122 



PESTS OF GARDEN AND FIELD CROPS 



Fig. 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 appUcation of carbolic acid 

 emulsion is the only direct remedy 

 available. Injury is apt to be 

 worse when manure has been ap- 

 phed to the fields in the spring, 

 probably because it attracts the 

 adult flies or offers them shelter. 



The Carrot Rust-fly {Psila rosce 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. 



Fig. 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 wiU be evident. Occa- 

 sionally 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. 



