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tiny midge
Sundew	#1 Posted on 19-10-2007 17:42
Member Location: Berlin and Baden-Württemberg, Germany Posts: 3890 Joined: 28.07.07	Hi, After some hesitation I decided to bother you with another tiny fly. I found it dead on my window sill. Even with the stereo microscope there are not many characters clearly to be seen, but perhaps give wing shape and venation a hint for the family. Also the rather long antennae could be helpful for ID. If you nevertheless say "no chance" I do not mind. - The scale bar in the left pic gives mm. Thanks, Sundew Sundew attached the following image: [135.37Kb]


Kahis	#2 Posted on 19-10-2007 19:21
Member Location: Helsinki, Finland Posts: 1999 Joined: 02.09.04	Based on wong venation Id's say Sciaridae. Kahis


jorgemotalmeida	#3 Posted on 19-10-2007 19:40
Member Location: Viseu - PORTUGAL Posts: 9296 Joined: 05.06.06	Yes, typically sciarid, Kahis. I agree.


Sundew	#4 Posted on 21-10-2007 00:20
Member Location: Berlin and Baden-Württemberg, Germany Posts: 3890 Joined: 28.07.07	I felt the wing venation would give a clue! Henceforth I will recognize Sciarids. What a feeling of success! Many thanks, Sundew


Tony Irwin	#5 Posted on 21-10-2007 13:53
Member Location: Norwich, England Posts: 7193 Joined: 19.11.04	Sundew wrote: I felt the wing venation would give a clue! Henceforth I will recognize Sciarids. What a feeling of success! Many thanks, Sundew Take care, Sundew! Some mycetophilids and some cecidomyiids have venation very similar to sciarids. But you can recognise sciarids from the wing venation and the presence of a dorsal eye-bridge and tibial spurs. Mycetophilids never have an eye bridge, and cecidomyids never have tibial spurs. Edited by Tony Irwin on 21-10-2007 13:54 Tony ---------- Tony Irwin


jorgemotalmeida	#6 Posted on 21-10-2007 13:56
Member Location: Viseu - PORTUGAL Posts: 9296 Joined: 05.06.06	Also Mycetophilidae have tibial spurs (usually two) in tibiae.


Sundew	#7 Posted on 21-10-2007 14:33
Member Location: Berlin and Baden-Württemberg, Germany Posts: 3890 Joined: 28.07.07	Oh Tony, how you disillusioned me... Looking for eye-bridges and spurs is much more difficult than checking wing venation alone! It seems to me, however, that Kahis (and possibly Jorge as well) relied only on this latter character. Well, in my pictures the head is not recognizable enough to find out whether there is an eye-bridge at all. A tibial spur I suppose to see in the lower right picture. So the fly could also be a mycetophilid? Provided that double spurs are not an absolute must in this family! Or shall we adapt a quote by Tony from another thread, "it just 'feels' like a sciarid!" - ? Sundew, rendered uncertain Edited by Sundew on 21-10-2007 14:34


jorgemotalmeida	#8 Posted on 21-10-2007 14:44
Member Location: Viseu - PORTUGAL Posts: 9296 Joined: 05.06.06	yes. Sundew, in the lower right you can see * REALLY* and very clearly one spur in two legs! In this case the wing venation was unmistakable, but there are other problematic cases and then you must apply the "rules" that Tony wrote. Usually Mycetophilidae have big and conspicuous spurs. (usually two) in ALL tibiae. But the eye bridge is safe to reach the family.


Tony Irwin	#9 Posted on 21-10-2007 18:05
Member Location: Norwich, England Posts: 7193 Joined: 19.11.04	Don't be depressed, Sundew - the mycetophilids with sciarid-like venation differ in other ways, but the eye-bridge (present in sciarids, absent in mycetophilids) is a good character to separate these families in all cases. Sciarids are typically dark-coloured with pale legs and have simple antennae. If you find such a fly with typical sciarid venation, it will be a sciarid 99.9% of the time. (I hardly ever check for the eye-bridge . - Anything I find that looks like a sciarid goes straight into alcohol for slide-mounting at a later date.) Tony ---------- Tony Irwin