A small fly of about 4 mm with distinctively patterned wings. There are other quite similar members of the family and care is needed in identifying this species.

Various habitats including grassland and areas where thistles occur.

March to October peaking in early August.

Larvae are found in the flower heads of Marsh Thistle and Creeping Thistle.

Widespread but occasional in England and Wales.

Occasional in Leicestershire and Rutland.