Oviposition preferences of Plodia interpunctella (Hubner)on selected dried fruits and nuts, with the identification of key volatiles

The Indian meal moth, Plodia interpunctella , is a globally important pest of dried fruits and nuts; however, little is known about its oviposition preferences among different dried fruits and nuts. The oviposition preference of Plodia interpunctella was measured on goji berry, fig, walnut, hazelnut, normal-oleic, and high-oleic peanut. Differential volatile organic compounds (VOCs) were identified using gas chromatography–electroantennographic detection (GC–EAD) and further validated using electrophysiological recordings, Y-tube olfactometer assays, and oviposition preference bioassays. Females laid significantly more eggs on goji berry, fig, walnut, hazelnut, and normal-oleic peanut than on high-oleic peanut. Nine active VOCs were identified using GC–EAD with undecane, eicosane, hexadecane, nonanal, ethyl caproate, 2-ethyl-1-hexanol, and octane, eliciting a dose response EAG activity. The Y-tube and oviposition bioassays further demonstrated that females were significantly attracted to nonanal and octane, which were abundant in the more preferred nuts and fruits. In contrast, females were repelled by 2-ethyl-1-hexanol, which was more abundant in high-oleic peanut. These findings provide insights into the chemical ecology of P. interpunctella and support the development of volatile-based attractants and repellents for the management of stored products pest.