Adult Behavior and Population Structure in Erebia Epipsodea (Lepidoptera: Satyrinae)

Data are presented on the effects of air temperature, wind, and solar radiation on the flight activity of the alpine butterfly Erebia epipsodea, a species which occurs, at least in montane central Colorado, in large, effectively panmictic populations which are continuously distributed over wide areas. Thermal—flight relationships in the adults are well adapted to the often marginal weather conditions prevalent in this locality during the flight season. Other aspects of flight behavior which may serve an epideictic function and insure greater spacing of males than would otherwise occur are also reported and discussed.