Performance of Aphis gossypii on Bt and non-Bt cotton varieties (n = 24 to 30).

Bioassays were performed at 25°C±1°C day/20°C±1°C night, 70%±10% r.h. and a 16-h photoperiod.Printed estimate refers to median and variability to first to third quartile in case of Cox-proportional hazard analysis, and to 95% confidence interval of the mean otherwise.a(rm) intrinsic rate of increase (days); (FD) number of nymphs produced during D; (DF) daily fecundity; (TF) total fecundity; (D) nymphal developmental time (days); (AL) adult longevity (days); (TL) total longevity (days).bbootstrap percentile method.c3-way ANOVA with experiment, cotton variety and Bt-transformation as factors.dCox-proportional hazard analysis with experiment, cotton variety and Bt-transformation as factors.eF = Test statistic for F-distribution; W = Wald test statistics.