which pincertail? SOLVED Large Pincertail - Onychogomphus uncatus

[lucy]

I've just been reading Steve's very clear account of the Small and Large Pincertail dragonflies on his Cornish nature site (which has tons of stuff on Iberian dragonflies too)

 http://www.cornishnature.co.uk/dragonflies-of-iberia-anisoptera/39-the-small-pincertail-onychogomphus-forcipatus.html

I just wish I'd read it before going out for a walk in Montseny. If I'd known how fiendishly difficult it is to separate these two species I'd have concentrated more on the distinctive features when taking photos. I've tried enlarging the relevant bits and quality is not good, but I think it's Onychogomphus uncatus - the Large one.

I think I can count four cells in the anal triangle of the wing.  

Although it's not reliable, there is a clear gap in the keel between the stripes on the thorax.  

Finally, I can't see a subterminal knob in the pincer - but this might be because the angle is just not quite right  

Expert opinions very welcome

[indalo]

I understand that it is also a male of O. uncatus. Look that the yellow stripes are connected dorsally, what does not happen in O. forcipatus.

Hope it can be useful.

Jesus

[parthenope]

Well done Lucy,

You are absolutely on the money. Sadly, as you say, the markings on the thorax are not 100% reliable, but you've definitely got the 4 celled anal triangle on the wing to back it up. As you pointed out, the angle on the claspers is not ideal but it looks pretty much as though there is no sub terminal knob (what a horrible phrase!).
So I'm with you, it's definitely a male Large Pincertail - Onychogomphus uncatus Aren't they really impressive looking insects. Those claspers look like they mean business, but they are of course completely harmless.

Thanks for the Cornishnature name check, it's great to see the information being put to such good use.

Regards
Steve  

[lucy]

Thanks all. I can't believe "sub terminal knob" came from a naturalist.  Maybe an engineer.