Leek moth (LM) is a relatively new pest severely affecting allium production in the Northeast. Positively identified in northern New York in 2009, the distribution of this pest now also includes parts of New Hampshire, Maine and Vermont. According to our recent monitoring efforts in Vermont, 75% of surveyed vegetable growers in the region with significant plots of alliums are experiencing LM damage. We estimate that the LM distribution is expanding at approximately 33 mile/year.
Marketable damage from LM can occur at both the pre and post-harvest stages of crop management. First, during the primary crop growth stage, larval feeding by LM can defoliate, damage and/or reduce the photosynthetic potential of hosts plants leading to reduced yields. In addition, wounds associated with larval feeding may expose host plants to secondary diseases and pest infestations leading to even greater crop losses. Finally, post-harvest damage from LM larvae can often lead to substantial losses in marketability during crop storage.
This project looks to test both pre and post-harvest tactics for reducing the impact of the pest at both the pre- and post-harvest stages. These tactics include: the release of a commonly available parasitoid wasp and the adoption of adaptive curing practices to reduce bulb damage from late season LM larvae. The development of non-chemical options for the control of LM reduces the dependency on chemical controls, limits the impact on non-target organisms and helps to provide a diversified IPM toolbox for more sustainable control of the LM.
Performance targets from proposal:
Fifty Northeastern growers will implement new sustainable leek moth management tactics, pre and/or post harvest, on 150 acres of allium cropland protecting $400,000/year worth of harvested alliums. Of these fifty growers, five will report their estimated average recovery of losses.