bushes completely,
with the result that the season's crop may be lost, and the
bushes so weakened that they can produce little fruit during the
following year. A characteristic feature of the pest is the
rapidity with which it increases whenever it is neglected.
Too frequently no notice is taken of an attack on one or two
bushes when the pest could easily be controlled, and the
following year, or even later in the same season, it is found
that the whole plantation is attacked, with the consequence
that much trouble must be taken and expense incurred in
destroying the caterpillars.

Description and Life-History. — The adult sawflies (Fig, 3)
first appear in April or May. The female is about one-third of an
inch in length, with clear transparent wings, and a body black
and yellow in front and yellowish-orange behind. The male
is similar but somewhat smaller in size and the upper part of the
body behind the wings is black and the size somewhat smaller.
Eggs (Fig. 2) are laid by the female on the gooseberry leaves,
usually a large number being laid on one leaf (see Fig. 5) ; they
are fixed into shallow slits in the surface of the leaf, but are
fairly conspicuous. In about a week the caterpillars, which at
first are pale green, slightly speckled with black, are hatched
from the eggs, and for some days feed together in a colony,
first eating the surface of the leaf and then nibbling holes.
As they grow older they spread all over the bush, eating the
whole of the leaf. They are then sage-green in colour, with a
black head and numerous black spots (Fig. 4). When full-grown
about four weeks after they have hatched, the caterpillars
lose the black spots and are pale green, almost orange behind
the head (which is now green) and near the " tail. " At this stage
they leave the bushes and make oval brown cocoons (Fig. 5) in
the soil, from which, in the summer, the adults emerge in
from 10-21 days. There are usually three broods of sawflies
in the course* of the season, and if the weather is very
favourable (dry and warm) there may even be four. In
consequence the pest may increase in numbers enormously

86

THE GOOSEBERRY SAWFLY.

(1.) Gooseberry shoot injured by Sawfly caterpillars. (2.) Leaf
showing Sawfly eggs. (3.) Gooseberry Sawfly. (4.) Gooseberry Sawfly
caterpillars. (5.)

87

by the close of the summer. There is considerable over-
lapping in the various broods, so that flies, eggs and larvae oi
all sizes may be found on the bushes at the same time. The
cocoons of the last brood of larvae remain in the soil during
the winter, and produce flies the following spring.

^Gooseberry Sawfly caterpillars are sometimes confused
with those of the Magpie Moth, but it is easy to separate
them, since Magpie larvae are black a-nd white with some
yellow at the sides, and are, therefore, very different from
the speckled green sawfly caterpillars.

In addition to the species here described, other species of
sawfly larvas are also found on gooseberries, but from the
growers' point of view it' is unnecessary to distinguish them.

Natural Enemies. — Several species of ichneumon fly have
been recorded as parasites on the caterpillars of the Goose-
berry Sawfly, but the latter do not appear to suffer from them
to an appreciable extent. As a whole, natural enemies do
not exercise a sufficient check on the sawfly, and artificial
measures of control are often necessary.

Methods of Control. — Attention is again drawn to the
advisability of dealing with small attacks. Otherwise it is
almost certain that serious trouble will follow.

(1) Hand-picking is the simplest method in the case of a
few bushes, but it must be done before the colonies of young
larvae have scattered over the bush. Some prefer to pick the
leaves on which eggs have been laid.

(2) Spraying is thoroughly effective against this pest; the
chief difficulty lies in the fact that the best washes are
poisonous. Lead arsenate may be used in the case of an
early attack where it can be applied before the gooseberries
have flowered, and also after the fruit has been gathered.
Hellebore, when fresh, and nicotine are also effective, and
though poisonous do not retain then: poisonous qualities for
long. They may therefore be used with safety if an interval
of three weeks be allowed between the dates of spraying and
picking. Pyrethrum, which must be fresh, may be tried where
a non-poisonous insecticide is needed, and there are also
certain proprietary insecticides now on the market which are
quite satisfactory and can be recommended for small gardens.

(3) Formula : —

A. Lead arsenate paste .... ... £ Ib.

Water ... 10 gallons.

B. Hellebore powder 2 Ib.

Water 10 gallons.

C. Pyrethrum powder ... ... 2 Ib.

Water ... .- ... ... 10 gallons.

D; Nicotine 98-99 per cent. ... f oz.

Soft soap *-l Ib.

.Water ... ... ... ... 10 gallons.

