Trip to Nam Bung (Yen Bai) - a superb surprise and a second Anotogaster*

*Adjusted on June 1, 2016. This subspecies now published as Orthetrum melania superbum.

July 11 I drove all the way to Nam Bung along the QL32 (in Yen Bai Province) in search of an enigma large Periaeschna species, of which I caught a female two weeks back. But I failed to see it again. I spent the beautiful day along a stream that runs through forest and a canyon, the same place where I had seen the Periaeschna.

The trail through the forest had some puddles and it was here that I spotted a large pale-blue Orthetrum with pale appendages, a dark face, and a black dorsum to the thorax with very prominent and clear antehumeral stripes. The wingtips had a darker crescent and the wing bases had a prominent blue-and-black basal patch. I was pretty convinced that by now the genus Orthetrum was not going to present surprises, but here I was faced with what was obvious a new species for Vietnam.

I collected a single male of the 4 males present at the puddles. It is very weird. These puddles were dirty, with buffalo crap and mud, nothing special. If you consider this, why on earth would this species be rare? Also interesting, Orthetrum triangulare was omnipresent (it is a very common species in this area), and also all around, but not at these few puddles. Clearly it can not compete with this species (in fact the abdomen of O. triangulare is 30mm, but of the present species 37mm, so it is much larger).

From the shape of the appendages, the coloration (face, wing base and tip, abdomen, thorax (but not the dorsum) I can only conclude this is Orthetrum melania. This species was long considered to be a subspecies of O. triangulare, although that is no longer the case and the co-exist in the south of China. Indeed, structurally the caudal appendages and sex apparatus look similar unless you look carefully. Originally this species was thought to be restricted to Japan, but it is now known to have a much larger range. O. melania has also been found in Guangdong, Guangxi and Yunnan. Therefore it is maybe not surprising it also occurs in Vietnam.

There are however a few aspects that indicate that this may be an (unknown) subspecies. The specimen is right at the top of the range for Japanese specimens, with abdomen 37mm. The median space in the hindwing is clear, but integral part of the basal patch in the Japanese specimens. The basal patch is also smaller, not covering the base of the anal loop. But most prominently, the dorsum of the thorax has no pruinosity. It is solid black with clearly demarcated antehumeral stripes that are not pruinose, but truly blue in color. These antehumerals are surprising, because they are absent in the true O. melania, which has a unicolored pale dorsum as immature, that gets covered in pruinosity like the rest of the thorax. Most Japanese specimens have all black appendages, but some have paler tips of varying extent. As can be seen in the photos of the Yen Bai specimens there is some variety there too, from all pale to pale in the apical halve. Nevertheless, the overlap in characteristics makes it unlikely this is a completely different species. I am curious to hear what specimens in the south of China look like. If they are the same as in Japan the present specimens are even more remarkable. I have not been able to find any similar species on the web.

Another surprise was Anotogaster klossi. I have seen A. gigantica in the same general area, but A. klossi only at Pia Oac. Interestingly, it passed over the same track and puddles where I found O. melania.

Let's get this out of the way. Anotogaster klossi, with characteristic reddish colour on abdomen, yellow mandible bases and long superior appendages in which no obvious tooth visible halfway. 

To start the argument: scan of Orthetrum triangulare (top) and O. melania (bottom). The size difference is obvious.

The first male O. melania I noticed. This specimen has completely pale appendages.

The same male in dorsal view. 

The same male in hand. The dark face clearly visible. But what is especially eye-catching is the dorsal pattern. Although the lateral grey is a powdery substance that is easily scratched, the antehumeral stripes (or maybe dorsal stripes is better) are not the result of powder. They contrast very strongly with the solid black remainder.

Note the lack of colour in the median space

Another male, with mostly black appendages with only pale apices.

Appendages in ventral view

In dorsal view

And in lateral view

The hamulus and lamina in lateral view

Two additional species of Burmagomphus

Burmagomphus asahinai was described as recently as 2012 by Kosterin et al. from Cambodia. Dennis Farrell has shown its occurrence in Thailand (where in fact it had also been recorded by Asahina, who left it unidentified (see Kosterin et al.). Last year James Holden caught a female Burmagomphus in Cat Tien National Park that appeared to be this species, but as it concerned a single female, released after in hand photography, its identity was hard to prove. In June this year James returned to Cat Tien and was able to take a picture of a male that quite clearly shows B. asahinai. Caution must be taken with the identification of such species on the basis of photographs, but it is quite distinctively patterned. Karube has also recorded this species from Dalat. Its occurrence is hardly surprising, given its presence in neighboring Cambodia and Thailand.

Another species of Burmagomphus recently published (Karube, 2014) from Vietnam and, based on its two records from Tam Dao in the north and Lam Dong in the south apparently widespread, if uncommon, is B. divaricatus. I ran into a teneral male when checking a relatively open river near Cao Bang City in Cao Bang Province on May 20. Subsequent visits did not show up other specimens, so I will have to make due with the teneral specimen for publication here.

A hazy shot from some distance, but good enough, I would venture to say. Burmagomphus asahinai, male, June 2015. Photo by James Holden.

