Chrysis.net Forum

Last april Arno van Stipdonk and I found some Chrysura specimens on a Dutch limestone grassland. They were inspecting snail shells that were also visited by Osmia aurulenta. We concluded that it had to be C. trimaculata, the 'normal' Osmia aurulenta Chrysura in adjacent areas. Only later we found out that C. rufiventris is expanding its range and recently found in northern France and nearby Germany.

As C. trimaculata has never been recorded in the Netherlands (nor has rufiventris) we only collected a male. Unfortunately we can't find any descriptions to distinguish between males of both species. Is such literature available?

Or is it possible to ID our (rather poor) pictures?

The first 2 concern a female (photo A. van Stipdonk); not very trimaculata like because T3 is not flat and rather strongly pitted but also different from the drawings by Berland & Bernard, 1938.

The last 2 concern the collected male.

Kind regards,
Ivo Raemakers.

Ivo!

Congratulations,
even if I can't see the genital capsula in dorsal view, the sternites, or the shape of metanotum,
I can tell you that it's Chrysura rufiventris for the apical margin of the last tergum folded down.

Nice finding!
Paolo

Thanks Paolo!

Interesting that C. rufiventris is expanding its range so swiftly northwards. Even into regions where its host has a very scattered distribution. Especially so, since C. trimaculatus is apparently not able/liable to do the same.

Kind regards, Ivo.

Ouahh nice finding : Chrysura rufiventris have a thick border in the profil view (fine in trimaculata & refulgens).

In the half north of France, there are not many data (in my knoledge, only in Manche and Bretagne, by F. Herbrecht & A. Livory), and in Bourgogne (M. Prost leg, I see the specimen).

For the identification see Berland L. and Bernard F. 1938 (download here : faunedefrance.org (in french), in Chrysis "Section Monochrysis", with the prominent or angulate metanotum (= postscutellum).