Technical and Bibliographic Notes / Notes techniques et bibliographiques

The Institute has attempted to obtain the t)est original copy available for filming. Features of this copy whi>:h 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.

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Coloured covers / Couverture de couleur

Covers damaged / Couverture endommagte

Covers restored and/or laminated / Couverture restaur^e 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 / Reli6 avec d'autres documents

Only edition available / Seule Edition disponible

Tight binding may cause shadows or distortion along interior margin / La reliure serr^ 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 6\a\\ possible, ces pages n'ont pas 6X6 film^s.

Additional comments / Commentaires suppl^mentaires:

L'Institut a microfilm^ le meilleur exemplaire qu'il lui a 6\6 possible de se procurer. Les details de cet exem- plaire qui sont peut-dtre uniques du point de vue bibli- ographique, qui peuvent modifier une image reproduite, ou qui peuvent exiger une modtfk»tion dans la mdtho- de normale de filmage sont indiqute ci-dessous.

I I Coloured pages / Pages de couleur

I I Pages damaged / Pages endommagtes

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

Q Pages discoloured, stained or foxed / Pages dteolor^s, tachet^s ou piques

I I Pages detached / Pages d^tach^es

r/J Showthrough / Transparence

I I Quality of print varies /

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Quality in^gale de I'impression

Includes supplementary material / Comprend du materiel suppl^mentaire

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

This Kern is filmed at the reduction ratio checlted below /

Ce document est film* au taux de rMuction indiqu* ci-dessous.

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The copy filmtd htr« has batn rtproductd thanks to tha gsnarosity of:

Library Agriculturt Canada

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

L'axamplaira filmi fut raproduit grftca k la gintto»\tt da:

Bibliothiqut Agriculturt Canada

Laa imagaa auivantaa ont tt4 raproduitaa avac la plua grand aoin, compta tanu da la condition at da la nattati da l'axamplaira film*, at •» conformity avac laa conditiona du contrat da filmaga.

Original copiaa in printad papar covara ara filmad baginning with tha front covar and anding on tha laat paga with a printad or illuatratad impraa* aion, or tha back covar whan appropriata. Ail othar original copiaa ara filmad baginning on tha firat paga with a printed or illuatratad impraa- aion. and anding on tha laat paga with a printad or illuatratad impraaaion.

Laa axamplairaa originaux dont la couvartura an papiar aat imprim4a aont filmta an comman9ant par la pramiar plat at an tarminant soit par la darniira paga qui comporta una amprainta d'impraaaion ou d'illuatration, aoit par la aacond plat, aalon la caa. Toua laa autraa axamplairaa originaux aont filmte an comman9ant par la pramiAra paga qui comporta una amprainta d'impraaaion ou d'illuatration at an tarminant par la darniira paga qui comporta una talla amprainta.

Tha laat racordad frame on each microfiche ahall contain the aymbol ^^ (meaning "CON- TINUED"), or the aymbol V (meaning "END"), whichever appliea.

Un dee aymbolea auivanta apparaTtra aur la darnlAre image de cheque microfiche, aalon le caa: le aymbole -*- aignifie "A SUIVRE". le aymbole V aignifie "FIN".

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

Lea cartea. planchea. tableaux, etc.. peuvent itre filmia i dee taux de reduction diffirenta. Loraque le document eat trop grand pour itre reproduit en un aaul cllcht. il eat filmi i partir de Tangle auptrlaur gauche, de geuche A drolte. et de haut en bea. en prenant le nombre d'imagaa nicaaaalre. Lea diagrammea auivanta illuatrant la mithode. -

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Miaiocorv rcjoiution tbt chart

(ANSI and ISO TEST CHART No. 2)

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A /APPLIED ItVHGE I

^K '653 East Main Street

y.g Rochester. New York 14609 tjSA

^S (716) 482 - 0300 - Phone

^= '716) 28a - 5989 - Fax

CIRCULAII No. sa

PROVINCE OP BRITISH COLUMBIA.

DEPARTMENT OF AGRICULTURE

(HoBTICfLTl'BAL BRANCH).

THE CABBAGE-ROOT MAGGOT

(Phorbia brassictc Bouche).

1HERE are few insects attacking vegetables which cause greater loss and disappointment than the one which as a small white naggot is often found infesting the roots of cabbages, cauliflowers, ape, turnips, and radishes.

During early spring and summer, in the seed-bed and in the

ermanent plantation, the leaves of certain cabbage and cauliflower

plants frequently turn yellow, wilt, and droop. If an examination is

Mkle.

Female.

Tbe adalt fliei.

(After Olbs and Treherne, Ent. Branch Bull. 12, Dom. De^.. Agrlc, Ottawa.)

ide of the roots a number of maggots, varying in size but attaining

^e length of '/^ inch will be found embedded beneath a slimy mass

decaying vegetation and soil. With radishes and turnips similar

white maggots will be found in burrows or galleries in the edible

portion of t'e roots.

The adults which produce these maggots arc small fljes, resemWmg the ordinary house-fly in general appearance, but more slender and slightly smaller. They are represented above. They appear on the wing in very early spring, having developed from over-wmtermg puparia in the soil. They lay eggs on or near the crown of the plant on the level of the soil surface, as shown in the accompanymg illustration.

Where the ecn are laid. (After Gibaon and Treherne, bS' BrtiJ^lf^Bvill. J J. Dim. Dept. Aifrlc. Ottawa.)

These eggs hatch in five to seven days into small larvae or n. which penerate the soil and attach themselves to the roots ot the plant. Here the larvae remain feeding and destroying the roots for from nineteen to thirty-two days.

