Ethyl formate (EF) and methyl salicylate (MS) are naturally occurring and generally safe substances for use. Sub-lethaldoses of EF and MS were evaluated to find synergistic fumigation action against azuki bean beetle (ABB), Callosobruchuschinensis (L.). Susceptibility of the ABB to EF was in the order of eggs =adults >larvae >pupae. Adults was most sensitiveto MS, and followed by eggs. Larvae and pupae were highly tolerant to MS. However, in synergistic effects of EF andMS showed that all the stages of ABB were highly sensitive in the order of adults >eggs >larvae >pupae. Highest synergisticratio was found against adults when using LC10 of both EF and MS as compared to other stages. Notably, MS synergizedthe EF exposure to all stages of ABB. This finding paves the way to exploiting synergistic activity of MS and EF againstABB for the safeguard of stored azuki bean grains.