Population responces of Aphis gossypii (Hem.: Aphididae) to sublethal concentrations of Beauveria bassiana (Asc.: Hypocreales)

In the present study, sublethal effects (LC10 = 255, LC20 = 3702 and LC30 = 25461 conidia/ml) of entomopathogenic fungus, Beauveria bassiana Bals. (Vuill.) on the biological attributes of Cotton aphid, Aphis gossypii Glover, was evaluated under laboratory conditions (25 ± 1 °C, relative humidity of 65 ± 5% and a light period of 16 h.). Data analysis was performed using the Age-stage two sex life table theory. Based on the results obtained, although sublethal concentrations had no significant effects on the female longevity, but their effects on the fecundity of treated individuals was significant. In addition to the treated individuals, we also present data supporting that the sublethal effects could carry over to their offspring. The lowest recorded value for pre-adult development of A. gossypii was observed at LC30 (4.36 day). Furthermore, the lowest value for duration of total pre-ovipositional period (TPOP) was also recorded at this sublethal concentration (4.60 day). The highest mortality of immature stages was recorded at LC30 (24.24 %). Different treatments had significant effects on the intrinsic (r) and finite (λ) rates of increase. The results obtained could be helpful for increasing efficiency of entomopathogenic fungi in management programs of different pests.