LOCUST ENEMIES: ASILUS-FLIES; DIGGER-WASPS. 



317 



able frora tbeir large size and occurrence in clusters. Dry clayey banks are preferred 

 and all the burrows I bave examined enter atrigbt angles to tbe surface of tbesoil, and 

 remain straigbt for tbree-fourths of tbeir lengtb, tben gradually curving. It is not un- 

 usual to see tbe larva3 after sundown, or earlier if tbe day be cloudy. Tbey are, bow- 

 ever, very sby, and I know of but one specimen being taken witbout considerable digging. 



A full description of this larva by Dr. Horn will appear in vol. vii of 

 the Transactions of the American Entomological Society, and we present 

 the accompanying figure thereof, with its several parts enlarged, from 

 an advance plate kindly furnished by the author. This larva had pre- 

 viously been mentioned (Ann. Lye. iv, 1845, p. 143) by Dr. LeConte 

 as that of Pasimachus. 

 Asilus-flies. — We have already referred to these flies (p. 303), the 



larvse of some of which prey upon the 

 eggs of the locust. The perfect flies are 

 very fond of the young locusts, pouncing 

 upon and seizing them, and then flying 

 off to some spot where, unmolested, 

 they can suck the juices of their victim. 

 Mr. Lawrence Bruner, of Omaha, 

 Nebr., who has had good opportunity 

 of observing, says that the larger species 

 live almost entirely on locusts during 

 the months of June, July, and August. 

 Most of the larger species'^^ doubtless 

 have this habit, and one of the most common and ferocious in which we 

 have observed it is the Proctocantlms milberti"''' Macq. (Fig. 54), and 

 popularly called the Missouri Bee-killer, on account of its habit of de- 

 stroying bees in the Southwest. These insects fly with a buzzing noise, 

 and have a sufficiently powerful beak to produce quite a severe sting on 

 the human hand. 



Digger-wasps. — These insects by means of their powerful jaws 



Fig. 54. 



-PROCTOCiVNTnUS MILBERTI. 



EUey.) 



(After 



Fig. 55.— Larrada semirufa.— Female. (Emer 

 ton del.) 



Fig. 56. — Larrada semirufa. — Female, grasping a 

 young locust, (Emerton (ZeD 



J^Mr. Brous found the following species feeding on sprctiis: Stenopogon consanguineus Loew, a species 

 with pale yellowish hairs on head and thorax, yellowL^h-brown wings, and pale rnfous legs and abdo- 

 men ; Promachus apivora F.toh ; Erax bastard'ii (Fig. 29) ; several allied species of Erax, and a species 

 of Tolmerus. 



'' The Asilus missouriensis Riley, 2d Mo. Ent. Eep. p. 122. 



