46 
Indiana University Studies 
Emergence of Cynips Fulvicollis 
Variety 
Source of Material 
Chief Emergence Dates 
at Bloomington, Ind. 
canadensis 
No. Mich. 
Late Nov., early Dec. 
fulvicollis 
So. Mich., no. Ind. 
Early to late Dec. 
So. Ind., so. 111. 
Mid- to late Dec. 
major 
So. Ind., so. 111., so. Mo. 
Late Dec., early Jan. 
vorisi 
So. Kans. 
Early Dec., to late Feb. 
The most interesting aspect of fulvicollis is its earlier emer- 
gence in northern varieties and its later emergence in south- 
ern varieties. If, as our data show, the emergence date is 
not determined by direct response of the individual insects to 
environmental factors, then how may we explain this apparent 
correlation of emergence dates with the latitudinal range of 
each species? If Lamarckian effects enter here, they must 
come as the result of influences continued over numerous gen- 
erations. Is it more probable that Darwinian selection has 
helped adjust these species to climatic conditions? Or is it 
possible that the apparent correlation is fortuitous ? 
All but two of the groups of species of Cynips complete 
their agamic lives within six to eight months. In Cynips m el- 
lea emergence is spread from the seventh to the tenth month 
(December thru March) with most of it in March. This is a 
departure from the ancestral tradition, but one specific for 
mellea. Cynips fulvicollis is a further departure, for most 
of its emergence is delayed until the eighteenth to twentieth 
month. This is particularly true of the more northern varie- 
ties of the species. The Kansas variety, vorisi , which is near- 
est the point of origin of the group, has the most normal life 
history, most of the individuals emerging during the first win- 
ter with only a few of them delaying emergence until the 
second season. The northern variety canadensis gives no 
emergence in the first year, most of it in the second year, and 
some stray emergence in the third year. The varieties rang- 
ing between vorisi and canadensis show a gradual shift from 
the one to the three-year cycle. It is an interesting case of 
new specific characters developing out of physiologic materials 
that have remained constant in other groups of Cynips for 
millions cf years. 
