172 



REPORT UPON COTTON INSECTS. 



FIG. 17. Erax bastardii. 



The early forms of the insects of this family are known of but few- 

 species. Of those that are known we can safely say they are vegetable 

 feeders, although in the first report on the Eocky Mountain Locust, the 

 larva of Erax Bastardii is figured (Fig. 17) and 

 spoken of ashaviug been observed by Miss Emma 

 A. Smith to feed upon the eggs of the locust. 

 In the same report, however, the larva of the 

 common "white grub" (Lachnosterna fusca) is 

 mentioned as feeding upon the eggs of the locust 

 also,* and the w r riter simply deduces from that 

 instance that it affords "another conclusive proof 

 that an essential vegetable feeder will excep- 

 tionally lake to soft animal food." This argu- 

 ment then, as the analogy between the two cases 

 is perfect, we can apply to the larva of Erax and conclude it with the 

 rest of the family to be normally vegetarian in the larva state. This is 

 the more likely to be the case as the larva of the same species is described 

 in the second Missouri Entomological Report as from "under a peach 

 tree" and "under a creeping vine." 



In order to give a general idea of the appearance of the larva and 

 pupa we will quote Harris' description of these forms of Asilus sericeous, 

 Say, the larva of which devours the roots of tart rhubarb. Speaking 

 of the larvae, he says : 



They were yellowish white maggots, about three-quarters of an inch long, not per- 

 fectly cylindrical but a little depressed and tapering at each end. Tho head \vas 

 small, brown, and partially drawn within the first ring, and was provided with two 

 little horny brown hooks. There was a pair of breathing pores on the first ring, and 

 another pair on the last but one. These maggots were transformed in the earth to 

 naked pupa} having the limbs free. The pupa was brown and had a pair of short 

 horns on the forehead, three spines on each side of the head, a forked tail, and a trans- 

 verse row of little teeth across the middle of each ring of the hind body. When about 

 to undergo their last transformation, the pupae work their way to the surface of the 

 ground by the help of the little teeth on their wings. I have repeatedly seen the 

 empty pupa-shells sticking out of the ground around rhubarb plants. 



So much for Asilus-flies in general. Three species 

 have been captured in the cotton-fields of Alabama. 

 These are Erax apicalis, Wied., Dioymites discolor, 

 Lw., and Dionyzias ? sp. By far the most abundant 

 species was Erax apicalis, Wied. This species (rep- 

 resented by Fig. 18) varies from an inch to an inch 

 and a quarter in length (25 to 32 mm ) and has a wing 

 expanse of nearly an inch and a half. The abdo- 

 men is black with silvery markings above and whit- 

 FIG. 18.-Erax apicalis. igU below The top of the tllorax is yellowish-white 



and brown above as seen in different lights. The legs are spiny and 



light-brown in color, and the face is nearly white. In the summer of 



1878 I observed large numbers of these insects flying around the cot- 



*First Ann. Rept. U. S. Eut. Com. on the Rocky Mountain Locust, 1877, p. 305. 



