maggot. Its injury, which constitutes the most important drawback to 

 the culture of onions, is accompHshed by the consumption of the bulb, 

 inducing subsequent decay of the afifected portions and their very fre- 

 quent destruction. 



The fly and the maggot resemble preceding species, although their 

 average size is a little larger. The length of the fly's body is about 

 three-sixteenths and the wing expanse nearly three-eighths of an inch. 

 The male is gray with black bristles and hairs ; it has a white face with 

 black hairs, and there are three dark lines on the body between the wings 

 and a row of black spots on the abdomen. The female is a little the 

 larger, and inclined to dark yellowish, with a pale yellowish face. 



As in the case of the cabbage maggot, two or three generations are 

 evidently the rule in the North. 



REMEDIES. 



The methods of control prescribed for the seed-corn maggot are fre- 

 quently about all that are necessary for this species. In case of severe 

 infestation the bisulphid of carbon treatment, discussed on page 5, as 

 also other remedies advised for the cabbage maggot, are useful, with 

 the exception of the tarred cards, which can not be conveniently nor 

 economically used on onion. The flies aie probably attracted to old 

 onion beds and to crop renmants; hence clean field methods are 

 advisable. 



Note. — This circular has been prepared to facilitate correspondence, 

 due to the fact that the three root-maggots mentioned herein have been 

 extremel.y injurious during recent years. A monographic account, which 

 has been of service in the preparation of this circular, was published in 

 1894 by Prof. M. V. Slingerland (Bui. 78, Cornell Univ. Agl. Exp. Sta., 

 pp. 481-577). It is now out of print. 



Approved : 



James Wilson, 



i^ecretartj. 



Washington, 1). C, Fibrnnnj I'J, l'.)()6. 



O 



