The Larvae of the Predaceous Diving Beetles Bidessusgrossepunctatus, Graptodytes granularis and G. pictus (Coleoptera: Dytiscidae)

Abstract

Descriptions are given of all three larval instars of Bidessus grossepunctatus Vorbringer, 1907, Graptodytes granularis (Linnaeus, 1767) and G. pictus (Fabricius, 1787). These species are among the smallest dytiscids and the larvae were reared from eggs deposited in aquaria. Additional larvae of the two Graptodytes species were collected in a river. All of the studied material is from northern Sweden, where all three species have a univoltine life-cycle with adult overwintering. The larval development is passed in the summer.