Dr Trudy Paap is a participant in the International Plant Sentinel Network who was tasked to do routine surveys for tree pests and diseases in the National Botanical Gardens of South Africa, a project funded by the South African National Biodiversity Institute. It was during one of these surveys that she noticed small lesions resembling shotgun marks on the stems and branches of mature London plane (Platanus x acerifolia) in the historical avenue of the KwaZulu-Natal National Botanical Garden in Pietermaritzburg.

The lane of London plane trees where the PSHB was first identified in Pietermaritzburg

"Upon closer inspection, I found that the lesions developed around entrance holes of small beetles. When I removed the bark, the sapwood was discoloured by a fungus. I brought samples back to UP’s Forestry and Agricultural Biotechnology Institute (FABI), and with the assistance of FABI team members, the beetle and fungus were identified based on DNA sequences as Euwallacea fornicatus, or polyphagous shot hole borer (PSHB), and Fusarium euwallaceae, respectively," said Dr Paap.