Biocontrol Potential of Native Entomopathogenic Bacteria Against Palpita persimilis in Peruvian Olive Agroecosystems

Olive, Olea europaea L. (Oleaceae), cultivation is affected by significant yield losses caused by Palpita persimilis Munroe (Lepidoptera: Crambidae), a defoliating pest in South America. Its control currently relies on synthetic pesticides, which have adverse environmental effects. This study investigated native entomopathogenic bacteria isolated from the rhizosphere of olive trees in Tacna, Peru. A total of 36 bacterial isolates were obtained, of which six strains showing more than 70% larval mortality were selected for further evaluation. Morphological and molecular analyses suggested a tentative affiliation of the isolates with bacterial groups related to the genera Lysinibacillus, Paenibacillus, Priestia, and Bacillus. Bioassays demonstrated that larval mortality depended on the bacterial concentration and exposure time. Strains such as Peribacillus sp. UNM achieved 100% larval mortality after 96 h at a concentration of 1 × 10⁹ CFU mL^-1. Analysis using a generalized linear model (GLM) with a binomial distribution confirmed that bacterial strain, concentration, and exposure time significantly influenced larval mortality, indicating that mortality responses varied according to bacterial concentration and exposure time. These findings provide preliminary laboratory evidence of entomopathogenic activity associated with native bacterial isolates against P. persimilis and support future investigations aimed at evaluating these isolates under field conditions in olive agroecosystems.