Western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae) is the most serious pest species in this genus in the world. In this research demographic analysis and population projection of Frankliniella occidentalis were studied on the six varieties of cucumber i.e. Girtap, Negin, Pouya, Salar, Zohal and Ygreen under laboratory conditions (25±2°C, 65±5% RH and 14:10 h L: D photoperiod). Based on the results, Frankliniella occidentalis had the lowest intrinsic rate of increase (rm) on Girtap variety. The development time of the egg, L1, L2, prepupal, pupal and female stages of Frankliniella occidentalis on Girtap variety significantly differed from others. Agestructure population growth rate of L1 on Negin, Zohal and Pouya varieties was similar.
