First visit to Huu Lien in 2015 - Trigomphus* **

*This entry was adjusted slightly after publication of the description of Trigomphus kompieri Karube, 2015
**And again after publication of Paracercion ambiguum Kompier & Yu, 2016

Sunday March 22 was supposed to become a sunny day. Sadly, the weather forecast is not very reliable in Vietnam, but after a very cloudy morning I did have some weak sunshine in the afternoon, just enough for things to become a little more active. Last year in April I had found a new species of Trigomphus in Huu Lien, but by then it was already scarce, as Trigomphus is an early genus (season-wise). I wanted to take some better photos of it, so for the first real dragonfly trip in northern Vietnam of the season I headed for Huu Lien. In the morning I saw two males and a female, but they did not linger. When the sun came out in the afternoon they showed better, but sadly no female anymore. This Trigomphus species is the most southerly (apparently) of the genus and with the broad dark line of the flanks quite exceptional. A lovely gomphid. It has recently been described by Haruki Karube as T. kompieri.

I was able to see 31 species over the day, not bad, given that the weather was not good and it is only March. Highlights included 5 freshly emerged Asiagomphus, likely A. auricolor, 3 Epophthalmia elegans, Anax guttatus, and Paracercion ambiguum.

Beautiful Trigomphus kompieri, male

Another male perched by the side of the stream

Same male as in the previous photo, perched this time on a snag 

A common species, but handsome, Trithemis aurora, female

Copula of Pseudagrion microcephalum, one of three Pseudagrion species observed today

Already subject of the blog on many occasions, yet another photo of the pretty Paracercion ambiguum.

One of five freshly emerged Asiagomphus, likely auricolor.

The female Paracercion ambiguum from Huu Lien*

*This post adjusted after publication of Paracercion ambiguum

This December 7 we went once more to Huu Lien, battling the traffic on "Highway" 1 and once again surviving. The objective was again to find the female of Paracercion ambiguum. The sun was only remotely present; it was rather misty and later on cloudy. We also got the distinct impression that numbers had dropped drastically. But I was in luck. I noticed a female damsel sitting on a stalk of grass emerging from the reservoir right by the grassy edge and was able to catch it. It was rather different from the females of P. microcephalum from last week. In fact, it had the sides of the thorax like the male, same pattern, but different colors. It was slightly larger than the male, with similar postocular spots, but the shoulder stripe was very Paracercion-esk. Close-up of the prothorax showed that it lacks the typical "horns" of Pseudagrion. So, is this not Pseudagrion after all, than what is it, as the male shows characteristics not really in line with Paracercion!

First some pictures of the female:

The female of Paracercion ambiguum, at last!

Close-up of the thorax. Note the same distinctive marking along the interpleural suture as in the male, the large postocular spots, but also the double light line along the humeral suture.

Now let's have a look at some other Pseudagrion prothorax and compare them with our specimen

Prothorax of female P. microcephalum, note the distinctive ridge and horns along the posterior edge.

In female P. rubriceps these are equally distinctive

Whereas in female P. spencei they are clearly visible, if not as large

But this distinctive Pseudagrion feature is missing from our species.

Here is an additional close-up of the ovipositor.

Pseudagrion microcephalum females

Last weekend we spent several hours trying to catch the female of the new Pseudagrion species, but to no avail. Once my net got stuck on a thorny bush, once a female flew off, but two I caught after all but swimming after them. However, there were also males P. microcephalum in the area and the two females that I caught were not in tandem, not directly associated with P. species. And after studying them they are either very similar to female P. microcephalum, or they are in fact P. microcephalum. Right now I have no reason to believe they are anything else. I have one more weekend to go and the sun is out, so who knows, but for now, these are P. microcephalum. Very different from each other in coloration, the one brownish, the other bluish, but otherwise, the same.

Pseudagrion microcephalum female, blueish, mature?

The same female in close-up

Another female, brownish, immature?

The same in close-up

A visit to Van Long - look what the cat brought in

So, what did I see at Van Long? The most interesting record was of a female Mortonagrion aborense. Now I have seen this species at Van Long, at Cuc Phuong, in Huu Lien and in downtown Hanoi. Clearly it is in fact a common species in northern Vietnam that has been very much overlooked until Sebastien ran into it.

Mortonagrion aborense, female

I also took a pretty good shot of Pseudagrion australasiae, a male. There were not many around. I saw maybe 5-6 males over the day.

Pseudagrion australasiae, male. Note the short superior appendages, half the length of S10. Otherwise very similar to P. microcephalum.

And the last species that deserves a bit of attention was Ceriagrion auranticum. There were quite a few flying and this female did me the courtesy of staying put. Note the long abdomen, protruding further beyond the wingtip than in C. nipponicum.

Ceriagrion auranticum, female, with wings up to 1/3 of S6

For convenience, the female C. nipponicum of a few posts back:

Ceriagrion nipponicum, female

And of course that other Paracercion, P. calamorum. There were still several around, including some females.

