Economic Benefits from the Use of Mass Trapping in the Management of Diamondback Moth, Plutella xylostella, in Central America

SIMPLE SUMMARY: Introduction of monitoring of male diamondback moth using lures emitting female sex pheromone allowed farmers to determine the populations of adult DBM in cabbages in several cabbage farms in Costa Rica and Nicaragua. Farmers were encouraged to use trap capture data to trigger insecticide applications as an alternative to their normal practice of calendarized insecticide applications. Those farmers with the highest insecticide application rates against DBM were the most receptive to the idea of using pheromone-baited traps and reduced their spray regime by the largest proportion. Reduced spray schedules do not increase damage but can increase profits for farmers. ABSTRACT: The diamondback moth, Plutella xylostella (L.), is a worldwide pest of brassica crops, resistant to a large number of insecticides. As an alternative, the use of pheromone-baited traps has been proposed but farmers are yet to be convinced. In the present study, we aimed to validate the benefits of the use of pheromone-baited traps for monitoring and mass trapping in cabbage production in Central America as means of Integrated Pest Management (IPM) in comparison to calendarized insecticide sprays, which are the farmers’ current practices (FCP). Mass trapping was established in nine selected plots of cabbage in Costa Rica and Nicaragua. Average captures of males/trap/night, plant damage and net profits of these IPM plots were compared to simultaneously evaluated or historically reported FCP plots. The results indicate that in Costa Rica, trap captures did not justify the application of insecticides and average net profits increased by more than 11% when the trapping methods were implemented. In Nicaragua, IPM plots were able to reduce insecticide applications to one third of those in FCP plots. These results confirm the economic and environmental benefits of pheromone-based management of DBM in Central America.