﻿CHAPTER II 



HYMEXOPTERA ACULEATA CONTINUED DIVISION II. DIPLOPTERA 



OK WASPS EUMENIDAE, SOLITARY TRUE WASPS VESPIDAE, 



SOCIAL WASPS MASARIDAE 



Division II. Diploptera — Wasps. 



repose; the pronotum 



Anterior wings longitudinally plicate in 

 extending hurl,-, so as to form 

 on each side an angle reposing 

 on the tegula ; the basal seg- 

 ments of the hind body not 

 bearing nodes or scales ; the 

 hind tarsi formed for simple 

 walking. The species either 

 solitary or social in their 



. . . , Fig. 26. — Upper aspect of pronoturn 



nanus; Some existing in three and mesouotuni of a wasp, Eume- 



forms, nudes, females, and nes coarctala. a, Angle of prono- 



tum ; b. tegula ; c, base of wing ; 

 Workers. ( /, mesonotum. 



This division of Hymenoptera includes the true wasps, but not 

 the fossorial wasps. The name applied to it has been suggested 

 by the fact that the front wings become doubled in the long direc- 

 tion when at rest, so as to make them appear narrower than in 

 most other Aculeata (Fig. 27). This character is unimportant 

 in function so far as we know, 1 and it is not quite constant in 

 the division, since some of the Masaridae do not exhibit it. The 

 character reappears outside the Diploptera in the genus Leucospis 

 — a member of the Chalcididae in the parasitic series of Hymen- 

 optera — the species of which greatly resemble wasps in coloration. 

 A better character is that furnished by the well-marked angle, 



1 Janet lias suggested that the folding is done to keep the delicate hind-margins 

 of the wings from being frayed. 



