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

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.