Abstract: To understand the effects of potassium nutrition of host-plant on the duration, survivorship, nymph body size and adult host selection of Bemisia tabaci, we conducted experiments with different potassium concentrations, K0(0 mg/L), K30(30 mg/L), K60(60 mg/L), K120(120 mg/L) and K240 (240 mg/L). The results showed that duration, survivorship and body size of the whitefly nymphs on the cucumber plants treated with different potassium concentrations were different. The total duration from egg to adult on plants with K240 potassium concentration was 21.4 days, and with K60 potassium concentration, 18.3 days. The total survival rates of the whiteflies from egg to adult were 71.4%, 84.7%, 83.8%, 76.2% and 64.8% on plants treated with K0, K30, K60, K120 and K240 potassium concentrations, respectively. In the host choice experiment, the number of adults and deposited eggs per plant were significantly higher on plants with K60 potassium concentration than on those with other concentrations. Implications of the current results in regulating sweetpotato whitefly populations through adjusting plant potassium nutrition were discussed.

Key words: Bemisia tabaci, potassium nutrition, cucumber, growth and development, survivorship, size, host selection