1972] 
Kurczewski & Evans — Bothy nostethus 
IOI 
the use of chrysomelids by Bothy nostethus and Entomognathus was 
acquired independently and, furthermore, that the similarity in the 
position of egg attachment of these two genera, was dictated by the 
morphology of the beetle [Compare Fig. 6 with fig. II in Grandi 
(1927) ( E . brevis) and with Fig. 3 in Miller and Kurczewski 
{E. ?nemorialis)]. 
The cocoons of species of Larrinae and Crabroninae are basically 
similar in shape and in having an outer covering of sand grains. 
That of Bothy wostethus contains beetle elytra affixed to the proximal 
end and thus resembles cocoons of certain species of the crabronine 
genera Lindenius and Crabro, in which prey remains cover the 
outside. On the other hand, in larrine genera such as Lyroda , 
PlenoculuSj and Tachysphex prey remains are not attached to the 
exterior of the cocoon and, in this respect, Entomognathus is much 
like a larrine [see Miller and Kurczewski, Fig. 4 (E. memorialis) ; 
Benoist, 1915 (E. brevis)]. The reliability of the exterior structure 
of the cocoon as an indicator of phylogeny can, however, be ques- 
tioned. For example, Oxybelus, a genus of the tribe Oxybelini 
which is usually placed in the Crabroninae, has a cocoon that is 
essentially indistinguishable from that of many Larrinae. 
Thus evidence on the relationship of Bothynostethus and Ento- 
mognathus based upon cocoon structure is equivocal, and that derived 
for certain behavioral components is difficult to interpret. Although 
larval structure suggests that the two genera are closely related, 
Bothynostethus does possess finger-like lobes on the prothorax, an 
important larrine feature. In spite of some similarities among these 
two genera in adult external morphology, Bothynostethus and 
Entomognathus for the most part retain their affinities with other 
Larrinae and Craboninae, respectively. Both Krombein (1951) and 
Menke (1968) concluded that Bothynostethus belongs in the Lar- 
rinae, while Entomognathus has consistently been placed in the 
Crabroninae. 
Despite considerable similarity in larval morphology and several 
common ecological and behavioral features, we believe the two 
genera are sufficiently different to warrant their being placed in 
separate tribes. Therefore, we accept Menke’s (1968) placement 
of Bothynostethus in the Bothynostethini, and support the retention 
of Entomognathus in the Crabronini. However, the resemblances 
among the larvae and cocoons of these and related genera lead one 
to ask again whether the larrine and crabronine wasps should not 
simply be considered as tribes within a single subfamily, as sug- 
