Bedford, E.C.G. 1989 The biological control of circular purple scale, Chrysomphalus aonidum (L.), on citrus in South Africa.. Technical Communication No. 218. Dept. of Agriculture & Water Supply Pretoria, South Africa 16 pp.

Notes: Summary/abstract in: English & Afrikaans. Abstract: Review of highly successful biological control project; led to integrated control of citrus pests; parasitoid Aphytis holoxanthus introduced; effect of low temperature; effect & expense of pesticides; culling. Keywords: biological control.