Cabbage maggot (Delia radicum)
Adult cabbage maggots are small (¼ inch long)
flies that lay their eggs on the soil surface near the
radish crown. The larvae that hatch are ¼ inch
maggots that tunnel into roots, causing wilting
and stunting of plants. Maggots feed for up to four
weeks, pupate in the soil, and emerge as adults.
Pupae overwinter in the soil and begin emerging
in late March. Multiple generations may occur in
a season. Planting early will help avoid the first
generation of flies. For extreme infestations,
floating row covers will prevent flies from laying
eggs. Cabbage maggots prefer moist, cool
weather.