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Hello!

This male St. Marks fly just found on the wall of our house (Ostwestfalen/Germany). It was bigger than B. johannis, but somewhat smaller than B. marci I think. Can the species be determined? Thank you?

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This is either B. marci or B. hortulanus.
Hortulanus fits your description best.
Characteristic are the light hairs on abdomen and usually also partly on thorax. The females are completely orange, quite easy.


Theo Zeegers

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Hello, Theo!



Thanks! But the problem is: I have never seen an orange female here over the years. Yesterday afternoon not only the small B. johannis were flying, but now also many Bibio (cf.) marci males and some females. All completely black (and slightly bigger than the above one), except one female with reddish legs (B. lanigerus?).

The links below are pics from 2005 (with my own unprofessional identifications), but the recent animals look quite the same:
http://insektenfo...en_004.jpg
http://insektenfo...la_001.jpg
http://insektenfo...en_001.jpg
http://insektenfo...en_004.jpg
http://insektenfo...en_006.jpg
http://insektenfo...en_001.jpg
http://insektenfo...la_001.jpg

And one from May 2003. Is this Dilophus febrilis? It was only half the size of B. marci.
http://insektenfo...e)_001.jpg

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Hello!

Today all Bibio species seemed to fly simultaneously in large numbers here in Germany :-). The most cute looking are the females with the red legs:

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Hi Juergen,


You are right:
The larger male is B. marci, given the new pictures.
The Dilophus febrilis is correct (a female: wings very dark).


Theo Zeegers

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Hello, Theo!



Thanks a lot!