eradication program of the oriental fruit fly, Dacus dorsalis Hendel (Diptera: Tephritidae), in the Ogasawara (Bonin) Islands. I. Eradication field test using a sterile fly release method on small islets

To confirm the effectiveness of the sterile fly release method for eradication of the oriental fruit fly, Dacus dorsalis HENDEL, experimental control was attempted utilizin this method on a group of small islets known as the Muko Jima Group of the Ogasawara Islands. Estimating the wild population density of this fly, we released about 3 million sterilized pupae per month against 98, 000 wild files from May 22 to September, 1978, a total of 11.3 million pupae were released during about four months. The ratio of marked to unmarked files caught in monitor traps was 26.27 in June, 1978 and increased rapidly, reaching 299 four months after the first release. Concurrent field surveys demonstrated that only one female emerged from 2, 088 host fruits collected in Muko Jima in August, 1978 and no fly was recovered from 15, 000 host fruits subsequently examined.