A new species of Docosia Winnertz fungus gnat was discovered in western Michigan. Males and females were collected in mid-spring in a Malaise trap in a paper birch-red maple-black cherry woods adjacent to a black ash swamp and cattail marsh. Docosia walpurga Taber resembles Docosia dichroa Loew but male terminalia and female coloration indicate a specific difference instead. A remarkable and yet-unidentified empidid fly that seems to mimic the fungus gnat was found with the new species.