Unknown fly dark with light markings

Unknown fly dark with light markings

Observation - Unknown fly dark with light markings - UK and Ireland. Description: Unknown fly spotted while taking part in the 2012 Garden bioblitz. Small and dark with light markings on the thorax. Any help with discerning the species would be most welcome.

Unknown fly spotted while taking part in the 2012 Garden bioblitz. Small and dark with light markings on the thorax. Any help with discerning the species would be most welcome.