CHAPTER III 



HYMENOPTERA ACULEATA CONTIXUED DIVISION III. FOSSORES OR 



FOSSORIAL SOLITARY WASPS FAMILY SCOLIIDAE OR SUBTER- 

 RANEAN FOSSORS FAMILY POMPILIDAE OR RUNNERS FAMILY 



SPHEGIDAE OR PERFECT-STINGERS 



Division III. Fossores. 



Aculeate Hymenorjtera, in which the abdomen, though very diverse 

 in form, does not hear prominences on the upper aspect of the 

 hasal segments ; front winy without longitudinal fold along 

 the middle ; hairs of lody not plumose. Only two forms 

 (male and female] of each species. 



FOSSORIAL Hymenoptera are distinguished from other Aculeates 

 at present only by negative characters, i.e. they are Aculeates, 

 but are not ants, bees or wasps. According to their habits they 

 fall into four, by no means sharply distinguished, groups (1) 

 those that form no special receptacles for their young, but are 

 either of parasitic or sub-parasitic habits, or take advantage of 

 the abodes of other Insects, holes, etc, ; (2) constructors of cells 

 of clay formed into pottery by the saliva of the Insect, and by 

 drying ; (3) excavators of burrows in the ground ; (4) makers of 

 tunnels in wood or stems of plants. Several species make use 

 of both of the last two methods. The habits are carnivorous; 

 the structures formed are not for the benefit of the makers, but 

 are constructed and stored with food for the next generation. 

 Their remarkable habits attracted some attention even 2000 

 years or more ago, and were to some extent observed by Aristotle. 

 The great variety in the habits of the species, the extreme 

 industry, skill, and self-denial they display in carrying out their 

 voluntary labours, render them one of the most instructive groups 

 of the animal kingdom. There are no social or gregarious 



