i6o DISEASES OF THE SWEET PEA 



Syrphid Flies. Syrphus ribesii. In 

 company with the plant lice are seen 

 greenish, flat sticky looking "worms," 



FIG. 34. SYRPHID FLY, Syrphus Americonus, whose larva 



FEEDS ON THE SPRING GREEN APHIS AND ALSO ON THE 

 SWEET PEA APHIS, a FEMALE FLY. b SECOND ABDOM- 

 INAL SEGMENT OF MALE. (AFTER WEBSTER AND PHIL- 

 IPS.) 



which are pointed at one end and seem 

 to have no distinct head, eyes, or legs. 

 These are larvae or maggots of a two- 

 winged fly commonly known as Syrphid 

 or Flower Fly. The maggots obtain 

 their food by puncturing the body wall of 



