When I first started out nature watching I really struggled with Latin scientific names. I may have been a Grammar School boy but I did not study Latin although I had the chance too! Anyway, after many years I have started to pick up bits and I know that rufo is red, from our word rufus of course. Maculata means spotted and so this fly could be called the spotted red fly but it is not, it is just known by its scientific name Eriothrix rufomaculata. It is red and does have black spots so it is an appropriate name.
Being a parasitic fly it lays its eggs in moth larvae, in fact in crambid moth larvae. Crambid moths are a selection of tiny insects, long and thin when at rest, that fly up as you walk across unimproved grassland and so that is exactly where you will find this fly. It emerges as an adult in July and August and is quite widespread and can be very common where it occurs.