The invasive Polyphagous Shot Hole Borer beetle (PSHB) has now been confirmed in Cape Town’s central business district and Hout Bay, which city officials have described as deeply concerning and requiring urgent public cooperation.

Samples taken from Boxelder and London plane trees in key locations across the CBD, including Long Street, St George’s Mall, Military Road and Tamboerskloof, as well as along Victoria Road in Hout Bay, have tested positive for the beetle. DNA verification by Stellenbosch University’s Entomology Department has confirmed the infestation.

This marks the first time PSHB has been formally detected in these high-density, high-traffic areas, significantly increasing the risk of rapid spread.

The City of Cape Town says its monitoring teams are currently conducting intensive surveys to determine how widespread the infestation is, but warns that the true extent is not yet known.

“We are extremely concerned about the latest sightings and urgently request the assistance and cooperation of residents and businesses that work with plant material,” said Deputy Mayor and Mayoral Committee Member for Spatial Planning and Environment, Alderman Eddie Andrews.

At this stage, the City cannot confirm how many trees are affected in the CBD and Hout Bay. Officials are calling on all private landowners across the city to inspect trees on their properties and to report any suspected symptoms immediately. Residents are also urged to allow City officials access to conduct assessments, noting that staff will carry official identification and wear City-branded clothing.

The Polyphagous Shot Hole Borer is considered one of the most destructive invasive pests threatening South Africa’s urban forests. The beetle bores into trees and introduces a harmful fungus, which blocks the tree’s ability to transport water and nutrients, often leading to death.

Boxelder trees are of particular concern. They are one of four highly susceptible reproductive host species in which both the beetle and the fungus thrive. Once infested, Boxelder trees typically die within a year, rapidly increasing beetle populations and placing surrounding trees at risk.

To help detect new outbreaks early, the City is urging all landowners with Boxelder trees to log them on the iNaturalist platform. This information will help officials focus monitoring efforts in areas where the beetle has not yet been confirmed.

PSHB has already been detected in numerous parts of Cape Town, including Somerset West, Gordon’s Bay, Strand, Newlands, Rondebosch, Claremont, Observatory, Kenilworth, Wynberg, Durbanville, Pinelands, Parow North, Bellville, Brackenfell, Kraaifontein, Penhill and Constantia.

Residents are urged to watch for the following warning signs:

• Branch dieback
• Cracking and leaf loss
• Small sesame-seed-sized holes in the bark
• Dark staining
• Oozing sap or gum from entry points

Suspected sightings can be reported via the City’s invasive species portal, by calling the Invasive Species Unit on 021 444 2357 during office hours, or by emailing invasive.species@capetown.gov.za

The City says it will aim to respond within 10 working days, depending on the volume of reports received.

Officials stress that early detection and swift reporting remain the most effective tools to slow the spread of this destructive beetle, adding that public vigilance could make the difference between containment and widespread loss of Cape Town’s trees.