Detection of wood-decay by Ganoderma adspersum in elm trees – A pilot study using a trained dog

Abstract

The use of biodetection dogs is increasing but systematic approaches to their certification and validation are lacking. In this pilot study, the ANSI/ASB standard 088 (2020) was used to assess the performance of a dog trained to detect wood-decay caused by the parasitic fungus Ganoderma adspersum in elm trees. Controlled tests were followed up with a field study where the dog examined elms in two cities. The health of the elms indicated by the dog and a number of trees that were not indicated were followed up by sonic tomography and visual inspection. The pilot showed that the dogs performance during the controlled testing was similar to the performance during the field study: an overall sensitivity of 91% during the controlled tests and a positive predictive value (PPV) of 81% during the field study. Where the dog was able to assess 30–60 trees in an hour, sonic tomography takes at least an hour per tree. Combining a biodetection dog trained to detect G. adspersum into routine tree inspections can help to identify the pathogen earlier than tree inspectors can and focus resources efficiently.