FIELD BOOK OF INSECTS. 



The Peckhams, in their account of Solitary Wasps, have 

 called the members of this family Grave Diggers. The 

 name was probably not intended to be distinctive; its 

 appropriateness depends upon the viewpoint for, as is the 

 case with other families, the grave of the victims is the 

 nursery of the wasps. Cerceris stocks up with beetles, 

 especially weevils; while Philanthus uses bees, especially 

 Halictus; and Aphilanthops, queen-ants. 



TRYPOXYLONID^E 



Our only genus is Trypoxylon. The abdomen is narrow 

 and longer than the head and thorax. The species are 

 either all black, or marked with red. They were formerly 

 accused of being parasitic because they had been reared 

 from nests made by other wasps. Then the charge was 

 changed to laziness, but I contend that they do well to use 

 perfectly good mud-daubers' nests, and the like, which 

 are no longer used by the original owners. Small species 

 use the hollows of cut straws and wood-boring beetles' 

 burrows. Chinks in masonry are also used. If the chinks 

 are too large, they may be made smaller by plastering them 

 with mud, and the partitions between the cells, each 

 containing an egg and sufficient food for one larva, are 

 made of mud. The nests are usually provisioned with 

 spiders. The male of Trypoxylon nibrocinctum is excep- 

 tional among Hymenoptera in the interest he takes in 

 household affairs. He stands guard at the nest while the 

 female is out hunting food. 



LARRID/E 



These wasps usually nest in the ground. While fairly 

 numerous, they are not very showy. The Larrinae usually 

 take Orthoptera for larval food ; and the Astatinas, Homop- 

 tera. 



i. Metasternum with a large process which is deeply 

 indented ventrally; middle tibiae with one apical spur; 



marginal cell with an appendage. Larrinae 2. 



Metasternum without a large, deeply indented pro- 

 cess; middle tibiae with two apical spurs; marginal cell 



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