The weather this week has been sunny, warm and very Spring like. It’s a shame that I’ve had to work throughout the week, whistfully looking out of the office window at the garden. Though I have allowed myself to have my coffee and lunch in sunshine. As it happens I’m not the only one taking advantage of the warm rays of sunshine. Sitting on the hedge basking in the sunshine are about 20 to 30 small greenish flies. Eudasyphora cyanella is certainly making the most of the warmth. It looks superficially very much like the green bottle flies that we are all so familiar with, the Lucillia, however they belong to a different family called Muscidae. The adults which are flying now are among the earliest of the flies that emerge after overwintering as adults. As the flight ages during spring its colour gradually changes from green to a bronze colour.
The female lays her eggs in cow dung before midday in the warm sunny weather. Cow dung is very much the preferred food for the growing larvae, but it is also thought that they use fresh horse and sheep dung as well. The female excavates a small cavity in the dung and lays between 25 to 30 eggs, which can hatch in as short period as a day. The larvae feed solely on the dung in which they are deposited and are ready to pupate between two and four weeks after hatching. There are usually two broods in the year, the first one in May and June from overwintered adults, and the second generation is from the current years progeny in July and August.
Eudasyphora cyanella doesn’t have an English name that I can find so we will have to continue to try and learn and remember its scientific name, even though it doesn’t exactly trip of the tongue easily. That said it is common throughout the UK and is often found something itself on walls or hedges. It has been known to overwinter in houses possibly among the other cluster flies which are common in loft and sheds over winter.
28 March 2019.