CIHM
Microfiche

(Monographs)

ICIMH

Collection de
microfiches
(monographles)

Canadian Institute for Historical Microraproductions / Institut Canadian da microreproductions historiques

Technical and Bibliographic Notes / Notes techniques et bibliographiques

The Institute has attempted to obtain the best original
copy available for filming. Features of this copy which
may be bibliographically unique, which may alter any of
the images in the reproduction, or which may
significantly change the usual method of filming are
checked below.

□ Coloured covers /
Couverture de couleur

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D

D

El

D

D

Covers damaged /
Couverture endommagte

Covers restored and/or laminated /
Couverture restaur^ et/ou pellicula

Cover title missing / Le titre de couverture manque

Coloured maps / Cartes g^ographiques en couleur

Coloured ink (i.e. other than blue or black) /
Encre de couleur (i.e. autre que bleue ou noire)

Coloured plates and/or illustrations /
Planches et/ou illustrations en couleur

Bound with other material /
Re\\6 avec d'autres documents

Only edition available /
Seule Edition disponible

Tight binding may cause shadows or distortion along
interior margin / La reliure serr6e peut causer de
I'ombre ou de la distorsion le long de la marge
int^rieure.

Blank leaves added during restorations may appear
within the text. Whenever possible, these have been
omitted from filming / Use peut que certaines pages
blanches ajout^es lors d'une restauration
apparaissent dans le texte, mais, lorsque cela 6tait
possible, ces pages n'ont pas 6\6 film^s.

Additional comments /
Commentaires suppi^mentaires:

L'Instiijt a microfilm^ le meilleur exemplaire qu'il lui a
6t6 possible de se procurer. Les details de cet exem-
plaire qui sont peut-dtre uniques du point de vue bibli-
ogr ..nique, qui peuvent modifier une image reproduite,
ou qui peuvent exiger une modification dans la m^tho-
de normale de filmage sont indiquds ci-dessous.

I I Coloured pages / Pages de couleur

I I Pages damaged / Pages endommagtes

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D
D

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Pages restored and/or laminated /
Pages restaurtes et/ou pellicul^es

0 Pages discoloured, stained or foxed /
Pages dteolortes, tachettes ou piques

I I Pages detached / Pages d^tach^es

[/J Showthrough / Transparence

I I Quality of print varies /

Quality in^gale de I'impression

Includes supplementary material /
Comprend du materiel suppldmentaire

Pages wholly or partially obscured by errata slips,
tissues, etc., have been refilmed to ensure the best
possible image / Les pages totalement ou
partiellement obscurcies par un feuillet d'errata, une
pelure, etc., ont 6\6 film^s k nouveau de fa^on k
obtenir la meilleure image possible.

Opposing pages with varying colouration or
discolourations are filmed twice to ensure the best
possible image / Les pages s'opposant ayant des
colorations variables ou des decolorations sont
filmtes deux fois afin d'obtenir la meilleure image
possible.

This Kem it filmed at the reduction ratio checked ImIow /

Ce document eat film* au taux de rMuction indiqui ci-deaaoua.

lOx

14x

18x

22x

26x

30x

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16x

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32x

The copy filmed h«r« has bctn rtproductd thanks
to tha ganarosity of:

Library
Agricuttura Canada

Tha imagaa appaaring hara ara tha bast quality
poaaibia conaidaring tha condition and lagibility
of tha original copy and in kaaping with tha
filming contract apacificationa.

Original copiaa in printad papar covara ara filmad
beginning with the front cover and ending on
the laat page with a printed or illustrated imprea*
sion. or the back cover when appropriate. All
other original copiaa are filmed beginning on the
first page with a printed or illustrated imprea-
aion. and ending on the last page with a printed
or illuatratad impression.

The laat recorded frame on each microfiche
shall contain the aymbol — ^- (meaning "CON-
TINUED"), or the aymbol V (meaning "END"),
whichever appliea.

