THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION

Aquatic Invertebrates in Pacific Northwest Freshwater Wetlands
An Identification Guide and Educational Resource

Adult hydrophilids can be collected from wetlands and ponds throughout the year. The larvae however, develop very quickly and are rarely collected. The adults are identified primarily by their antennae: the last three segments are swollen to form a club. The segment immediately before the club is usually cup shaped. In some genera, the legs have long swimming hairs and the body has a keel. The larvae have prominent mandibles. They have small soft lobes on the hind end instead of tails. The antennae are located between the mandibles.