Biological Control for some Insects by Using Plant Growth Promoting Bacteria in Laboratory and Field Conditions

The cotton leafworm and aphid insects are major pests in Egypt that attack many host plants. Pesticides use can cause different problems in the plant system. So, it is very important to use nature products to be safe as a alternatives to synthetic pesticides. This research aimed to evaluate the efficacy of three bacterial types: Lysinibacillus macroides, Brevundimonas olei and Acinetobacter sp. in laboratory and field conditions throughout two seasons 2021 & 2022. L. macroides and B. olei showed more toxicity and LC50 levels than Acinetobacter sp with > 90 % corrected mortality towards the cotton leafworm and bean aphid after 3 days exposure time under laboratory conditions. Under field conditions, there were two insect pests fall armyworm (Spodoptera frugiperda) and aphid insects (Myzus persica (Sulzer) that investigate pepper plants in Ismallia Governorate. The results also showed a high efficacy of two bacterial strains, L. macroides and B. olei against M. persicae and S. frugiperda with more than 80% and 60% reduction percent respectively. The data stated that, L. macrolides strain was the most effective on suppressing the aphid and fall armyworm insects population. Some bacterial enzymes and biochemical products produced by bacteria used, such as protease, chitinase, catalase, glutathione peroxidase, polyphenol oxidase (PPOs) and HCN. They play a role in insect population reduction in laboratory and field conditions throughout integrated crop management.