— 5(J — 



ones cany on their ^vork of destruction among the ranks of 

 those that are one-half to fitll-grown. 



Not only do these predaceous beetles kill and feed upon the 

 young locusts, but many of them, in their larval state, also feed 

 on locust-eggs. Some of them are particularly useful in this 

 direction. 



RoBBER-FLiES. — Thcsc large, fierce, hairy flies are exceeding- 

 1}^ fond of the young locusts which they pounce upon and 

 seize as a cat would a mouse. When once in their possession 

 they fly off to some spot upon the bare ground or to the stem 

 of a plant, where, unmolested, they can suck the juices of their 

 victim. At least four or live distinct kinds of these flies have 

 been observed to capture the saltonas of our locust ; and 

 undoubted]3Miiost of the larger species do likewise, since it is 



Fig-. 13. — Robb.T Fly. 



a common habit among the North American representatives 

 of the family ( Asilidoc ). 



Other insects. — Still other kinds of insects are also known 

 occasionally to destroy saltonas of various species of locusts. 

 Some of these are the pre3'ing mantis, different kinds of ants, 

 and several of the predaceous bugs ( Heteroptera ). 



Of course we cannot hope for relief from the locust-plague 

 to come by the efforts of these predaceous insects alone. Still, 

 by knowing that there are so many and varied agencies at 

 work, we can take new courage and fight the more faithfully 

 ourselves, knowing" that when once reduced to a certain point 

 these natural enemies of the locust Avill keep it within proper 

 limits. 



