Estimations of attractive area of pheromone traps and dispersal distance, of male adults of sweet potato weevil, Cylas formicarius (Fabricius)(Coleoptera, Curculionidae)

As a preliminary study on an estimation of the population of male adults of sweet potato weevil, Cylas formicarius (FABRICIUS), by using the pheromone trap, the attractive area of the trap to their population, and also dispersal distance were evaluated in sugarcane fields in Amami-Ohshima Island in 1989. 1) Most males were captured by traps at less than 1 m high from ground level. 2) Based upon the mark-recapture experiments the effective radius of the attractive area of the pheromone trap was estimated by the area-ratio model of HARTSTACK et al. to be about 55 m for 100 μg of pheromone loaded in the trap and about 64 m for 400 μg. 3) From the mark-recapture data the mean dispersal distance of male adults was estimated by HAWKES' model to be about 55 m/d.