A beetle smaller than a sesame seed kills huge trees throughout South Africa, and little can be done to stop it.
The polyphagous shuttle, a native of Southeast Asia no larger than 2 mm, has found its way to South Africa and infected trees at an alarming rate.
According to Professor Marcus Byrne, a winner and entomologist of the Ig Nobel Prize at the University of the Witwatersrand, the beetle drills tunnels in tree trunks where it spreads the fungus Fusarium euwallaceae, which effectively cuts off the vascular system of the trees, causing them to die. "It is an ambrosia beetle, which means that it carries a fungus on which it nourishes its babies.
When it introduces that fungus into trees that have never experienced it, it threatens those trees with disease or death. & # 39;
Byrne says that nobody really knows how the beetles have found their way to South Africa.
"We happen to be a very connected world and today's trade makes goods traffic all over the world possible, and we are not very good at screening those animals that lift our consumer goods around the world."
According to Byrne, there is no solution to remove trees from these beetles once they have been infected.
"You can apply a fungicide, but the scale on which you should apply it is just ridiculous.
"There are many snake oil traders who try to sell what they see as solutions, but none of these works."
The local beetle infection was first noticed by Dr. Trudy Paap – a postdoctoral fellow at the Forestry and Agricultural Biotechnology Institute at the University of Pretoria – at the National Botanical Garden KwaZulu-Natal in Pietermaritzburg, and has since been found nationwide, including in Johannesburg and up to the North Cape.
Johannesburg has what is considered one of the world's largest urban forests with an estimated 10 million trees.
According to Andrea Rosen, co-director of the Johannesburg Urban Forest Alliance, up to 100,000 trees in Johannesburg could already be infected and the contamination spread quickly.
"The polyphagous brothel borer is of great concern," Rosen said Tuesday.
"Some projections amount to half a million trees that have only been affected in Johannesburg, which is a substantial part of our urban forest canopy."
Rosen says that there is no effective treatment for infected trees, apart from cutting and destroying or burning the wood.
A local company, Pan African Farms, has developed a solution that has been shown to be effective in laboratory conditions, but awaiting emergency registration before it can be used on real trees. Rosen hopes that it will be available within the next two months.
According to Rosen, many trees in the gardens of the residents of Johannesburg could be infected without being aware of it. -News24