• Fleischer, Shelby Jay (PI)

Project: Research project

Project Details


Allium leafminer is an invasive species that has crossed the Atlantic, reaching the U.S. in 2016, and established itself as a pest of multiple Allium species, which include onion, garlic, leek, scallions, shallots, and chives. Onion is the crop with the largest acreage, grown commercially in over 20 states, literally border-to-border and coast-to-coast. The annual farm-gate value of onion and garlic in the US exceeds $1.2 billion and generates $5-7 billion at consumer purchase level. Over 20% of the world's onion seed is produced in the US and is valued at over $100 million annually. Allium leafminer is currently causing economic damage in diversified farm settings in the northeastern US, where allium production is often associated with a highly diverse, fresh-market production system distributed among heterogeneous landscapes and farmer demographics. These farms include local CSAs, certified organic farmers, and Amish-Mennonite farming communities, that rely on producing onion, garlic, leeks, scallions and chives at volumes that ensure continuous supply to local customers. This pest also infests ramps ('wild leek'), a native of forestlands with strong cultural ties and economic development opportunity tied to tourism throughout Appalachia. Ramps have rapidly grown in popularity as a wild food delicacy, but the utilization of ramps by this invasive species only exacerbates growing concerns about the sustainability of this agro-forestry crop. Allium leafminer also could pose a threat to an endangered Allium species in California, and the potential exists for this new invasive pest to affect import, export, and interstate transport of Alliums. Science-based trials to provide management solutions are sparse, and initial responses include increased insecticide inputs, which in addition to creating environmental and farm-worker concerns, also exacerbate existing problems with management of other insect pests of alliums, such as onion thrips. Until recently, thrips control had been unpredictable because of resistance, but extensive research has reduced the average number of foliar insecticide applications in half in large onion production areas. However, additional insecticides aimed at Allium leafminer could upset this balance.The goal of our proposal, which is focused around four objectives, is to provide solutions for managing ALM in the currently infested area and in areas yet to be invaded. The first objective develops a science-based approach to understanding and predicting when crops are at risk, and rapidly delivering that information to growers, enabling them to minimize the time frame of deploying insecticides or other management tactics. The second develops a science-based approach to understanding how behavior by this pest is mediated through host-plant volatiles cues, variation in response to host species and age, and locations within fields. This enables growers to develop trap-cropping methods, and tools for monitoring the pest. Our third objective is focused on advancing biological control, building from our finding of parasitism within US populations. Our fourth objective strives to provide effective insecticide management solution that are relevant to both conventional and organic growers, avoid exacerbation of other pest species, and minimize the time span over which insecticides are needed.Our work is designed to be useful for both large and small producers, in both large-acreage and highly diversified production systems, and for both conventional and organic growers. Anticipated impacts from the integration of all objectives include a more rapid and effective management of an invasive species, thus slowing its geographic expansion. Our work will shed light on the 'why' and 'how' pest status is minimized and provide solutions for when pest status is reached in both currently invaded areas, and areas that may become invaded. Results will be communicated to stakeholders via an experienced network of extension educators.

Effective start/end date9/1/188/31/22


  • National Institute of Food and Agriculture: $325,000.00


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