A progress report on the eradication program of the sweet potato weevil, Cylas formicarius (Fabricius) (Coleoptera: Brentidae), with both male annihilation using sex pheromone and sterile insect releases in Kume island, Okinawa, Japan

In order to eradicate Cylas formicarius (Fabricius), an experimental project was started in Kume Island (5600ha) in 1994. The suppression of wild weevils by male annihilation technique (MAT) was conducted from November 1994 to January 1999. Wood fiberboard squares containing synthetic sex pheromone and MEP was used for the MAT. The infestation and trapping data show that the density of the weevil population on the island decreased to approximately one tenth of that before the control experiment began. In February 1999, we started the mass release of sterile weevils. In 2000 and 2001, the infestation rates of vines were 0.4% and 0.16% in peak season. During this period, we conducted intensive host surveys and identified high density areas (hot spots). As a result, we started additional releases into these hot spots in June 2001. From January through December 2002, no wild weevils were found, except on the southeastern coast (20ha) of the island. We thus concluded that C. formicarius seems close to being eradicated. (author)