Thursday 14 April 2011

Unidentified Diptera

Took this picture of a rather splendid fly on a Lesser Celandine flower earlier today in Bruaich Jeraich.  I have no idea what it is so have joined the Dipterists Forum and posted it with an appeal for help.  If anyone comes to my aid I will let you know the outcome.


  1. Thanks to the Dipterists Forum - it could be Bibio marci - 'St Mark's Fly'

  2. Further comments from the Dipterists Forum...

    Brian Harding - If the tibiae are orange (as the hind tibia appears to be) then a small Bibio is B. johannis. In addition the black spot on the wing is in line with that identification.
    However you will need more evidence than that for a definitive identification. But I have been finding B. johannis on several sites recently.
    I suggest that you look at pictures on line and see if you are content with that opinion.

    Howard Bentley - Is the stigma dark enough for B. johannis? I've also seen a lot of B. lanigerus this year. Who knows?

    Brian Harding - I think that Howard's suggestion of B. lanigerus is a good one. I thought that the stigma was a bit too defined and dark for B. lanigerus, but the pale lateral hairs on the front of the abdomen certainly point away from B. johannis.
    This demonstrates that without being able to observe all of the characters mentioned in the keys, some of which are not visible in the picture and would require examination under a microscope, it is difficult to be definitive.