SA forestry plantations threatened by yet another pest

South Africa’s R40 billion a year commercial forestry value chain is likely to be hit by a recently discovered pest.

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It targets Eucalyptus trees and, while its identity is still to be confirmed, experts believe it might be the red gum lerp psyllid (Glycaspis brimblecombei). According to Forestry SA’s executive director, Michael Peter, the country’s commercial forestry sector already loses around R200 million of wood annually due to the depredations of pests and diseases. In turn, this leads to a yearly loss in revenue of around R1,23 billion from wood and paper products.

The Tree Protection Co-operative Programme (TPCP) of the University of Pretoria’s Forestry and Agricultural Biotechnology Institute (FABI) is already in the process of confirming the identity and current national distribution of what’s believed to be Glycaspis. The results will help devise a control strategy. 

“Glycaspis brimblecombei is a sap-sucking insect that feeds on eucalypts. Native to Australia, it’s known as an aggressive insect that spreads rapidly. Symptoms of its feeding include dropping leaves and drying of leading shoots. Heavy infestations can totally defoliate and kill trees,” said Dr Brett Hurley, an entomology researcher with the TPCP.

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After Glycaspis was discovered there, the US imported one of the pest’s natural enemies, the parasitic wasp Psyllaephagus bliteus, from Australia. This has since become an established biological control agent for Glycaspis in North America.
If the new pest is confirmed to be Glycaspis, the TPCP may consider trials for using the wasp in SA.

“We’re not surprised to learn of the possible discovery of Glycaspis here,” said Peter. “We’ve been told consistently that these pests and diseases can move very fast around the world. But we are delighted that we have a world-class team at FABI watching, and working on, these problems. There are many other pests and diseases that we know will be coming in due course.”