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Bibionidae_Bibio nigriventris (female) is the correct name? Slovak Republic, Malá Fatra, approximately altitude cca 514 m a. s. l. Thank you very much for your help. Best regards. Fote date: 22. 04. 2020.

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[quote]Mucha Fero wrote:

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[quote]Mucha Fero wrote:

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[quote]Mucha Fero wrote:

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[quote]Mucha Fero wrote:

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Dear Mucha,

the antenna has too many segments for nigriventris.
I thinkk, this is a female of B. johannis.

Theo

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Theo thank you very much.

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Theo, why not varipes?
Libor

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I have the same question. Yesterday I saw a rather similar female; both fit the description by Loew in Linnaea Entomologica (1846, p. 349 https://www.biodi...3/mode/1up). Loew states that the venter of B. varipes females is yellowish, and that the sides of the thorax are partly reddish. B. johannis females, on the contrary, have a completely black abdomen. How reliable are these traits?

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In North America the common species of Bibio have several synonyms based on color variation. Loew redescribed one of Walker's species at least three times.

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OK, but are there also B. johannis females with more or less yellow venter? Steven Falk (https://www.flick...181555290/) also says regarding B. varipes females: "They can be very difficult to separate from B. lanigerus but tend to have a yellow venter (black in most other Bibio's)."

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I said “ I think”. for a reason.
I am reluctant to make IDs of females from oicture and to be honst, I am reluctant to make IDs for females without males.

If you follow your lead, you end up with more females varipes than males, which is statistically highly improbable. That makes you wonder ...

Theo