108 



(Fig. 24.) The hop plant louse, male. (Enlarged.) 



(Fig. 2o.) Winter egg of the hop plant louse, and the shrivelled sliin of the sexual 

 female which laid them. (Enlarged.) 





(Fig. 26.) The hop plant louse, third generation on plum. — the generation which flies 

 to the Imp plant. Head below at right. (Both enlarged.) 



