174 WASP STUDIES AFIELD 



to dig up the finished product, we were surprised to find 

 that she had deserted it just as we had left it that morning. 

 The nest remained slightly unfinished, and the hopper nearby 

 was being dismembered by ants. 



Two other unfinished and deserted burrows of Priononyx, 

 probably atratum, were found. One was evidently ready for 

 the closing; even the hopper, a Melanoplus femiir-rubrum, 

 was in place at the bottom, but the owner was gone, the dirt 

 was dry and the locust was being carried away in bits by 

 ants. The other was almost as far advanced ; the prey, an 

 Arphia corinata ? , lay directly in front of the hole and fac- 

 ing it the last position before the wasp drags it in but 

 this too was being plundered by ants. There is, of course, 

 a possibility that both of these failures had been caused, not 

 by the faithlessness of the mother wasp, but by some tragedy 

 which had overtaken her. We might add here that the 

 mothers themselves are not exempt from enemies, for Pierce 6 

 records this species as being stylopized by Ophfhalmochlus 

 dwyi, and in one instance where a male parasite emerged 

 three days after the death of the host. 



On one August morning we were interested in watching 

 the courtship of a P. atratum. At 8 : 42 a black female was 

 seen at rest on a small Melilotus. After a few seconds a 

 second insect appeared, flew directly to the first, mounted 

 and tried hard to effect a union, and flew off. During the 

 next fifteen minutes this performance was repeated about a 

 dozen times; occasionally the male would fly to a distance 

 of fifteen feet, rest for a second and then return to the female 

 and resume activities, but more often the flights were short. 

 The male would hover to and fro in a space of about three 

 inches in the air in front of the female before mounting; 

 then he would curl his abdomen beneath hers. Mating prob- 

 ably occurred during this coquettish performance, but if so, 



6 Bull. U. S. Nat. Mus. No. 66 : 38. 1909. 



