Woolly Apple Aphid,Eriosoma lanigerum(Hausmann), in South Africa: Biology and Management Practices, with Focus on the Potential Use of Entomopathogenic Nematodes and Fungi

Abstract

Eriosoma lanigerum, woolly apple aphid (WAA), is an important pest of apples in the Western Cape province of South Africa and in other apple-growing areas of the world. The aphid forms densely packed colonies covered with white, waxy, filamentous secretions, on the above-ground parts and on the roots of apple trees. The management of WAA primarily entails the use of resistant rootstocks, chemical and biological control, or the integration of all three strategies. Although Aphelinus mali is a specialised parasitoid of WAA, its level of control has been reported to be unsatisfactory as its parasitism is confined to the above-ground populations of WAA. Entomopathogenic nematodes and fungi that are important natural biological control agents of many insects and other arthropods are used to control a wide range of soilborne insects. The successful applications of these entomopathogens to control other soilborne insects raise the possibility of using them to target the subterranean populations of WAA. The review represents a combination of previous and current information on management practices for the control of WAA and the potential of integrating biocontrol agents such as entomopathogenic nematodes and entomopathogenic fungi in a pest management system.