ABSTRACT
The population structure, genetics and ecology of the checkerspot butterfly, Chlosyne palla, in an area of Gunnison County, Colorado were investigated. The population structure was found to be quite different from that of most butterflies and from all of those aspects known for its thoroughly studied relative, Euphydryas editha. The population unit of Chlosyne palla may cover an area some five to eight times the size of the largest known Euphydryas population and twice the size of an Erebia epipsodea population in the same county of Colorado.Genetic variation at eleven loci of Chlosyne palla was examined by electrophoresis. Three samples of Chlosyne palla separated by 1.6, 4.7, and 12.0 km were not significantly different. Comparison with Euphydryas editha yields a genetic similarity of 0.186, about the same level as found by Ayala (1975) for different genera of Drosophila. Euphydryas editha from the same Colorado location were more similar to California E. editha than to C. palla, showing concordance with the phenetic classification. Decreased heterozygosity was observed for the Colorado E. editha and C. palla compared to California populations of E. editha and E. chalcedona.
