Natural Enemies. 



135 



such as were hopping about, the bodies have presented the 

 appearance of a mere shell, filled with maggots ; and so 

 efficient is this parasite that the ground in parts of the 

 Western States is often covered with the Rocky Mountain 

 Locust dead and dying from this cause. 



The Common Flesh-fly (Sarcophaga carnaria, Linn.) 

 — This fly, which is at once distinguished from the Tach- 

 ina-fly by the style of [Fig. 33.] 



the antenna, being hairy 

 (Fig. 33, i,) instead of ^M^J 

 smooth, is also a great 

 enemy of the Rocky 

 Mountain Locust, 



though I think it must 

 be looked upon more as 



«j «r>QTorfrpr tlnn cm Sakcopha-ga s.vrkacenijs :— a, larva'; b, pupa: c, 



a SCa\engei man as an flyithehairlines lowing average natural lengths; 



i^fivp nnrflsitp and rf < enlarged head and first joint of larva, showing 



active pclld-felte, d-liu. curved hooks, lower hp (g) and prothoracic spir- 



.-•.•,« -1 acles : e, end of body of same, showing stigmata 



that it IS attracted (/) and prolegs and vent ;/;. tarsal claws of flv, 

 with protecting pads; i, antenna of same— en- 



niore especially to those larged. 



specimens which are feeble or already dead. I have 

 received it among the Tachina parasites sent by Mr. Shat- 

 tuck, from Colorado, and from Professor C. E. Bessey, of 

 Ames, Iowa, who bred it from the Differential Locust, and 

 published the following description of its work : 



A Commendable Fly. — During the summer I noticed that many 

 of the large yellow grasshoppers (Caloptenus differentialis) were in- 

 fested by the maggot of a species of fly very nearly resembling, if 

 not identical with, the common Flesh-fly (Sarcophaga carnaria.) 

 Many of the grasshoppers were almost completely eaten out when 

 found, retaining just sufficient strength to hop feebly over the 

 ground. I estimate that this particular species of grasshopper was 

 diminished in numbers at least one-tenth, possibly one-eighth, by 

 these new friends. It is to be hoped that these new parasites will 

 increase rapidly. Professor C. V. Riley informs me that the Mi- 

 gratory Locust {Caloptenus spretus) is also infested by a similar one. 

 Thus far, however, I have failed to detect any in the specimens 

 collected in this vicinity. 



