فهرست نشریات علمی دسترسی آزاد ایران

The influence of three host plants, cucumber, tomato and eggplant on functional response of Encarsia formosa was investigated at different densities of early fourth nymphal instar of Trialeurodes vaporariorum under laboratory conditions at 25 ± 1°C, 65 ± 5% RH and a photoperiod of 16:8 (L: D) h. Whitefly nymphs were offered to the parasitoids in densities of 2, 4, 8, 16, 32, and 48 on leaf disks (8-10 cm2) in 12 replicates. After 24 hours, the parasitoids were removed and the number of parasitized as well as the killed nymphs by host feeding activity was recorded. Logistic regression results showed a type II functional response for both types of "parasitism" and "parasitism + host feeding" activities in all three host plants. There were no significant differences between attack rates (a) across three host plants, but the handling time (Th) estimated on tomato was significantly shorter than those estimated on cucumber. The attack rate of E. formosa in "parasitism" activity on cucumber, tomato and eggplant was 0.2580±0.0963, 0.3895±0.1331 and 0.3283±0.1368 h-1 and handling time was 0.6870±0.0810, 0.3364±0.0399 and 0.5584±0.0692 h, respectively. Based on the results, it seems that tomato is the most suitable plant for the parasitism and host feeding activities of E. formosa to control of the greenhouse whitefly T. vaporariorum in greenhouse conditions.