Field Guide

Fishfly larvae look a lot like their cousins the hellgrammites, but they lack cottony or hairy gill tufts along the abdomen, and they have 2 short, fleshy tails at the hind tip.

Alderfly larvae look a lot like their cousins the fishflies, but instead of having pairs of fleshy tails, they have only a single tail pointing straight back.

Stonefly larvae are aquatic and somewhat resemble the larvae of mayflies and damselflies. Their presence usually indicates good water quality.

Damselfly larvae are narrow-bodied aquatic insects with large eyes, six thin legs, and three paddle-shaped, tail-like gills at the hind end.

The aquatic larvae of caddisflies are famous for building portable, protective cases out of local materials, including grains of sand, bits of leaves and twigs, and other debris. The adults are mothlike.

The larvae of horse and deer flies are fairly straight, segmented, wormlike maggots that are tan, whitish, or brownish. They are aquatic or live in mud, and most are predaceous.

Hellgrammites are the aquatic larval form of eastern dobsonflies. They are fiercely predaceous and look a little like centipedes. Anglers often use them as bait.

The larvae of mosquitoes, often called “wrigglers,” have a large head and thorax and a narrow, wormlike abdomen; they typically hang just below the water surface. When disturbed, they wriggle downward.

Adult horsehair worms can be nearly 3 feet long and live in water. They are practically featureless, smooth, aquatic worms that writhe into knots and curls.

Tubificid worms, as a group, include the tubifex worms that aquarists feed to their pet fish. These segmented worms are related to earthworms and like them are detritus eaters.