REPORT OF THE SOCIETY 



83 



darker and abdomen crossed by several bands. Migrates to Sfachys and Galeopsis 



{Gillette). 



Hop Plant Louse {Phorodon humuli Schrank). — Migrates from plum to hop 

 in the third generation; yellowish-green, with a prominent tubercle on head at 

 base of each antenna, and another smaller tubercle on the base of each antenna. 



Winged and apterous females of the plum and hop louse, Phorodon humuli Schrank. (After Rihy.) 



APPLE WOOLLY APHIS 



{Consult Bid. 256 Maine Agr. Expt. Stn., 1916, and Report loi, U.S. Bureau 

 of Entomology, by A. C. Baker.) 



This native woolly aphis is frequently injurious to many varieties of apple 

 trees, causing deformations both on the stems and leaves and on the roots. It 

 occurs also on pear, hawthorn and mountain ash, and passes part of its life on the 

 elm. The injury to the roots consists in the formation of hard fibrous enlarge- 

 ments resembling knots or clubs, often causing the death of the affected part. 

 Nursery stock is liable to infestation and severe injury. The injury to the branches 

 is not so serious, but in cases of severe infestation it causes stunted growth and 

 yellowing of the leaves. Colonies often collect at the axils of leaves, on water- 

 sprouts, and at abrasions and wounds. 



The common form seen on roots and limbs is wingless, 1-10 inch long, 

 reddish-brown, and covered with a woolly waxy excretion. 



WooUy Aphis of elm and apple (Schizoneura lanigera) (Americana in part), 

 migrant from elm rcsette. (After Patch). 



\'enation of wing of spring 



