Radish Root Maggot – Delia planipalpis

Radish Root Maggot (Delia planipalpis) Common Name: Radish Root Maggot Latin Name: Delia planipalpis Appearance: The radish root maggot is an especially obnoxious insect in the vegetable garden. These pale larvae dig into the root flesh of many root crops, producing unattractive slimy brown tracks in their wake. Members of the mustard family, such as radish and turnip, are the most commonly afflicted. This damage is not obvious until the produce is gathered and processed. Before harvest, there may be some wilting of the leaf. Eggs: Small and white eggs are deposited 50-200 at a time along the stems of host plants at the soil line. Larva/Nymph: Larva is 8-9 mm tall and yellowish to white in hue, with a cylindrical tapering towards the head. Adults: Adults are 6-7 mm tall. Dark gray to brown in color, with the appearance of little houseflies. Pupa: Pupation happens within the host plant’s root or in the surrounding soil. Host plants: Cruciferous plants include cabbage, radish, turnip, Chinese cabbage, and a variety of mustard weeds. Territory: Radish root maggot is a naturally occurring species in the western United States. It is known from Alaska to Manitoba, and from California to New Mexico. Damages caused by Radish Root Maggot: Radish root maggot is the most common pest species in radishes crops. Because the insects eat inside and are difficult to detect, even a minor infestation can damage a crop’s commercial worth. Because there are normally just a few larvae per radish, the plants are rarely severely harmed. Life history and habits: The radish root maggot is the larval stage of a small insect. The adult female fly deposits her eggs on the leaves of host plants. The larvae descend to the ground and begin burrowing into the root tissue once the eggs hatch. They survive the winter as pupae that resemble seeds in the soil.