A NEW SPECIES OF CEP HA L ON OMIA EXHIBITING 
AN UNUSUALLY COMPLEX POLYMORPHISM 
(HYMENOPTERA, BETHYLIDAE) 1 
By Howard E. Evans 
Museum of Comparative Zoology 
Polymorphism is well known in Cephalonomia and certain other 
genera of Bethylidae. Kearns (1934) has studied the phenomenon 
in C. gallicola (Ashmead), a species in which the females are always 
apterous, the males either apterous or macropterous. A different type 
of polymorphism occurs in C. formiciformis Westwood (Richards,, 
1939) I in this species the females are either macropterous or brachyp- 
terous, the males always macropterous. In the related genus Sclero- 
derma 1, most species appear to be dimorphic in both sexes, either fully 
winged or completely apterous (e.g., Bridwell, 1920). As compared 
to fully winged forms, brachypterous and apterous forms tend to 
exhibit reduction in eye size, ocelli, width of the head, and some of 
the sutures of the pterothorax. Thus apterous individuals may look 
very different from macropterous ones of the same species. 
A few years ago Hugh B. Leech, of the California Academy of 
Sciences, sent me a series of a minute, polymorphic Cephalonomia 
which he reared from ciid-infested fungi collected in Baja California. 
More recently John F. Lawrence, of the University of California at 
Berkeley, has sent me examples of this same Cephalonomia from ciid- 
infested fungi collected in numerous localities in Oregon, California, 
Arizona, Baja California, and Nayarit. This wasp is quite distinct 
from any other North American Cephalonomia , its closest relative 
apparently being the Palaearctic formiciformis, which also attacks ciid 
beetle larvae in fungi. This new species, described below as perpusilla, 
differs from formiciformis in its smaller size and also in minor details 
of color and structure. It also differs from formiciformis and from all 
other bethylids, so far as I know, in that no less than six well-differ- 
entiated types of individuals can be discerned, each type differing in 
certain aspects of wing development, size of the eyes and ocelli, head 
shape, or other details. In brief, the males are either alate (i.e., 
macropterous) and broad-headed or apterous and narrow-headed, the 
females macropterous, micropterous (in either case narrow-headed, 
about like the apterous males), subapterous, or apterous (in these two 
’Research supported by a grant from the National Science Foundation, 
No. GB-1544. 
Manuscript received by the editor January 15, 1963. 
