The onion thrips and the seedcorn maggot are practically the only onion pests in North Carolina.
The onion maggot does occur here but poses a severe problem only in the northern states. Onion
and seedcorn maggots cause the same type of damage and are virtually indistinguishable in the
field.
KEY TO ONION PESTS
Onion thrips - Foliage-rasping pest; pale yellow to dark brown body 2 mm or less in
length; adult with 2 pairs of narrow, fringed wings (Fig. 154); causes silvery
blotches or scratch-like markings on leaves; some infested leaves distorted, curling upward
Seedcorn maggot - Bulb-feeding pest; white to yellow-white maggot up to 7 mm
long; legless body with pointed head (Fig. 155); feeds underground in bulbs,
causing plants to yellow and die.
