Chrysis.net Forum

Dear colleagues,
please, help to ID one specimen:
female, 8,5 mm, reared from the nest of Eumenid wasp in the Crimea (Ukraine).

It obviously belongs to Cornuchrysis and to cerastes-goup within it.
I think it is Chrysis cerastes Ab., 1877, though species of this group are hard for ID for me.
Can anyone confirm? or it is other species?

Thanks for the attention,
Kate

Hi Kate,

you're right, it looks like C. cerastes, but genae are shorter.
According to Linsenmaier, the colour of the thorax of your specimen is typical for Chrysis cerastes, but the short malar spaces and shape of the genae is the one of Chrysis ambigua. I cannot see the shape of the head in dorsal view, could you take:
1. an other picture of the vertex of the head, look at Linsenmaier (1959a) fig. 626, 630 and 631, they have a different angle: in the picture we shuold see partially the malar spaces.
2. a picture of the sternites

Thanks
Paolo

Hello Paolo,

this is the best I could get, sorry.

First I determined the specimen as ambigua by Linsenmaier's key, and features of ambigua lygaea Lins., 1997 from Southern Russia seemed very similar, than I began to doubt and translated original descriptions, but it made only worse. I have nothing to compare the specimen with.
The first two photos is 'the same" at different depth resolution - looks more like ambigua at this angle, as for me.
What do you think now?

Kate

Thanks Kate,

yes I agree with you and I would say Chrysis ambigua.
Did you ever try to use Combine ZP, or other similar photostaking software?

Ciao
Paolo

I've heard about this program, but my microscope is an old model, I can only put the camera close to the ocular of microscope and press a button. I have an opportunity to work on good optics at Donetsk Botanical garden, but it takes time to get there and arrange the work. Any way, thanks for the tips, I'll consider.

Thank you very much!
All the best,
Kate