Fruit Fly
Alighted on a rotting log surface and engaged in a mating display. Nairobi, Kenya, July 2014.
From Wikipedia: Tephritids are small to medium sized (2.5–10 mm) flies that are often colourful, and usually with pictured wings, the subcostal vein curving forward at a right angle.The head is hemispherical and usually short.The face is vertical or retreating and the frons is broad, Ocelli and cellar bristles are present. The postvertical bristles are parallel to divergent.