Comparison on allowable use of Bromus tomentellus in semi-steppe and mountainous rangelands of Alborz and Zagros.

In order to study the effects of different host plants on population development of cotton whitefly Bemisia tabaci, a greenhouse experiment was conducted at Agricultural Biotechnology Research Institute of Iran, Karaj in 2012. In this experiment the effects of two cotton varieties (Varamin and Sahel) was evaluated on pre-adult developmental time, pre-adult mortality, adult longevity, mean daily and total eggs number, sex ratio and life table parameters of Bemisia tabaci. Results indicated that the pre-adult developmental time of Bemisia tabaci on the var. Varamin and Sahel was 21.08 and 18.04 days, respectively. Also the adult longevity of females on the var. Varamin and Sahel was 11.12 and 14.58 days, respectively. Bemisia tabaci reached the adult stage faster on var. Sahel than var. Varamin. The fecundity of Bemisia tabaci on var. Sahel was more than that on var. Varamin. No significant difference was observed between the sex ratio of Bemisia tabaci on two cotton varieties. Intrinsic rates of increase in Bemisia tabaci on var. Varamin and Sahel were 0.08 and 0.14, respectively. The results indicated that the life history of Bemisia tabaci was influenced by host plant quality and var. Varamin was not a suitable host for this pest.