178 WASP STUDIES AFIELD 



July 19 revealed a light-brown cocoon just completed; the 

 hopper had all been eaten. On August 15, scarcely one 

 month later, a perfect adult female emerged. This shows 

 that in this species there is more than one generation each 

 year. 



Hartman, 8 .in an interesting account of this species, tells 

 of how he accidentally ran into eight nests all in a space "not 

 larger than half of this page." The chambers were so close 

 together that some had but a quarter of an inch of wall be- 

 tween them. He says the chambers were oblong, about two 

 inches in length and one-half to seven-eighths inch across and 

 two inches below the surface of the earth. 



Williams 9 observed two specimens that secured locusts 

 belonging to the genera Amphitornus and Anlocara. 



Another chapter in the life of P. thomae, the hunting of 

 the provisions, must be taken from another individual. 



A terrific commotion in the low grass attracted our at- 

 tention. An adult grosshopper, Arphia xanthoptera Burm. 

 [A. N. Caudell] lay on its back violently flapping its wings 

 against the earth, as if in great distress. A little red lump 

 on the ventral side of the thorax explained the mystery; it 

 was the abdomen of a P. thonme with its sting buried deep 

 in the hopper's thorax; the rest of the body of the wasp was 

 curved around the grasshopper's side. The struggle was 

 more violent than that of an insect on its back trying to 

 right itself; besides, a grasshopper seldom has much diffi- 

 culty in turning over if it happens to become inverted in 

 fact they are seldom so clumsy as to get into that predica- 

 ment. The point is, this action was simply an aimless and 

 conclusive muscular contraction, a writhing resulting from 

 the sting of its enemy. A grasshopper is so seldom seen in 

 this position that the wasp must have either attacked it on 



8 Bull. Univ. Tex. No. 65 : 64. 1905. 

 9 Kans. Univ. Sci. Bull. 8: 227. 1913. 



