Xuan Son in late October

*This posting was updated on November 15, 2025. Please refer to Kompier et al. (2021) for more information: The genus Planaeschna McLachlan, 1895 and its subgroupings in Vietnam, with descriptions of three new species (Odonata: Aeshnidae). Also, the genus Planaeschna has been synonymized with Aeschnophlebia. I have added the current names between square marks [] below for clarity.

With apologies for the lack of postings in recent months. I have been busy writing papers.

Saturday October 21 I decided to go to Xuan Son. I have had little time recently, but now is the time the Planaeschna [Aeschnophlebia] fly there. In fact this was the only weekend available to go, so although the weather was not very promising, I went anyway. For three years I have been catching a small pale-faced Planaescha female, but never a male. I was getting a little desperate, as this was the last chance I had.

The weather was a little better than expected and quite soon I caught another female. Then several hours nothing, but fly by's of the large Planaeschna spec. nov. female and of female P. guentherpetersi [Aeschnophlebia ishigakiana guentherpetersi]. I did in the meantime tun into something unexpected: a male Coeliccia chromothorax. The 8th species of this genus along this 1.5 km stream. No idea how it got there. It is a striking species and I had never seen it on a large number of previous visits. Strange.

I also found a female Cryptophaea vietnamensis. In itself that is not strange, but it was covered in algae. I remember a discussion on this on the Facebook page on neotropical dragonflies. I do not remember ever having seen it in Vietnam, but apparently it does happen here too.

And then I caught a male "large" Planaeschna spec. nov. [described now as Aeschnophlebia tsuchi] and shortly after a much smaller one: the pale-faced male [In fact not the male of the pale-faced females, but Aeschnophlebia cucphuongensis]! I now have the males of all four species of Planaeschna occurring on this particular stream, 3 of them new to science.

Female Cryptophaea vietnamensis. Note the algae on the wings and abdominal tip!

Male Coeliccia chromothorax. Exciting find!

And there it is: Male pale-faced Planaeschna spec. nov. at last! [Aeschnophlebia cucphuongensis]

Appendages very different from P. [ishigakiana] guentherpetersi

And its pale face

So does Planaeschna guentherpetersi occur in Huu Lien or not?

*Updated on November 15, 2025. The genus Planaeschna has been synonymized with Aeschnophlebia. Moreover, Kompier et al. (2021) addresses the specific identity of the Planaeschna species known from Vietnam. Below the proper names of species are inserted between square brackets []. This species is described as Planaeschna [Aeschnophlebia] sp. 2 in Kompier et al. (2021) and occurs in both Huu Lien and Xuan Son.

On December 1, 2014, I caught a female Planaeschna [Aeschnophlebia] in Huu Lien that seemed to be a P. [ishigakiana] guentherpetersi, complete with the typical dorsal and lateral pattern on S2. Please see the concerned post. The facial pattern however was much more vivid than anything I have ever seen in Xuan Son, where the species is quite common. So, when I discussed with Haruki Karube a little while back we decided that it was not likely these two were in fact the same species. But I had no material from Huu Lien for comparison (I may have released the specimen at the time, or it was eaten by vermin, anyway, I do not have it), so it was/is undetermined. I had a single specimen last year that flew off. Finally yesterday I noticed an Aeshnid in the dark of the forest flying about. It hung from a twig, but I could not get to it, so decided to make some pictures with flash. These made it clear is was a male, and that it was a Planaeschna for sure. It also has the same dorsal pattern as the female on S2. Interestingly, the pattern on the remainder of the abdomen and on the lateral side of S2 is the same as in P. guentherpetersi. The shape of the appendages, insofar as can be judged from the pictures is not at variance with that of P. guentherpetersi either. Although the fact remains that the female has quite a more pronounced facial pattern, it seems for the time better to assume this is a local variant than enough grounds to claim this is a different species. But of course, I will try to catch it at the next occasion. It would be great to sample the populations for DNA.

The enlightened photo of the Huu Lien specimen, showing the typical dorsal pattern of S2 and remainder of the abdominal pattern. Compare with the below scan of the Xuan Son male.

The Xuan Son male. Planaeschna species have a lot of variation in the pattern of S2 or the abdomen, so for these specimens to very similar is likely too much of a coincidence. [In fact the species shown here in the photo is Aeschnophlebia ishigakiana guentherpetersi and is a sister species.]

The Huu Lien male at a different angle, showing the intense green and black thorax pattern and the lateral pattern of S2, with the yellow auricle and two spots on the distal edge.  This is very much the same pattern as can be seen in the scan below.

See the pattern of S2 on this male from Xuan Son. No other species in Vietnam, out of the other 9 or so I have found, has a similar pattern, but the specimen from Huu Lien has it. See also the heel on the ventral side of the superior appendages, visible in both the scan and the photo. For what it is worth, of course.

