Volatiles from endangered <i>Braya longii</i> (Brassicales: Brassicaceae) influence oviposition choice by <i>Plutella xylostella</i> (Lepidoptera: Plutellidae)

Long's Braya, Braya longii Fernald (Brassicales: Brassicaceae), is an endangered plant in the family Brassicaceae found only on the Limestone Barrens of the Great Northern Peninsula of Newfoundland, Canada. Conservation of this species hinges on management of pests, diseases, and disturbances, which threaten their small populations. In particular, a global agricultural pest, diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), causes significant damage to persistence of B. longii and contributes to possible extinction. This study investigates if there are key volatiles that attract P. xylostella to B. longii, thereby contributing to the pest's impact on the plant. Headspace collections, GC-MS, and GC-EAD revealed a unique volatile profile for B. longii, with (E)-2-nonenal as a key volatile that elicited strong antennal responses in P. xylostella. Oviposition assays confirmed female preference for E2-nonenal-baited radishes. This finding has implications for P. xylostella pest management, highlights the importance of chemical ecology in both crop protection and endangered species conservation.