1a.Objectives (from AD-416)
The objective of this cooperative research project is to develop an acoustical monitoring tool for detecting subterranean termites. Primary target pest is the Formosan subterranean termite (Coptotermes formosanus) in structures, trees, and soil.
1b.Approach (from AD-416)
Acoustical apparatuses will be constructed to detect unseen infestations of insects. Devices will be based on recognition of sound-producing acitivities. Recognition will be developed from databases sounds recorded under an array of substrates and environmental conditions.
Our main mission is to develop instruments and devices that can help in detecting Formosan Subterranean termite (FST) infestations in a non-invasive and cost effective manner. One of the main ways to detect termites non-invasively is to monitor surface vibrations on walls infested with termite activity. Two ways to measure these vibrations are contact methods using surface mounted accelerometers or non-contact methods usually utilizing laser-based vibration measurements (Laser Doppler Vibrometery or LDV). We have continued to investigate the various features and problems of both systems. Previously discussed measurements of Micro Electro-Mechanical Systems (MEMS) have indicated that while they are a possible low cost solution, they are not sensitive enough yet to provide detection. For laser systems, a new lower cost portable laser (Canon DS-80 micro laser interferometer) often used for industrial applications was tested against the more expensive Polytec system discussed in previous reports. The new system was less expensive but required significantly more labor to initially set up and use. It may, however, have value if an improved housing package that allows for better, easier calibration can be designed and this work may be pursued in the upcoming year. Due to a significant change in personnel, the research has shifted slightly. Previous work has often focused on termite detection in a somewhat qualitative manner. Measurements were performed to determine if detection from one system was better than another or if a particular system was able to detect signals at all. A new batch of experiments is underway to quantitatively investigate detection. Measurements of detection in terms of range of detection from infestation, as well as detection limits for infestation of known density levels, are being investigated. Furthermore, previous work has shown that contact measurements require a waveguide (or spike) be placed in the wall to aid detection, but this requirement mitigates the benefits of “non-invasive” detection. To work around this requirement, these new experiments will attempt to use existing drywall nails or screws already present in the wallboard to act as a waveguide. This requirement will necessitate the user in the field to find said drywall attachment points, but this type of experiment will aid in determining the practicality of any proposed field measurement technique. Progress in this project is monitored through Annual FST Technical Committee Meetings, reports, regular meetings with cooperators, routine phone calls, and e-mail correspondence.