Monochroa lutulentella, the black neb, is a moth of the Gelechiidae family. It is widely distributed in northern Europe and the central European mountains, east to the Ural Mountains. The habitat consists of fens, marshes and on river-banks. The wingspan is 14–16 mm. Adults are on wing from the end of July to the beginning of August. The larvae feed on Filipendula ulmaria. They feed within the roots of their host plant.