268 The Hunting IVasps 



able to prevent with my larva, treated I dare 

 say too sumptuously. I therefore lower the 

 figure obtained and reduce it to some sixty 

 pieces, of middling size, between that of the 

 House-fly and of the Eristalis tenax. This would 

 about represent the number of Flies supplied by 

 the mother to the larva when the prey is of a 

 moderate size, as is the case with all the Bembex 

 of my district except the Rostrate Bembex 

 (B. Yostrata) and the Two-pronged Bembex (B. 

 hidentata), who have a preference for Gad-flies. 

 With them, the number of victims would be 

 from one to two dozen, according to the size of 

 the Fly, which varies greatly in the different 

 species of Gad-flies. 



To avoid reopening this question of the 

 nature of the provisions, I will here give a list 

 of the Flies observed in the burrows of the six 

 species of Bembex that form the subject of 

 this essay. 



1. Bembex olivacea, Rossi. I only once saw 

 this species, at Cavaillon, feeding on Green- 

 bottles. The five other species are common in 

 the Avignon neighbourhood. 



2. Bembex oculata, JuR. The Fly carrying 

 the Q^g is most often a Sphserophoria, especially 

 S. scripta ; sometimes it is a Geron gibbosus. 

 The later provisions include Stomoxys calcitrans, 

 Pollenia nificollis, P. rudis, Pipiza nigripes, 



