Detection of a new pest in South Africa – the polyphagous shot hole borer

The Department of Agriculture, Forestry and Fisheries (DAFF) recently released a statement regarding the shot hole borer that has been active in the suburbs.

The department wishes to inform the farming community and members of the public about the detection of a new pest of concern commonly known as the polyphagous shot hole borer (PSHB).

According to the statement, it affects ornamental, indigenous and urban forest trees.

The pest was detected in South Africa for the first time last year in Pietermaritzburg (Botanical Gardens), KwaZulu-Natal, by the Forestry and Agricultural Biotechnology Institute (FABI) of the University of Pretoria.

It was detected again early this year in Gauteng near Sandton. There are also reports of an infestation on pecan trees in Hartswater, Northern Cape.

The department has since established a working committee with other relevant stakeholders to do more research on the pest on how it can be effectively controlled and/or managed.

The polyphagous shot hole borer has a wide host range that includes important crop tree species such as avocado, macadamia, peach, orange, grapevine and pecan trees, as well as forest trees such as the cabbage tree, monkey plum, common coral tree and honey flower.

The PSHB is associated with a fungal pathogen species, Fusarium euwallacea. This pathogen is a symbiont of this beetle (meaning they live in close association) and can eventually kill an infested tree.

The pest bores into the wood, transmitting the fungal pathogen in the process and the entire tree may die because of the fungal rot. The PSHB is a tiny beetle of about 2,0 to 2,8 mm long in size. Matured females are very dark brown to black in colour and are larger than their male counterparts.

Chemical control (injecting infested trees with fungicides and insecticides) may prove to be effective to control this tiny beetle and its fungus but may be expensive.

Plant materials showing similar symptoms, or infested trees, should be reported to the relevant authorities or alternatively cut down and chipped.

In terms of the sub-control measure 7(2) of the Control Measures R. 110 of 27 January 1984 as amended, “Any individual or organisation or institution that has for the first time identified or recorded a new pest to be present in the Republic, shall immediately report it to the relevant executive officer.”

Have you reported the shothole borer to the Department yet? Share your experience with us on the Sandton Chronicle Facebook page

Previous reports:

https://staging.citizen.co.za/sandton-chronicle/206991/craigpark-community-updated-on-the-shothole-borer-2/

https://staging.citizen.co.za/sandton-chronicle/196534/beware-the-borer/

https://staging.citizen.co.za/sandton-chronicle/208158/beetle-infestation-threat-still-looms/