赤眼蜂防治荻芦茎螟研究

ON THE APPLICATION OF TRICHOGRAMMATIDS AGAINST REED STALK BORERS

棘禾草螟(Chilo hyrax)和芦禾草螟(C.lutellus Mostchuleky)等茎螟是洞庭湖区为害荻(Miscanthus sacchariflorus)和芦苇(Phragmites communis)的大害虫。从1984年起利用赤跟蜂防治这类害虫,取得了良好的效果。试验表明,松毛虫赤眼蜂(Trichogramma dendrolimi)尤其适于苇田生态环境。初次放蜂的苇田,于棘禾草螟第一代始盛卵期、盛卵期和盛卵末期3次放蜂效果最好。亩放蜂量5—6万头,盛卵期放蜂量应占全部放蜂量的三分之二。放蜂点距离以10米为宜。连续放蜂2—3年后,亩释放量可缩减至3—4万头。

The reed stalk borers(Chile hyrax Bls.and C.lutellus Mots.)are important reed(Phragmites communis and Miscanthus sacchariflorus)insect pests in Dongting Lake Region.It is not available to use chemical meas- ure against these insects,due to the difficulty of spraying,high cost, low efficacy of control,and lake pollution.Since 1984,the trichogra- mmatids were used in reed stalk borer control,the effect was satisfac- tory. Experimental results showed that the T.dendrolimi was most adapta- ble species to the ecological condition of reed field.50—60 thousands per mu of trichogrammatids released at the beginning,peak(two third of the total amount released),and end of oviposition period in the first generation of Chilo hyrax were good enough to control the damage of these insects.The appropriate distance between release points was 10 meters.The released amount might be reduced to 30—40 thousands per mu after 2—3 years successive trichogrammatids release.