Unidentified fly

Unidentified fly

Observation - Unidentified fly - UK and Ireland. Description: Can anyone tell what this is? I spotted it patrolling the lily leaves in my garden pond. The apparent object of it's affections was a smaller fly with same colour body but no wingtip flashes. As it approached what I take to be the, smaller, female it wo

Can anyone tell what this is? I spotted it patrolling the lily leaves in my garden pond. The apparent object of it's affections was a smaller fly with same colour body but no wingtip "flashes". As it approached what I take to be the, smaller, female it would flash it's wings by displaying them at right angles to the body. I don't ever recall seeing a fly with these markings before.