PSHB Beetle

Polyphagous Shot Hole Borer Beetle (euwallacea fornicatus)

The polyphagous shot hole borer (PSHB) beetle has been introduced into South Africa and it is spreading rapidly within the urban forests – millions of trees are projected to die.

View pictures of what the PSHB beetle looks like.

Affected trees develop wilted brown leaves on infested branches. The most obvious sign of infestation is branches have brown stains around each hole where the borer has penetrated the tree.

View pictures of what trees infested by the PSHB beetle look like.

Indigenous and exotic trees are attacked – the PSHB is generally indiscriminate since is does not eat wood, rather it feeds on fungus that it introduces into it’s host tree. The fungus (Fusarium euwallaceae) grows in the tunnels made by the borer – it is the fungus that kills the tree. Fusarium dieback occurs when your tree’s vascular system begins to fail, leaves begin to thin on the ends of branches, they turn brown, the branch and eventually the tree will die.

Boxelder, London Plane, English Oak, Chinese Maple are attacked particularly hard.

View the list of trees known to be affected.

View the photographic record of bark that has been removed to reveal the damage caused by the PSHB and the fusarium fungus in different tree genus.

The distribution of established PSHB infestation in South Africa are Johannesburg, Durban, Richards Bay, Pietermaritzburg, George, Knysna  and Hartwater.

Johannesburg with its dense urban forest has been hit part particularly hard.

FABI (Forestry & Agricultural Biotechnology Institute) within the University of Pretoria are extensively researching the PSHB here in South Africa. FABI has setup the following PSHB research portal.

PSHB – FABI Information sheet
PSHB – FABI Life stages of the beetle
PSHB – FABI How to sample
PSHB – FABI Symptoms
PSHB – FABI External symptom types
PSHB – FABI How to photograph for diagnosis