Harnessing Leguminosae Typical Scents for a More Effective and Eco-Friendly Pheromone Trapping of Pest

The utilization of pheromone-based products for insect pest management has been a longstanding practice. However, mounting evidence suggests that pheromones of insect pests could also inadvertently attract natural enemies, leading to their unintentional entrapment by pheromone baits. In East Asia, pheromone traps of the bean bug Riptortus pedestris capture several species of natural enemies, which reduces top-down control of the pest and could lead to failures of pest management programs. Here, we identified novel fragrances that could be incorporated into standard pheromone traps to enhance pest attraction while minimizing the unintended captures of natural enemies. Chemical analyses of flowers from 28 phylogenetically related species in the Leguminosae highlighted that 2,6,10-trimethyltridecane and 1-octen-3-ol were the main volatiles produced, which were sensed by the R. pedestris antennae, and attracted the adults to fields of various host plants. The addition of each compound to the pheromone increased the number of R. pedestris caught and reduced the trapping of nontarget insects, including predators and parasitoids, compared to pheromone alone. In sum, a combination of typical host plant volatiles and pheromone is likely to be a reliable approach to improve both trapping efficacy and safety, hence offering a more effective pest management practice.