Non-destructive Detection of an Invasive Drywood Termite, Cryptotermes brevis (Blattodea: Kalotermitidae), in Timber

Abstract

<p>Reliable drywood termite detection in structures is challenging but is critical for effective management. A microwave-based non-destructive method was evaluated for detecting termite activity. This study evaluated factors affecting the ability of this device to reliably detect <em>Cryptotermes brevis</em> in timber. The device displayed a high probability of successfully detecting <em>C. brevis</em> in naturally infested boards. The system detected termites 97% of the time when used at the highest sensitivity level, while producing few false positives. The number of termites did not affect detection ability, and detectable signals were produced even when a single termite was present. Detection success decreased with both increasing wood density and testing perpendicular to the grain in abrupt transition timber species. The device detected termites to a maximum depth of 45 mm in southern pine (<em>Pinus</em> spp.), but sensitivity declined with increased wood density with the detection limit declining to only 20 mm in denser Tasmanian oak (<em>Eucalyptus</em> spp). The device could only detect termites in samples with densities between 392 to 511 kg/m<sup>3</sup> in 38 mm thick radiata pine samples. The results support the ability of microwaves to reliably detect <em>C. brevis</em> in timber.</p><p> </p>