Methyl salicylate reduces aphid abundance in maize through multiple modes of action

• Methyl salicylate effectively deters both wingless and winged aphids by disrupting their ability to colonize and infest maize plants. • Methyl salicylate can attract predatory natural enemies of aphids. • Exposure of maize to methyl salicylate reduces aphid numbers and impacts their development and fecundity. Maize is a cornerstone of global food security, but it faces increasing challenges from corn aphids, particularly with the widespread adoption of genetically modified Bt maize. This trend suggests a growing need for sustainable pest control strategies. Methyl salicylate has been proposed as a volatile compound with the potential for managing aphids. In this study, Y-tube olfactometer and Petri dish dispersal assays showed that methyl salicylate can repel wingless and winged aphids at 0.1 to 1,000 ng μL –1 . Moreover, at concentrations of 100 and 1,000 ng μL –1 , it was found to attract beneficial insects such as adults and larvae of Harmonia axyridis . Exposing maize plants to methyl salicylate resulted in a prominent reduction in the number of aphids compared to the control. In addition, clip cage experiment assays showed that the nymphal development duration was increased, while the adult duration and generation time were reduced, and the reproductive duration and total number of aphid offspring in plants treated with methyl salicylate were dramatically lower than in the control. Over two years of field trials, methyl salicylate-impregnated alginate beads provided significant reductions in the populations of key aphid species, including Rhopalosiphum padi , Rhopalosiphum maidis , and Aphis gossypii . Concurrently, there were marked increases in the presence of natural predators such as H . axyridis , Propylaea japonica , Syrphus corollae , and Chrysoperla sinica . These compelling results underscore the potential of methyl salicylate as a key component in integrated pest management strategies for maize, offering a green alternative to traditional chemical control.