Leek-moth damage stunts plant growth, introduces rot, compromises the storage life of onions and garlic and negatively impacts the marketability of the crops.
Cornell University entomologist Dr. A. M. Shelton is evaluating insecticidal treatments in his Ithaca campus lab. He is developing a growing day-degree model to help growers target optimal insecticide application timing.
As part of the NNYADP-funded grant, Shelton is also investigating opportunities to use biological control agents effective in controlling leek moth.
“Eradication is not realistic, so we are learning to properly time treatments to reduce leek-moth populations and the associated crop damage,” Ivy said.
Two insecticidal products are currently approved for use on organic crops; three for use in conventional production.
Ivy encourages growers to implement the cultural practices currently available to growers to prevent leek-moth infestation. Those practices include the use of row covers immediately after planting to prevent adults from laying eggs on host crops, crop rotation, delayed planting, good field and harvest hygiene, scouting and destruction of leek moth pupae or larvae, and early harvesting before the final seasonal flight occurs.
Leek moth, native to Europe, was first discovered in North America in Ontario, Canada, in 1993. Leek moth is able to overwinter in the northern climate. The damage done by leek moth can resemble that caused by thrips, snails, salt-marsh caterpillars and Botrytis leaf blight.
Leek moth has also been found in Allium crops in Vermont. Ivy and Seto have met with horticulturists at the University of Vermont to develop an information exchange to keep educators and growers in both states current with leek-moth sightings.
A Cornell Cooperative Extension Fact Sheet on leek moth is available at local CCE offices and online at http://web.entomology.cornell.edu/shelton/leek-moth/images/RESOURCES/factsheet2011.pdf.
More information on leek moth is available at www.nnyagdev.org under Horticulture and through the Leek Moth Information Center for the U.S. at Cornell University: http://web.entomology.cornell.edu/shelton/leek-moth.