INSECTS INJURIOUS TO BEANS AND PEAS 321 



the cabbage and onion and are about one-fifth an inch long. 

 The male may be distinguished from nearly related species by a 

 row of nearly equal, short bristles on the inner side of the hind 

 tibiae or shanks. 



The life history of the species has not been carefully observed, 

 but is probably similar to that of other root-maggots. The 

 flies deposit their eggs either upon the young seedling just as it 

 appears above ground, or probably more often on the seed itself. 

 Injury is called to attention by the seed failing to germinate, 

 which, when examined, is found to contain one or more small 

 white maggots, which have destroyed the germ or the young 

 seedling. Thus in 1895, large areas of beans were destroyed in 

 Minnesota.* 



The maggots are about one-fourth an inch long, slightly 

 smaller than the onion-maggot, from which they may be dis- 

 tinguished by the tubercles of the anal segment. 



Control. It has been noted that injury often occurs where 

 stable manure has been turned under, and it may be possible 

 that the flies are attracted to it to oviposit or that they are 

 attracted by decaying seed. In preventing attacks of root- 

 maggots it would seem advisable to apply stable manure the 

 previous fall so that it may become well rotted and incorporated 

 into the soil before seeding. Rolling the seed-bed after planting 

 might also be of value in preventing the access of the flies to the 

 seed. 



Applications of commercial fertilizers , which will ensure a 

 quick growth of the seedling are advisable. The use of carbolic acid 

 emulsion and sand and kerosene upon the surface of the seed-bed 

 after planting and as the seedlings are appearing, as advised 

 for the cabbage root-maggot (see page 352) , will also be of value. 

 Inasmuch as the injury is sporadic and affects the seed before it 

 can be readily detected, reliance must be placed chiefly upon 

 general cultural methods as outlined above and others which 



* See Lugger, Bulletin 43, Minn. Agr. Exp. Sta., p. 207 (1st Rept. Minn. 

 State Entomologist.) See Circular 63, and Bulletin 33, p. 84, Bureau of 

 Entomology, U. S. Dept. Agr. 



