is the study insects that inhabit freshwater for at
least part of their lives. Usually it is the larval
(immature) or nymphal stage that inhabits freshwater
streams or lakes.
insects are dragonflies & damselflies (Odonata),
stoneflies (Plecoptera), caddisflies (Trichoptera)
and mayflies (Ephemeroptera). Large larvae of these
insects are sometimes used as bait by fishermen and
replicas of the adult insects are used by "fly"
fishermen as well.
Mayflies [pictures] are the most
primitive of the aquatic insects. Larvae live in
freshwater streams and ponds feeding on algae and
detritus. Adults emerge, often in large numbers, but
only live a short time.
Dragonfly and damselfly
are familiar to most people but the larvae may not
be. Larvae live in freshwater while adults are
generally found near water. Both larvae and adults
Stonefly adults [pictures] are medium-size,
drab-colored insects with the wings folded flat
across the back. Larvae live in freshwater where
they are predatory but also feed on plant material.
Caddisfly adults [pictures] resemble moths and
are the most advanced of the aquatic insects.
Caddisfly larvae are caterpillar-like and often live
within a case made of sand grains or plant material.
Some larvae are free-living predators.