16 



GENERAL ZOOLOGY 



they become abundant enough to threaten cultivated crops. 

 One of the commonest of these is called the hopperdozer. 

 As this is dragged across a field the grasshoppers start to 

 fly or jump but strike an upright wall and drop into a 

 trough filled with oil. 



Since grasshoppers are chewing insects, one of the best 

 means of exterminating them is by use of sweetened poi- 

 soned bran, which they eat in preference to the vegetation. 

 In years when they are abundant many millions of dollars 



worth of grain are saved 

 annually by poisoning and 

 by capturing the swarms 

 of grasshoppers invading 

 the fields. 



Grasshoppers in History. 

 There are several species 

 of migratory grasshoppers 

 in the Old World whose 

 visitations in the past 

 have been destructive, 

 especially in Egypt, Palestine, Syria, Asia Minor, China, 

 Russia, France, and Germany. The prophet Joel has de- 

 scribed the onslaught of grasshoppers in the lines beginning 



A day of darkness and of gloominess, a day of clouds and of 

 thick darkness, as the morning spread upon the mountains: a 

 great people and a strong; there hath not been ever the like, 

 neither shall be any more after it, even to the years of many 

 generations. 1 



It is easy to appreciate the fact that in thickly settled areas 

 famine and pestilence may follow the visitation of these in- 

 sects. Out of the twelve hundred or fifteen hundred species 

 of grasshoppers in the world, only about twelve have the 

 habit of migration to any great extent, and these are mostly 



» Joel ii, 2. 



Fig. 6. A meadow grasshopper 



From the Illinois State Natural History 

 Survey 



