126 The Rocky Mountain Locust. 



[Fig. 24.] 



n^PALUS* Laeva:— B. under-side of head; h. under side 



The other Ground-beetle, belonging probably to the 

 same genus as the above, is of about the same size and has 

 precisely the same structure. It is at once distinguished, 

 however, by a series of broad, dark-brown, horny plates 

 along the back, by paler horny pieces along the sides and 

 beneath; by the darker, somewhat narrower prothorax; by 



the pale legs, 

 and by the 

 shorter anal 

 cerci. I have 

 found three 

 specimens of 

 this last feed- 



of different joints of body. ing oil the 



eggs, and one was sent to me as having the same 

 habit, by Mr. Whitman, of St. Paul. Mr. G. F. Gaumer 

 has sent me what he took to be a minute Rove-beetle 

 (StaphyMnidce) found feeding on the eggs, and they prove 

 to be newly hatched specimens of the above Carabid 

 larva. 



It is probable that most of the Carabid larvae will* feed 

 on the eggs, and I introduce the figure of a larger species 

 (Fig. 24) and its probable parent, the Pennsylvania 

 Ground-beetle (Harpalus pennsylv aniens, DeGeer, Fig. 25). 

 I have every reason to believe, also, that certain Click- 

 beetle larvse (JE later idee) and certain Myriapods devour the 

 eggs, while I have actually caught the common White 

 Grub (larva of Laehnosterna fusca) feeding upon them. 



INSECTS THAT DESTROY THE ACTIVE LOCUST. 



In a general way it may be stated that all the larger 

 predaceous species prey on the locusts. The Ground- 

 beetles ( Carabidce) are conspicuous among these, and the 

 Fiery Calosoma (Fig. 26) and the Elongate Ground-beetle 



