Protection from beetle-predation in cochineal insects (Dactylopiidae : Homoptera)

Abstract

From introduction: In South Africa the native ladybird beetle Exochomus flaviventris Mader feeds on the introduced cochineal insect Dactylopius opuntiae (Cockerell) (Pettey, 1943, 1946, 1948; Geyer, 1947 a, b; Pettey and Marais, 1950). It has also been reported to feed on Dactylopius austrinus Lindley (Geyer, 1947 a; Pettey, 1948), but this appears to occur rarely in the field (H.G. Zimmermann and H.G. Robertson pers. camm. ; Appendix 1 ). This thesis attempts to determine why E. flaviventris feeds on D. opuntiae in the field but not on D. austrinus.