Page:The Gall Wasp Genus Cynips.pdf/33

 0.20), and there are species in which the wings are completely absent.

If taxonomic classifications may be taken as an expression of an author's conclusions on the evolutionary origins of his group, all previous workers have implied that the short-winged species represent genetic stocks separated from the long-winged species since the day that the first short-winged ancestor came into existence. The genera Acraspis, Philonix, Xanthoteras, Xystoteras, Biorhiza, Parateras, and others have been erected to receive the short-winged gall makers, and the long-winged species have been restricted to genera which contained nothing but long-winged species. It is the familiar story of evolution being conceivable as a function of the remote past, but unacceptable as a matter of moment in the affairs of the present. It is in essence implied that some great cataclysm once upon a time wrought one short-winged cynipid from which all the others have inherited, directly or thru more devious generic paths, all of their unusual characteristics.

There are more than wings to justify these existent classifications. Many of the short-winged species have certain reductions of thoracic characters, enlarged abdomens, often fused abdominal segments, and several other structural peculiarities not recognized among any long-winged species. Thus, the typical Acraspis has a blunt hypopygial spine (figs. 407-429) which is of uniform width for its whole length and terminated by a heavy tuft of hairs, and altho this structure occurs among all the other short-winged species which are Acraspis, this type of spine is not known in any long-winged cynipid. Similarly, the other short-winged genera have been based on groups of characters which would seem to establish their phylogenetic relationships.

Our first doubts of the existent interpretations were aroused when we reached our study of Cynips clavuloides, a common species on the Valley white oak, Quercus lobata, in central California. The typically long-winged agamic female clavuloides (fig. 164) develops in a leaf gall (fig. 142) which more or less resembles a minute Indian club in shape. The form is so distinctive that it naturally brought to mind the only very similar gall known at that time, Weld's species, Xanthoteras teres. Our previous studies (Kinsey 1920-1923)