Life history performance of Aphis gossypii Glover (Aphididae) on seven cucumber cultivars

The cotton aphid, Aphis gossypii Glover (Aphididae) is an important pest of indoor and outdoor cucumber crops in Iran. We studied the life history performance of A. gossypii on seven cucumber cultivars (Negin, Pierro, Davos II, Royal safa, Dominus (Ps), Super pretty and TN-94-203) at 27 ± 1 ºC, 50% ± 10% RH and a photoperiod of 16:8 (L:D) h. The developmental time for the nymphal stages ranged from 4.27 days on Pierro to 4.47 days on Negin, but differences among cultivars were not statistically significant. The lowest and highest survival rates for immature stages were 68.33% and 95% on Royal safa and TN-94-203, respectively. The total fecundity of A. gossypii significantly differed among cultivars, being the highest on Pierro (44.66 nymphs/female) and the lowest on Dominus (Ps) (69.89 nymphs/female). The lowest intrinsic rate of natural increase (r_m) was obtained on Negin, and the highest on Super pretty. The generation time (T) was shortest on Pierro (7.41 days) and longest on Negin (8.32 days). According to our results, Super pretty and Negin were partially susceptible and resistant to A. gossypii, respectively. The findings of this study provide direction to design a more comprehensive integrated pest management program for this pest.