Biological effects of Beauveria bassiana and Akanthomyces attenuatus isolates on Aphis gossypii Glover (Hemiptera: Aphididae)

The biological effects of entomopathogenic species, Beauveria bassiana (Bals.-Criv.) Vuill and Akanthomyces attenuatus Zare & Gams on cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae) nymphs at 1x108 conidia concentration (ml-1) were investigated at the laboratory conditions. The experiments were conducted at 25°C, 65% relative humidity, and 16:8 hours of lighting in a climatic cabinets. Alive nymphs were recorded on the 1st, 3rd, 5th, 7th, and 9th days of incubation. B. bassiana caused higher mortality of the nymphs than A. attenuatus did. A statistical difference was determined between the isolates on the 7th and 9th days of the experiment. The highest mortality rates were determined in the isolate of B. bassiana with 72% and the isolate of A. attenuatus with 54% on the 9th day. The LT50 value for the isolates of B.bassiana and A. attenuatus was 6.02 days and 8.33 days, respectively.