SAWFLIES, ANTS, WASPS, BEES, ETC. 109 



habits are very much advanced, the care of the 

 home and the general good of the community being 

 the main features. 



Classification of the Order Hymenoptera. 



This order is divided into two main groups. The 

 first embracing comparatively few species, the 

 second group including the vast bulk of the families 

 and species of Hymenoptera. 

 I . I. Group Sessiliventres.— This term means 

 "stalkless bodies," and includes sawflies which are 

 thick-set in appearance, for the thorax and abdomen 

 are similar in width. The abdomen has not nar- 

 rowed to form a stalk or petiole at its junction with 

 the thorax — it is sessile or stalkless, c.v. : sawflies. 



II. Group Petiolata (ants, wasps, bees). — The 

 abdomen has a petiole or stalk at its junction with 

 the thorax. This is well seen in the mud-dauber 

 wasp (Pelopacus)- 



This group can be again subdivided into 



(i) Parasitic Wasps, including Chalcids, Bra- 

 conids, and Ichneumons. 



(2) Fossores (Digging Wasps), including 

 Thynnids, Scoliids, Sphegids, Pompilids. 



(3) Diplopterids or True Wasps (wings folded 

 fan-wise")-, including Eumenids (Masons), 

 Vespids (Paper-nest Wasps). 



(4) Heterogyna (various females). — Ants 



(5) Anthrophila (flower lovers). — Bees. 



Group I. Sessiliventres. 

 Family Tenthredinidae (Sawflies). — These are 





