No. 6.] RILEY — ROCKY MOUNTAIN LOCUST. 363 



THE ROCKY MOUNTAIN LOCUST.* 



The subject which you have assigned to me is entitled The 

 Rocky Mountain Locust and the Army Worm. Both these 

 insects are extremely injurious to the agriculture of the United 

 States, and as it would be difficult to do justice to both in the 

 compass of a brief address, I shall confine my remarks at the 

 present time to the first named. So much has been written and 

 said, by myself and others, upon this Rocky Mountain locust 

 during the past two or three years that it would seem difficult 

 indeed to say anything about it that is new or of value. Yet I 

 may safely assert that most of the definite and accurate know- 

 ledge regarding its habits and life history was first given to the 

 world during the present year. 



Though popularly known as the " grasshopper," yet the term 

 " Rocky Mountain locust," proposed by myself, has been very 

 generally adopted as most appropriate. The insect belongs to 

 the same family as the locusts of Scripture. The term grass- 

 hopper is very loosely applied to many insects that hop about 

 in grass, but strictly belongs to the long legged, long-feelered 

 species. Locusts have short and stout legs, short and stout 

 feelers, and are mute, or, if they stridulate at all, do so by rub- 

 bing the hind thighs against the sides of the folded front wings; 

 their prevailing colour is brown ; they are gregarious, and they 

 oviposit in the ground by means of short, drilling valves. True 

 grasshoppers have long and slender legs and feelers, and stridu- 

 late by vibrating the front wings, which in the males are fur- 

 nished, generally near the base, with talc-like plates crossed by 

 enlarged and hollow veins; their prevailing colour is green; they 

 are solitary, and they mostly oviposit in different parts of 

 plants, by means either of a sword- or scimeter-shaped ovipositor. 

 It is the grasshoppers, the katydids (which are a tree inhabit- 

 ing section of them), and the crickets which make field 

 and wood resound with shrill orchestry in autunm ; but the 

 locusts take no part in the concert. While our insect belongs 



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* Preprinted from the ''American Naturalist." 

 Vol VIII. x No 6 



