ii8 INSECTS OF ECONOMIC IMPORTANCE 



Control — Strengthen fertility of soil to produce 

 strong- plants; burn stubble where not seeded or 

 plow under deeply ; rotate crops. 



The army worm ^ {HeUophila iinipiincta) 

 Order — Lepidoptera 



For years there have been outbreaks of this pest 

 in various localities in the eastern United ^States. 

 Outbreaks in New York State in 1861, 1875, 1880, 

 1896; the larvae migrate in immense numbers from 

 one field to another, destroying the vegetation in 

 their path. 



The eggs are deposited in unfolded grass leaves 

 or into the sheath of the leaf where it clasps the 

 stem; the larvae attain their growth in about 30 

 days and go into the ground to pupate; the pupal 

 stage lasts from 12 days to 3 or 4 weeks depending 

 on the season; the winter is passed as larvae; there 

 are evidently two broods, the July brood being the 

 most abundant and injurious ; in the south there are 

 more generations. 



Control — Usually fought by barriers in the 

 same way as the chinch bug and by poison baits. 



Grasshoppers ^ 



There are several destructive species of grass- 

 hoppers in the United States; perhaps the red- 

 legged grasshopper (Mclanoplus fcmur-nihnnn), 

 the differential grasshopper {Mclanoplus diffcrcn- 

 tialis), the lesser migratory grasshopper (Melano- 

 plus atlanis), and the two-striped grasshopper 

 (Mclanoplus bwitfafus) are the most generally dis- 

 tributed of any of the injurious species. 



In general the eggs of grasshoppers are laid in 



8 Knight— Cornell Univ. Expt. Stat., Bull. 376. 

 9Herrick and Hadley— Cornell Univ. Expt. Stat., Bull. 378. 

 Walton— U. S. Dept. Agr., Ear's' Bull. 747- 



