2种啮小蜂对棕榈植物3种主要害虫的寄主适合度

The host suitability of two Eulophidae spp. to three main pests of palm plants

寄生蜂对寄主的选择和适合度不同会影响对害虫的控制效果。为评价不同种类寄生蜂对棕榈食叶害虫控害效能,通过强迫寄生实验和寄主选择实验研究2种啮小蜂[椰心叶甲啮小蜂Tetrastichus brontispae Ferriere和周氏啮小蜂Chouioia cunea Yang)对棕榈植物上3种主要食叶害虫(椰心叶甲Brontispa longissima (Gestro)、水椰八角铁甲Octodonta nipae(Maulik)和椰子织蛾Opisina arenosella Walker]的寄主适合度和选择趋性。啮小蜂强迫寄生实验结果表明:椰心叶甲啮小蜂对椰心叶甲寄生率(76.67%)显著高于其在水椰八角铁甲(63.33%)及椰子织蛾(0.00%)上的寄生率,周氏啮小蜂(北京、海南种群)对椰子织蛾的寄生率(56.67%、63.33%)显著高于其在椰心叶甲(23.33%、15.44%)及水椰八角铁甲(0.00%、0.00%)上的寄生率,它们的出蜂量、性比、寿命等也有显著不同。选择寄生实验结果表明:椰心叶甲啮小蜂更偏向于寄生椰心叶甲(选择频率73%),周氏啮小蜂更喜欢寄生椰子织蛾(选择频率95%)。实验结果表明生产中释放周氏啮小蜂能控制椰子织蛾,也可能兼治椰心叶甲,但不能控制水椰八角铁甲;释放椰心叶甲啮小蜂能有效控制椰心叶甲和水椰八角铁甲,但不能控制椰子织蛾。

The differences in host selection and fitness of parasitoids affect their efficacy of controlling pests. To evaluate the control efficacy of different species of parasitoids on palm leaf pests, this paper studied the fitness of two Eulophidae spp.（Tetrastichus brontispae Ferriere and Chouioia cunea Yang） on three main palm leaf pests〔Brontispa longissima（Gestro）, Octodonta nipae（Maulik）, Opisina arenosella Walker〕by non- choice and choice test. Non- choice test showed that the parasitism rate of T. brontispae on B. longissima（76.67%） was significantly higher than that on O. nipae（63.33%） and O. arenosella（0.00%）. The parasitism rate of C. cunea on O. arenosella （56.67%, 63.33%） was significantly higher than on B. longissima （23.33%, 15.44%） and O. nipae （0.00%, 0.00%）. There were also significant differences in their offsprings number, sex ratio and life span. The choice test showed that two parasitoids had different preferences for their hosts. T. brontispae preferred to B. longissima（select frequency： 73%） while C. cunea preferred to O. arenosella（select frequency 95%）. Our results indicated that the release of C. cunea could control O. arenosella, might also contol B. longissima, but could not control O. nipae; the release of T. brontispae could effectively control B. longissima and O. nipae, but it could not control O. arenosella.