Genomic Analysis of Gut Bacteria in Tecia Solanivora: Insights into Host Functions and Their Potential in Biocontrol

Gut bacteria in insects play critical roles in host physiology, contributing to both beneficial and harmful functions. However, the functional role of gut bacteria in Tecia solanivora, a major pest of potato crops in Central and South America, remains poorly understood. This study provides the first genomic and functional characterization of bacteria isolated from the gut of T. solanivora, focusing on their contributions to host fitness and their potential applications in pest control. Seven bacterial strains were identified: Duffyella gerundensis Ts1, Enterobacter ludwigii Ts2, Serratia quinivorans Ts3, Duffyella sp. Ts4, Rahnella variigena ATs1, Rahnella variigena ATs2, and Stenotrophomonas sp. ATs4. Genomic analyses revealed genes implicated in digestion and nutrient acquisition (e.g., ribABCDE operon for riboflavin synthesis and the ISA gene for isoamylase synthesis), insecticide detoxification (e.g., nfsAB encoding nitroreductase), and protection against natural enemies (e.g., impABCEFGHJLM operon for type VI secretion system). Experimental validation confirmed the activity of key functions. Notably, E. ludwigii Ts2 and S. quinivorans Ts3 exhibited entomopathogenic activity against their host insect, causing larval mortality rates of 63.3% and 40.8%, respectively. Notably, R. variigena ATs1 and Rahnella variigena ATs2 demonstrated phytopathogenic activity against potato tubers (97% damage), identifying them as opportunistic pathogens. These findings advance understanding of insect-microbe interactions, identify promising candidates for biological pest control, and highlight the importance of comprehensive safety assessments in agricultural applications.