Rhogogaster scalaris

This was swept from Birch. I keyed it to Rhogogaster viridis using the RES key and momentarily got quite excited when I saw how few records of viridis there are. My excitement was tempered by a vague recollection that there has been some revision taxonomy or nomenclature, and sure enough it turns out that the species called viridis in that key is in fact Rhogogaster scalaris - probably the commonest member of the group!

female Rhogogaster scalaris showing forewing, hindwing, head from in front, head obliquely from side/above, top of abdomen and saw teeth, Wendling Beck Project (Norfolk, UK), 27th May 2025

As with the one above, this keyed to Rhogogaster viridis using the RES key. Rhogogaster is differentiated from green Tenthredo by seeing if the eyes are parallel when viewed from in front (Rhogogaster) or converging towards the clypeus (Tenthredo). Some care is required though as when viewed from slightly the wrong angle (from too low) they do appear to converge a little. However, at the bottom they are still wider apart than the width of the clypeus, so this should prevent any miskeying at this point.

female Rhogogaster scalaris showing forewing, hindwing, head from in front (two views), forewing and saw teeth, Rush Meadows (Norfolk, UK), 11th June 2026