The Tachinid Fly is a family of many species (Tachinidae), this one is Eriothrix rufomaculata. It is a very bristly fly and has large red/orange patches on the sides of its abdomen. The adults feed on nectar from flowers, but the larvae are not so pleasant, feeding on moth larvae.

They are quite small (under 1 cm in length) but if you look carefully in the second photo you can see another insect at its feet, which is minute by comparison.