Joburg could lose thousands of its trees due to an infestation of a borer beetle that carries fungal spores that eventually kill trees.
Some 10 million trees, about six million of which are street and park trees, could be affected.
Johannesburg City Parks and Zoo (JCPZ) has already received some 30 complaints and is holding urgent workshops with relevant interested parties to discuss the outbreak and infestation of the polyphagous shothole borer (PSHB).
Residents in Hurlingham, Craighall Park, Dunkeld, Sandton, Parkview, Kensington and Houghton have reported diseased trees in their yards and on the street.
The city’s member of the mayoral committee for community development, Nonhlanhla Sifumba said the likelihood of the infestation being more widespread is a possibility.
“JCPZ is working closely with institutions such as the Forestry and Agricultural Biotechnology Institute to survey the extent of the spread of the infestation and is set to start a chemical-controlled trial in Hurlingham. We are yet to identify the extent of the shothole borer infestation in Joburg,” she added.
Residents are urged to look out for diseased symptoms which vary in different tree species, from patches of white powdered wood called frass, to blotches of oozing resin or gumming along the holes in the tree.
“Pesticides are not effective because the beetle bores deep into the wood. The only known method of managing the spread is to cut down infested trees hosting the beetle, and to dispose of it in a controlled manner, through burning,” Sifumba explained.
While the beetle has been devastating in other parts of the world, including Asia and California in the USA, Sifumba was cautious not to cause panic until the true extent of the infestation was determined and advised that, “the pine species seems to display a natural repellant to the shothole borer and we are, therefore, very fortunate that the paper manufacturing industry, is not affected,” she added.
Reports received indicate that indigenous trees native to Southern Africa have also been affected such as the acacia sebreana or commonly referred to as the paperbark.
Sifumba, through the JCPZ, has established a committee to source the necessary resources to:
-- Undertake a thorough assessment to understand the true extent of the infestation
-- Train personnel to monitor, dispose of trees and to identify the borer and other fungal hosts that accompany the beetle
-- Put in place a designated area for the controlled dumping and burning of trees and
-- Ensure that a tree replacement strategy is in place.
“We will work with all bodies and concerned groups to ensure that we tackle the infestation collectively to preserve and protect Joburg’s man-made forest.”
Residents have been urged to examine both trees in their gardens and on their streets for signs of infestation.Residents should include photos of symptoms, tree species, location and contact details and report this to trees to [email protected]