The Centre for Biological Control took over this facility outside Kariega/Uitenhage in April 2015, after the success of the Waainek mass-rearing facility in Makhanda (Grahamstown). The Kariega facility focuses on the rearing of agents for alien invasive cacti, which are serious environmental and agricultural weeds throughout South Africa. Biological control of cacti has been very successful in both South Africa and Australia.

The very first biological control agent introduced into South Africa was a cochineal insect which targeted the drooping prickly pear (Opunita monocantha) over 100 years ago. Drooping prickly pear was a major problem in the Eastern Cape Province at that time, covering large areas of bush and grazing land in high densities. After the release of the cochineal insect there was a dramatic decline in drooping prickly pear populations and it is no longer considered a problem.

At present, six species of agents are being mass-reared on six cactus weeds at the Kariega facility (see table below). All but one (Pereskia stem-wilter) of the agents are types or species of cochineal. Cochineal insects are a genus of scale insects which feed only on cacti in the genus Opuntia. The most familiar stage of the cochineal insect’s life-cycle is the sedentary adult phase where white fluff covers the insect, protecting it from predators and parasites. Each different cochineal species specialises in feeding on one particular weed species so it is essential that the correct type of cochineal is used to control the correct weed.

A team of eight people are employed to mass-rear and release these agents. Farmers, conservationists and landowners make requests and the agents are provided free of charge. The team is also involved in monitoring how effective the releases are in controlling the weeds. If you have a problem with invasive cacti please contact the CBC and we will advise on the best way of controlling that species and provide you with control agents if appropriate.

The Kariega mass-rearing facility is managed by Ruth Scholtz and she can be contacted on: 
Phone: 073 673 8234
Email: scholtzruth4@gmail.com

The table below lists the biological control agents that are mass-reared for Cacti weeds: 

Last Modified: Thu, 09 Sep 2021 15:59:17 SAST