Observations on the Effectiveness and Biology of the European Predator Laricobius erichsonii Rosen. (Coleoptera: Derodontidae) in Oregon and Washington

Abstract

In 1957, a program of introducing insect predators for control of the balsam woolly aphid, Chermes (= Adelges) piceae Ratz., was begun in Oregon and Washington. This program was made possible through the generous cooperation of the Canadian Department of Agriculture, which provided many of the predators. Eighteen predator species from Europe, Asia, and Australia were liberated from 1957 through 1960. Four of the species are known to have survived one or more winters and show promise of becoming permanently established.