Showing posts with label Libellula. Show all posts
Showing posts with label Libellula. Show all posts

Thursday, 24 July 2014

Loose ends

So, wah loose ends remain from the mid-summer road trip around northern Vietnam? In Pia Oac in early July I ran into a whole bunch of small gomphids one afternoon. The turned out to be Davidius. But which species? There has been some confusion about Davidius fruhstorferi, with various subspecies described and some split as separate species, or lumped again. Clearly, this species belongs in the fruhstorferi corner, but the thorax pattern is a little different, it is a little smaller and the appendages, although similar, are not excavated laterally and smaller than in the specimens I saw in early spring at Yen Bai. Now, it is possible that indeed this is subspecific variation, but I am not so sure. It would not surprise me if in fact this turns out to be a different Davidius. Nevertheless, for the time being it look as if it will go down in history as Davidius cf. fruhstorferi.

A tiny gomphid, and please note the nice black square mark laterally. But let's pretend it is Davidius fruhstorferi, a male
Then this is the female. And clearly the square mark is not a fluke. All individuals, including this female, displayed that characteristic, which I have not been able to find in any description of any subspecies.

In copula, working to produce many little gomphids

A female in dorsal view. Along a tiny stream in the forest it was quite common

What else do I still have to show from my odyssee? A yes, Leptogomphus elegans. Known from Ba Vi and from Pia Oac only in Vietnam and indeed, after seeing it in Ba Vi, I now ran into a single mail in Pia Oac.
A nice male Leptogomphus elegans. At this angle it is hard to tell, all Leptogomphids look the same, basically.

But like this is it very clear! Leptogomphids can reliably be identified on the basis of their appendages.

Still more? Yes, forgot to mention one of the few Libellulines that I took a picture of: Libellula melli. It flew at the Love Waterfall in Sa Pa middle of April and it was still there July 2. At least one male.

Male Libellula melli, nice species that reminds me of home, because it looks a lot like L. depressa.
Anything else? Yes, yet another gomphid. Phaenandrogomphus tonkinicus, found at the end of May for the first time in Xuan Son National Park, turned out to be a common species in medium sized rocky currents. I saw it many times in Bac Kan and Cao Bang provinces. Many females were seen ovipositing in Pia Oac.

This is what the female looks like, pattern much like the male

And Phaenandrogomphus tonkinicus male. Hovering for prolonged periods over the little sandy spits where the females would come to oviposit, but with terrible timing, as invariably he was there when they were not and vice versa.
And that, dear readers, concludes the report on damsels and dragons from the northern provinces in late June and early July.

Friday, 18 April 2014

Sapa, 14-16 April

To continue the saga of Sapa, we arrived late on Sunday 13th after a grueling drive, persuaded by my Papago! to drive a different route, not as I planned along QL 32, but first along QL 70, where we eventually ran into a traffic jam and had to U-turn, drive back for an hour and then followed TL 151, equally disastrous, as it was no more than a off road dirt track ruined by working traffic for the highway being built. But we made it. In Sapa we noticed great dragonfly spots, but did not specifically explore them, as this was a birding trip. However, the swampy field along the trail to Love Waterfall was very productive and birding the lower areas of Phan Xi Pang mountain was also great, irrespective of the time of the year (early) although diversity was still low.

I will need some time to sort everything out, but this is the information I can share right now. Any suggestions on the IDs are very welcome. The streams were still mostly empty, but the pools and swampy fields had interesting species. Orthetrum glaucum, O. pruinosum, O. triangulare and O. sabina were to be expected, but O. internum was the commonest species by far. I had not seen it before in Vietnam. The presence of Anax nigrofasciatus was a nice surprise, with 2 males at the marsh of Love Waterfall and another somewhere over a pond. A freshly emerged, but somewhat damaged Anotogaster male was also a wonderful find on Phan Xi Pang. And Libellula melli was yet another species I had not expected. This cousin of the Eurasian L. depressa occurs in Southern China but to my knowledge is new for Vietnam.

Damselflies were also very interesting, although I encountered only a few. A Megalestes species was found emerging at various locations and once a mature female was seen, but escaped before it good be photographed. Common in a variety of habitats was a species that seems to be a Mesopodagrion species, and as it does not look like M. tibetanum, it could be M. yachowensis. To be continued. Another species seen only once is also an unknown, suggestions are welcome. This was a beautiful species similar in size to the Mesopodagrion and interacting with it in the forest. I am at a loss for now. And the last damsel found was Ceriagrion fallax. It was common at one particular stream near Sapa town.

Let's start with the completely unknown, suggestions welcome!

The same damsel, detail of thorax


The same damsel, lateral view of appendages

Anax nigrofasciatus, male

Ceriagrion fallax, male

Orthetrum internum, male

Megalestes spec, work in progress, female

Very cool Mesopodagrion species, male

Mesopodagrion species in tandem

Libellula melli, male, new for Vietnam

The unfortunate Anotogaster male, something went wrong during emergence