Cabbage Maggot (Delia radicum) The Cabbage Maggot (Delia radicum) is a very destructive fly pest, attacking plants of the genus Brassica: cabbage, broccoli, cauliflower, brussels sprouts, radishes, rutabagas, turnips, etc., –all cool-season plants. Wilting leaves and a delay in plant growth are usually a sign of maggot damage and indicate that