Guide to Benthic Macroinvertebrates

This resource is designed to provide a better understanding of the wide vareity of benthic macroinvertebrates found in our rivers, streams and wetlands. In addition to images, general information is included about the distinguishing features of the aquatic stage that aid in identification. Also included are the organisms feeding group, and scales for tolerance, size range and habitat preferences. Adult images are also provided for many families. The illustrations are courtesy of Cacapon Institute and artist Jennifer Gillies.

Benthic macroinvertebrates are excellent indicators of watershed health because they: Live in the water for all or most of their life; stay in areas suitable for their survival; are easy to collect; differ in their tolerance to amount and types of pollution; are easy to identify in a laboratory and in the field; often live for more than one year; and are important components of a streams nutrient and energy system.

Plants and animals are classified according to a hierarchal system that arranges the organisms into groups based upon their similarities. These groups are arranged from general to very specific. The science of classification is known as taxonomy.

Insect Groups	Non-Insect Groups
Order Ephemeroptera ^Mayflies	Class Arachnida ^{Spiders and Mites}
Order Plecoptera ^Stoneflies	Sub-phylum Crustacea ^{Crayfish, Scuds and Sowbugs}
Order Trichoptera ^Caddisflies	Phylum Annelida ^{Leeches and Worms}
Order Lepidoptera ^{Butterflies and Moths}	Class Turbellaria ^Flatworms
Order Odonata ^{Damselflies and Dragonflies}	Class Gastropoda ^Snails
Order Coleoptera ^Beetles	Class Bivalvia ^{Clams and Mussels}
Order Hemiptera ^{True Bugs}	Class Hydrozoa ^Jellyfish
Order Megaloptera ^{Alderflies and Hellgrammites}	Class Spongilla ^Sponges
Order Diptera ^{True flies}
Order Collembola ^Springtails	Functional feeding groups
Order Neuroptera ^{Spongilla flies}	Glossary and References
CLICK-HERE to download the guide	Evaluating biological integrity