Alternative Approaches to Diamondback Moth Management: An Analysis of Mating Disruption Techniques in Virginia

Commodities

Practices

The diamondback moth (Plutella xylostella, Lepidoptera: Plutellidae) is a destructive pest that profoundly impacts sustainable agriculture through its development of insecticide resistance to 99+ insecticides [1]. Growers rely heavily on the use of insecticides to control these pests and protect crop production but are limited in their options for management. Therefore, there is a need for alternative integrated pest management control tactics in brassica systems. Integrated pest management (IPM) employs a combination of safe and effective pest management strategies to control a large variety of pests that threaten desired crops [2].

Mating disruption is an IPM control tactic that utilizes the release of female sex pheromone of a target pest into the atmosphere to prevent mating and oviposition. It serves as a form of competitive attraction where male moths are not physically impaired by mating disruption [3]. Dispensers deployed in the field release synthetic pheromone at a higher ratio than the natural sex pheromone, hindering male moths' ability to locate females [3, 4].

The objectives are to 1) Determine the efficacy of mating disruption technologies during the growing season; 2) Use adult moth capture on pheromone-baited traps to determine the key population peaks. This study will serve to provide insight on the use of mating disruption against Plutella xylostella and serve to aid growers in making the best IPM management decision against this destructive pest.

Objective 1: Determine the Efficacy of Mating Disruption Technologies on Plutella xylostella

This objective aims to determine the efficacy different mating disruption technologies, such as physical solid dispensers, sprayable, and tablets in brassica systems in Carroll County, VA. The overall goal is to discern the efficacy of mating disruption technologies of reducing Plutella xylostella populations to allow growers to reduce the amount of insecticide applications in the field.

Objective 2: Determine Population Peaks of Plutella xylostella during the Growing Season

This objective investigates fluctuations in Plutella xylostella populations by using adult moth capture on pheromone-baited traps in the field. Results from field-collected data can provide growers with accurate peaks in DBM populations, resulting in more effective timing of IPM tactics and management applications.

Over many decades, researchers and growers have experienced significant losses of crop systems mostly due to insecticide resistance. Insecticide resistance is an increasing global challenge as pests are becoming resistant to newly developed modes of action. Using similar modes of action within the same IRAC group can lead to resistance development in field populations [1]. It is pertinent to rotate modes of action used when managing pests to reduce the risk of resistance.

The outlined objectives are designed to identify the best management practices for diamondback moth and timing of application in brassica systems. Investigating the objectives in the study will result in a better understanding of IPM practices for combatting diamondback moth, reduce the heavy reliance on insecticides, and provide growers with the effective evidence-based options for maintaining crop yield using standard IPM practices. The outcomes of this study could potentially be used to help other researchers develop plans for the use of IPM practices in other agricultural systems.