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.