The tree killing pest, the Polyphagous Shot Hole Borer Beetle (PSHB), has made an appearance in the Penhill area after sowing devastation in Somerset West.
The City said it was first notified of a possible infested tree in the Penhill area on 1 February 2024.
“The case was investigated, and samples were sent to Stellenbosch University (SU) for DNA testing. The SU confirmed on 15 March 2024 that the samples tested positive for the Polyphagous Shot Hole Borer beetle (PSHB).
Mayco member for Spatial Planning and Environment, Eddie Andrews said this makes Penhill a new PSHB hotspot area.
“We are extremely concerned about the latest sighting as to date we have managed to contain the invasive Asian borer beetle to the Helderberg area and the Southern suburbs, with the assistance and cooperation of residents and businesses that work with plant material.
‘The City’s Invasive Species Unit conducted surveys in the Penhill area over the past seven weeks, and I can confirm that unfortunately, we have identified a total of 24 infested trees – eight of which are on City-owned land, and 14 on private properties. These are Boxelders, London Planes, English Oaks, Beef Wood, Weeping Willow, Cape Chestnut, Black Locust, Paperbark and Maples.
“This is of great concern, and the City is encouraging all private land owners to inspect their trees for symptoms and to contact the City immediately, if so,’ said Andrews.
Furthermore, the City needs access to private properties to conduct a full assessment to determine the extent of the infestation in Penhill.
‘We will be doing more surveys in Penhill and the surrounding neighbourhoods in the coming weeks. Thus, I ask property owners to please assist us, and to allow City officials on site to do these inspections,’ said Alderman Andrews.
To date, 24 trees have been infested in Penhill, Eerste River. All-in-all, 258 sightings of infested trees have been recorded in Newlands, Rondebosch, Mowbray, Claremont, Kenilworth, and Observatory along the Liesbeek River. Over 4 961 infested trees have been sighted in the Helderberg Area since 2019 to date.
The City urged residents to look out for symptoms. These include branch dieback – cracks on the branch; discoloured leaves; dry and leafless branches; branch break-off revealing webs of galleries filled with black fungus; Gumming – blobs of goo coming out of the bark; oozing of liquid and gum from the beetle holes, entry and exit holes – very small holes on the bark of the tree, the size of a sesame seed (2mm); shotgun-like scars developing around the holes, staining – brown or dark stains on the bark of the tree.
The City said it is important that infested trees must be chipped on site and may not be removed from the property as the removal of the chipped wood will spread the pest to other areas.
“Do not buy and move fire wood from areas where trees are infested.”
The City gave these instruction to get rid of infected trees: “Chip the tree, place the infested material in refuse bags, seal it and put these in direct sunlight for at least six weeks.
“Dump the chips in your compost heap as the heat build-up will kill the beetle. Burn infected wood chips at an appropriate incineration facilities. Where chipping is not possible, cut infested wood into smaller pieces that can fit into solarisation plastic bags.
“Tightly close and seal the bag with infested material and place it in an area with direct sunlight and leave it to solarise for at least six weeks in summer and up to six months in winter. Seek assistance from trained and equipped service providers with sound knowledge of PSHB. Do not move plant/tree material/firewood outside of areas where PSHB has been confirmed to be present to other areas
“Do not transport any form of green waste in open vehicles, cover it with sail covers even if no PSHB has been identified as such green waste. Clean tools and equipment used to trim/cut/prune plants.
“The City will try its best to respond within 10 working days to verify a reported sighting. However, the response time will depend on the number of sightings reported.
The PSHB poses a serious threat to Cape Town's urban forest as infested trees have to be chipped.
Importantly, the use of pesticides and fungicides have not proven effective at eradicating PSHB from infected trees. The PSHB beetle can easily spread across suburbs if extra precaution is not taken. Apart from infected wood, the beetle can also spread through clothing, vehicle crevices, or unclean horticultural equipment.
‘We are also encouraging residents to attend any of the free training sessions offered by the City of Cape Town, especially if you have trees on your private property. The knowledge is useful and will empower property owners to take care of their gardens in a safe and responsible manner,' said Alderman Andrews.
How to report PSHB beetle sightings: Online, at www.capetown.gov.za/InvasiveSpecies; Call the City of Cape Town’s Invasive Species Unit on 021 444 2357, Monday to Friday, from 07:30 to 16:00; Send an email to: invasive.species@capetown.gov.za