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32
Indiana University Studies

Fulvicollis and its immediate relatives are short-winged insects (fig. 234) which we had concluded were Cynips of the subgenus Philonix, but no long-winged Philonix had been recognized among entomologists. But the bisexual insect, Cynips pallipes, came to our attention as a possible bisexual form of fulvicollis (for reasons given on p. 271), altho pallipes had a peculiar wing-body ratio of 1.17 not then recognized in any subgenus of Cynips, and a hypopygial spine (fig. 251) distinct from that of fulvicollis (fig. 252). There was only one other long-winged Cynips which we had not placed at that time in one of the six subgenera, and that was the agamic C. plumbea of the southwestern United States. Upon reexamination of the data, plumbea proved to have the same wing-body ratio and the same spine as pallipes, while the gall of the agamic plumbea (figs. 225-226) was hardly distinguishable except in color from the gall of the agamic fulvicollis. The peculiar spine of fulvicollis had to be taken as one more case of a modification accompanying wing reduction. Thru galls, alternate generations, wing-body ratios, and interpretations of reduced wings and transferred spines the data became interpretable without contradiction in any part.

For all of the 42 short-winged insects which we are considering as true Cynips there is this same coördination of the evidence. Our conclusions are summarized in the following table, where the style of indentation will indicate the phylogenetic affinities of each form, and the order will show the development from the more primitive to the more specialized members of each group. The number that follows each name shows the average wing-body ratio in that species. It will appear that there are at least 11 stocks of Cynips in which the subapterous condition must have arisen independently, and it is possible that a still larger number of the 42 subapterous species have arisen directly from long-winged ancestors.

Wing-lengths in Agamic Cynips

1. Subgenus Cynips
folii
folii 1.50
bisex. form 1.50
flosculi 1.50
bisex. form 1.50
ilicicola
atrifolii 1.50
longiventris
longiventris 1.50
bisex. form 1.50
forsiusi 1.50
divisa
divisa 1.50
bisex. form 1.50
atridivisa 1.50