352 



FRUIT INSECTS 



surface turns a bright red, variegated with yellow and green. 

 Later the badly injured leaves may fall from the bushes and 

 thus prevent the fruit from maturing properly. The fruit is 



also injured by a black 

 fungus which grows on 

 the sticky substance, 

 known as honey-dew, 

 secreted by the lice. 



After the middle of 

 July the hce become 

 greatly reduced in num- 

 l)ers, owing to the at- 

 tacks of their numerous 

 predaceous and parasitic 

 enemies, but a few fe- 

 males are able to sur- 

 vive, and at the ap- 

 proach of cold weather 

 give rise to true males 

 and females. The latter deposit the winter eggs on the twigs 

 during the latter part of October. 

 Treatment. 



The currant plant-louse is not an easy insect to control, 

 owing to the way in which it is protected in the pocket-Uke 

 cavities of the curled leaves. These soft-bodied lice are easily 

 killed by ordinary contact insecticides, such as kerosene emul- 

 sion, soap solutions and tobacco extracts; the difficulty is in 

 reaching them. To be effective, the spraying must be done with 

 great thoroughness soon after the hatching of the eggs and 

 before the leaves curl ; an upturned nozzle should be used so as 

 to hit the leaves from beneath. 



Fig. 313. — A colony of currant plant-lice on 

 the underside of a leaf. 



Reference 

 N. Y. (Geneva) Agr. Exp. Sta. Bull. 139, pp. 660-663. 1897. 



