New bioinsecticide based on Streptomyces griseoflavus PAL114 for biocontrol of black bean aphid Aphis fabae

Abstract

This research highlights the efficiency of a new bioinsecticide based on Streptomyces griseoflavus PAL114 for black bean aphid control and its effect on fava beans. Three actinobacterial strains were tested in vitro for their aphicidal activity. The PAL114 strain was then formulated in talc powder at two densities (≈ 106 and ≈ 108 spore ml− 1) and tested again. Furthermore, the bioinsecticide was applied to the plant in two modes in pot experiments to assess its effect. The results showed that PAL114 was the only strain that significantly influenced mortality (p = .001). It induced a very highly significant mortality when formulated (p˂.001), which exceeded 90% after 58 hours. The influence of both densities didn't differ significantly. There was no adverse effect of bioinsecticide on fava bean; in contrast, there was an improvement in growth especially when combined with soil amendment. The present study opens up prospects for field studies for the biocontrol of this crop pest.