The onion maggot, Hylemya antiqua, can be a serious pest in home gardens. This pest attacks only those crops in the onion family.
Onions grown from sets, transplants and seeds are susceptible to attack by the onion maggot.
The adults of the onion maggot are flies, which resemble houseflies but are smaller. These flies are greyish-black in color. In New York State there are three overlapping broods which occur. On Long Island the first adults appear in the spring, usually around May 1. This brood that will follow is the most damaging to the crop.