OF WASHINGTON. 237 



the rain from the nest proper, since the latter was always placed 

 in that branch which would be certain to catch any water that 

 might find its way into the burrow. Nor could it be for the pur 

 pose of misleading intruders, since these, by following the bur 

 row, would be led directly into the nest, with the possible exception, 

 if any such exist, of those that make their way along the upper 

 side, or roof of the burrow ; these would be led into the empty end 

 of the main burrow. No parasites of any kind were found in 

 any of the numerous nests examined by us. 



Only one Bembex inhabited each burrow, and at the time of 

 our visit, larvae, pupae, and recently excluded images occurred. 

 The terminal portion of the burrow which contained the nest 

 did not differ in character from the remaining portion. The 

 nest proper was stored with Diptera only, among which were 

 Musca domestica, a second, undetermined species of Musca, Lu- 

 cilia ccesar, Sarcophaga sp. ( ?), and Psilocephala costalis. 

 One of the nests contained one specimen of each of these flies, 

 with the exception of the Psilocephala, of which there were two, 

 and of the Musca sp. (?) eight specimens, or thirteen flies in all, 

 and these were to serve as food for the single Bembex larva. 



After attaining full gowth this larva spins a dense black, very 

 elongate oval silken cocoon. Many of the empty cocoons were 

 lying about on the surface of the sand, either having been brought 

 from the burrow by the wasp in its efforts to escape therefrom, 

 or else they had been unearthed through the combined action of 

 the wind and rains. 



The species is rather rare in southern California, where I have 

 observed it only in the vicinity of the sea-coast. The adults are 

 seen resting upon the bare sand during the warmer portion of 

 the day ; they are very active and shy, seldom permitting a near 

 enough approach to allow of being captured by means of an or 

 dinary butterfly net. 



Mr. Howard asked how the habits of this species differ from 

 those of other species of the same genus. Mr. Ashmead stated 

 that Bartram, over 100 years ago, observed that Bembex will 

 supply its larvas with fresh food from time to time and that this 

 observation had been substantiated more recently by European 

 observers. Mr. Coquillett, however, had not noticed this with 

 the present species, and stated that at the time of his visit the 

 mouth of the nest was closed with sand by the adult wasp. ' Mr. 

 Ashmead remarked that all species of Bembex store up Diptera. 



