Melanostoma

A genus of small hoverflies, similar in appearance to Platycheirus species. Males of Melanostoma species lack the swollen fore tibia and tarsi of that genus, whilst females have distinctive triangular spots on the abdomen. Two species (scalare and mellinum) are common and widespread in the UK, whilst a third (dubium) is a localised upland species, although there is some question as to the validity of the latter as a distinct species. To further complicate matters, there may be a fourth species showing a mixture of the characters of the other species, referred to as form A in Stubbs and Falk.

Melanostoma scalare - Male with elongated abdomen, female with dust spots on face and extensive yellow on antennae.

Melanostoma mellinum - Male with normal abdomen, female without dust spots on face.