Seasonal and Daily Patterns in Activity of the Western Drywood Termite, Incisitermes minor (Hagen)

Activity of colonies of the western drywood termite, Incisitermes minor, was measured with acoustic emission (AE) technology in five loquat (Eriobotrya japonica) logs. Termite activity, whether it was feeding, excavation or movement, was monitored for 11 months under ambient conditions in a small wooden structure maintained at the University of California Richmond Field Station. AE, temperature, and humidity data were measured in 3-minute increments. Termite activity was greater during the warmer summer months compared to the cooler winter months. Termites in all five logs displayed a similar daily cycle of activity, peaking in the late afternoon. Seasonal and daily fluctuations in termite activity were significantly associated with temperature, whereas humidity did not appear to have a noticeable effect on termite activity. Possible mechanisms that drive the seasonal and daily cycles in termite activity, as measured by AE technology, and the possible implications for inspections and post-treatment analysis are discussed.