The Great Cerceris 25 



left her in undisturbed possession of her ninth 

 capture. 



By this means, or by violating cells already 

 provisioned, I procured close upon a hundred 

 Weevils ; and, notwithstanding what I was 

 entitled to expect from what Leon Dufour has 

 told us of the habits of the Buprestis-hunting 

 Cerceris, I could not repress my surprise at 

 the sight of the singular collection which I had 

 made. Whereas the Buprestis-slayer, while con- 

 fining herself to one genus, passes indiscrimin- 

 ately from one species to another, the more 

 exclusive Great Cerceris preys invariably on the 

 same species, Cleonus ophthalmicus. When 

 going through my bag I came upon but one 

 exception, and even that belonged to a kindred 

 species, Cleonus alternans, a species which I 

 never saw again in my frequent visits to the 

 Cerceris. Later researches supplied me with a 

 second exception, in the shape of Bothynoderus 

 alhidus ; and that is all. Is this predilection 

 for a single species adequately explained by the 

 greater flavour and succulence of the prey ? 

 Do the grubs find in this monotonous diet juices 

 which suit them and which they would not 

 find elsewhere ? I do not think so ; and, if 

 Leon Dufour's Cerceris hunts every sort of 

 Buprestis without distinction, this is doubtless 

 because all the Buprestes possess the same 



