Huynh, M.; Ho, K.-V.; Phillips, A.; Ernwall, A.; Ludwick, D.; Finke, D.; Lei, Z.; Jack, A.; Hibbard, B.; Breakfield, N.

Pink-pigmented facultative methylotrophs (PPFMs) are known to promote plant growth and enhance pathogen resistance, but their role in insect defense remains largely unexplored. Here, we report that TS201, a U.S. EPA-registered bioinsecticide composed of Methylorubrum extorquens, enhances maize defense against corn rootworms (CRW) and improves yield through plant-mediated mechanisms. Over seven years of small-plot trials at 22 U.S. Midwest locations, TS201 increased yield by 220 kg/ha under moderate to high CRW pressure. Additional trials demonstrated rooting and lodging benefits. Large-scale trials across 81 sites in eight U.S. states (2023-2024) validated its agronomic benefit. Transcriptomic and metabolomic analyses revealed activation of anthranilate production and increased accumulation of methyl anthranilate, a volatile CRW-repellent compound. Insect assays indicated significant larval avoidance of TS201-treated roots. These findings reveal a novel mode of action for PPFM-induced plant defense and demonstrate TS201 as a strategic microbial tool for integration into broad-spectrum integrated pest management programs.