Evaluation of a novel, hand-held, acoustic emissions detector to monitor termites (Isoptera: Kalotermitidae, Rhinotermitidae) in wood.
A hand-held, battery-powered acoustic emissions (AE) detector designed to locate and monitor wood-feeding insects was evaluated for its ability to detect termites in wood. It was possible to detect 20 Coptotermes formosanus, Incisitermes snyderi and Neotermes jouteli pseudergates in small wooden blocks 100% of the time during an experimental 5-min interval. If undisturbed, 20 Reticulitermes flavipes pseudergates could be detected at a 98% frequency. AE production was governed largely by termite species and density. In detection tests along longitudinally oriented wood grain, termites could be detected up to 80 cm from the AE sensor, although detection at progressively shorter distances from termites was increasingly more likely. Detection of termites in wood in a tangential orientation (against grain) was unlikely beyond 8 cm. Although counts were high (up to 299/min), there was a poor relationship between I. snyderi numbers and AE event counts in naturally infested logs. The only termite behaviour observed to elicit detection by the AE units was wood feeding. Most ambient noises were not registered by the detector. It was concluded that this device offers a reliable method for localized, nondestructive detection of termites in wood.