Ground beetles for root maggots
UMass names predatory ground beetles as important enemies of cabbage and onion maggots, eating the eggs, larvae and pupae, and the RHS calls some ground and rove beetles efficient predators of root-feeding maggots. Mulch and permanent edges give them shelter. UMass warns that these soil beetles are susceptible to insecticides and advises avoiding broadcast soil treatments, so rely on row covers rather than soil insecticides where the beetles are working.
Before you act
Shiny, dark, long-legged beetles that run for cover when a stone, board or pot is lifted. They hunt at night on the soil surface, and both adults and larvae eat slugs, caterpillars and the eggs and larvae of soil pests. How to recognise it, what it is confused with and how to keep it around are on the full Ground beetles profile.
Other controls for root maggots
- Steinernema feltiaeNematode · 100,000–125,000 infective juveniles per transplant (UMass, from trials)
- Rove beetlesWild predator · Nothing to release — conserve them