Studies of Predators of the Balsam Woolly Aphid, Adelges piceae (Ratz.) (Homoptera: Adelgidae) VIII. Syrphidae (Diptera),

Abstract

Several species of native syrphids have been found to prey upon the introduced balsam woolly aphid, Adelges piceae (Ratz.), in New Brunswick and three of these, Syrphus torvus O. S., Metasyrphus lapponicus (Zett.), and Neocnemodon coxalis (Curr.), are sometimes very common. As part of a long-term study of the biological control of the balsam woolly aphid by native and introduced predators, the life histories, natural control, population fluctuations and control value of these native syrphids have been investigated.