Paracercion calamorum, male

Paracercion calamorum, female

Pseudagrion spencei, new to Vietnam (but likely common)

Some research into the literature on Pseudagrion lead me to Fraser 1933 and his treatment of the Odonate Fauna of British India, after some pictures from southern China already pointed me to widespread P. spencei, known from Bangladesh, Pakistan, India, Nepal, Southern China and Hong Kong. Not from Vietnam, but we can change that now. For my species is a perfect match with the description from Fraser. So, I have changed the captions to the earlier entries on this species and added a post script.

Pseudagrion enigma*

I already posted earlier on my suspicion that there is another species of blue Pseudagrion besides P. microcephalum and P. australasiae. Today on the way to Cuc Phuong we stopped just outside the park at a pond where I knew in summer the possible third species had been present. We were lucky, because there were two male P. microcephalum sitting on the vegetation in the middle of the pond (which is part of a small stream). I collected one male. Then our attention was drawn to two other males in the grass by the side of the pond. Indeed, the enigma Pseudagrion! Due to the morning cold the colors were not vivid, but it did seem the right species and I collected also one of these. A female, the strange brownish female I published before, turned up with the two males, heightening the excitement! Under the microscope there is no room for doubt. This is a different species, with different, but long appendages, smaller size, much shorter lower appendages, and different ocular spots. For comparison I scanned the male with two P. microcephalum (we saw several more inside Cuc Phuong National Park at Ho Mac) and P. australasiae that I had on file from Van Long. For the moment, I treat the enigma species as Pseudagrion, but I am open to any suggestions.*

* Subsequent literature research pointed out that this species is P. spencei, a widely distributed species, but not known from Vietnam.

P. australasiae, top, P. microcephalum (two specimens center) and P. spencei, bottom

I took some photos both in the field and in the hand of the two species with long appendages, M. microcephalum and M. spencei.

Pseudagrion microcephalum, male

Pseudagrion spencei, same as in scan, so actually more vivid when warm

A second male Pseudagrion spencei, also cool

Same male as in previous picture

In hand they look like this:

Pseudagrion microcephalum, male

Pseudagrion spencei, see appendages

The appendages in close-up:

P. microcephalum, dorsolateral

P. microcephalum, dorsal

Pseudagrion spencei, dorsolateral

Pseudagrion spencei, dorsal

And the post-ocular spots

P. microcephalum, male

P. spencei, male

Tidying up the last bits of Xuan Son

Just before the weekend starts with new adventures time to tidy up the remainder of records from Xuan Son. I will start with another new species for me, Vestalaria miao. And to be honest, I cannot be a 100% sure of the ID. Noguchiphaea yoshikoae occurs also in the area, but has characteristic horns on the prothorax, not present in Vestelaria. And Vestalaria miao was recorded right there in Xuan Son, but who knows, maybe another species is present too. So the search for more evidence continues. Here she is:

Vestalaria miao, female, with slightly tinted wings

The same female in hand, note the absence of horns on the posterior lobe of the prothorax

For comparison female Noguchiphaea yoshikoae of Tam Dao in September, very similar although wings slightly different in shape and clear, eyes of different color

Note the horns on the posterior lobe of the prothorax

The second species to publish here is Cratilla lineata, of which I encountered a female in the rain. Cool as addition to the earlier male. She is very similar in markings, but of course with a differently shaped abdomen.

Cratilla lineata, female

What else was worth to mention? How about a teneral male Pseudagrion pruinosum? Here he is, as a possible stumbling block for the unwary.

Pseudagrion pruinosum, immature male. The appendages are a give-away. The neck looks rather bull-like, due to a rain drop that has lodged itself there.

Close-up of the neck and the rain drop. Soon after it would remove it by brushing.

The last to enter for today was an array of Calopteryds. The first is Calopteryx coomani, a species I have seen regualrly at Tam Dao National Park and that also frequents Xuan Son. Especially the female is superficially similar to the female of Matrona basilaris, but that species has, just like the male, a milky shine to the bases of the wings due to the fine maze of veins there, absent in C. coomani. Both are large species, but C. coomani is even more robust.

Atrocalopteryx coomani, male, with blueish shine to abdomen and visibly here translucent areas in the wings.

Male showing the largely translucent front wings and bases to the hind wings.

Atrocalopteryx coomani, female

Matrona basilaris was already introduced in an another entry, but not the female. Compare here to the female of Atrocalopteryx coomani, to which it is rather similar when perched and the milky bases to the wings are not visible. The color of the wings is more greenish and the wings are more slender.

Matrona basilaris, female. I saved this one from the water, where it had become entangled in cobwebs when ovipositing. It did not linger when I released it and perched far away, which explains the grainy picture.

Matrona basilaris, male, for completeness sake

And finally, because it is such a special species, another Matrona taoi male. I find this species much more like A. coomani than like M. basilaris, when it comes to size and shape of the wings.

Matrona taoi, male