Bid to stump borer beetle

A tiny, 2mm insect is well on its way to boring through some of South Africa’s most treasured trees.

The polyphagous shot hole borer beetle, native to Southeast Asia, was first detected in 2017 in Pietermaritzburg, but has since spread to Durban, Johannesburg, Pretoria, Knysna, George and Hartswater.

Since then, conservationists across the country have been on the lookout for them. But the tiny beetles continue to thrive and kill both invasive and indigenous species.

In the Kruger National Park (KNP), there is intense monitoring to prevent the beetle from entering the park. South African National Parks (SANParks) senior head of conservation Navashni Govender said the effortless spread of the beetle was of particular concern for the park.

The beetle has not invaded the Kruger Park region, but one tree was infested in Mpumalanga.

Govender, along with CropWatch Africa’s Roedolf Nieuwenhuis, have set up 31 traps, pictured, from the Crocodile River to Bafuri to detect the presence of the beetle as early as possible. The traps, disguised as trees, contain pheromones to attract male beetles. As the males attempt to land, they fall into the traps.

Surveys and maintenance are done on the traps once a month and the collection bucket at the bottom of the trap is emptied. Specimens are sent to the Forestry and Agricultural Biotechnology Institute in Pretoria to be identified.

SANParks also regularly checks trees in the area for the beetles.

The monitoring programme will continue until funding runs out, Govender said, which was why SANParks was trying to persuade both local and international universities to assist with research.

US agriculturalists based in Pretoria have come onboard to help curb the spread of the beetles. The beetles spread primarily when firewood is purchased in a region where they are rife and taken to a different place, allowing the beetles to invade trees in the new area.

This vicious cycle had to be curbed as soon as possible, Govender said, imploring people to remember the phrase “burn where you buy, and buy where you burn”.