Female of B. asahinai. Summer 2014. Photo by James Holden. As can be seen from  the cluster of eggs she was ovipositing.

With its distinctive thoracic pattern and divaricate appendages, this male B. divaricatus could be identified without capture, which was lucky for it, given its fragile state.

Close up of the dorsum of the thorax.

And close-up of the divaricate inferior appendages. 

Indothemis carnatica - easily overlooked?

Last year summer James Holden did a survey of dragonflies in Cat Tien National Park. I joined him for a bit and later revisited to expand a little on his work. One interesting species he found was Indothemis carnatica. In fact I failed to recognize the species when he showed it to me on photos and assumed it was Trithemis festiva. But James looked into it further and eventually solved the puzzle. In retrospect a clue to its identity was that it was seen at the deserted swimming pool in Cat Tien, a choice of habitat that does not suit T. festiva well, as that species prefers running water.

This spring Natalia von Ellenrieder et. al. published an article on their records in northern Vietnam, including Cuc Phuong National Park, and in it record I. carnatica from two locations in the park, the large lake in the middle and the abandoned swimming pool near the end of the central road. There is a pattern here…

Even though these records constitute the first for Vietnam, the choice of habitat indicates that it readily occupies new areas and / or ponds that combine relatively clean, but deeper water with rocky or stony surroundings.

Superficially they can easily be mistaken for the common T. festiva. Not only is it similar in coloration and shares a brownish basal patch to the hindwing, but it also has the habit of hovering over water or perching on nearby rocks or vegetation. If you google T. festiva you will find several misidentified I. carnatica amongst the photos. This indicates it may not be as rare as thought.

According to IUCN this is a little known and scarce species, but in fact this may partially be because it is overlooked.

Anyway, on June 16 part of my mission to Cuc Phuong was to see the species for myself, after having overlooked it in Cat Tien. In the middle of the morning I found several males over the abandoned swimming pool. I did not see any females. When it became too warm most species withdrew from the pond and so did I. carnatica.

Indothemis carnatica, male. Note the black-and-blue pattern on the abdomen and pale appendages.

Another photo of the same specimen

The same specimen up close in hand.

The male has a characteristic bulge on its lower belly (posterior on its venter, so to speak)

    

Finally Atrocalopteryx laosica

On June 24 I decided to check out the Cat Cat Touristic Area at Sa Pa as a last resort measure to find Atrocalopteryx laosica. The Sa Pa area is the only site for the species known from Vietnam and although I searched a lot in the area, I had yet failed to find it. But this day was a very dark and cloudy, rainy day to start with and I decided that the Cat Cat area might at least show some new habitat and who knows, a nice stream. This proved just right. At the bottom of the touristic area there is in fact a very nice broad stream bordered by a paved, but almost unused, trail. Following it the weather cleared just a bit and just when I was thinking it was not to be, I noticed a male A. laosica perched on plants along a small stream coming of the hills. It was also the only specimen I saw there, but one is enough. Clearly this is not only a limited distribution species, it is also a low density one.

Atrocalopteryx laosica was transfered to the genus Atrocalopteryx by Matti Hamalainen in 2014, from Calopteryx.

Atrocalopteryx laosica, male, at Sa Pa. Note the lighter bases and tips to the wings, plus the marginally darker sub apical band.

Another shot of the same, beautiful, specimen

And briefly held, to get a shot of the open wings.

Gynacantha ryukyuensis - an exciting duskhawker!

June 16 I visited Cuc Phuong National Park and towards dusk visited a field with several muddy areas along the forest edge where earlier during the day I had seen Gynacantha subinterrupta. I admit it, I was rather jealous of the Gynacantha hyalina recorded in the park by Natalia von Ellenrieder et. al. in their recent publication. So I wanted to see if I could get lucky too.

I noticed a few Gynacantha males that appeared to be G. subinterrupta, hovering in their characteristic way by the forest edge. But when it got really dark I noticed some patrolling Gynacantha along small trails through the grass, just flying up and down. I was able to catch one and was immediately struck by its weird coloration. The thorax was mostly yellow. Moreover, the inferior appendage was whitish, so clearly this was not G. subinterrupta. But also not G. hyalina. So what was it?

It took some searching, but finally it dawned on me that this should be Gynacantha ryukyuensis, a species known from islands between Japan and Taiwan, from Taiwan and from at least Hongkong. But not (yet) from Vietnam.

A beautiful species, Gynacantha ryukyuensis. Yellowish thorax, but with largely sky blue metepimeron. Note the little yellowish squares at the anterior ventral part of segments 4-7.

In dorsal view the deep yellow frons with black T is obvious, as are the greenish eyes (blueish in male G. japonica) 

The appendages, with epiproct less constricted in posterior half compared to G. japonica.

