14 Peovincial Board of Horticulture. 1897 



During the summer months they reproduce in the same manner as green aphides, but 

 winged forms appear only in the fall. 



During our mild winters in the coast districts, woolly aphides may be found in different 

 stages of development, showing that if egg laying takes place, the eggs probably hatch off at 

 once, and new colonies are started, or that viviparous reproduction goes on without the 

 necessity of egg laying. The prevalence of dead-spot or bark disease in apple trees gives just 

 the condition of the bark which favours the pests, by providing them with shelter, and 

 increases the difficulty of reaching them with spraying mixtures. 



It is therefore important that, as far as possible, dead and decayed bark and all superfluous 

 limbs and branches of infested trees should be removed before Spraying is done, to allow the 

 mixture used to penetrate all parts of the trees. 



The best winter wash is the No. 1 spray; the lye and soap wash (No. 15) is also effective. 

 At least two applications should be made to badly infested trees, and, the spray applied warm, 

 with all the force possible; by means of a good spray pump. During the summer months, 

 masses or colonies of the aphides occurring on the trunk or limbs may be destroyed by touch- 

 ing them with a swab or brush dipped in coal oil, or either of sprays No. 6 or 7, applied with 

 the spray pump. It will be neeessary to repeat the treatment at intervals to keep .the pests in 

 check, until the strong winter washes can be used. For the root form of woolly aphides the 

 No. 1 spray is effective, or the lye and soap wash used freely, especially where the stem and 

 roots join. These substances will also act as fertilisers to the trees. To increase their effect, the 

 roots of infested trees should be uncovered as far as possible before applying. Refuse tobacco 

 dug in about the roots will also help to keep down the pests. 



The Missouri Experimental Station have made extensive experiments with different 

 methods of killing woolly aphides, particularly the root form of the pest, and a bulletin issued 

 by the station states that the root form may be cheaply and easily killed, and kept away from 

 the roots of apple trees by a liberal use of tobacco dust, applied by removing the earth from 

 around the trunk for a distance of two feet, and four inches in depth, evenly filling the space 

 with tobacco dust, and covering it with earth. 



As a preventive measure, tobacco dust should be used freely among an^ over the roots of 

 newly planted trees and nursery stock. 



Specimens of woolly aphides of different species were sent by Mr. E.-A. C Gibson to Dr 

 Fletcher, who writes in regard to them as follows :— "In the box of which you describe the 

 specimens as taken off an apple twig badly infested with woolly aphides ; these were the true 

 ^. lavigera, but amongst them were some other specimens of aphis malifoKce, which has the 

 venation very similar to that given of apMs mali, on page 163 of my last report The differ- 

 ence between these two last named species are chiefly colourational and in the size of the insect 

 ihe other box contaming specimens of the woolly aphis, which has given you so much trouble 

 to Identify, and which are flying in such myriads in your woods, are neither the alder aphis 

 nor the true woolly aphis, but a species called Pemphigus pyri, which belongs to the same 

 genus as the alder woolly aphis. 



o„t I'^^flff""^'"'^ ^^^^^"^ these two genera is very easy to recognise when once pointed 

 out, and that is, m the genus Schi^ oneura, the third discoidial vein is forked while in 

 pemphigus all the veins are simple. 



Hiff^ "^'I'^P^^P'^oPy^' probably is a native species with you, and occurs through your woods on 

 different species of pyrus and crat^gus." * -^ """"» "" 



1 ^"jj'.fPr^'f^ T?°"y ""f"}^ {Pemphigus tessellata) Ab very common upon alder trees in 

 lower British Columbia, and is often confounded with the woolly aphis of the appe from 

 The Woolly -^-\'* - .q-te distinct^ Like other aphides,'they reproduceTVv°S 

 . Alder Aphis. ^^,^\ ^^ ^^^"ig yo""?;^ Vast numbers of winged specimens appear ?n Uif 

 . , . .*l" ^J^!^ spread over the country, the air sometimes appearing full of tl^^ 



insects moving with the wind. They have not been found injurious to fruTt trees a tlLl 

 t^^V/oXTptt'^^'"^"^ '- ''''''' "'^ '''-■ 'They ^onitseem to reprodr-exc^pt-^S 



