Local Government, Environmental Affairs and Development Planning
(1) How effective is the use of the Cypermethrin insecticide in treating trees infected with the polyphagous shot hole borer beetle;
(2) whether the trees would survive if the beetles were eliminated at the early stages of infestation; if so, what are the relevant details;
(3) what is the latest research to address the challenges that infestations with the shot hole borer beetle hold for trees?
[1] Cypermethrin pyrethroid insecticide is not effective since it is not specific to treating the polyphagus shot hole borer and can kill many insect species which are indigenous and beneficial to the environment.
[2] Survival of the trees will depend on several factors including the species of tree infected, the health of the tree and the environmental conditions such as climate, moisture regime, slope, aspect and radiation.
[3] There is active research at the Forest and Agricultural Biotechnology Institute at the University of Pretoria and Stellenbosch University. Main recent findings are that the polyphagous shot hole borer beetle is capable of invading many different species in South Africa although it is not capable of successful breeding in all these species. It occurs widely in South Africa and predicted damages may be extensive based on the current control methods [tree removal]. Restricting the movement of wood and host plants are suggested measures to curb the spread of the polyphagous shot hole borer beetle.
