| At the condition of constant temperature, we had studied the development, survivorship and reproduction of B-biotype B. tabaci on 5 host plants (sweetpotato, Chinese kale, tomato, cotton, tobacco), and E. formosa on 3 host plants (sweetpotato, Chinese kale, tomato); on the other hand the population dynamics of B-biotype B. tabaci simulated with the life-table and Lesile matrix model. And the parasitoid's preference of E. formosa to different larval stages of the whitefly were studied. The biology and life-table parameter of coldly stored E. formosa brown scale at different developmental days and stored days formed by parasitizing B-biotype B. tabaci were studied to investigate the effect of cold storage on E. formosa population quality. At the end, we explored the simple method of 3-room for reproduction of E. formosa. The development, survivorship and reproduction from egg to adult of B-biotype B. tabaci on five host plants (sweetpotato, Chinese kale, tomato, cotton, tobacco) were studied. The developmental time on sweetpotato was the shortest, which on the cotton was the longest, which were 19.11 days and 20.90 days respectively. The percentage was whitefly immatures that survived on sweetpotato was the highest, the tobacco was the lowest, which were 95.68% and 48.89% respectively. Adult females were significantly longer on tobacco (40.80 days) than cotton (20.70 days), Most females began to lay eggs with in 24th of emergence, and the ovipersitional periodes on those hosts lasted as long as adult longevity. The average number of eggs deposited perfemales were 308.79 (on sweetpotato, the highest), and 87.50 (on cotton, the lowest).Based on the analyses of life-table of whitefly population on different hosts, B-biotype B. tabaci reared on sweetpotato had a highest populationtrend index (181.25), on the other were 105.13 (Chinese kale), 103.33 (tomato), 89.23 (tobacco) and 38.89 (cotton). The population trend index reflects the suitability of the plant, and so sweetpotato was the best, Chinese kale and tobacoo were the better, and tobacco and cotton were the least suitable.According to the data of biology and life-table of B-biotype B. tabaci , population dynamics were conducted by Leslie matrix model. The exponential grow equations on sweetpotato, Chinese kale, tomato, cotton and tobacco, were Nt=10.2502e0.1440t, Nt=10.9485e0.1346t, Nt=10.9867e0.1111t, Nt=14.2692e0.1385t, Nt=10.3044e0.1333t respectively.The parasitoid's preference to different larval stages of the whitefly was determined at 25℃. The parasite rate on prepupal stages was the highest, 50.4%, which on 1st instar was the lowest, 10.5%. The developmental time of E. formosa from egg to pupae stages were the shortest on prepupal stage (7.56 days) and the longest on the 1st instar(11.6 days).The development, survivorship, reproduction, host-feeling and population trend index of E. formosa on Chinese kale were better than sweetpotato and tomato, which were 97%, 23.6±1.6, 162.4±4.3, 69.3±3.4 and 197.2 respectively. And these parameters on sweetpotato were he lowest, which were 66.7%, 18.3±1.5, 138.2±7.8, 132.9 respectively. The developmental times from eggs to adult of E. formosa were 14.97±0.9 (sweetpotato), 14.50±0.8(tomato), 14.31±0.7 (Chinese kale). Thus, Chinese kale was the suitable plant for living of E. formosa.The biology and life-table parameter of coldly stored E. formosa brown scale at different developmental days and stored days formed by parasitizingB-biotype B. tabaci were studied to investigate the effect of cold storage on E. formosa population quality. Among those populations developed from 1 to 6 days stored at 11℃ for 10 days, the 3 day-instar scale was better than others in its emergence rate, adult longevity, oviposition number and host-feeding quantity. At the same time the above mentioned biological properties of 3 day-instar brown scale stored at 11℃ significantly decreased with the storage time from 10 to 30 days, but the populations stored for 10 days did not significantly differ f...
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