TIMING OF MATING FLIGHTS IN THE WESTERN HARVESTER ANT, POGONOMYRMEX OCCIDENTALIS CRESSON (HYMENOPTERA, FORMICIDAE)

Nuptial flights of the western harvester ant, Pogonomyrmex occidentali s Cresson, were observed over five consecutive years at a site in the shrub-steppe of southwestern Wyoming and their seasonal timing related to local precipitation patterns. Ah flights followed within 1-2 days of a rain. Nest soil temperature following a rain may be the proximate cue that determines daily flight timing. We relate the timing and fre quency of mating activity observed in our study with those observed fo r Pogonomyrmex species in other environments.