22 PESTS OF GARDEN AND FIELD CROPS 
Fic. 92.—The Seed-corn Maggot. 
Enlarged and natural size. Orig- 
inal. 
sprouts are pushing above the 
ground. A later generation works 
in similar fashion. The adult is 
a two-winged fly. 
The application of carbolic acid 
emulsion is the only direct remedy 
available. Injury is apt to be 
worse when manure has been ap- 
plied to the fields in the spring, 
probably because it attracts the 
adult flies or offers them shelter. 
The Carrot Rust-fly (Psila rose Fab.) 
The leaves of the plants attacked turn red or rusty looking, while the 
roots are tunneled by small brown maggots, one fourth of an inch long. 
Fic. 93.— Work of the Carrot Rust-fly. Original. 
On the surface the root may not show much evidence of injury, but 
when it is cut through, the brown burrows will be evident. Occa- 
siona'ly celery is attacked by the same species. 
The adult is a slender-bodied, two-winged fly. There is one genera- 
tion annually in the field, but breeding may at times go on in carrots 
in storage. 
