Heliaeschna crassa new from Phu Quoc

On April 14 I was trying my luck towards dusk at a small pool inside swamp forest on Phu Quoc. This was the pool where I had found Rhyothemis aterrima during the daytime and although nearby a dead dog had been dumped in a bag, it was not nearly smelly enough to keep me from staking out for Aeshnids. And as luck might have it, a large Aeshnid did in fact show up and even luckier, when I struck out for it I caught it. It was large and did not look familiar. The appendages looked a bit like what I remembered from Asahina and indeed: when I checked later it turned out to be Heliaeschna crassa. Having said that, this species may be a junior synonym of Heliaeschna idae. However, since convention calls the specimens in countries just west of Vietnam H. crassa, I will stick with that.

This species has long superior appendages that bend inwards towards the apex and are slightly expanded, but the epiproct is short and hooked upwards towards the posterior end. The face is ochre, with an indistinct dark spot on the postfrons that does not form a real T-spot. The eyes are also largely ochre in colour. The thorax is green with reddish lines over the sutures. The wings are pale brownish enfumed, but with dark brown along the subcosta becoming less distinct after the first 6-7 cells or so. Asahina actually describes the thorax as mainly dark reddish brown and the face as reddish brown. Maybe he worked with faded specimens?

The beautiful monster: Heliaeschna crassa. Note the largely ochre eyes.

And the ochre face, for that matter

Positrons with dark vague diamond

Appendages in lateral view, with hooked epiproct.

In dorsal view. Sadly the right appendage was damaged

Heliaeschna uninervulata - Swarming at Cat Tien

On November 17 we were checking the road from the lodge to the fishponds in an open, disturbed, area, with some forest and shrub cover. Close to dusk, we were looking for Gynacantha. As luck would have it, a species appeared in good numbers, with several score dancing around. But not so lucky, they stayed quite high. Kameliya discovered a place where they were flying somewhat lower and I was able to net two females. In hand, they had very broad leaf-like appendages. But my mind was set on Gynacantha, so it did not occur to me this could be something else. It was only after Oleg Kosterin (thank you Oleg!) responded to a later email by me, that it dawned on me that this was a Heliaeschna. Venation in the wing made it clear it was H. uninervulata, a species that had been reported from Vietnam before (1953, Lieftinck), but otherwise apparently had gone unnoticed. It occurs widely over south-east Asia, so it probably occurs more commonly.

Heliaeschna uninervulata, female. In coloration and appearance rather Gynacantha-like. Note the single cross-vein in the median space.

Dorsal view of the frons

Facial pattern, rather simple

The distinctive leaf-shaped appendages