It must be understood that all of the adult flies do not emerge from the soil in the spring at the same time. The process of emergence may be continued for over a month. .A.s each female emerges she mates and proceeds at once to lay eggs. Thus we find a continuou> and overlapping series of stages in existence. It may be possible, it can be seen, for the larva, which have developed from flies whicl emerged the earliest, to be nearly mature at the time the latest flie^ are emerging from the soil. This complex and difficult situatioi proceeds, throughout the year, and results in the fact that some egg

are being laid every day from April until September. This point must be clearly borne in mind, as upon it is based one of the essential features of satisfactory control.

When the larvae become full-y. » they form what are known .''s .puparia. a stage in their life-history which corresponds to the

Whero the magKOta teeA and the type of Injury thev cauiie. (After Olbson ami Treherne, Knt. Branch Bull. 12, Dom. Kept. Agrlc. Ottawa.)

chrysalis of a butterfly. The puparia of this fly resemble grains of wheat in size and colour, and may be found in decaying roots or in the soil adjacent to infested plants. From two to three weeks are passed in this stage during the summer months, but towards autumn the stage is lengthened out and the winter is passed in this form. The puparium stage is merely a resting stage from which eventually the adult flies emerge, and, as can be realized, this emergence of adults may be more or less a continuous process throughout the summer months.

■'.Si

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Familial MMmrw.

from gaining accw. to the olants Rr-«. V 5 **'"'* ^'"

.houIdT frown under .u^r "'""L' *"'*"^'^ '°' ^^'^ »*"« Cabbage, anrjuliflot" sZl ^ ^iStd ^'' TT firit month under this protection aJi ^m-" / *^°*" ''"' ^ some such screen fo, in thu ^" ',""''• '^^'1"» »houW possess

from the ob„"xl'^:„ll':f;'/^ -y .»- Ifuaranteed free

unpleasant to eat Cabt^es fu th- " ""- ' '^'°^" ''^•' "^

» W^H--

cond,.,o„. Th. piece of ^„„d defined fo.r;:rar„r«°?j:^j

plantation should be thoroughly cultivated during thta week and finished off with a light roller and harrows. It is essential that the surface of the soil be sunrnth and not lumpy.

One-ply Felt Tar-paper Disks.— hi the plants are removed from the seed-bed and set in the permanent plantation a disk of one-ply felt tar-paper «hi »jld be placed around the crown of the plant, flush to the soil. The illustration on the preceding page indicates the correct procedure.

These disks may be circular, square, or hexagonal in shape, approxi- mately 3 inches in diameter, with a slit to the centre, whici. enables it to be quickly arranged by the planter. If nothing better than ordinary tar-pap jr -an be obtained, two disks to a plant may be

riant protected by tarred-paper dl«k. (After Rrltton and Lowry. Connecticut, 190.)

necessary, i elt tar-paper does not curl from the heat of the sun and is therefore prefera' le. The idea of these disks is partly to detract the fly by the odou: of tar, and partly, if eggs are laid, to guide the young larvae away from the root system. It is essential that the disks lie flush to the ground-level, otherwise the adult flies may crawl

benetth them and depcwt egg.. The virtue of havii* ■ nnooth

t^So t^!;S" H '":""' f^'*^" «r.n.pl.„ti„g. there i. J^MHy

^IhITh r """ 'r ^'^ ^^'^ °' •"• Thi. method i. recommended for commercial plantatbni.

ff'^rW.V W'^wA'-i-If the Ur-|*prr di.ki arc not used, applications of hquid. should be applied to the root., once a week. The ob^t ^ the^ apphcatKin. » to destroy the young maggots l-fure thirca, destroy the plant. It will be recalled that egg-lfying is J^re or les . contmuous proce.,s during the summer anTthat the e^ hatch"

Sl^ .n f L!"^ "' ""''" '° "^' «»"''" °' *«'" «^e effect ve. Ddution, of carbohc-acid or kerosene emulsions may also be app ied These solutions have been found of special value in gardens. Under field^cond.t.ons they are not practicable, chiefly on Scount of their

flow:r:Ts''ad'l'nr'^h" ' '•' '"^'"^ °^' ^^""'"^ '^''''»-«" -d -"«-

nowers IS adopt.,! by many growers to ensure carliness the following year and ,s mtended that the plants should be able better to coZ!

tlluT. °' r ^'-'"«««"»» ^y 'he mere fact that the plants a ewd estabhshed m the sprmg. Growers who follow this method wouldT. well advsed to seed a few radishes early i„ the spring in the oZ ne^ by. to attract the adult females and thus to act L tfaps. Ex^^Jience has shown that the success of these autumn-planted cabCs il altogether dependent on the number of flies present in the Spring and oTl^l P'ants available on which they are able to dej^si*';^ Other Remedial Measures.-Thtrc is possibly no insect affecSmr P.rden produce that has been the subject of more conflic^g :vide"cf m Che matter of control than the cabbage-root maggot Eve^

^t7Jr VT'"' "'r ■"^"' °' ^^"^'^^•°" '» combatTe mag^;^ of mer? These applications frequently take the form of solu^ns

tZuT' . ?l!" '°'''''' "^•■*^^'' °'- P^'*"' «>'"tions bought through local supply-houses. Soot, wood-ashes, tobacco powder, lime

their n' I '''"'" ^''? '^''' ^^P"^^ ^^^^ ^^^ °''^" --^» * tnlg on a Z f''^'"'"''^ '''^" '"^^"^^"'- There is no reason whv

on a garden scale any mixture properly and frequently applied should

insecticidalv.'' In a commercial way and under prooer control

Further information regarding the habits and control of the

lo^crBrnch'T -'' n °''""'' '^^ ^""^*'" ^^ ''' ^ntomo- Jogical Branch. Dommion Department of Agriculture, Ottawa.

Victoria, B.C.. issued March, ipi8.