The predaceous diving beetles are
a large and fairly common group. They are found in aquatic habitats and can grow to lengths of 38 mm long. Feeding on small organisms, their food selection is governed by their ability to catch the prey.
Merritt, R W., K W. Cummins, and M B. Berg. An Introduction to the Aquatic Insects of North America. Dubuque, Iowa: Kendall/Hunt Company, 2008