emerald green stripes on the abdomen, bright green undersides, a good 25mm long
No interactions present.
Andy, sticking my neck RIGHT out - could it be a Tenthredo - thorax marks, no green wing-stigma, not green enough?
THREE MARINE PROJECTS
Yes, you are right - it could be Tenthredo. I'm possibly being biased by the sheer numbers of Rhogogaster that I've seen in my area lately.......
I am quite new to Rhogogasters (like four days and one single post - http://www.ispotnature.org/node/426638). But I have looked at all the posts of this lovely green 'fly' and this one seems not to fit - no agreements either.
It's kind of cheeky to challenge one so experienced and rude not to give you (Andy) the opportunity. But I thought Id like to try my hand!
PS - you have agreed! I expected a real counter-challenge, me being so, well....you know!
Lat/Lng: 50.9227, 0.5152
OS grid ref: TQ768167