Population dynamics of Bactrocera dorsalis,B.cucurbitae and B.tau(Diptera:Tephritidae) in Xishuangbanna

Annual monitoring was conducted on the population dynamics of the oriental fruit fly,Bactrocera dorsalis,B.cucurbitae and B.tau((Diptera: Tephritidae) through lure-traps all year around from 2000 to 2003 in Jinghong,Menglong and Daluo of Xishuangbanna Prefecture.The results indicated that fruit fly occurred year-round in Xishuangbanna.Bactrocera dorsalis was the absolute dominant species,B.cucurbitae and B.tau took the second place.The population dynamics has similar trend at three sites.The increasing peak appeared from the end of May to at the beginning of July.The amount of population went up from end of May to mid of June,and the amount of population was relative higher.After that,the fly population declined remarkably after September.The data analyses indicated that the amount of fly population had no significant difference among three sites,and there had no significant difference among years at the same site.Mango and longan were the main favorite host species of the fly in Xishuangbanna,so the planted areas,fruiting period and productions exerted essential effects on the fly population fluctuations.Besides that,temperatures and rainfall influenced the population dynamics of the fruit fly in Xishuangbanna.