Suspension and Filter Feeding in Aquatic Insects

Abstract

Aquatic insect feeding occurs at the nexus of habitat, food source and size, and behavior and relies largely on the complexities of mouthpart morphology. This intersection has important consequences for tropic interactions, nutrient processing, and ecosystem function. In aquatic habitats, immature insects feed in a variety of ways; however, consumption of small suspended particles (seston) in the water column is a common mode for representatives of several insect groups. Ingestion of seston can occur via active or passive removal and broadly encompasses filter and suspension feeding. In this chapter, we explore the ways in which various aquatic insects acquire food particles. We focus on food sources and particle sizes, feeding behavior, morphology of mouthparts, and trophic importance. The major groups explored include Ephemeroptera (mayflies), Diptera (true flies), and Trichoptera (caddisflies), each of which have evolved unique strategies for obtaining particles from the water column. Members of this feeding group are critical as food sources for aquatic and terrestrial organisms, they play large roles in nutrient cycling, and some are vectors of important human and animal diseases.