烟蚜茧蜂规模扩繁冬寄主筛选研究

为筛选出烟蚜茧蜂(Aphidius gifuensis Ashmead)规模扩繁中的最佳繁蚜冬寄主,比较了自然条件下7种不同冬寄主上烟蚜的种群数量变化,烟蚜茧蜂对各寄主上烟蚜的防控效果及僵蚜羽化率.结果表明:烟蚜在7种寄主上种群数量的自然增长从大到小依次表现为烤烟K326、芥菜、芥菜型油菜、甘蓝型油菜、萝卜、红菜薹、白菜;芥菜上烟蚜茧蜂的寄生率为70.56%,显著高于其他寄主;7种冬寄主上僵蚜羽化率均高于70%,其中芥菜最高,为97.33%,萝卜最低,为72.87%,二者差异具有统计学意义.烟蚜茧蜂均能寄生7种冬寄主植物上所饲养的烟蚜且僵蚜羽化率相对较高,但总体而言芥菜上烟蚜的种群数量增长较快,烟蚜茧蜂的寄生率和僵蚜羽化率均最高,可利用芥菜来替代烟草作为冬季繁蚜寄主,也可在春烟种植前对芥菜田释放烟蚜茧蜂使其在田间建立自然种群.

Studies on Election of Aphid (Myzus persicae Sulzer) Winter Hosts for Aphidius gifuensis Ashmead Propagation

In order to select the optimal winter hosts of aphid breeding for propagation of Aphidius gifuensis Ashmead, the population changes of Myzus persicae Sulzer, the control effect of A. gifuensis on M. persicae, and the emergence rate of mummified aphids among seven winter hosts were explored under natural conditions. The results showed that the natural growth of M. persicae populations on the seven host plants was expressed as:Nicotiana tabacum cv. K326 > Brassica juncea > B. juncea var. gracilis > B. napus > Raphanus sativus > B. campestris var. purpuraria > B. pekinensis. The parasitic rate of A. gifuensis on B. juncea was 70.56%, which was significantly higher than that on other winter hosts. The emergence rates of mummified aphids on the seven winter hosts were all higher than 70%, being the highest on B. juncea (97.33%) and the lowest on R. sativus (72.87%). In conclusion, M. persicae feeding on the seven hosts could be parasitized by A. gifuensis and all had a fairly high emergence rate of mummified aphids, but the natural growth population of M. persicae and the emergence ratio of A. gifuensis was the highest on B. juncea. Therefore, it is recommended that B. juncea be used to replace tobacco for establishing natural populations of A. gifuensis, or A. gifuensis be released to a B. juncea field before the planting of spring tobacco so that a natural population of the parasite may be established.