Zimmermann, H.G., Burger, W.A., & Annecke, D.P. 1974 The biological control of jointed cactus in South Africa.. National Programme for Environmental Sciences: Terrestrial Biology Pretoria, S. Africa

Notes: [Papers presented at the First National Weeds Conference, 13-14 August 1974, Pretoria, S. Africa. 1974?] A brief historical survey of jointed cactus, Opuntia aurantiaca Lindley ex Gill., in South Africa is given and all the control measures since 1933 are described. The reason for the failure of the first biological control attempt by the jointed cactus cochineal Dactylopius austrinus De Lotto are analysed. The results of 18 months' field trials with D. austrinus De Lotto demonstrated the continued efficiency of this insect as a biotic agent against jointed cactus in the Eastern Cape.