FLIGHT BEHAVIOR OF SCOLYTID BEETLE IN RESPONSE TO SEMIOCHEMICALS AT DIFFERENT WIND SPEEDS

The response of the striped ambrosia beetle, Trypodendron lineatum (Olivier) (Coleoptera: Scolytidae), to a semiochemical-baited funnel trap was studied in a wind tunnel in the first of two experiments. Wind speeds were tested over a range of 0.0-0.9 m/sec. Percent beetle capture decreased linearly with increasing wind speed within the range tested. A second experiment showed that in the presence of wind, beetles flew upwind to a semiochemical-baited substrate. In still air, they tended to fly randomly and erratically; yet in close proximity to the baited substrate, a greater proportion of the beetles were arrested in response to the chemical stimuli and landed on the substrate than when an airflow was present. These results suggest that T. lineatum are capable of responding to semiochemicals under varied wind conditions typically present in a forest where they use wind to orient to olfactory stimuli. However, greater numbers are arrested in response to the stimuli under relatively still conditions.