The real female Planaeschna tomokunii

*This post was updated on November 15, 2025. The genus Planaeschna has been synonymized with Aeschnophlebia and Kompier et al. treated the Planaeschna [Aeschnophlebia] species of Vietnam in detail. Proper names have been updated below between square brackets []. As pointed out in Kompier et al. (2021) A. tamdaoensis and A. gressitti are likely both junior synonyms of A. suichangensis (Zhou & Wei, 1980).

On September 24 I went to Tam Dao to look for Planaeschna [Aeschnophlebia] tamdaoensis and P. tomokunii. The first I wanted to catch to see if it is truly different from P. gressitti, and the other to verify what I had concluded was P. tomokunii from Pia Oac and Yen Bai. The day started dismally. It was misty and the road to Tam Dao 2 was blocked. So I went to the stairway to the antenna above Tam Dao. This is the location where Cuong had caught the species before and I was hoping that I might see it at a small stream in the forest there. Previously I had not been lucky, but this time, after some staking out, I noticed a female searching for a place to oviposit. I could not reach her, but several other specimens made an appearance and eventually I could net one. This is a remarkably robust species at 71mm body length. And even if I could not find a male, this female as enough to show that the drawings and description of Cuong are very accurate. It also made clear that this species is certainly not identical to what occurs at Pia Oac and at Yen Bai. It is of course still possible that the males are variants of the same species, but I for sure had no similar females yet. Whatever the females from Yen Bai and Pia Oac (at least two different species) are, they are not P. tomokunii. I hope that soon I will have time to try for the male again.

Planaeschna [Aeschnophlebia] tomokunii, remarkably robust and with relatively dark abdomen.

Its face is not as bland pale brown as in most. The labrum is distinctly pale and there are clear  brown flecks on the postclypeus.

The pattern on S2 is very interesting. The dorsal line is indeed interrupted, and the distal mark is quite narrow

Yet another Aeshnid hunt at Xuan Son

*Post updated on November 15, 2025. The genus Planaeschna has been synonymized with Aeschnophlebia. Also, Kompier et al. (2021) treated the Planaeschna [Aeschnophlebia] species of Vietnam in detail. Names are adjusted below between square brackets [].

On November 29 I drove again to Xuan Son with the objective of finding Planaeschna [Aeschnophlebia] species. It was a brilliant sunny day, possibly the last of the year, so maybe the last chance to find additional males. In a way I was lucky. There were Planaeschnas all over the place. However, they were all females. Over a dozen Planaeschna [ishigakiana] guentherpetersi were around and one of the similar, but different, Planaeschna sp., also a female. I hoped hard for a male, but although I saw a male fly by in a hurry, there was no chance to catch any.

Two other Aeshnids were around. I saw literally hundreds of Boyeria karubei at dusk and a few during the day and I saw a male Gynacantha japonica hanging in a bush. Below a few photos.

One of the several females Planaeschna [sihigakiana] guentherpetersi that I caught. A record shot. Note the typical pattern on S2.

Another female discovered perched. Note the typical pattern in the dorsum of S2 and the yellow wing bases. 

The female Planaeschna sp., different in for instance the pattern on S2 and the much shorter cerci. [This species, described as Planaeschna sp. 1 in Kompier et al. (2021), likely is Aeschnophlebia owadai.]

Facial pattern of Planaeschna sp.

Hanging male Gynacantha japonica. Note the small, light-colored epiproct.

One of the many Boyeria karubei around

Two new species for Xuan Son

*Post updated 15 November 2025. The genus Planaeschna has been synonymized with Aeschnophlebia. Also, Kompier et al. (2021) treated the Vietnamese Planaeschna [Aeschnophlebia] species in detail. Names below are adjusted accordingly between square brackets [].

23 November I drove to Xuan Son, yet again, in search of Planaeschna [Aeschnophlebia] species. Sadly, the weather was not as good as hoped. It only become clear from 4 PM, way too late. But I did see some Planaeschna [ishigakiana] guentherpetersi and I also bumped into two species I had not seen at Xuan Son before. The first was Gynacantha japonica. I had seen that at Huu Lien, until now the only location in Vietnam, but evidently it is more widespread. I saw 3 flying around over a dried out muddy pond and was able to catch one. At the same location I had seen G. subinterrupta before, so it was a bit of a surprise to now catch a different species here. The other new species for the reserve was Anisopleura qingyuanensis. Not only a rather late observation, this was also interesting, because these are conspicuous insects and I have by now visited the area and the concerned stream so many times, it is truly a surprise to see it.

Very nice male Gynacantha japonica

And also very nice, male Anisopleura qingyuanensis. In fact more yellow than it looks in this picture.

