Observations on the immature stages of Georissidae (Coleoptera : Hydrophiloidea), with remarks on the evolution of the hydrophiloid egg cocoon

Abstract

Specimens of Georissus crenulatus have been reared in the laboratory, and aspects of the life history are described. Egg cocoons and pupa (previously unknown in Georissus) are described and compared with those of other hydrophiloids. First instar larvae of Georissus lack cephalic egg bursters and, contrary to current assumption, these seem to be generally absent in Hydrophiloidea. The variation of egg cocoons in Hydrophiloidea is outlined and the evolution of the different types discussed.