Effect of bean plant treatment with Trichoderma harzianum TR6 on the biology of bean aphid Aphis fabae

Trichoderma species are important biocontrol agents of plant pathogens. However, potential of Trichoderma species in insect pest management, remain poorly understood.  In this study, the effect of T. harzianum TR6 on the life table parameters of black bean aphid, Aphis fabae, was evaluated under glasshouse conditions as compared to control. The Vicia faba and black bean aphid were grown in a growth chamber at 25 ± 2 0C, %50 ± 5 RH and a photoperiod of 14 L : 10 D hours. Then, five ml of fungal spore suspension (with concentration of 1 × 106 ml-1) was added into the soil of sown mugs with a sterile syringe. The results obtained in this study revealed that T. harzianum scientifically affected the biological properties of black bean aphid in comparison with the control. Treatment with T. harzianum resulted in the highest developmental time (20.36 days) and the lowest fertility rate in black bean aphid. There was significant differences in terms of inherent rate of population increase (P≤0.5) compared to the control. The highest rate was occurred in control treatment (0.42 ± 0.01 day-1) and the lowest in treatment with T. harzianum (0.16 ± 0.01 day-1). The life expectancy of black bean aphids, which was grown on T. harzianum treated soil, was significantly lower than control. According to the results, it can be stated that treatment of faba bean plant with T. harzianum can be effective in reducing the population of the aphids of the bean.