Last week I tagged along with a fellow blogger (Rediscovering the moths of Whittingehame) to the Entomology collection of the National Museums of Scotland, no longer at the handy downtown Chambers Street Museum, but now kept in distant Granton. After a couple of hours working as a dogsbody, fetching trays of moths, counting them up and looking for any with “A.B.B” (Alice Blanche Balfour) on their label, I took up the offer from Ashleigh Whiffin, the Assistant curator, to show me some of the much more interesting fly collection. First I asked to see Volucella zonaria – the mystical hoverfly of my youth whose image taunted me from the front cover of Flies of the British Isles – and there it was, bigger and brighter than I had imagined.
My next choice was to see the trays for Bibionidae – March flies – since I had caught one a few days before and had a key to the family, and wanted to check that my identification was along the right lines. These are familiar flies of spring, mostly black and bristly and my kind of family with only 18 British species to decide between. It is a completely different experience going through a key when you can look at specimens with contrasting characters – so that it was easy to see that my fly was in the genus Bibio and not Dilophus in which the front tibia has a no-nonsense set of spikes at the tip. Some species in Bibio are very large or with bright red legs, all of which tended to confirm my identification as this one being Bibio johannis, a common Spring species in lowland Scotland.
But, my feeling of satisfaction at having identified a March fly was short lived. One of the volunteers told me that they weren’t actually March flies, but St Mark’s flies, the reason being that they appeared around St Mark’s day (25th April). That name and the explanation for it was confirmed by Flies of the British Isles, while the internet told me that in Australia, March flies are notorious biters and members of the family Tabanidae. Had I been calling them the wrong name all these years having misheard “St Mark’s” as “March”, just as for a long time I thought that one of the choruses in Handel’s Messiah was “A wee black sheep” (“All we like sheep have gone astray”). Or even better, was it like Dave Allen’s innocent boyhood improvement on the burial service “In the name of the Father, and the Son and in the hole he goes.” To my relief however, bibionids are known as March flies in America, and so I can blame my mixed parentage for my confusion – and the first sightings of Bibio johannis can be March – so everyone was right!