Ephemeroptera, Plecoptera and Trichoptera microhabitat distributions in streams

A habitat is composed of a variety of microhabitats identified by different physical and biological characteristics. This study documented Ephemeroptera, Plecoptera, and Trichoptera distributions with respect to natural and manipulated microhabitats and depth at three field sites. Microhabitat distributions may be affected by interactions with heterospecifics. This study also examined conspecific and heterospecific microhabitat selection differences between Helicopsyche sp. and Hydropsyche occidentalis (Trichoptera) in laboratory streams. Insect communities across stream sites, microhabitats and depths were significantly different. Specific (focal) species were significantly differentially distributed across microhabitats regardless of their availabilities. There were significant effects of microhabitat, species and relationship (conspecific vs. heterospecific) trends on Trichoptera species' abundances. Community structure can differ over relatively short distances and microhabitat species' distributions were not related to microhabitat availability. Also, heterospecific interactions play a role in driving Hydropsyche occidentalis microhabitat selection while in the presence of Helicopsyche sp