Syrphus ribesii?

[PeterD]

This hoverfly has a much lighter thorax than the others in this species. Have I got the ID correct?



Link my website for larger image.

Thanks

[JRsbugs]

Hi Peter,

I don't think it is, for female S. ribesii the hind femora are either all yellow or with black only at the very base. It's very difficult to tell at that distance, and not enough of the hind femora is visible.

Ok, just linked to your other pic, it looks too dark on the hind femora.

Adding that it will be one of the other Syrphus species.

Janet

[PeterD]

Originally Posted by JRsbugs

Hi Peter,

I don't think it is, for female S. ribesii the hind femora are either all yellow or with black only at the very base. It's very difficult to tell at that distance, and not enough of the hind femora is visible.

Ok, just linked to your other pic, it looks too dark on the hind femora.

Adding that it will be one of the other Syrphus species.

Janet

Hi Janet,

Thanks for your reply. I have close cropped the rear leg if that helps

Cropped image

Thanks

[JRsbugs]

It looks to be at least 3/4 dark. I can't see any hairs on the eyes, ruling out S. torvus.

That leaves S. vitripennis, and it does look to have yellow only hairs on the apical quarter of the front and mid femora. S. rectus is the dark horse, a relative newcomer, the hind femora are much the same as S. ribesii on females.

I could stick my neck out at risk and say S. cf. vitripennis, unless someone else can say any different!


Entomology Collection > Syrphus vitripennis

Syrphus

[Geoff F]

S. vitripennis = 'Ocellar triangle narrowest at base'. Difficult to tell from that angle but it might show up better on the original.

But it does have some yellowish hair on the front femur, as Janet mentioned.

So at the moment, I'm not totally convinced either way.

[PeterD]

Thanks Janet and Geoff. I have enabled the download of the original on the following link here.

[JRsbugs]

Originally Posted by Geoff F

S. vitripennis = 'Ocellar triangle narrowest at base'. Difficult to tell from that angle but it might show up better on the original.

But it does have some yellowish hair on the front femur, as Janet mentioned.

So at the moment, I'm not totally convinced either way.

Geoff, look at the Syrphidae site, you will see at the top in notes that both S. rectus and ribesii have all or nearly all yellow hind femora. The latter is outlined on the other site also.

I think if there was hairs on the eyes they would be visible, maybe not but S. torvus is the only other one it can be.

[JRsbugs]

Thanks for the other image Peter, the eyes look crisp and hair free.

S. vitripennis then it is.

[PeterD]

Thanks again Janet and Geoff. I have another one which I am not sure about



Larger image on my website here.

Thank you

[JRsbugs]

Melanostoma mellinum female. Face is mostly black and shiny, lacking noticeable white dust triangles between the eyes. Nice shot too!