52 INSECT LIFE tv 



contrary, selects vertical ground. By this slight 

 architectural modification she avoids most of the 

 dangers which might threaten her tunnel ; therefore 

 she is not particular as to the nature of the soil, 

 and hollows her gallery either in friable earth with a 

 little clay, or in the crumbling soil of the Mollasse, 

 which makes the labour of excavation much easier. 

 The only indispensable condition seems to be that 

 the soil should be dry, and exposed to the sun for 

 the greater part of the day. It is therefore in the 

 steep bank along a road, and in the sides of hollows 

 made by rain in the sandy Mollasse, that our 

 Hymenopteron makes its abode. Such conditions 

 are frequent near Carpentras in what is known as 

 the hollow way, and it is there that I have found 

 C. tuberculata in the greatest abundance, and have 

 collected most of the facts relating to its history. 



It is not enough to choose this vertical situation ; 

 other precautions are taken to guard against the 

 already advanced season. If some bit of hard 

 sandstone project like a shelf, or if a hole the size 

 of one's fist should have been hollowed naturally in 

 the ground, it will be under this shelter or in this 

 cavity that the gallery is made, a natural vestibule 

 being thus added by the Cerceris to its own edifice. 

 Although there is no kind of community among 

 them, these insects like to associate in small parties, 

 and I have always found their nests in groups of 

 about ten, with orifices, though usually far apart, 

 sometimes touching. 



When the sun shines it is wonderful to see the 

 ways of these hard-working miners. Some patiently 

 extract bits of gravel from the bottom of a hole 