88

In mixing lead arsenate it is best to work up the paste
into a thin cream with a little water, subsequently adding
the remainder.

Sprays B and C are improved by the addition of i-l lb.
of soft soap to each 10 gallons, and when being used they
should be kept well shaken up. Half a pound of soap will
be enough in the case of B, C and D unless the water is
hard, when the full quantity may be allowed.

THE RASPBERRY MOTH.

(Lampronia rubiella, Bjerk.)

The Raspberry Moth, also known in the caterpillar stage
as the Red Raspberry Grub, occurs throughout England and
Scotland, sometimes causing considerable losses both in com-
mercial plantations and private gardens. Next to the Rasp-
berry Beetle (Byturus tomentosus) it is perhaps the most
serious insect enemy of raspberries in Great Britain. Abroad
it is widely distributed on the Continent and appears to be
specially harmful in Holland.

Nature of Injury. — If an infested plantation be examined
towards the end of April or early in May it will be found that
many of the young shoots, particularly those towards the
tops of the canes, have withered or died owing to the fact
that the inside of each attacked shoot has been eaten away.
Inside the tunnel in the shoot is usually found a small red
caterpillar or, later, a brown chrysalis. The damage is, there-
fore, very characteristic and when a large proportion of the
shoots are attacked, great loss of crop may occur, since each
injured shoot dies without producing flowers. The only pest
with which the larva of the Raspberry Moth is sometimes con-
fused is that of another small moth (Aspis udmanniana, L.)
which may be known as the Blackberry Leaf Spinner. This
pest sometimes feeds on raspberries, the leaves of which it ties
up into a large bundle. The caterpillar is brown or chocolate
coloured and feeds within the bundle of leaves ; it never burrows
into the shoots and may be recognised both by its habits and
colour.

Description and Life-History. — The Raspberry Moth is
a small insect with a wing expanse of from J-g- inch. In colour
the wings are dark purplish brown, often with a satin-like
sheen and with several conspicuous yellow spots. The moths
appear at the end of May and in June and lay their eggs in
the raspberry flowers. In about a week young caterpillars,
whitish in colour, are hatched from the eggs and burrow into
the receptacle (or plug) of the fruit in which they feed, but

89

during^ this period they do practically no dam;i-r, and in
fact it is difficult to tell which fruits have been attacked. When
the fruits begin to ripen the caterpillars leave them and crawl
about searching for places in which to make cocoons. These
cocoons are about one-tenth of an inch in diameter and are
placed sometimes in cracks or crevices in the canes or support-
ing stakes, sometimes among the soil or rubbish round the
stools. The young caterpillars spend the winter in the cocoons
and then, early in April, leave them and crawl up the canes to
the shoots into which they burrow. Each caterpillar then
feeds within a shoot for four to six weeks, and during this
time it becomes bright pink in colour, with a blackish head
and plate 011 the first segment. When mature it changes to
a brown chrysalis, usually within the burrow in the shoot, and
three or four weeks later the moth appears.

(1) Methods of Control. — After an attack every effort
should be made to clean all rubbish from the stools, carting
it, and also old canes, a short distance from the plantation,
where the whole should be burnt if possible. Old cracked
stakes should be renewed and the soil forked or hoed right
up to the stools.

(2) There appear to have been few experiments in spraying
in this country but the following trials should certainly be
made.

(a) Spray the canes, the soil round the stools and all

stakes during the winter with paraffin emulsion (or
miscible oil*) at winter strength, the object being to
soak the cocoons ajid kill the larvae inside.

(b) At the end of March spray the canes, soil round the

stools and stakes heavily with lime-wash as used for
apple a.nd plum trees. At this period the larvae will
be preparing to leave their cocoons and the object
in spraying is to cover the canes, stakes and soil
round the stools with a coating of lime which will
prevent the larvae reaching the buds.

(c) At the beginning of April spray the young shoots with

lead arsenate using a. strong mixture. In Russia,
Paris green and lime used in this manner have been
found quite effective and might also be tested here.
The object in this case is to cover the shoots with a
poisonous coating so that the larvae must eat the
poison and be killed while entering the shoots.

(3) In plantations which are so badly affected that little
crop is obtained, a radical cure may be attempted by cutting

* Miscible oils may be taken as comparable to paraffin emulsions in
their action. They are so prepared as to emulsify at once in water
without the addition of soap, but are not usually designed for summer
washes— only for winter use. The makers' instructions for mixing should
be taken.

