Kinsey: Gall Wasp Genus Cynips 
383 
terial collected at Bay City, Michigan, the type locality of 
wheeleri, the percentages are 
erinacei 10.2% 
wheeleri x erinacei 81.2% 
wheeleri 8.6% 
As one goes south, the proportion of wheeleri decreases until 
it gives way to erinacei in northern Illinois, Indiana, and Ohio, 
or to pezomachoides on the Atlantic Coast south of Boston. 
Wheeleri is also very common southward thru the Allegha- 
nies, the Blue Ridge, the Cumberland Highlands, and even into 
the southern Appalachians in northern Georgia and Alabama. 
In this extension of range the variety parallels many of the 
other Canadian and Transition Zone organisms. What is cer- 
tainly true wheeleri also appears now and then outside of the 
mountains as far south as Georgia and Missouri, even where 
other varieties of Cynips pezomachoides are the dominant in- 
sects. Under erinacei we present evidence that that variety 
has had a hybrid origin from a wheeleri x derivatus (or 
wheeleri x pezomachoides) cross, and under advena is pre- 
sented similar evidence for origin from a wheeleri x pezo- 
machoides parentage. Thus in the areas occupied by erinacei 
and advena , wheeleri’ s occasional appearance is as a segregate 
from the hybrids. Further, true wheeleri appears eastward 
on a part of the Atlantic Coastal Plain where it hybridizes 
with variety pezomachoides, and from Kentucky to southern 
Missouri wheeleri hybridizes with variety ozark (if, indeed, 
ozark is not also of hybrid origin with wheeleri as one parent) . 
This widespread scattering of wheeleri, far beyond the north- 
ern area where the insect occurs in the purest population, is 
to be explained as the consequence of the southern projection 
of northern faunas during the Pleistocene glaciations. One 
examining the series which have been available for our present 
study must surely be impressed by the persistence, or reap- 
pearance as a segregate from hybridization, of this very dis- 
tinct variety over a great area embodying most of the normal 
ranges of five other varieties of the species. It is noteworthy 
that wheeleri extends everywhere from fifty to a hundred miles 
south of the limits of glaciation, but beyond that it goes south- 
ward only in the mountains and lowlands directly adjacent to 
those highlands. 
The galls of wheeleri in northern Michigan are almost al- 
