Cornell Cooperative Extension asks for crop growers' assistance in tracking destructive moth
Friday, August 30, 2013 - 6:19 am

CANTON -- The Cornell Cooperative Extension is asking growers to report any sightings of the leek moth, a pest that feeds on onions, garlic, chives, shallots, leeks, and other Allium crops.

Cornell University and CCE researchers are working with a Northern New York Agricultural Development Program grant to trap the pest in order to identify its range. If the leek moth becomes established in the major onion production areas of New York, the economic damage could be significant to the $54 million industry, according to researchers.

The nocturnal leek moth adult is rarely seen outside of traps.

“The Northern New York Agricultural Development Program grant will help us determine where [the] leek moth is, how fast it is spreading, and will help growers properly time control treatments,’ said Cornell Cooperative Extension Executive Director Amy Ivy, a horticulture specialist.

Leek moths are currently living in St. Lawrence, Clinton, Essex, and Jefferson Counties, as well as portions of Vermont, according to Masanori Seto of Cornell University.

The moth was identified in St. Lawrence County near Canton in 2010.

The adult leek moth is speckled brown, black, and white with a white spot halfway down its outer pair of wings.

Larva feeds mainly on plant leaves, but occasionally bore downward into the plant bulb and leave feeding damage.

Leek moth damage stunts plant growth, introduces rot, compromises the storage life of onions and garlic, and negatively impacts the marketability of affected crops.

Cornell University entomologist Dr. A. M. Shelton is developing a growing day-degree model to help growers target optimal insecticide application timing. He is also investigating the use of biological control agents effective in controlling the 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.

The use of row covers immediately after planting, crop rotation, delayed planting, good field and harvest hygiene, scouting and destruction of leek moth pupae or larvae, and early harvesting can help prevent moth infestation.

A fact sheet on the leek moth is available at local extension offices and at

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