276 



ECONOMIC ENTOMOLOGY 



Dep. Agr. Canada, 1916; Bull. 419, N. Y. Agr. Exp. Stn.; Cornell Univ., 

 Bull. 78.) 



Onion Maggot {Phorbia ceparum Mg. = Hylemyia antiqua Mg.). 

 Adult. — Slightly larger than Cabbage Root Maggot Fly; body and 

 legs with many black bristles; back of thorax of male with four indistinct 

 dark colored bands; abdomen with a distinct blackish band down 

 the middle; May-June. Probably three broods a year. Pre-oviposi- 

 tion period about 10 days (Fig. 180). 



Fig. 179. — Onion maggot (Phorbia ceparum), female and head of male. 



Eggs. — Cylindrical, white, distinctly ridged; groove not so deep or 

 long as in P. brassicce; duration 3 to 4 days. 



Larva. — White, cylindrical, rounded, truncate at posterior end; 

 ^5 inch long; central tubercles of blunt end single-pointed, with a pair 

 of additional tubercles. Duration 2-3 weeks, occasionally 4-5 weeks. 

 Young larva works its way down within the sheath of the plant to the 

 forming bulb, in which it feeds. 



Pupa. — Puparia formed in soil or in outer layers of onion. Found 

 13^^-3 inches below the surface. Summer duration about 2 weeks; 

 hibernates. 



