Ill 



It is geiieraly considered tlie most troublesome insect pest of apple trees 

 we have, from tlie difficulty experienced in cleausiug sm orchard infested with 

 it. and its harmful effect upon the trees. Its name of woolly aphis is derived 

 from the secretion resembling fine cottony fibre, which more or less covers its 

 body. The insects appear on infested trees during the summer in masses like 

 tufts of cotton, attached to the twigs or leaves, beneath which will be fomid 

 the bodies of the in.sects. 



In the winter months they shelter under the bark or in cavities in the 

 wood of the trees, or descend to the roots; large numbers will often be found 

 at or near the collar of the root. 



The eggs of woolly aphides are stated by Dr. Smith " to be found singly 

 in crevices of the bark, enveloped in the dry skin of the female." 



During the summer months they reproduce in the same niiinner 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 dilferent stages of develoiiment, showing that if egg laying takes 

 place, the eggs iirobably hatch off at once, and new colonies are started, or 

 that viviparous reiiroducticm goes on without the necessity of egg laying. 

 The prevalence of dead-spot or bark disease in apple trees gives just the con- 

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

 and increases the difficuty of reaching them with spraying mixtures. 



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

 and all surplus limbs and branches of infested trees should be removed before 

 spraying is done, to allow the mixture u.sed to penetrate all parts of the trees. 



The best winter wash is the Xo. 1 spray; the l.ve and soap wash (Xo. 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 touching them 

 with a swab or brush dipped in coal oil, or either of sprays Xo. C. or 7, 

 applied with a spray-pump. It will be necessary 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 Xo. 1 spray is effective, or 

 the lye and soap wash used freely. espe<-ially where the stem and roots join. 

 These substances will also act as fertilisers to the trees. To increa.se 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 lias made extensive exiieriments 

 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 remo\-ing the earth from around the 

 trunk for a distance of two feet, and four inches deep, evenly tilling the 

 space with tobacco dust, and covering with earth. 



As a preventive measure, tobacco dust should be used freely among and 

 over the roots of newly jilanted trees and nursery stock. 



