烟粉虱对四种蔬菜寄主的选择性

Preference of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) to four vegetable hosts

为探讨利用趋避作用防治烟粉虱的可能性 ,进行了 3方面试验 :1)烟粉虱Bemisiatabaci (Gennadius)对黄瓜、花椰菜、油菜和莴苣等 4种蔬菜的寄主选择性 ;2 )互喷烟粉虱不同嗜好的寄主植物汁液对其寄主选择性的影响 ;3)不同间作方式对黄瓜叶上烟粉虱成虫密度的影响。结果表明 ,烟粉虱对供试植物有明显的选择性 ,其嗜好程度为花椰菜 >黄瓜 >油菜 >莴苣。喷施莴苣和花椰菜汁液对烟粉虱的寄主选择性均有显著影响 ,喷施莴苣原液后 ,花椰菜和黄瓜上的成虫数分别减少 79 6 %和87 4 % ,花椰菜上的着卵量减少 84 3% ;喷施花椰菜原液后 ,莴苣上的成虫数和着卵量分别增加 82 4 %和 79 2 % ,表明不同蔬菜中的内含物是引起烟粉虱对寄主选择性的重要原因。在黄瓜中间作莴苣可使黄瓜叶上烟粉虱成虫数平均减少 76 5 % ;间作花椰菜时 ,通过诱集作用 ,也可使黄瓜叶上的成虫数平均降低 6 9 7%。这些结果为利用喷施蔬菜汁液和间作方式控制烟粉虱危害提供了理论依据。

To explore the feasibility to control the tobacco whitefly (TWF), Bemisia tabaci (Gennadius) using repellent properties of plant, three experiments were conducted under various conditions: (1) The host preference of B. tabaci among cucumber Cucumis sativus L., cauliflower Brassica oleracea L., rape Brassica campestris L. and lettuce Lactuca sativa L. was tested; (2) To evaluate effects of phytochemicals on the host preference, juice of the favorable and unfavorable hosts were mutually sprayed onto each other; (3) Effect of intercropping patterns on host preference of B. tabaci was evaluated. The results showed that B. tabaci preferred cauliflower most, followed by cucumber, cole and lettuce. Spraying various concentrations of plant juice significantly affected the host preference of B. tabaci. Spraying original juice of lettuce onto cauliflower leaves reduced densities of B. tabaci adults and eggs by 79.6% and 84.3%, respectively. Spraying original juice of lettuce onto cucumber plants reduced adult population by 87.4%, while spraying original juice of cauliflower seedlings onto lettuce leaves increased densities of B. tabaci adults and eggs by 82.4% and 79.2%, respectively. The results indicate that phytochemicals in vegetable plants play an important role in host preference of B. tabaci. By intercropping cucumber with cauliflower, the number of B. tabaci adults on cucumber leaves was reduced by 76.5% compared with the control of mono-cultural cucumber. By intercropping cucumber with lettuce, the number of B. tabaci adults on cucumber leaves was reduced by 69.7% compared with the control. The potential to control the whitefly on cucumber by spraying vegetable juice and intercropping was discussed.