Abstract: 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 auliflower, 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.

Key words: Bemisia tabaci, host preference, cucumber, cauliflower, lettuce, host plant juice, intercropping