Plant volatiles drive Spodoptera frugiperda behavioral preference to sweet corn

The Fall Armyworm (FAW), Spodoptera frugiperda , is a globally significant invasive lepidopteran pest responsible for severe crop damage, particularly to maize ( Zea mays ). In this study, we investigated the preference of FAW larvae and adults for regular corn (RC) versus sweet corn (SC) using a two-choice behavioral assay. Potential semiochemicals underlying this preference were isolated and identified through headspace volatile collection coupled with Solid-Phase Microextraction–Gas Chromatography–Mass Spectrometry (SPME-GC-MS). The behavioral activity of identified differential volatile compounds was then comprehensively evaluated using electroantennography (EAG), a Y-tube olfactometer, and cage-based oviposition preference tests. Our results demonstrate that FAW larvae exhibit a significant feeding preference for SC leaves, while adult females show a marked oviposition preference for SC plants. Volatile profiling revealed four compounds consistently expressed at higher levels in SC compared to RC: hexanal, trans-2-hexen-1-ol, linalool, and β-caryophyllene. EAG recordings indicated that trans-2-hexen-1-ol elicited the strongest antennal response in FAW adults. In behavioral assays, FAW larvae showed significant attraction to all four volatiles at concentrations of 10 and 100 mg/mL. Similarly, adults exhibited significant preference for most compound-concentration combinations, with the exception of linalool at 100 mg/mL. The volatile compounds identified in SC present promising candidates for use in behavior-based disruption techniques, offering a more environmentally benign alternative to conventional insecticides for FAW control. These findings provide a scientific foundation for developing volatile-mediated strategies as part of integrated pest management programs against this invasive pest.