The Polyphagous Shot Hole Borer Invasion
The PSHB beetle’s presence has been detected in several regions across South Africa, and its expansion is a cause for grave concern. Infested areas such as Johannesburg, Midrand, Durban, Pietermaritzburg, George, Mpumalanga, Knysna, Kruger National Park, and Hartswater are grappling with the onslaught of this invasive pest. However, it’s crucial to recognize that it’s not the beetle itself that directly leads to tree demise; rather, it’s the insidious Fusarium fungus it carries.
The Deadly Partnership: PSHB and Fusarium
The PSHB beetle, no larger than a grain of rice, burrows its way into the heart of our trees, introducing the malevolent Fusarium euwallaceae fungus into the inner tunnels. This sinister partnership sets off a chain reaction within the tree. As the fungus spreads, it begins to compromise the tree’s vascular system, resulting in a cascade of observable symptoms. Leaves on infested branches start to wither and thin, turning a disturbing shade of brown. Unless swift intervention occurs, this process culminates in the branch’s death and, ultimately, the demise of the entire tree.