Diary: August 2003

Today I was lucky enough to see a beautiful species of hoverfly in my garden which I have not noted there before.

The powerfully built Sericomyia silentis is so robust that at first I took it to be a good-sized wasp. As soon as it settled on a plant though, I saw that it was a hoverfly; its single pair of wings held to the side of the body in the manner more characteristic of flies (Diptera) than wasps (Hymenoptera) which more often fold their two pairs over the abdomen.

The size of this fly and its striking black and yellow banded abdomen make it a very effective wasp mimic, which must be a good defence against predatory animals. Its larvae apparently develop in marshes and bogs where they are thought to feed on filtered sediment. This one may have spent its larval stages in my pond (the 'beach' area has resembled more bog than pond these last few dry months) but, I suppose, it is equally likely to have come from near-by moorland.