BackgroundInsects rely on chemosensory perception, mainly olfaction, for the location of mates, food sources, and oviposition sites. Plant-released volatile compounds guide herbivorous insects to search for and locate their host plants, further helping them to identify suitable positions for oviposition. The fall armywormSpodoptera frugiperda(S. frugiperda) was found to invade China in 2019 and has since seriously threatened multiple crops, particularly maize and rice. However, the chemical and molecular mechanisms underlying oviposition preference in this pest are not fully understood. Here, the oviposition preference ofS. frugiperdaon maize and rice plants was investigated.ResultsGC-EAD and GC–MS/MS techniques were used to identify the antennally active volatiles from maize and rice plants. The attraction and oviposition stimulation of identified components to female adults were tested in both laboratory and field settings. The odorant receptors (ORs) on female antennae were expressed inXenopus oocytes, and their functions evaluated by RNAi. Ten and eleven compounds of maize and rice plants, respectively, were identified to possess electrophysiological activity from headspace volatiles. Among these compounds, (Z)-3-hexenyl-acetate specifically presented in maize volatiles was found to play a critical role in attracting females and stimulating oviposition compared to rice volatiles. Among the cloned ORs on the antennae of both sexes,SfruOR23with highly female-biased expression mediated the responses of females to (Z)-3-hexenyl-acetate. Knockdown ofSfruOR23using RNAi markedly reduced the electrophysiological response of female antennae and oviposition preference to the compound.Conclusions(Z)-3-Hexenyl-acetate is a key volatile mediating the host and oviposition preference ofS. frugiperdaon maize. The olfactory receptor of (Z)-3-hexenyl-acetate was identified to beSfruOR23, which is mainly expressed in the antennae ofS. frugiperda.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12915-023-01642-x.