90

back all young canes in the spring to within six or eight
inches of ^ the ground exactly as if a new plantation had been
made. No flowers will then be produced and in consequence
the moths will have nowhere to lay their eggs and there will
be no fruit in which the young larvae could feed. The
following year the plantation should be almost free of the
pest.

J4) In small gardens it is quite possible to keep the pest
1 in check by picking off the shoots as soon as they begin
to wither in the spring, destroying the pink grub inside.

(5) Spray Formulae.—

(ai) Paraffin Emulsion, winter strength.

Paraffin Oil ' 1 gallon

Soft Soap ... l£-2 Ib.

Water 10 gallons.

Dissolve the soft soap in about a gallon of boiling

water, remove the solution from near the fire and, while

( still hot, add the paraffin. Churn the mixture very

' thoroughly by syringing it back into itself. When

required for use add soft water to make 10 gallons and

mix again thoroughly so as to make sure that there is no

free paraffin floating on the surface.

(b) Lime Wash.

Best Quicklime 10-15 Ib.

Water 10 gallons.

Obtain only best stone quicklime and store carefully
to prevent it from air-slaking. Builder's lime, which is
often partially air-slaked, should not be used.

Slake the lime with a little water, and when slaked
into a fine powder, add the remainder of the water, stirring
vigorously the whole time. Strain carefully before filling
the spraying machine and keep the lime-wash well agitated
throughout the application.

(c) Lead Ar senate.

Lead Arsenate paste 1 Ib.

Water 15 gallons. ;

In mixing lead arsenate it is best to work up the
paste first into a thin cream with a little water, subse-
quently adding the remainder.

(d) Paris Green.

Paris Green paste 1 oz.

Quicklime ... 1 Ib.

Water, ..10 gallons.

Slake the lime to a cream with a little water and
make it up to nearly 10 gallons with water. Then work
up the Paris green with a little water and add it to the
mixture of lime and water, stirring well before use. The
quantity of lime used has been increased considerably
' above the normal in order that a better coating over the
shoots may be obtained.

91

WINGLESS WEEVILS.

The Clay-Coloured Weevil (Otiorrhynchus picipes, Fab.),
the Black Weevil (0. sulcatus, Fab.), and the Plum Weevil
(0. tenebricosus, Herbst.), are three species of beetle varying
slightly in size but not unlike in general appearance. In the
grub or larval stages they not only possess more or less similar
habits, but also resemble one another so closely that no simple
distinguishing characters can be given. The adult beetles are
wingless and therefore unable to fly. They make their appear-
ance in late spring and early summer, feeding upon a large
variety of plants and trees, attacking leaves, shoots or bark,
and causing much damage. During the summer eggs are
deposited, probably in the soil near suitable plants, and the
resulting white, foofless grubs find their way to the roots,
where they continue feeding until full-grown early in the
following spring. They then turn to white pupae in the soil,
a stage which is of comparatively short duration, the perfect
weevils soon emerging. This life-history is more or less typical
of each of the three species, but it is naturally subject to
variation when the insects are living under greenhouse
conditions.

Description and Nature of Damage.

(1) THE CLAY-COLOUBED WEEVIL (Otiorrhynchus picipes,

Fab.).

This weevil is the most harmful of the three species just
mentioned and the smallest in size, varying from £-£ inch in
length. In colour it is chocolate-brown, speckled with light
brown, but from living in the soil it becomes dirty, and then
appears practically the same colour as the soil in the neigh-
bourhood which it inhabits.

THE CLAY-COLOURED WEEVIL.
1. Adult Beetle. 2. Larva. 3. Pupa.

In habits the weevils, are mainly nocturnal, spending the
day hidden among clods of earth and to some extent among
dense foliage on trees and bushes. At night they crawl out
to feed and much havoc is wrought to fruit blossoms, fruit
buds, and tender shoots of raspberries, the outer skin of the
latter being gnawed and not infrequently the bark of the canes
lower down being also devoured; the leaves are eaten into

92

holes, and in a severe attack quite stripped. Though some-
times known as the Raspberry Weevil, the insect does not
confine its attention to raspberries : it is also very harmful to
young grafted stock and to young trees in orchards. In the
former case it eats the graft or the bark at the junction of
scion with stock, and in the latter case the leaves and shoots,
and it may even bite the bark from off the main stem and
larger branches. In addition to fruit the weevils attack hops
and sometimes such annual crops as peas and beans. Wood-
land is usually overrun with these insects, and may easily serve
as a centre of infestation for neighbouring fruit plantations.
The larvae or grubs feed at the roots of many plants, but
owing to their resemblance to those of other similar kinds of
weevil, it is not possible to say precisely how much damage
they do.