The appendages in dorsal view

A fourth Planaeschna species from Xuan Son

*Post updated November 15, 2025. The genus Planaeschna has been synonymized with Aeschnophlebia. Also, Kompier et al. (2021) described the known Vietnamese Planaeschna [Aeschnophlebia] species in detail. Names are adjusted in square brackets [] below.

Sunday October 26 was highly productive for Planaeschnids, with 4 species observed at Xuan Son National Park. This is rather exceptional for me, but I love them. Haomiao Zhang in personal comments stated that this highly speciose genus has at least 50 species with many in southern China. It comes as no surprise that the same goes for northern Vietnam. Indeed, we are only starting to scratch the surface. Partly this is because visiting scholars have been focussing on spring and early summer, whereas many Aeshnids fly in autumn.

After I caught the first "not gressitti" (see earlier posts) [this species is A. celia] I saw another patrolling a square meter of open water on a stream inside the forest. I was able to catch it and although it looked similar, it also clearly was much larger. In fact the "non-gressitti" was 65mm total body length, but this specimen was 75mm. Of course, in detail it is also rather different. For now I need to treat it as yet another species incertae.

Planaeschna species novum / species incertae, male. Note the straight appendages (see below). [This species is described in Kompier et al. as Planaeschna [Aeschnophlebia] tsuchi]. 

The four males caught. Left P. guentherpetersi [= A. ishigakiana guentherpetersi], middle row P. "not gressitti" [= A. celia] and right the present larger species. Note also the variation in the pattern of S2, with 6 marks in the larger species, 5 in P. guentherpetersi and 4 in "not gressitti"

Appendages in dorsal view, robust, straight

But also suddenly expanded in dorso-lateral view

Robust and straight in lateral view

Penile distal segment in ventral view, Angular in outline and with moderate earlobes

In lateral view, earlobes visible

Facial pattern in brown, not black

Two pale-faced Planaeschna species from Xuan Son

* Post updated November 15, 2025. The genus Planaeschna has been synonymized with Aeschnophlebia. Also, Kompier et al. (2021) treated the Vietnamese Planaeschna [Aeschnophlebia] species in detail. Adjustments are made below between square brackets [].

October 26 I was working the streams of Xuan Son. This is the place where P. guentherpetersi [= A. ishigakiana guentherpetersi] was described from. I ran into it last year and again this Sunday I bumped into several. Females were flying about and ovipositing in the trees over the water, sometimes at several meters height. But I also noticed them ovipositing on logs floating on the water. Although I saw several, I was only able to catch one female and take pictures of another. Only late in the day, not far from dusk, did I finally catch a male. I also caught another rather similar female, but somewhat smaller, with different ovipositor and different pattern on S2. This somewhat smaller species is different from P. guentherpetersi, but I have as yet not been able to find what it then might be.

Another female Planaeschna guentherpetersi. Note again the characteristic pattern on S2.

Facial pattern of female P. guentherpetersi, largely orange-yellow, but darker anteclypeus.

The male of Planaeschna guentherpetersi.

In dorsal view, the same male. Note the 5-spot mark on the dorsum of S2.

Facial pattern of male P. guentherpetersi, similar to female, but antefrons much darker brownish black towards dorsal half.

       

Appendages in lateral view of P. guentherpetersi, clear uplift

And in dorsal view. Epiproct looks shorter than it really is through angle (distorted in death)

Penile final segment in ventral view. Not rounded and no "earlobes", very different from the "gressitti" types

  

In lateral view,  no earlobes

The other pale faced Planaeschna female caught hunting over the stream. Note the very different pattern on S2 and the lack of pale markings between the two greenish yellow lateral stripes. [This species is treated as Planaeschna sp. 1 in Kompier et al. and is Aeschnophlebia owadai.]

The face of Planaeschna species incertae, with pale anteclypeus.

The two females in dorsal view. Planaeschna species incertae on top and P. guentherpetersi below.  Apart from the smaller size and reduced amber bases to the wings of the species incertae, note also the very different pattern of S2.

The same in lateral view. Note the different lateral marking on S2 and the different relative length of the paraprocts.

Which becomes obvious here. Much longer and differently shaped paraprocts. Also, the ventral projection of S10 is less pronounced. Female P. guentherpetersi

The same for Planaeschna species incertae. Shorter paraprocts and more pronounced ventral keel. Clearly this is a different species.

Planaeschna - just when it started to make sense

*This post was updated November 15, 2025. The genus Planaeschna has been synonymized with Aeschnophlebia. Also, Kompier et al. (2021) treated the Vietnamese species of this genus in detail. Below adjustments are made between square brackets []. As became apparent later and is detailed in Kompier et al. (2021), A. gressitti, A. tamdaoensis and A. suichangensis are likely all synonyms. The species from Xuan Song is A. celia, a species previously known only from Hainan.

