A SOLITARY WASP THAT PREYS UPON LACEWINGS 
(HYMENOPTERA: SPHECIDAE; 
NEUROPTERA: CHRYSOPIDAE)* 
By Howard E. Evans 
Department of Zoology and Entomology, 
Colorado State University, Fort Collins, Colorado 80523 
The tendency of solitary wasps to restrict predation to members 
of specific groups of arthropods is well known. There are several 
hundred records for diverse species of Bembix, for example, which 
suggest that all Northern Hemisphere species of this genus prey only 
upon Diptera. This includes 16 of the 19 species occurring north of 
Mexico; the remaining three have remained unstudied. Two of 
these, gillaspyi Evans and Matthews (1968) and frommeri Bohart 
(1970) were described only recently, while the third, stenebdoma 
Parker (1917) was described long ago but has remained one of the 
most infrequently encountered members of the genus. Although 
stenebdoma was placed in the belfragei species-group by Evans and 
Matthews (1968), largely on the basis of the partially preserved 
ocellar lenses, the species fits poorly in that group on most features 
and in fact is unique in the genus in having the first intercubital vein 
straight rather than angulated. Evidently this species is also unique 
in the genus, indeed among all digger wasps, in that the prey consists 
of lacewings (Chrysopidae). 
The use of Neuroptera is not, however, unknown among Bembi- 
cini. Evans and Matthews (1973) presented a record of the Aus- 
tralian species Bembix wilcannia Evans and Matthews preying upon 
adult ant lions (Myrmeleontidae), and Alcock (1975) found Xeros- 
tictia longilabris Gillaspy preying upon adult ant lions as well as 
flatid buds in southern Arizona. Thus the record of Bembix 
stenebdoma using Chrysopidae seems less unusual than it would 
have seemed a few years ago. Why this species appears so rare when 
it has apparently entered a new and unexploited adaptive zone 
remains a mystery. 
* Manuscript received by the editor October 10, 1978. 
81 
