پراسنجه های رشد جمعیت شته‌ی جالیزAphis gossypii (Glover) روی چهار رقم خیار در شرایط گلخانه‌ای

The melon aphid, Aphis gossypii is one the most important pests of the cucumber plant. the effect of four cucumber plant including Arshia®, Tarom®, Caspian® and Danito® was investigated on the population growth parameters of A. gossypii at 25 ± 2 °C, 65 ± 5% RH and a photoperiod of 16:8 (L;D) h. The experiment started using 50 first instar nymphs (< 24 h old). The nymphs were separately reared on the leaves of each cucumber cultivar. After emergence of adults, their fecundity and survival were recorded daily until all of them were dead. The parameters were estimated using two-sex life table procedure. The highest values of intrinsic rate of increase (r) and net reproductive rate (R0) of the aphid were estimated on Tarom 0.443 ± 0.009 and 30.14 ± 2.05, resp. and the lowest values were on Caspian 0.297 ± 0.009 and 16.78 ± 1.55, resp. and Danito 0.305 ± 0.011 d-1 and 16.62 ± 1.60 per generation, respectively. The finite rate of increase (λ) ranged from 1.346 ± 0.013 on Caspian to 1.557 ± 0.015 d-1 on Tarom cultivar. The lowest values for mean generation time (T) and doubling time (DT) of the aphid were estimated on Arshia and Tarom cultivars. Based on the results, the cultivars of Caspian and Danito are considered to be least suitable hosts for A. gossypii.