THE MICRODISTRIBUTION OF ALLOCAPNIA NAIADS (PLECOPTERA: CAPNIIDAE)

The microdistribution of Allocapnia (Plecoptera: Capniidae) naiads was assessed through late fall and winter of 1970-71 by using leaf pack samplers placed in a pool and on riffle and bedrock substrates in Little Pine Creek, Warren County, Indiana. Over all sampling dates, sig nificantly greater numbers of stonefly naiads were collected in riffle sam plers. On a weekly basis, analysis of size of naiads collected from riffle and bedrock samplers revealed no significant differences in their size frequency distributions, however, similar comparisons for riffle and pool samples revealed significant differences on four sampling dates. Generally: (1) the greatest range in size of naiads was found for those collected in riffle samples; (2) species composition in pool, bedrock and riffle samplers was the same; and