(2) THE BLACK WEEVIL (Otiorrhynchus sulcatus, Fab.).

The Black (or Vine) Weevil is a beetle which is more
troublesome under glass than in the open. It is about one-
third of an inch long, in colour black, minutely speckled with
yellow, and the elytra (wing cases) are rough with raised lines
like a file or rasp.

The adult weevils appear under glass in spring (early or
late according to the temperature of the house), and may be
found more or less throughout the summer, but it is not known
whether there is more than one generation in the year. In
the beetle stage they are chiefly injurious to vineshoots and to
the shoots and foliage of fruit trees or shrubs grown under
glass, but they have also been recorded as attacking rasp-
berries in the open in much the same way as the Clay -Coloured
Weevil.

The larva, which is a white, legless grub with a brown head,
is very injurious to plants in pots — notably to ferns, primulas
and cyclamens. They feed on the roots and cause the plants
to have an unthrifty look — ferns usually show a bad colour
and fail to make proper growth, while primulas and cyclamens
may be completely killed. If such plants are examined the
grubs will usually be found lying half curled up (like the letter
C) near the crown of the plant, eating the thicker or more
fleshy parts. It is not uncommon to find 6-8 grubs in one
pot. Out of doors the grubs are also injurious to many garden
plants and also to strawberries.

(3) THE RED-LEGGED OR PLUM WEEVIL (Oiiorrliynchus

tenebricosus , Herbst.)

This black, shining weevil, half an inch long with dull
reddish legs, is very injurious to plum trees in years when it
appears in large numbers. Peaches, nectarines and apricots
are also attacked, and it has been known to damage raspberries
severely, chewing the young shoot and destroying tender

93

foliage. Little appears to be known as to the damage done
by the larva of this species.

Methods of Control.— (1) Prevention.— The weevils dealt
with in this leaflet are exceedingly difficult to eradicate once
they have become established in the nursery or greenhouse,
and it is therefore of great importance to prevent them from
obtaining a foothold. This is less difficult than in the case of
many pests owing to the fact that the weevils cannot fly, and
can therefore only reach fresh ground by crawling or by being
carried in soil when in the grub stage.

(a) In the case of land to be used for nursery stock or for
such semi-permanent crops as raspberries or strawberries, it
is well worth devoting a year to making sure that no weevils
are present. There will be little likelihood of this if the land
in question has been well farmed arable, but if it has
carried fruit, nursery stock, or has been at all weedy and foul,
a season should be devoted to getting it thoroughly clean,
either by fallowing, followed by mustard ploughed-in in the
autumn, or by growing potatoes or roots, the choice to be
made according to the state of the land and local circum-
stances. If a dry spring permits of thorough working in
February., March and April, when the grubs are full-fed and
pupating, this will do much to reduce the number of adult
weevils which would emerge in May and June.

Where the land is adjacent to a wood or uncultivated land—
a common source of infection — the intervening ditch should
be kept cleaned out (or dug out if necessary) the hedgerow
trimmed, and if possible overhanging boughs lopped from the
trees at the edge of the wood.

(&) In the case of greenhouses devoted to growing ferns,
primulas, &c., the fresh stock should be watched carefully and
if the plants do not thrive the roots of the least healthy should
be searched for the white grubs. Ferns, for instance, though
full of leaf tend to remain rather yellow when attacked by
weevil. Potting soil should also be examined carefully for
grubs, and if grub-infested soil has to be used then it should
first be sterilised by heat. Before restocking an old green-
house the clearing out should be very thorough, particularly
as regards soil under the stages and ornamental " rock work "
in ferneries which are both often infested by weevil grubs.

(2) Treatment.— (a) In the case of infested nurseries and
orchard land already planted, young trees and grafted stock
can be protected from the adult weevils by banding as for
Winter Moth since the weevils spend the day in the soil and
only crawl up at night. Apart from this the only treatment
is to catch the weevils at night by shaking them on to tarred
trays or boards or on to special trays made for such purposes.
Vast numbers of weevils can be caught in this way by a careful

94

worker, but care is necessary as the insects readily fall off when
alarmed either by too strong a light or by jarring the bushes
or canes. No insecticide has proved of any use against the
weevils when in the soil but spraying the plants with a poison
has not been properly tested. Suggestions to this end will be
sent on request.

