Rhyzobius ventralis (Erichson) and R. forestieri (Mulsant) (Coleoptera: Coccinellidae), their biology and value for scale insect control

Abstract

AbstractLife-cycles and voltinism are described for Rhyzobius ventralis (Erichs.) and R. forestieri (Muls.) living in the region of Sydney, Australia, and also the role each plays in its particular biocoenosis. Colour variation and wax production are described for the larvae, prepupae, pupae and adults of both species, also the defensive and feeding behaviour. New and known host records are listed for both species. Reasons are suggested for the success, partial failure or failure of the species as biological control agents in various parts of the world.