52 



farmers' bulletin 856. 



other root maggots are frequently injurious, as are certain wire- 

 worms (p. 17) and the tarnished phint bug (p. 19). 



When onions are affected with mildew the tops wither and die. A 

 violet mildew ma.y be seen on the diseased areas. If detected in time, 

 spray with Bordeaux mixture and resin fish-oil soap. 



57. — The seed-corn maggot {Pegomya ftisciccps) : a, Male fly, dorsal view; h, female, 

 lateral view ; c, puparium ; d, larva, from side. All much enlarged. 



In onion smut the young seedlings are covered with pustules fdled 

 with a black powder. This disease remains in the soil. If no clean 

 ground can be had, apply formaldehyde solution in the drill, after 

 dropping the seed and before covering it, at the rate of 3 to 4 

 (juarts per 100 feet of row. Onion sets are not subject to smut 

 injury. 



PEAS. 



Garden peas are attacked by the same insects as those mentioned 

 under " Beans" (p. 25). For convenience cowpeas will be mentioned 

 here as they are generally known throughout the South as '' peas," 

 while in the North one form is called black-eyed peas, or beans, a 

 variety which is much cultivated for human food. Among those 

 insects which feed on the leaves are the bean ladybird, blister beetles, 

 and cutworms and other caterpillars. See "Beans" (p. 25). There 

 are, however, a few insects which attack peas in preference to beans. 

 The principal ones of these are the pea weevil and the pea aphis. 



