Abstract
A butterfly fauna encompassing two plant communities in the Sierra <br /><br />Nevada foothills was surveyed and was found to contain 59 resident and 35 non- <br /><br />resident species. 63% of the residents but just 3% of the non-residents are uni- <br /><br />voltine, and only 44% of the resident species are shared by both plant commu- <br /><br />nities. Dispersal between them by residents normally found in only one of the <br /><br />plant communities rarely occurs. Information on climate, relative abundance, <br /><br />flight season, dispersal, behavior, and bionomics are presented. Based upon pa- <br /><br />leobotany inferences, butterfly species endemic to the Foothill Woodland are pre- <br /><br />Pleistocene, whereas the Yellow Pine Forest endemic subspecies are post-Pleis- <br /><br />tocene (Holocene).
