iv] DIPLOPTERA 37 



nests of mud which it attaches to twigs of heather; 

 and, like all the solitary Diploptera, provisions them 

 with small caterpillars. We have fifteen species of 

 Odynerus, all very much alike in general appearance, 

 though exhibiting considerable differences in their 

 nesting habits. 0. spinipes makes her nest in banks, 

 generally of rather stiff soil, and constructs with 

 pellets of mud a remarkable curved projecting en- 

 trance which juts out from the face of the bank like 



Fig. 5. Odynerus parietum 

 (about twice natural size) 



a downwardly directed spout. The wasp has to climb 

 up this spout before reaching the down-shaft leading 

 to her larder. Some of the other species of Odynerus 

 make their nests in bramble stems and line the tunnels 

 with a coating of fine sand. Others construct mud 

 cells inside door locks, in the slots for window-catches, 

 in crevices in masonry, or in any angle afforded by 

 walls, window-ledges and so forth. 



It was in one of these last situations that I had 

 the opportunity of closely observing a specimen, 



