That pesky pest, the invasive Polyphagous Shot Hole Borer beetle (PSHB), has made its way to Durbanville and has nested in a Boxelder and Sweet Viburnum tree on a private property. The City has stated that this latest infestation is the first to be discovered in this area and is of great concern.
The City was first notified of a possible infested tree in Durbanville and deployed a team of monitors from the Invasive Species Unit to assess the area and collect samples for DNA verification. “Following the DNA verification, unfortunately, it has been confirmed that the Boxelder and Sweet Viburnum trees are indeed infested with PSHB. Several other trees, including English Oak, Liquid Amber, and Chinese Cottonwood on the same property and the neighbouring property, have also been found to exhibit PSHB symptoms.
“At this point, we cannot confirm the number of infested trees in the Durbanville area as a whole, as surveys are currently underway. I urge all private landowners in Durbanville to urgently inspect the trees on their properties for symptoms and to contact us immediately should any of these be visible on any trees. The City also needs access to private properties to conduct a full assessment to determine the extent of the infestation in and around Durbanville. I therefore ask residents to please give the teams access to their properties so that we can determine the extent of the PSHB infestation. We are extremely concerned about the latest sighting and request the assistance and cooperation of residents and businesses that work with plant material,” said the City’s Deputy Mayor and Mayco member for Spatial Planning and Environment, Eddie Andrews.
The City has announced that it will communicate information on an important community training session for Durbanville residents once details have been confirmed. Boxelder trees, for example, are one of the four highly susceptible reproductive host trees for PSHB. Both the beetles and the fungus can establish, and the beetle successfully reproduces in these trees. Once attacked, Boxelder trees typically die within one year, amplifying the PSHB population and increasing the risk to surrounding trees. Boxelder is thus an ideal tree that can be used as an indicator of an early infestation in a new area. All landowners across the City with Boxelder trees on their properties are urged to notify the City by logging these trees on iNaturalist. This will help the City set up monitoring interventions that will assist in catching a new invasion early.
All staff conducting the survey and tree assessments will wear City of Cape Town branded clothing and will present official staff identification cards to gain access to properties.
Latest infestation statistics (excluding Durbanville) indicate that to date, 26 trees have been infested in Penhill, Eerste River, among which are Boxelders, London Planes, English Oaks, Beef Wood, Weeping Willow, Cape Chestnut, Black Locust, Paperbark, and Maples. Over 400 sightings of infested trees have been recorded in Newlands, Rondebosch, Mowbray, Claremont, Kenilworth, and Observatory along the Liesbeek River. Furthermore, over 5,700 infested trees have been sighted in the Helderberg Area since 2019 to date.