302 



INJURIOUS INSECTS AND FUNGI. 



[March 1895. 



Life History, 



This aphis belongs to the genus Schizoneura of the Aphididce. 

 It is quite distinct from another species of aphis, styled Aphis 

 mall, which also infests apple trees. The Aphis mali is fur- 

 nished with cornicles for the secretion of honey dew ; the woolly 

 aphis is without these appendages, and it differs also in many 

 other respects. 



The winged viviparous female is dark brown, having large 

 wings with black veins. The cubital vein has only one fork 

 differing in this from other tribes of the Aphididce. This 

 form appears in the late summer, and has been found as late 

 as September. From this form, egg-bearing, wingless females 

 are produced without beaks, or rostra, and are therefore 

 unable to feed. A female produces only one egg, which is very 

 small, and is deposited in the crevices of the bark. Propaga- 

 tion, the regular continuity of existence, however, is principally 

 carried on by means of the hibernating viviparous larvae which 

 pass the winter upon the trunks of the trees, their branches and 

 twigs, as well as upon their roots. They are protected from 

 cold by the bark, the folds of rind, and their own woolly 

 coats. These wingless females are woolly, of a brown colour, 

 and broad in shape, as shown in the illustration, which Mr. 

 Buckton has kindly allowed to be copied from his Monograph of 

 British Aphides. The young larvae from these, which again 

 reproduce larvae, are at first rather lighter in colour, and after a 

 time emit wreaths of woolly material from their dorsal pores 

 and become fully covered, so that a group of them has the 

 resemblance of a piece of cotton wool. The pupa is leather 

 darker than the larva, is squat in shape, and without wool, 

 while the wingless male is brown, without wool, and fully 

 equipped with an efiicient rostrum. 



There appears to be no visible difference between the genera- 

 tions of this insect that are found upon the branches and the 

 roots of apple trees. 



Preventive and Remedied Measures. 



Apple trees should be kept free from lichenous and mossy 

 growths which serve as shelters for woolly aphides as well as for 

 many other injurious insects. Lichens and mosses can be killed 

 by throwing hot finely powdered lime over the trees during the 

 winter, in damp weather, when the lime will adhere to the trees. 

 This can be done with tin scoops fastened to the end of long 

 poles. Sulphate of iron, dissolved in water at the rate of 1 lb. to 

 one gallon of water, sprayed in winter over the trees by a 

 powerful garden engine or hop-washer, will also kill lichens and 

 mosses. 



In young orchards, tiie apple trees should be carefully and 

 systematically pruned from the beginning, so that boughs do not 

 intertwist, and that plenty of air and light is afforded. Periodical 

 search should be made for woolly aphides and other insects. 



