Genus Macrolabis Kieffer, 1892

The genus includes 214 species and is almost entirely restricted to the Palearctic region. Most species are inquilines in the galls of other gall midges, while some are independent gall makers. The adult males have conspicuously large genitalia. We have barcoded 10 specimens of Macrolabis collected from seven different plants/galls. Of these, M. fagicola Barnes, 1939, nested far from the others in the barcoding tree, indicating that it may not belong in Macrolabis . This is discussed further under the species.