Gut content analysis of aquatic insects from wood substrates

The contents of the guts from 108 taxa of aquatic and semi-aquatic insects collected on or within woody debris in streams wereexamined for the primary dietary components. Contents were iden-tified as fungi, diatoms, animal material, and detritus includingwood. Leaf materials and filamentous algae were noted. The resultswere used in part to indicate the types of utilization of the woodhabitat, and in particular to identify those taxa that may contributeby their feeding habits to particle-size reduction of wood. At least45 taxa of detritivores contained significant amounts of wood.Many of the surface associates were scrapers that fed on periphytonand aufwuchs.