A short video Polyphagous Shothole Borer Beetle

The invasive Polyphagous Shot Hole Borer (PSHB) has now spread to the southern suburbs of Cape Town. Due to the infestation many reproductive host trees have been removed. This pest poses a serious threat to our urban forest, natural forest, and valuable monumental trees. Serious actions and decisions from the authorities and those working in the green industry have to be taken.


Posted on 22 April, 2023 07:09 by tonyrebelo tonyrebelo


My comments come from my experience of the PSHB here in George.
It will be remarkable if the City of Cape Town is able to curb the spread of this pest. They have proven ability to do well wrt AI matters and I encourage them to be as pro-active as possible.
It was heart-breaking to watch the 'sit-back and do as litlle as possible' attitude encountered from the local municipality. The lack of registration of approved methodology became a convenient shield. At no point was a dumping site made available - even less a chipper.
As for the 'put the cut wood in clear plastic' in the sun for how many months (as winter approaches) - the householder can be expected to house this operation? Reality check needed here, please.
My saga commenced with a huge Acer negundo that I had years before offered to contribute towards the removal of - it got nailed in the first burst of PSHB here and my well-treed garden was right next door.
A local 'Tree man' was being pro-active and offering treatment - so 5 of my trees (2 x Liquidamber, 2 x Robinia frisia hybrids and 1 x Searsia chirendensis) were treated. So too a large old English Oak on the corner opposite. We missed seeing the tell-tale signs on my Ilex mitis - it is tucked into a copse of different trees and it was too late when I saw its damage.
A year later the treatment was repeated. My trees are still here and doing okay. The two Liquidambers were topped this spring. I reckon their regrowth has not been as vigorous as it would have been had they not suffered some long-term damage, but time will tell. In any event the species is too large for a 1000 sq metre stand, hence the need for topping.
I was recently advised that the company here in George offering treatment (and borne out by many home-owners here) has a new lease of life and has a new owner. (The original operator sadly passed on thanks to covid.)
It must be at least 5 years since my trees were first treated.

Posted by annsymons about 1 year ago

What was the treatment?
Apparently Los Angelos has contained it with vigorous removal of infested trees, especially amplifier species (those which breed up huge numbers for release).

Posted by tonyrebelo about 1 year ago

A proprietory mix of insect-repellant and fungicide, quantity per size of tree - mixed in a bucket and fed to a series of tubes into the phloem of the tree via hollow 'bolts' drilled at intervals around the base. The trees then draw this fluid up into their trunks, and branches.
George has lost almost all its many old English Oaks - there are a few beyond Witfontein. Otherwise just a few miserable skeletons - I counted over 20 entering from the Knysna side recently.
The Acer negundo I guess is one of the amplifier species? Only ones left of them are on 'wasteland' or tucked into state-owned land - some small percentage appear to be growing again - I see leaves in a neighbours rental property.

Posted by annsymons about 1 year ago

Did the Oak on the corner survive?

Posted by tonyrebelo about 1 year ago

It got the chop courtesy of the tenants in the house closest - it was going to 'kill one of her children' - and the blighters have since moved away - I lost a friend who had been in my mountain view for the past 34 years. I still see the hole in the sky there... It still had one main stem that I was keen to preserve in hope of recovery.
My question re Acer negundo?

Posted by annsymons about 1 year ago
Posted by tonyrebelo about 1 year ago

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