Field Identification
Seedcorn maggot’s onion-obsessed cousin—flies lay eggs at the base of seedlings; larvae tunnel stems and bulbs until plants flop like cheap props. Onions planted too deep into cold mud send a VIP invite.
Linear scars and hollow hearts in sets; wilting that pulls easily from soft necks. Three flights a year in many zones—spring sets and late scallions both get hit.
How to Deal With It
Organic Control Methods
Spinosad or neem soil drenches during egg-lay peaks; entomopathogenic nematodes around crowns when soil is moist and warm enough for nematode mobility.
Ground beetles and rove beetles; parasitic nematodes reduce maggot counts in trials—field moisture makes or breaks them.
Avoid fresh manure before planting; rotate Allium blocks; wait for soil warm-up; disk in overwintered culls before flies wake.
Floating row cover on seedbeds and transplants—edges buried, no gaps for romantic flies.
Yellow sticky stakes for flight monitoring; delay planting until soils dry slightly—soggy fields smell like fly perfume.
Let Nature Handle It
Natural Enemies
- Ground Beetles
- Rove Beetles
- Entomopathogenic Nematodes
Threat Map