Search Results - Field Guide

Showing 11 - 20 of 25 results
Photo of a predaceous diving beetle
Predaceous Diving Beetles (Water Tigers)
Species in the beetle family Dytiscidae
Like many aquatic insects, these large oval beetles prey voraciously on other aquatic organisms. Excellent swimmers, they fly well, too, and are often attracted to lights.
Riffle beetle larva photographed in water in a dish
Riffle Beetle Larvae
About 100 species in North America north of Mexico
Riffle beetles live underwater, in shallow, swift-flowing streams, as both adults and larvae. The larvae are elongated, multi-segmented, and rather hard and stiff; they reach about ½ inch long. The adults, the size of small ants, are oval with long legs.
Adult riffle beetle walking on a rock under water
Riffle Beetles
About 100 species in North America north of Mexico
Riffle beetles live underwater, in shallow, swift-flowing streams, as both adults and larvae. The adults, the size of small ants, are oval with long legs. The larvae are elongated, multi-segmented, and rather hard and stiff; they reach about ½ inch long.
Photo of a stonefly naiad clinging to a rock underwater
Stonefly Larvae
There are hundreds of species in North America
Stonefly larvae are aquatic and somewhat resemble the larvae of mayflies and damselflies. Their presence usually indicates good water quality.
Water boatman viewed from above
Water Boatmen
About 125 species in North America in the family Corixidae
Water boatmen are one of the few aquatic true bugs that are not predatory and do not bite people. Instead, they suck juices from algae and detritus. Only a few types eat other small aquatic creatures.
Photo of two water penny beetles clinging to a wet rock.
Water Penny Beetle Larvae
Beetles in the family Psephenidae
Water penny beetle larvae are truly nifty aquatic invertebrates that bring out the child in all of us. Some of them really do look like pennies!
Photo of a collared water scavenger beetle showing back.
Water Scavenger Beetles
Beetles in the family Hydrophilidae
Water scavenger beetles are a mostly aquatic family. They are similar to predaceous diving beetles, but unlike them many have a distinctive spine running down the center of their bellies.
Photo of a water scorpion, genus Ranatra, captured in a jar of pond water.
Water Scorpions
Ranatra spp. and Nepa apiculata
Water scorpions remain still, looking like a random bit of plant material. Then they suddenly grab their prey and deliver disabling fluids with a quick jab of their knifelike beak.
Photo of a whirligig beetle viewed from above
Whirligig Beetles
Species in the beetle family Gyrinidae
Groups of whirligig beetles swim on the water surface in quick, random patterns, searching for food. They have two pairs of eyes — one pair above water, one pair below — to help them quickly and accurately capture their prey.
Photo of caddisfly larva with case made of detritus
Caddisfly Larvae
About 1,500 species in North America north of Mexico
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.