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An entophytic bacterium. Paenibacillus polymyxa promotes plants growth and defending them against pathogens and pests. There are considerable studies that have focused on effect of this bacteeri on pathogens but have no study to their effect on pests. In this research. P. polymyxa strain N179 was used as soil treatment to evaluate their impact on Aphis fabae population growth parameters. The Vicia faba L. and black bean aphid were grown in a growth chamber at 25±5 0C. %50 RH and a photoperiod of 14L: 10D hours. P. polymyxa were transferred to the soil of the cultures. The results of the experiment showed that the average total length developmental of the A. fabae in bacteria and control treatments was 18.09±0.16. 17.73±0.16 days respectively. Adult preoviposition period (APOP) and Total preoviposition period (TPOP) was longer in bacteria treatment than the control. Also net reproductive rate (R0) in the bacteria treatment was significantly changed in comparison with control. The intrinsic rate of increase (r) in bacteria and control treatments were 0.23±0.0001 day-1. 0.42±0.0001 day-1 respectively. Entophytic bacterium. P. polymyxa showed adverse effects on survival and fitness of black faba bean aphid; hence can be noticed in a control program for A. fabae on faba bean plants.
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