Dispersal Potential of Male Cylas formicarius (Coleoptera: Brentidae) over Land and Water

To determine the size needed for buffer zones in an eradication program, dispersal ability of male Cylas formicarius (F.) was evaluated by the mark-release-capture method in the central part of Okinawa Island, Japan. Approximately 36,700 marked males were released from 2 islets. Forty-five pheromone traps were placed on 6 islets near Okinawa Island and 24 on the eastern seashore of Okinawa Island. Two traps were put at the 2 release points on the last day of the experiment. Of 71 recaptured males, 34 were caught by 3 traps on the Sea Road (a 5-km bank connecting Okinawa Island and an islet) located 2 km northwest of a release point. Sixty-two traps did not capture marked males. This result suggests that for C. formicarius eradication projects, a buffer zone with a minimum radius of 2-4 km should surround the area targeted for control.