Demographic parameters of silverleaf whitefly Bemisia argentifolii Bellows and Perring on cotton in Iran

摘要

The demographic parameters of silverleaf whitefly, Bemisia argentifolii Bellows and Perring (Homoptera, Aleyrodidae) as important pest of cotton fields were studied during 2001. The infested leaves containing nymphs and pupae were collected from cotton fields at different location in Iran. Experiments were conducted in a growth chamber at 24±2 °C, 55±3% RH and 16:8 (L:D) photoperiod on cotton, Gossypium hirsutum L. (Varamin 76 variety). The newly emerged populations from each locality were released into a large cage placed on cotton plants separately. Using mean data obtained on 40 adult whiteflies stable population parameters including intrinsic rates of increase (r_m), doubling time (DT), mean generation time (T_c), intrinsic birth rate (b), intrinsic death rate (d) finite rate of increase (A) were 0.0715, 9.79, 30.0, .0.0811, 0.0095 and 1.07 respectively. Age specific reproduction parameters such as net fecundity rate, net fertility rate, gross hatch rate, gross fecundity rate and gross fertility rate were calculated to be 19.03, 12.60, 0.67, 71.85 and 48.93 respectively. Other parameters of reproduction such as mean age gross fecundity and fertility, mean age net fecundity and fertility, mean age hatch, number of eggs/female/day and daily reproductive rate were also calculated.