New pest of concern - Polyphagous Shot Hole Borer (PSHB)

The Department of Agriculture, Forestry and Fisheries wishes to inform the farming community and members of the  public about the detection of a new pest of concern Euwallacea sp. nr fornicates, commonly known as the Polyphagous Shot Hole Borer (PSHB) that affects ornamental, indigenous and urban forest trees.

This pest was detected in  South  Africa  for  the  first  time in  2017, in Pietermaritzburg  (Botanical  Gardens), KwaZulu - Natal province, by the Forestry  and  Agricultural  Biotechnology  Institute (FABI) of  the  University  of  Pretoria. It  was detected again in early  2018  in Gauteng province  near the Sandton suburb of Johannesburg. There are also reports of infestation on  pecan trees in Hartswater,  Northern Cape province.

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 (i.e. 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 2,8mm 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”.


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