Tuesday, 25 July 2017

Saying good-bye, a last visit to Xuan Son National Park

After 4 years of oding in Vietnam, I will be leaving. This blog will continue, because there is still a lot to publish. I have just been too busy trying to clean up some remaining issues. There simply was not enough time to write entries. Articles are the priority and even there I am behind. Not sure how many species the tally is, after 4 years. Probably around 440 species, but many first need a formal description. And then there is so much out there still to discover.

This spring and summer has been awful for dragonflies. It has just been cloudy and rainy. Some of the puzzles I wanted to solve therefore remain unsolved for now. But at least Sunday 23 July was a good and sunny day, even if I got soaked in the morning. The upside: only one leech lodged on my stomach.

Xuan Son has been wonderful, although the forest is being opened up by road building. I hope that will not lead to further incursions. The trees still stand and the stream remain good. Not sure how many species I actually saw there, somewhere in the range of 125-135 species. With several new species described and several more on the way. So, with the promise of some sun, this is where I went for my very last outing.

And to my huge surprise I ran not into 1, not 2, but 3 species I had not recorded there before. The first was a male Orthetrum melania superbum, a subspecies of O. melania described, and also only recorded, from Yen Bai. A large and conspicuous dragonfly that apparently tolerates abysmal conditions (puddles with muddy, water buffalo dung infested, water), but is nevertheless hardly ever seen. A single male attended a small pond. Fantastic.

This remains one of the most beautiful Orthetrum species I have seen 

By the early afternoon I wanted a change of scenery and drove to a nearby hill in the forest and noticed a dragonfly seemingly ovipositing on the wet concrete road. I got out and caught it and was very surprised to see it was a male, so why was it dipping its body in the wetness of the concrete? And it was a Chlorogomphus, in fact it was C. auratus, which I had never recorded in the park before. I guess I focus too much on the one fantastic stream, but ignore trickles on other mountains.

What is splendid discovery, Chlorogomphus auratus

Further afield still I wanted t check the area on the other side of the central hamlet and stopped by a small stream. A tiny trail ran next to it and I went in to see what it had to offer. And bumped into a small, Coeliccia pyriformis-sized, Coeliccia with large pale blue dorsal markings, a little like larger C. uenoi, but more rounded, and much like the even larger species we are currently describing from Ba Be. Indeed, under the microscope it is clearly closely related to that species, with similar genital ligula, similar appendages (although details differ), but obviously different thorax pattern and abdomen pattern (apart from the total insect being smaller than the abdomen of the Ba Be species alone, which is very robust).

To make sure it was not just aberrant I searched high and low and eventually, in a rather different location, was able to locate a second male, which was exactly like the first. How wonderful, to wrap up Vietnam with a new species of Coeliccia (coincidentally the 9th species of the genus occurring in Xuan Son, amazing).

Wonderful Coeliccia spec. nov. 
Close up of the thorax

So, back to the Netherlands and time to write up in earnest!