A Faboideae-Specific Floral Scent Betrays Seeds to an Important Granivore Pest

Abstract

Seed predation by insect herbivores reduces crop production worldwide. Foraging on seeds at pre-dispersal generally means that females need to find the suitable host plant within a relatively short timeframe in order to synchronize larval development with seed production. The mechanistic understanding of host finding by seed pests can be harnessed for more sustainable pest management strategies. We here studied the chemical communication between the bean bug Riptortus pedestris, a major pest of legumes, and several crop species and cultivars in the Fabaceae. Via a comparative chemical analysis, we found that 1-octen-3-ol is the principal constituent of the floral scents of most species tested in the subfamily Faboideae, including soybean and faba bean. With field trapping and laboratory bioassays, including electroantennography, we further revealed that this compound can be perceived, and stimulate attraction responses, by R. pedestris nymphs and adults. The addition of 1-octen-3-ol to pheromone traps might therefore improve trapping efficacy for controlling populations of this important granivore pest on legumes.