تغییرات فصلی و توزیع فضایی جمعیت سفید بالک پنبه Bemisia tabaci روی خیار پاییزه در منطقه ملاثانی- استان خوزستان

Cotton whitefly,  Bemisia tabaci is considered as one of the most important pests of fall cucumber in Khouzestan province. Studies were conducted to examine the seasonal dynamics and spatial distribution of B.tabaci on fall cucumber during 2006 and 2007 in Mollasani area. In both years, adult whiteflies first appeared on the plants in early September. In 2006 and 2007, mean maximum of adults occurred on 15^th of September (58 adults / leaf) and 7^th of September (25 adults/ leaf), respectively. In the above mentioned years, the mean maximum of eggs was found on 15^th of September (134 eggs/ 2cm² leaf) and 7^th of September (92 eggs/ 2cm² leaf). Likewise the mean maximum numbers of nymphs in 2 cm² were 81 and 39 nymphs on 15^th of September and 7^th of September, respectively. In the aforementioned years, the mean maximum pupae were counted on 20^th of September (2.3 pupae/2cm² leaf) and 14^th of September (1.4 pupae/ 2cm² leaf), respectively. The population of all developmental stages reached zero in the beginning of November. The results of this study have applications for integrated management of cotton whitefly.