(b) In the case of greenhouses, the only complete treat-
ment is to clean out the house and repot the stock, shaking
out the soil from the roots and killing the grubs. The pest
can be kept in check by searching plants and stages carefully
at night (especially in spring and early summer) for the adult
weevils. Watering the plants with insecticides and mixing
insecticides with the soil in the pots have given variable results
but no treatment of this nature has yet been sufficiently
standardised to justify a recommendation in a leaflet. Where
a grower has the time and inclination to experiment, an
insecticidal treatment is well worth consideration.

THE VAPOURER MOTH.

(Orgyia antiqua).

VAPOURER MOTH : a. Male; b. Female; c. Cocoon, surrounded by eggs;
d. Caterpillar.

The caterpillars of this moth attack the foliage of a great
variety of plants, including most of the fruit trees and a large
variety of forest trees both hardwoods and conifers. They'
also devour herbaceous plants in gardens and greenhouses, and
may in fact be described as general feeders.

From May to September the caterpillars may be found ; from
Tuly up to.iind including October the adult moths appear.

Ihe insect is common throughout Great Britain and Irelami,
especially in urban districts, and abroad its range extends
through Europe, N. Africa and Western Asia.

Description.— Moth.— The two sexes are extremely

different in appearance. The male (Fig. a.) measures from
1 inch to 14 inch in expanse of wings. The body is brown : the
wings are pchreous.or chestnut brown, the fore-wings having
dark markings. Near the hind angle of each fore- wing is a
somewhat crescent-shaped clear white spot. The female
(Fig. &.) is yellow-grey in colour, hairy, and unable to fly,
the wings being reduced to mere stumps.

•Eggs.—rlhe> eggs (Fig. c.) are whitish-grey in colour and
are laid in great numbers on or about the empty cocoon of the
female moth.

Caterpillar. — The caterpillar (Fig. d.) is very hairy and
of gay colouration, a mixture of red, yellow and brown, with
four brushes of hairs on the back, and a pencil of long black
hairs protruding from each side of the head, one on the sides
and one similar at the tail. There are two red warts on eacli
ring of the body. When full grown the caterpillar measures
about an inch.

Pupa,.— The chrysalis is dark brown and lies under cover of
a somewhat oval-shaped yellow-grey web or cocoon (Fig. c.).
Mixed in the web are hairs from the caterpillar.

Life-History. — The male moth being in possession of
normal wings flies actively during the day, . and usually
rather high above the ground. The female, wingless and
sluggish, does not go far from the cocoon, but pairs and
remains on the outside of it for the remainder of her life,
laying on and all around it up to 300 eggs or more. Some
of these eggs hatch in a fortnight to three weeks, while others
laid at the same time may not produce caterpillars until the
following spring. From this it follows that all stages of the
insect may be met with at the same time. Soon after hatching
the young caterpillars scatter over the tree. When they are
full-fed they spin cocoons, which are attached to leaves, twigs,
bark, or to a neighbouring post or fence. The moths emerge
from the pup*e in about three weeks. Two broods or even
three in the year are possible, for if the eggs that have passed
through the winter hatch' in the early part of May, the
resulting caterpillars may become adult in time to allow for a
second and perhaps even a third brood of moths by October. On
the other hand (and probably this is more usual) there may be
only one generation in the year, in which case the eggs laid
by the first brood pass through the autumn and winter and
hatch in the following spring. Weather conditions have great
influence on the production of second broods, which are usually
most numerous in a hot summer. Owing to the irregularity

96

in the hatching of the eggs and the varying extent to which
a second brood is produced, there is considerable overlapping
between the successive generations, and Iarva3 may be found
throughout the whole summer and early autumn.

Methods of Control. — 1. The cocoons with eggs may be
destroyed during the winter.

2. The caterpillars which are conspicuous may be dealt with
by hand-picking if spraying is not desirable, or shaken off
their food plant and destroyed from May to September.

3. Attacked plants may be sprayed with load arsenate to
poison the foliage on which the caterpillars are feeding.

Formula — Lead Arsenate Paste ... lib.

Water 20-25 gallons.