Planaeshnids are beautiful, generally slender and brightly patterned Aeshnids. They are also notoriously difficult to separate. What is more, some characteristics are difficult to ascertain. As I tried to point out, drawings of the penile organs depend on the state of the specimen. That is not to say the shape is of no meaning. Far from it. There are also subtle differences in markings between similar species. Then there are small differences in the appendages, but it seems that many species have largely similar appendages. Thus a combination of minor differences may point the way to specific identification. Then there are many species and maybe many more awaiting description, but also there may well be several names that are synonyms referring to the same species. It does not help that many species are described based on just one of a few types and rarely recorded. Good photographs are generally lacking and with the slight differences in patterning and shape the quality of drawings is of great influence. And thus with 4 species bagged this Sunday in Xuan Son I knew there would be no end to my troubles. Today I will start with the easy species. Planaeschna gressitti [= Aeschnophlebia gressitti. Kompier et al. points out that A. gressitti and A. tamdaoensis are both likely synonyms of A. suichangensis]. After Sebastien found it this spring on Mau Son in Lang Son Province I have also found it at Pia Oac. There are hardly any differences between specimens of the two locations. I already noted that it is somewhat worrying that very similar P. tamdaoensis was recorded from the same altitude somewhere in between these locations. Going back to the literature I found that P. suichangensis was in fact also extremely similar. Wilson (2005) points out that differences between P. tamdaoensis and P. suichangensis are slight and that the former may be a junior synonym of the latter. Problem is that although Wilson gives good drawings of both the dorsal view and patterning of the abdomen and lateral of the first few segments, this is not so in Asahina (1996) or Karube (2002). This somewhat complicates comparison. Now, the patterning on S1-3 is a close match especially with P. suichangensis as depicted in Wilson. The pale line on the dorsum of S3 or the dorsal patterning of S1-2 and the lateral patterning on these same segments is identical. The dorsal or ventral view of the appendages is somewhat paddle shaped, clearly broadened in the apical half. This is also a good match, but this is the same for P. tamdaoensis or P. gressitti. The angle of the superior appendages in lateral view is the largest difference between these species, with P. gressitti being the straightest and P. tamdaoensis the most sinuous. The facial patterning of all these species is depicted as characterized by an all black antefrons.
Now, the specimens from Pia Oac and Mau Son are similar in these respects, but also characterized by a clear yellow lower border to the antefrons. The sides are also yellow and this moves up high towards the apex. They share the pale line of the dorsum of S3, have slim lines almost touching centrally on S2 forming a cross, and paddle shaped appendages. In these respects they are very similar, but they differ from the drawings of all three species concerned in the yellow lower border to the antefrons.
Now let's consider the very similar species of Xuan Son, a location much lower (450m asl). My first impression was that this too is M. gressitti (if that is what the others are). But they do not have a lower yellow margin to the black antefrons. Also, the labrum is bordered by an even blacker anteclypeus and has not only black borders, but the yellow is split in the center into two distinct yellow spots. The yellow on the sides of the antefrons also does not extend as far towards the apex. The appendages are not as paddle shaped at all. And the pattern on S1-3 is different too. The cross on S1-2 is more robust, but also more separated, and S3 misses the dorsal line. It is possible that these are regional differences and little is known about the variation, either geographically or within populations, but the two males I caught at Xuan Son are highly similar to each other and so where the different specimens of Pia Oac and Mau Son, but of course not to those from Xuan Son. [In fact these specimens are a different species, Aeschnophlebia celia, see Kompier et al. (2021).]

Male Planaeschna with black and yellow face from Xuan Son No. 1

Male No. 2

Male No. 1 face. As you can see the yellow area on the labrum is heavily bordered black and split in the middle by a black line. The anteclypeus is very dark blackish brown and the antefrons has no lower yellow border and the yellow sides do not extend towards the antennae. See the posts on P. gressitti for the facial view of the species.

Male No. 2 face, very similar, but even dark on anteclypeus

Dorsal view of specimen from Mau Son. Note the dorsal line on S3 and the cross on S2.

Dorsal view of specimen from Pia Oac. Very similar

Dorsal view of No. 1 male from Xuan Son, note lack of dorsal line and robust but open cross on S2

Dorsal view of No. 2 male, very similar

The appendages of the Mau Son specimen in dorsal view

The same in lateral view

No. 1 from Xuan Son, undulating and not as paddle shaped

In lateral view one smooth broad curve, not sinuous

No. 2 male exactly the same differences

Indeed, smooth broad curve of male No. 2

Although extremely similar in patterning, it is clear from the shape of the appendages and the facial pattern that this is most likely a different species. But the undulating outline of the appendages in dorsal view is different from P. tamdaoensis, P. gressitti and P. suichangensis. So what is it?