VARIATION IN THE EPIPROCT OF ARSAPNIA DECEPTA BANKS, 1897 (PLECOPTERA: CAPNIIDAE), WITH COMMENTS ON ARSAPNIA COYOTE (NELSON & BAUMANN 1987)

Epiprocts and tergal processes were examined using scanning electron microscopy for scattered populations of Arsapnia decepta Banks, 1897 and A. coyote (Nelson & Baumann, 1987) from throughout their known ranges. Epiproct lengths ranged from 379-578 μm among A. decepta males from 19 sites, and from 575-618 μm for A. coyote males from two sites. Among A. decepta males, the numbers of thick spine-like epiproct setae ranged from 10-34 per cluster. We conclude that A. decepta, as currently defined, shows considerable variation in epiproct dimensions, numbers of epiproct setae per cluster, and width of the dorsal process on tergum 7. In addition, the limited data from our small sample of A. coyote specimens, and the molecular data published recently by colleagues, support continued recognition of this closely related species. SEM images are presented to document the observed variation in these structures from various populations in western North America.