Mapa, plataa, charta, etc., may be filmed at
different reduction ratioa. Those too large to be
entirely included in one exposure are filmed
beginning in the upper left hand corner, left to
right and top to bottom, aa many framea aa
required. The following diagrama illustrate the
method:

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2

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1

2

4

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L'txamplaira film* fut reproduit grice k la
ginirosit* da:

Bibliothiciui
Agriculturi Canada

Lts imagaa auivantes ont M rtproduitas avae la
plua grand aoin, compta tanu da la condition at
da la nattat« da I'axamplaira film*, at an
conformity avac laa conditiona du contrat da
filmaga.

Laa axamplairaa originaux dont la couvartura an
paplar aat ImprimAa aont filmAa an commandant
par la pramiar plat at an tarminant soit par la
darniAra page qui comporto una ampreinte
d'impraaaion ou d'illuatration. aoit par la second
plat, salon la caa. Toua las autrea axemplalraa
originaux sont filmta en commen9ant par la
pramiAre page qui comporte une empreinte
d'impression ou d'illuatration at en terminant par
la derniAre page qui comporte une telle
empreinte.

Un dea symboles auivants apparaTtra sur la
dernlAre image de chaque microfiche, aelon le
caa: le symbole -*> signifie "A SUIVRE". le
aymbole V aignifia "FIN".

Lea cartes, planches, tableaux, etc.. peuvent itre
fllmte A dea taux de reduction diff4rents.
Lorsque le document est trop grand pour Atre
reproduit en un seul clichi. il est film* i partir
de Tangle sup<rieur gauche, de gauche * droite.
et de haut en bas. en prenant le nombre
d'imagas nAcessaira. Lea diagrammes auivanta
illustrent la mAthode. -

2 3

5 6

MOOCOPV tnOlUTKM TBT CHART

(ANSI and ISO TEST CHART No. 2)

A y^PPUEn IM^GE Ir

1653 East Main Street

Rochester. New York 14609 USA

(716) 482 - 0300 - Phone

(716) 288-5989 - Fa»

UHUIT. WEST HOCK. OnAWA.
..4AN 5...IB2J niiisE lETiiiN.

CIRCULAR No. 41
(N»w HortlcuttHfal »«rlM).

'^ J

PROVINCE OF BRITISH COLUMBIA.

DEPARTMENT OF AGRICULTURE

(HOBTICULTIBAL BRAMCII).

THE OYSTER-SHELL SCALE

(Lepidosaphcs ulmi Linn.).

THE oyster-shell scale is a familiar object to fruit-growers. It
occurs commonly in the Lower Kootenays, in the Lower Fraser
\'alley, and in the developed sections of Vancouver Island. It is

Twic Infested by oyster -.shell .scale, (Author's illustration.)

present also in the Dry Belt fruit areas of the Okanagan, but it finds
circumstances more suited to its taste in districts re the astmos-
pheric conditions are moist and humid.

It derives its name, first, from the fact that it In^longs I., that class
of insects which devebps a waxy shield over its liody, so-called :,
scale under which it lives, protected f<om any adverse conditions
secondly, from the fact that the waxy scale resembles an oyster-shell
in shape. In colour this insect may Ik one of several shades of brown
depending very largely upon the colour of the bark uijon which it is
living I<ruit-growers, therefore, will be able to identify th.s scale b\
Its colour, by its shape, by its size, which is approximately 'A inch in
length, and from the fact that it often occurs in great numbers on a
piece of bark, often overlapping and forming deep encrustations At
times the fruit itself may jxissess an occasional specimen.

Food-plants.

