As the Polyphagous Shot Hole Borer beetle (PSHB) continues to spread across the southern suburbs, many private property owners may soon have to budget for the extra cost of having infested trees removed.
According to the Invasive Species Unit’s management protocol, the priority is the swift identification and removal of highly infested trees to reduce the beetle population.
Infested trees must be chipped on-site. Infected wood can either be solarised on-site or incinerated at a high temperature (over 50°C) which kills both the beetle and its fungus. Property owners who decide to go the incineration route are required to have the infected material carefully removed under cover of heavy-duty plastic to “an appropriate site” where the biomass will be incinerated.
People’s Post asked Paul Barker, a consulting arborist with extensive experience in managing PSHB, what homeowners could expect to pay. Barker says the removal of a tree could cost anything from R3 000 upwards, depending on the size of the tree and the amount of work involved.
When a tree is infested with PSHB, biosecurity measures are required which adds to the cost.
“Arborists who come in to deal with a tree that’s infested know from the beginning, depending on the scope of the work, that they are going to need to spend an hour or two after the job, cleaning their equipment and I mean properly cleaning the equipment,” he says.
Barker explains that reputable arborists usually have equipment set aside for working with pathogens.
“Arborists are cognisant of the fact that they work with tree diseases. So they thoroughly clean their equipment often but when it comes to PSHB, they actually have to decontaminate all of our equipment.”
If the infected material cannot be kept safely on-site and needs to be transported to an incineration facility, the cost goes up even further.
According to Barker, the most affordable option is to chip the wood and solarise the infested material on-site. He explains solarisation happens when the material is covered in plastic and left to bake in the sun for up to six months.
“The temperature rises and gets so hot that it kills everything. Chipping kills 98% of the beetle; to kill the remaining 2%, we need to solarise it. Also, it is better to solarise in the summer. For example, if your tree comes down from December to February, it will only need to sit in the sun for about six weeks. Outside of these months, this goes up to six months.”
He says if you can’t afford to have the infested material chipped, and if it is a reasonably small tree, it can be cut into firewood pieces, bagged up in clear plastic bags and left in the sun, again for six months. But, he warns, do not burn the wood on your property before the solarisation process is complete.
“The minute there is smoke, the beetles start to leave the nest. Burning the infested wood spreads it further.”
