双尾新小绥螨对烟粉虱和土耳其斯坦叶螨的捕食选择性

Prey Preference of the Predatory Mite Neoseiulus bicaudus Wainstein (Phytoseiidae) on Bemisia tabaci and Tetranychus turkestani

为了明确双尾新小绥螨Neoseiulus bicaudus Wainstein对不同密度下烟粉虱Bemisia tabaci (Gennadius)和土耳其斯坦叶螨Tetranychus turkestani (Ugarov&Nikolskii)的捕食选择性,在实验室条件下,测定24 h内双尾新小绥螨对不同比例下猎物的捕食情况(烟粉虱和土耳其斯坦叶螨数量比为20:10、15:10、10:10、10:15、10:20和10:40)。结果表明双尾新小绥螨雌成螨对猎物的捕食量随猎物数量的升高而增加,其中对土耳其斯坦叶螨幼螨的捕食量最高。双尾新小绥螨除对烟粉虱1龄若虫和叶螨卵在10:10的相同密度下选择指数无差异外,其他各密度下,双尾新小绥螨对土耳其斯坦叶螨的选择性均显著高于烟粉虱。当烟粉虱和土耳其斯坦叶螨同时发生时,双尾新小绥螨对土耳其斯坦叶螨的选择性高于烟粉虱,对土耳其斯坦叶螨控制效果更好。

The objective of this study was to determine the prey preference of the predator mite Neoseiulus bicaudus for preys Bemisia tabaci and Tetranychus turkestani at different stages and prey ratios in the laboratory. The number of preys consumed in different treatments(at ratios of B. tabaci to T. turkestani were 20:10, 15:10, 10:10, 10:15, 10:20 and 10:40) were recorded in 24 hours. The results show that the number of preys consumed increased with the increase in prey density and the larva of T. turkestani were predated most in all treatments. The preference for T. turkestani was always higher than for B. tabaci except in the treatment with B. tabaci first instar and T. turkestani eggs at the ratio of 10:10. When B. tabaci and T. turkestani coexist in crops, the predator mite N. bicaudus has better control effect on the spider mites.