CHAPTER II 



HYMEXOPTERA ACULEATA COXTIXUE1> - DIVISION II. DIPLOPTERA 

 OR WASPS - EUMENIDAE, SOLITARY TRUE WASPS - YESPIDAE, 

 SOCIAL WASPS - MASARIDAE 



Division II. Diploptera Wasps. 



Anterior wings longitudinally plicate in repose; the pronotum 

 extending back, so as to form 

 on each side an angle reposing 

 on the tea id c i .; the based seg- 

 ments of the hind, bodi/ not 

 bearing nodes or scales ; the 

 hind tarsi formed for simple 

 ti-<ill-ing. The species either 

 or social in their 



77.. ... . FIG. 26. Upper aspect of pronotum 



habits; some existing rn three and mesonotum of a wasp, - 



forms, males, females, and nes coarctata. a, Angle of prono- 

 -. turn ; b, tegula ; c, base of wing ; 



WOT/CeTS. (^ iriesonotum. 



THIS division of Hymenoptera includes the true wasps, but not 

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

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

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

 must 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 Zei(cc>-- 



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. 