With this insect, jwssibly more so than with any other insect which
attacks cultivated fruit-trees in this Province, it is correct to agree with
the common expression that the " woods are full of it." It is known
to attack a wide variety of native plants, among which may be
mentioned, Nuttal's dogwood, bnx,m, willow, poplar, vine-maple
hawthorn, amelanchicr, flowering currant, mountain-ash, and th(
cascara-tree. It is essentially, however, a fruit-infesting insect, attack-
ing varieties of apple, crab-apple, pear, peach, apricot, cherry, and
currant. Its presence is noted more often in apple-orchards than in
plantations of the other fruits, and in certain sections of the Trovinci^
Its numbers have increased to such an extent that apple-trees, naturallv
weakened by several contributing causes, have finally succumbed to
Its attacks

Life-history.

In ti i e of British Columbia the oyster-shell scale has only

one gei-. m the year. Its life-history is as follows: If durinij

winter some of the familiar scales are overturned on the point of a
penknife, a number of shining, white, oval objects will be seen vary-
ing in number from 20 to 100. These are eggs, and it is in this
stage that the winter is passed. As the spring arrives these eegs
commence to hatch, and usually at the time the apple-irees are in
blossom, small white or cream-coloured objects may be seen issuing
from beneath the scale. These are the larvs, or young scale-insects
Owing to diflferences in climate, which the various fruit districts of tin
Province present, and owing very often to a marked dissimilarity in
the spring seasons at any one locality, one year with another, tlu
period of hatching varies considerably. However, at some time in th.
four weeks surrounding the period of full bloom, hatching takes

2

,.!ii> e and the young larvic iK'conic ilisctrnihK- to the naked eye as small
^ r. iin-coloiircd dots, moving, in proiwrtion to their size, cfmiparatively
rai'idly over the bark. They are wingless and very delicate at this
st;i>fc,'and their sole object is to find a suitable si)ot upon which to
stttle and feed. After a few hours' activity they establish themselves,
i!i,crt minute sucking mouth-organs, with which they are provided,
,„i,, the bark and connnence to suck the sap. Once the female has
stilled on a particular sixjt she never moves again to take up any
uilRT position on the tree. The young larva" gradually excrete a waxy
Mil)stance over their bodies which forms and hardens into the familiar
scale or protective shield. In the autumn or during the winter the
fnnale. which remains for ever wingless, dies beneath the scale she
has constructed, leaving behind her complement of eggs. The male
insect undergoes a similar metamorphosis in the early part of the
summer, but later in the year, about July, emerges with wings which
ai)i)arentiy are only strong enough to enable it to reach and fertilize
tlio stationary female.

Means of Control.

A study of the life-history of this insect reveals the facts ( i ) that it
is single-brooded, (2) that it has a reproductive capacity of an
approximate average of 60 eggs, and (3) that it is not capable of much
movement. Thus a commercial orchardist has no right to clami this
insect as an imoortant fruit-tree pest, on the understanding that
practical horticulture to-day demands proper attention to timely appli-
cations of spray. A thorough application of lime-sulphur, 1-30 or 35
I specific gravity 1.009), immediately after the petals fall, under ordinary
nrcumstances suffices to hold this insect in check. Moderately severe
cases of infestation may be treated also with a winter strength lime-
Milphar solution at the time the buds are bursting, to act as an
additional means of control.

In some of the older orchards of the Province, where trees are
nicrusted with superfluous bark and growth of lichens (locally
referred to as " moss "), an application of Gillett's lye at the rate of
I lb. to 4 gallons of water will be found advantageous. This may
l)c performed in the autumn and applied direct to the trees by the
■ nost convenient method.

I'ictoria, B.C.. issued March, 1918.

This circular has been prepared by R. C. Treherne, l-icld Officer for
r'ush CoSia. Entomological Branch, Dominion Department of Agn-
ilture, at the request of the Horticultural Branch.

Copts ot this circular may be obtained free of ^^'^^ v^ ,l^?^'TS or
(• Horticultural Branch, Department of Agriculture, Victoria, B.C., or
om local branch offices of the Department.

•-.-,w.....„.e....:-r/;o';£w.

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M"»t Kxccllmt MajMty.