The allium leafminer, also known as the onion leafminer, has been confirmed from infested leeks and onions collected in December 2015 from Lancaster County, PA, according to a Penn State pest alert report.
This finding is said to be the first confirmed infestation in the Western Hemisphere.
This pest has been known to infest leeks, which has been noted as the “most damaged host,” as well as onions, garlic, chives, shallots, and green onions. The full host range is unknown.
Symptoms of damage include wavy, curled, and distorted leaves. Larvae mine leaves and move into bulbs. This pest is said to be evident in species with thin leaves (chives). In larger leaves, growers are advised to peel back the leaves to find the insect. Both the leaf punctures and mines serve as entry routes for bacterial and fungal pathogens, according to the report.