Towards lower-cost, user friendly acoustic detection systems for hidden insect infestations in trees

The larvae of insects such as the red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae), and Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), damage trees by burrowing and feeding inside the trunks. RPW infests 50% of all date palm-growing countries, including Saudi Arabia. Asian longhorned beetles have devastated both old- and new-growth North American forest, resulting in a massive eradication effort, and some $3.5 billion in annual damage in the U.S. ALB tend to fly from tree to tree only over short distances, and only after its base tree has a high ALB population. RPW spend months as larvae in infested trees before emerging as flying adults and spreading to other trees. Pre-emergent detection methods are therefore very useful for these insects. In these species as well as in many others, larvae and adults produce sound when they feed and move. Vibrations produced by RPW in palm trees in Saudi Arabia, Spain, and Aruba, and ALB in America, were recorded using the AED-2010 preamplifier and field recorder. The recordings were analyzed using a lab-developed program, DAVIS, to assess insect presence from spectral and temporal patterns. Once detected, infested trees are treated or removed to prevent pest spread. We are currently optimizing and porting DAVIS to new, lower cost embedded-system platforms, developing fully-automated devices for the detection of these invasive insect species.