As they feed, Swede midge larvae produce a secretion that breaks downthe surface of the growing point of the plant and liquefies the cell contents, resulting the formation of leaf and flower galls and a misshapen growing point. Damage caused by Swede midge larvae feeding results in distorted growing tips and may produce multiple (or no) growing tips; young leaves may become swollen or crumpled and leaf petioles or stems may exhibit brown scarring. Swede midges feed only on cruciferous vegetable crops, such as cabbage, cauliflower, broccoli, and Brussels sprouts, frequently causing severe losses. The insect also damages canola, collard, horseradish, kale, mustard, rutabaga, turnip, and radish.