And in lateral view

A Lamelligomphus feast - two additional species

Lamelligomphus is a fascinating genus of pretty much similar looking gomphids with massive and impressive appendages. They have a habit of hovering over fast streams, often again active towards dusk. Absent from Do & Dang, I soon found out that they did in fact occur in northern Vietnam, as is evident from the various entries on the genus in this blog. Additional species occur in the south (for sure L. castor), but I focus on the north. After verifying L. camelus and L. formosanus, both easy to recognize, L. camelus due to distinctive appendages and typical humps on S8 and L. formosanus due to the extensively protruding inferior appendages, raised distal carina of S8 and typical penile organ and thumb-like extension of the anterior hamule, the first hurdle was the unidentified species that recently was described by Karube as L. vietnamensis. This species is very similar outwardly to L. hainanensis, another species often encountered. But L. vietnamensis is larger (similar in size to L. camelus and L. formosanus), without any protrusion of the inferiors, antehumeral stripes connected to collar and line over frons interrupted. Smaller L. hainanensis has similar anterior hamule and penile organ, but generally black labrum (sometimes with two small spots), uninterrupted stripe over frons and normally no connection between antehumerals and collar. Importantly, it has a limited, but obvious, protrusion of the inferior appendages.

So, four species, and all in their inconspicuous ways different. And that was that. Or so I thought. The first crack in this simple scheme occurred on June 13, when I was checking a stream in Nghe An Province. This was a small species, like L. hainanensis. But the pattern of the face and on S2 was different. Triggered by this inspection of the appendages showed the lack of any protrusion. In fact it looked like a miniature L. vietnamensis. Penile organ and hamuli were in accordance with both these species. However, it is neither and appears to be an as yet undescribed species.

On June 22 I had a nightmare of an afternoon in Lang Son, having gotten caught in a terrible thunderstorm on an unpaved road in the mountains that had been turned into something reminiscent of Verdun by trucks. There was no way back and I continued struggling in 4WD motion at a speed of 8km an hour average. Towards dusk I got closer to national road 4 and in flatter terrain and crossing a stream decided to give the last moments of the day a try. The obligatory Lamelligomphus was hovering over the water, but in hand showed many characteristics that I had not seen before. The extensive lateral patterning was one, the indistinct humeral line another. Combined with the lack of a thumb-like extension of the hamulus (verified under the microscope), the lack of raised distal carina and other characteristics L. formosanus could quickly be ruled out. That species, although not in the populations I have seen in Vietnam, does sometimes have more extensive patterning. But it was not that. The key in Chao proved helpful. I tentatively identified it as Lamelligomphus tutulus, an addition to the Vietnamese list, but one that has been verified by Wilson for both Guangxi and Guangdong in neighboring China.

Let's start with something easy: Lamelligomphus camelus, with clear protrusion and humps. It also has a distinct boomerang on S2.

As can be also seen in this specimen in hand. This year alone I have seen this common species in Lang Son, Phu Tho, Bac Giang, Yen Bai, Thanh Hoa, Nghe An and Ha Tinh Provinces.

This is the recently described L. vietnamensis. No protrusion, but fairly large species. No humps and no raised distal carina on S8, amongst others.

Another male in hand. This spring I have seen them in Thanh Hoa, Cao Bang and Lang Son Provinces. Not rare, but not as common as L. camelus.

No this is the exciting L. species novum from Nghe An. No protrusion and only a single egg-shaped spot on S2.

Facial pattern not dissimilar to L. hainanensis, but frons with separation and labrum with spots.

These are its appendages, no protrusion at all.

Compare this to these appendages, of a male L. hainanensis

These are preserved specimens, with L. species novum on top and bottom L. vietnamensis, showing the obvious difference in size.

And no it is time to turn to the star of this blog entry. Lamelligomphus tutulus. Note metepisternum with three separated spots, both a humeral spot and indistinct humeral line, extensive yellow pattern on S1-2.

Facial pattern with large markings on labrum, bases of mandibles and lateral on postclypeus.

Very interesting appendages, protruding well, but different in shape from for instance L. formosanus.

As can also be seen in this dorsal view

A third Sympetrum species for Vietnam - Sympetrum eroticum ardens

On June 23 I visited the Sa Pa area again, in the hope of finding Somatochlora dido. Alas, it was (yet again) not to be. But I did run into a very attractive Sympetrum species at several locations, both at the Love Waterfall and just below Sa Pa along a stream. It was immediately obvious from the lack of clear yellow tones that this was not Sympetrum hypomelas. The face with the "sunglasses" and the hooked appendages also were not in line with either S. hypomelas or S. speciosum. In fact these fitted very well S. eroticum, a species I know from Japan. But that does not have such extensive black markings on the abdomen. Looking into it later, I found that this characteristic fits very well the other subspecies of S. eroticum, S. e. ardens, which has also been recorded from the south of China, for instance from Yunnan and Guangxi, just around the corner, so to speak. Nevertheless, to my knowledge it had not been recorded from Vietnam previously.

The first male Sympetrum eroticum ardens, perched in the little swamp of the Love Waterfall area. Note the hooked appendages and black spots on the abdomen.

A second male at the same area, still younger and thus more yellow on the thorax

The "monkey face" with the distinctive spectacles.

Yet another male, this one caught about 6km from Sa Pa in the direction of Lao Cai along a stream.