DISPERSAL POTENTIAL OF MALE CYLAS-FORMICARIUS (COLEOPTERA, BRENTIDAE)OVER LAND AND WATER

To determine the size needed for buffer zones in an eradication progra m, dispersal ability of male Cylas formicarius (F.) was evaluated by t he 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 trap were placed on 6 islets near Okinawa Island and 24 on the eastern seashore of Okinawa Island. Two traps were put a t the 2 release points on the last day of the experiment. Of 71 recapt ured males, 34 were caught by 3 traps on the Sea Road (a 5-km bank con necting Okinawa island and an islet) located 2 km north-west of a rele ase point. Sixty-two traps did not capture marked males. This result s uggests that for C. formicarius eradication projects, a buffer zone wi th a minimum radius of 2-4 km should surround the area targeted for co ntrol.