THE MONTHLY BULLETIN. 



65 



Natural Enemies.— While practically all of the enemies enumerated 

 in the beginning of the article on plant lice work upon this louse, the 

 writer found it to be specially heavily parasitized by an internal para- 



Ym 53— The oleander aphid (Aphis nerii Fonsc). A and B, adult females; C, 

 D and E, antenna, cornicle and lateral aspect of pygidium of winged female; P, G 

 and H, same for apterous female. (Essig, P. C. Jr. Ent.) 



site. The larva? of the small syrphid fly, Allograpta ohliqua, were also 

 responsible for destroying great numbers of lice. These natural 

 enemies must certainly be responsible for keeping the corn leaf-aphis 

 from becoming a pest. 



5— H 



