40 



SMITHSONIAN MISCELLANEOUS COLLECTIONS \0L. IO7 



Cook (1944) in Zaraea aniericana (Cress.), to include, on the upper 

 part, the labral and pharyngeal muscles, and, on the lower part, the 

 cibarial muscles. The two sets of muscles are separated as in other 

 insects by the frontal ganglion and its brain connectives. The region 

 in question, therefore, is frontoclypeal. The arms of the cleavage 

 line, however, turn somewhat mesally at their distal ends and do not 



CL 



Fig. 14. — Hymenoptera. 



A, Neodiprion scrtijcr (Geoff.), Diprionidae, head of larva. B, Neodipriou 

 dyari Rohwer, Diprionidae, head of adult female. C, Polistcs sp., Vespidae, head 

 of larva. D, Vcspula sp., Vespidae, head of larva. E, Vespa crabro L., Vespidae, 

 head exuviae of last larval instar. F, Xylocopa sp., Apidae, head of larva. 



extend entirely through the clypeal area. Just laterad of each mandib- 

 ular condyle of the clypeus a short groove (^/) containing the 

 anterior tentorial pit {at) extends upward close to the corresponding 

 arm of the cleavage line, but does not blend with the latter. This 

 groove and its mate on the other side evidently are larval representa- 

 tives of the epistomal sulcus of the adult (B, ^^). At ecdysis the 

 exuvial splits follow the frontal cleavage lines, so that the apotome 

 does not carry the anterior tentorial arms. 



The adult head of Neodiprion (fig. 14 B) differs in many respects 

 from that of the larva (A). The larval line of ecdysis is entirely 

 absent, the antennae have taken positions much nearer the middle of 



