by Richard Jones

[...] suddenly my eye is caught by a flick of yellow. Perched on the end of a leaf is a dung-fly.

Dung flies matingIt's finally arrived - that November damp chill enough to make me nag the girls into wearing a proper coat as they set off to the bus-stop for school. They're having none of it though. As I wander round the garden, examining the scorched earth from last weekend's fireworks and peering into the deep murky gloom of the pond, there seems nothing about. But suddenly my eye is caught by a flick of yellow. Perched on the end of a leaf is a dung-fly. 

This was the common yellow dung-fly, Scathophaga stercoraria. It's scientific name means, rather unsurprisingly 'dung-eating dung-inhabiter' and it's one of those insects that is very easy to overlook in the garden. In a grazing meadow they are obvious and multitudinous insects, speckling the fresh cow pats with their furry yellow bodies. There they enact a complex dance-like behaviour as the more brightly coloured males arrive first to jostle for small territories and wait for females. After mating the males often remain aboard the females piggy-back, guarding them to prevent other suitors taking advantage until the eggs are laid. 

At present there are approximately no cow pats in my garden, but we have two well-fed cats, and the regular procession of foxes leave more than their fair share of strong-smelling faeces. Even this late in the year the dung-flies are ready to recycle. 

The adult flies, although only 7-10 mm long, are fierce predators, attacking other small insects they catch on the wing. Unlike houseflies, they do not come indoors, are not attracted to human food, and are not implicated in the spread of any diseases. For the benefit of gardeners everywhere, these small but handsome insects are active almost all year round. It might be something to do with their furry coats.

PS. Dungfly, dung-fly or dung fly? This is a tricky area, not much helped by examination of dictionaries or spell-checkers. Originally there were hover-flies, snipe-flies, house-flies and blow-flies, which were all flies, and dragonflies and butterflies which were not. Now the hoverfly people use one word along with soldierfly and robberfly, but they retain bee-fly rather than the bovine-sounding beefly. Dung beetle is two words. The trouble with dung flies is that it invites the reposte: only if you throw it.

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Gardeners' World Web User 21/11/2009 at 14:52

I never knew dung-flies existed, I thought most flies like dung? They're not very pretty are they, not like dung beetles.

Gardeners' World Web User 26/03/2011 at 23:16

i have a load of these in my polytunnel and hope they dont carry disease, or eat my veg or flowers!

Gardeners' World Web User 28/11/2011 at 18:39

It gets complicated if you invoke the Chinese, Dung Chow Ping the famous statesman.