INSECTS INJURIOUS TO MISCELLANEOUS CROPS 245 



ever have been noticed in recent years injuriously affecting the 

 onion crop. 



The Imported Onion Maggot (Pegomya cepetorum Meade). — 

 This maggot injures the onion by eating into the bulbs, the 

 subsequent decay of the affected portions frequently destroying 

 them. It is a most important drawback to the culture of onions 

 here and in Europe, from which continent it was introduced 

 years ago. It is nearly related to the seed-corn, and cabbage, 

 maggots treated in former pages. In the adult state it re- 

 sembles, as do the others, the common house fly. The average 

 size is a little larger than the flies of the two root-maggots that 

 have been mentioned, the body being about 3/16-inch long and 

 the wing expanse nearly 3/8-inch. The maggot itself and the 

 puparium can be distinguished from those of other root-mag- 

 gots only by careful comparison. 



The life history is very like that of the cabbage maggot, 

 the differences being due to the different character of the 

 vegetables attacked. It follows that the natural enemies which 

 prey on one are liable to attack the others, and the remedial 

 measures to be adopted are also much the same. 



Remedies. — For a discussion of remedies the reader is re- 

 ferred to the account of the seed-corn maggot. 



The Black Onion Fly (Tritoxa flcxa Wied.).— This is an 

 old enemy of onion and a native 

 species, recorded from the Atlantic 

 coast to Illinois. The fly is about 

 one-third of an inch long, black, 

 with three oblique white stripes 

 on each wing. The maggot itself 

 is white and larger than the root- 

 feeding species previously treated. Fie- 159.-Black onion fly. Three 

 T^ , , . , . , , . • times natural size. (After Walsh) 



It feeds on onions and cives both m ' 



the field and in store. General remedies are the same as for the 



