ENEMIES OF MAIZE 



247 



327. Insect Enemies. — Two hundred and fourteen species 

 of insects are known to be more or less injurious to the maize 

 plant. Insect injuries are more common and more extensive in 

 the Southern States than in the Northern States. Except, 

 however, for those insects which attack the young plant and 

 make replanting necessary, destruction of the crop is seldom 

 complete. The larger number of the injuries to maize occur 

 after plowing up grass land of long standing, or are due to con- 

 tinuous culture of maize upon the same land several years in 

 succession. Some of the insects also pass a portion of their 

 life on or can use weedy plants for food. Generally, there- 

 fore, the most effective remedies against insect attacks are short 

 and systematic rotations, accompanied by clean culture of the 

 maize field and the surrounding territory. Where the land is 

 neither in grass nor maize more than two years in succession 

 the attacks of insects are comparatively Hmited; except, per- 

 haps, in the case of certain migratory insects, such as the chinch 

 bug, locusts and army worms, whose increase in numbers has 

 been brought about by special conditions. The insects of most 

 economical importance to growing maize are as follows : 



(1) Wireworms {Elateridae), 



(2) Cutworms {Xociuidae). 



(3) ^^^lite grubs {Lachfiosterna spp.) 



(4) Com root worms (Diabrotica long-icornis Say and D. l2-punctata OUv.). 



(5) Com root web-worms {Crambiis spp.). 



(6) Com root louse {Aphis maidi-radicis Forbes). 



(7) Com bill bugs (>S"/^«^//jk7r«j spp.) 



(8) Com ear-worm {Heliothis anniger Hubn.) 



(9) Stalk borers {Xociuidae and Pyralidae). 

 (10) Chinch bug {Blissus leucoptert*s S)2i\) (151). 



The insects most injurious to the stored grain are the same 

 as those affecting stored wheat. (156) 



328. Wire wo RMS are the lar%-ae of the large family of click baetles or 

 " Jumping Jacks," eight species of which are known to be injurious to maize. 1 The 

 norms vary in length from one-half to one and one-quarter inches, have a bard, 



» III Bui. 44, p. 224. 



