What a Dol(i)

28th June 2011, Tuesday

While out on the weekly butterfly/dragonfly transect this afternoon I came across several weird looking flies on a gate post. They are called Medetera diadema and belong to the dolichopodidae, also called ‘long-legged flies’ or more often ‘dolis’ by enthusiasts. They are generally small flies with a metallic green colouration and are predatory on other invertebrates (the larvae are either predators or scavengers in aquatic or terrestrial habitats). Truth be told they are a group that I know very little about, with this being one of only two species I can identify with any confidence. They are striking looking flies though, with this genus in particular looking very alien indeed.
Medetera diadema

Highlight on the transect itself were a few Marbled White near the viewpoint, the first I have seen this year, and several male Black-tailed Skimmer, while Roy Gardener reported Turtle Dove at Castle Water Hide and a Wood Sandpiper on the pit itself. The two fledged Marsh Harrier were also seen, hunting over the viewpoint mid-afternoon. In addition while collecting rubbish around the upper reaches of the saltmarsh this morning I came across both male and female of the rare jumping spider Phlegra fasciata – not a bad day in the end!