Entomopathogenic effects of different endophytic bacteria on Spodoptera littoralis (Boisduval, 1833) (Lepidoptera: Noctuidae)

This study was conducted in 2024-2025 in the laboratories of Ege University, Faculty of Agriculture, Department of Plant Protection. Spodoptera littoralis (Boisduval, 1833) (Lepidoptera: Noctuidae) is an important pest in T & uuml;rkiye and causes extensive economic losses in many cultivated crops. During our field observations, some blackening and dead individuals were observed in Leptinotarsa decemlineata (Say, 1824) (Coleoptera: Chrysomelidae) larvae. As a result of the isolations made from blackened larvae and plant samples, 6 different bacterial isolates were obtained. Pseudomonas fluorescens Migula (Pseudomonadales: Pseudomonadaceae) strain 184, whose entomopathogenic effect was proven in our previous studies and molecular diagnosis and sequence analysis were performed, was also used in these tests. As a result of two seperated experiments, it was observed that endophytic bacteria isolates caused 20 to 93% mortality compared to untreated negative control. As a result of conventional and molecular identification and sequence analysis, the bacterial isolates with the highest entomopathogenic effect against S. littoralis larvae were isolates 441 and 442, which were definitively identified as Serratia marcescens J. and Enterobacter cloacae M. (Enterobacterales: Enterobacteriaceae), respectively. This study revealed that these bacteria may have potential for biological control against S. littoralis.