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Borer Beetle Alert

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Date: 22 January 2025 – Borer beetle pest spreading and increasing concerns for Bishopscourt residents
Polyphagous Shot Hole Borer beetle (PSHB).
This page will be updated as information changes and is pertinent to the Bishopscourt area

Latest infestation statistics

• To date, 26 trees have been infested in Penhill, Eerste River, among which 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
• Over 5 700 infested trees have been sighted in the Helderberg Area since 2019 to date

The City of Cape Town wants to inform residents that samples taken from a Boxelder and Sweet Viburnum tree on a private property in Durbanville tested positive for the invasive Polyphagous Shot Hole Borer beetle (PSHB). 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 to 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 have PSHB symptoms.

Boxelder trees for example are one of the four highly susceptible reproductive host trees for PSHB. Both the beetles and the fungus are able to establish, and the beetle successfully reproduces in these trees. Once attacked, Boxelder trees typically die within one year and they amplify the PSHB population and increase 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 to please notify us by logging these trees on https://www.inaturalist.org/projects/box-elders-cpt. This will help the City set up monitoring interventions that will assist with catching a new invasion early.

All staff doing 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.

What to look out for and symptoms of infested trees:
•        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

Important: 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.

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

What to do:
•        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 facility
•        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 from 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

Residents are urged to attend an online information session about the invasive borer beetle

Update 23 January 2025

The City of Cape Town is urging residents to attend a vitally important online information session about the invasive Polyphagous Shot Hole Borer beetle (PSHB). The session will take place on Tuesday, 28 January 2024, from 17:00 until 18:30. The webinar will be hosted by Deputy Mayor Eddie Andrews and officials from the City’s Invasive Species Unit. Following the latest sighting of PSHB in Durbanville, we recommend that residents who have trees on their properties set time aside to learn more about the beetle including the threat posed by the PSHB to Cape Town’s urban forest.

Residents to please email MMC.SpatialPlanEnvironment@capetown.gov.za  for access to the webinar.

Some of the trees affected in Cape Town include Boxelders, London Planes, English Oaks, Beef Wood, Weeping Willow, Cape Chestnut, Sweet Viburnum, Black Locust, Paperbark, Liquid Amber, Chinese Cottonwood and Maples.

The City will be sharing the following information during the webinar:
• How to identify infested trees and what symptoms to look out for
• What to do next, what not to do
• How to handle infested biomass
• How to safely dispose of infested biomass
• How to transport green waste
• How to handle equipment and machinery in a manner that will not spread the pest to other areas

The City will share important information with all residents at the webinar on Tuesday.

‘We are urging all private land owners to urgently inspect the trees on their properties for symptoms and to contact us immediately should any of these be visible on any trees. I would like to remind residents in Durbanville to give our 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 Mayoral Committee Member for Spatial Planning and Environment, Alderman Eddie Andrews.

• Residents across Cape Town are also encouraged to notify the City if they have Boxelder trees on their properties by logging these trees on https://www.inaturalist.org/projects/box-elders-cpt .

Boxelders are one of the four highly susceptible reproductive host trees for PSHB. Both the beetles and the fungus are able to establish, and the beetle successfully reproduces in these trees. Once attacked, Boxelder trees typically die within one year and they amplify the PSHB population and increase the risk to surrounding trees. Boxelder is thus an indicator of an early infestation in a new area.

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.

The PSHB poses a serious threat to Cape Town’s urban forest as infested trees have to be chipped.

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.

Original Source: Media Office, City of Cape Town

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