4. Owing to the females being wingless and moving very
little, the species can only spread in the caterpillar stage, nnd
so if care is taken in dealing with the first attack, the insect
is not thereafter difficult to control.

GOAT MOTH (Cossus Ugniperda) and WOOD LEOPARD

MOTH (Zeuzera cesculi).
1. THE GOAT MOTH.

Rjjj

, <>,'''"•'.:•,' i

Trees Attacked.— The caterpillars <»f this moth bore
galleries in the stems of many species of broad-leaved trees,
e.g., willow, poplar, walnut, birch, elm, beech, lime,
sycamore, ash, and various fruit trees. The softer woods are
more commonly infested.

The caterpillars are large and a great number may be found
at work in the same tree; the wood, on this account, is so
tunnelled and honeycombed as to be rendered useless for
technical purposes.

Indications of Infestation.— (a) The little heaps of excre-
ment and frass thrown by the feeding caterpillars
from their galleries to the outside.

(h) The odour of the caterpillars, which by some has
been compared to that of the goat. The burrows
also have the same characteristic smell.

Isolated trees, or those in an avenue or at the edge of a
wood, are chosen by the females for their egg laying in
preference to trees in close forest, though the latter are some-
times attacked.

Description. — Moth. — The goat moth, which flies at night,
is large and plump. The female measures 1£ inches or more
in length, and over 3 inches in spread of wing; the male is
somewhat smaller. The head is small and the eyes large; the
proboscis and antennae are short. The antenna} of the male are
distinctly comb-like, whilst those of the female are saw-like.
The fore wings are pale-brown mottled with ashy-grey, and
have numerous irregular black streaks and marks ; the hind
wings are darker greyish-brown. The thorax is densely hairy,
brown and grey in front, and with a blackish band across it
behind. The large heavy abdomen is grey with whitish rings.

Caterpillar. — The caterpillar is somewhat flattened, and
hence the galleries are oval in shape. When young the
caterpillar is dull pink, but as it grows the upper surface
becomes dark red or purple, the sides and under-surface being
yellowish flesh-coloured. The head is black; the segment
behind the head bears a dark shield, and the segments have
fine bristle-like hairs. The full grown caterpillar may measure
about 4 inches in length.

Pupa. — Pupation takes place in the burrow in the stem,
near to the outside, the chrysalis being surrounded by a cocoon
covered by wood chips and sawdust. Sometimes the cater-
pillar leaves the tree and pupates in the soil, in which case the
cocoon consists chiefly of particles of soil.

98

Life-History. — The moths fly in June and July ; the eggs
are laid in little heaps in cracks and crevices in the bark
generally very low down, but sometimes up to the height of a
man. The caterpillars on hatching feed at first below the
bark, but later they gnaw irregular ascending galleries in the
wood. In cases of overcrowding (and more than 100 cater-
pillars have been taken from one stem) some of the caterpillars
may leave the tree and bore into another. When full grown
the caterpillar pupates, and the .pupation stage lasts about a
month or on occasion somewhat longer. Before the emer-
gence of the moth the pupa pushes its way partly out of the
burrow in the tree and the empty pupal skin may be seen
projecting after the emergence of the moth. The cocoon has
been found projecting from the soil of a garden near an
infested balsam poplar.

The life cycle appears to vary in length. A period of two
years is given by some authorities but the majority consider
that it extends to three years, and that under exceptional con-
ditions it may last for four or even five years.

Methods of Control. — (1) Trees which are badly attacked
and are of no great value should be cut down and the larv;i>
destroyed.

(2) When a tree is only slightly attacked or when it is of
special value for shade or ornamental purposes, one of the
following methods may be employed: — (a) Small quantities
of carbon bisulphide may be injected info the holes in the
trunk, (b) Small pieces of potassium or sodium cyanide may
be pushed into these holes. Whichever poison is used the
holes must be thoroughly blocked with clay immediately after
the operation.

Injections of carbolic acid, paraffin, or a solution of nicotine
are also s-iid to have succeeded in certain cases, but either
cn.rbon bisulphide or one of the cyanides will be found most
effective. The latter substances must however be fcrealerl with
care, as carbon bisulnhide is exceedingly inflammable whilo
the cyanides are virulent poisons.

(3) As a preventive against the eg£-layin<r of the moth the
trunk of Hie tree. UP to a height of eic:ht feet, mav be pnintor?
with a mixture of chv, lime and soft soip or clay ;uid cow
Hung. The mixture should nlso cover any exposed roots n* the
base of the trunk and should be applied during the month of
Mnv. This measure is mainly of service in parks and gM-Vns
where a few trees are affected and it is desired to take every
precaution to prevent the insect from spreading.

