Aquatic and Semiaquatic Beetles
The key for Colepotera can be found in Chapter 12 of the Guide to Aquatic Invertebrates of the Upper Midwest , pages 145-158. Once you have keyed out your insect, you can use the photographs on this website to verify your identification. If you click on the link to the family on the right, you will be directed to a page that has photographs of that family along with close-up photos of their identifying characters.
Larvae of aquatic Coleoptera can be recognized by the presence of a sclerotized head, three pairs of segmented thoracic legs, and the absence of wing pads. Characters such as the number of tarsal claws, number of leg segments, body shape, and antennal length are diagnostic characters for Coleoptera larvae.