In the second of this series of five programmes exploring the aims and enthusiasms of their members, Brett Westwood gets to the heart of our natural history societies and finds that here in the UK they are it is in surprisingly good shape. The Dipterist's Forum was established to study the 7000 and more species of two-winged flies which occur in the UK, from bluebottles to mosquitoes. At a field centre in Shrewsbury he learns how to navigate his way around a fly, pursues winter gnats over a garden compost-heap and gets to grips with the finer points of fungus gnats, a bewildering group of several hundred species most of which are less than 5mm long. Show less