2. THE WOOD LEOPARD MOTH.

Trees Attacked.— Like the Goat Moth, this pest has
importance both for the forester and the fruit-grower. The
caterpillars of Zeuzera cesculi feed in the stem and branches
of a number of broad-leaved trees, e.g, lilac, lime, sycamore,
birch, beech, oak, sweet chestnut, ash, willow, poplar, and
such fruit trees as apple, pear, and cherry, where they may
cause considerable harm. The horse chestnut, from which the
scientific name of the moth is derived, is not so frequently
attacked as other trees. In the case of this insect, the cater-
pillars are not found many together in an attacked stem, but
generally singly. The presence of the caterpillar may be
betrayed by its copious out-throw of frass and wood-coloured
excrement. The moth is frequently found in the Metropolitan
districts, and sometimes causes considerable destruction to trees
and shrubs in the public parks and private gardens of the
Metropolis.

Description. — Moth. — The moth, which is named
" Leopard " on account of its spotted wings, measures1 between
2 and 3 inches in expanse of wings in the case of the female,
the males being smaller. The fore wings are white, with a
number of black or blue-black spots. The hind wings are
similarly marked, but the spots are fainter. " The thorax is
white, with 6 large dark spots arranged in pairs, and a smaller
spot between the hindmost pair.

Caterpillar (1). — The full-grown caterpillar may measure
2 inches in length. It is white or yellow- white in colour with
black spots; the head is dark, the joint behind the head
bearing a black shield or plate, whilst a black plate is also
present on the last segment.

Pupa (2). — The pupa is brown and may be found at first just
below the place of exit, and later, after the emergence of the
moth, it may be seen projecting from the tunnel in" the infested
tree.

100

Life-History. — The moths lay their eggs singly on stems
and branches late in June or July, and the caterpillar on hatch-
ing gnaws at first irregularly below the bark. After wintering,
the caterpillar bores into the wood, arid the gallery or tunnel,
running in the long axis of the infested stem, is round and
regular and may reach 8 inches in length. The life cycle is
said to be either two or three years. The caterpillars have
been known to leave their first feeding place and attack
younger and fresher growths.

Methods of Control. — (1) When the trunk of a tree is
badly attacked it should be cut down and burnt. Branches
which are dying should be cut back until the end of the burrow
is reached. If the larva has not been found during this process
the cut portions must be split and the larva killed.

(2) In the case of branches and stems which are slightly
attacked or which it is desired to save, a pointed wire may
be pushed down the burrows to kill the larva, or the methods
suggested against the goat moth, Section (2), may be employed.
The fumes of burning sulphur or tobacco forced into the holes
by means of a pair of bee bellows have also been found
effective.

IX

GEO. MONRO, LTD.,

Registered GEO. MONRO Trade Mark.

COMMISSION SALESMEN

for Indoor and Outdoor

FRUIT, FLOWERS, VEGETABLES, and all
kinds of IMPORTED FRUITS.

Directors- :

MAJOR EDWIN G. MONRO, A. J. MONRO,

GKO. MONRO, CHAS. COLE,

B. J. MONRO, CAPT. J. STUART MONRO.

Covent Garden, London

Telephone No. — Gerrard 5461.

and at

Smithfield Market, Manchester.

Telephone No. — 1453 City.

SUNDRIES DEPARTMENT

For the supply of all Horticultural Sundries
required by the Trade.

4, Tavistock Street,

Covent Garden,

Telephone No.— Regent 3042. "W.C.2.

"BUNYARDS"

MAIDSTONE.

(Established 1796.)

THE Secret of Success in Fruit
Growing is to keep two points
in mind:—

(1) Start properly — with healthy, well-grown
and vigorous trees, true to name and on
the right stock.

The Best is the Cheapest in the end, so
plant Our Trees and avoid disappoint-
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(2) Having started with the Best Trees, keep
them in first-class condition by using: —

BUNYARD'S Lime Sulphur.
BUNYARDS American Blight Cure.

BUNYARD'S Fruit Tree Manures,

Spraying Machinery, Pruning Knives,

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Lists FREE on Application.

GEO. BUNYARD & CO., LTD

The Royal Nurseries, Maidstone.

.^...BERKELEY

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