Rainy day in Huu Lien

Saturday July 24 I ventured to Huu Lien. Like Sebastien's visit last week in Xuan Son, to turned into a major wash out. After a good start in the forest or what is left of it, thunder sounded and the heavens opened. I found large parts of the reserve inundated anyway, presumably the result of the typhoon passing last week. As usual, a visit to Huu Lien gave mixed emotions. There is a lot to see, but on the way there I was met by dozens of motorbikes carrying logs and passing unnoticed by the entry gate. Clearly these are not people from inside the reserve using the forest. And the trail to the waterfall, described by Cuong as in largely pristine forest, is now open in several parts, where trees have been cut and right there turned into coal in shallow pits. It is really sad. Several people where busy producing coal while I was there and of course this continues day after day. Somehow nobody does anything about it.

Nevertheless the forest was full of Atrocalopteryx atrocyana, a fabulous damsel. I had not seen it yet this year, but now there were a great many fluttering about. Not easy to get good pictures, as they are both shy and because there is a need for flash in the dark surroundings where they were lurking. As distance varies, so does the lighting.

Female Atrocalopteryx atrocyana. If the forest disappears near the stream, it will be a severe blow for this species.

Male of the same species. The flash brings out the beautiful blue wings. Note also the long spikes on all legs.

Another male

Another great find was a male Rhinocypha of the drusilla group. It is different in detail from the species inhabiting Xuan Son. Last year I saw only a few and could only take pictures of one. This is the first for this year. In Xuan Son I have not seen its sibling species yet.

Note the extensive pattern of red on S9-10, but also extensive red on the remainder of the abdomen, but restricted to the dorsum of S2.

Another speciality that was present in good numbers is the small Coeliccia that also occurs in Cuc Phuong. I hope it description and name will be published soon.

Coeliccia sp, the female

And the male. A pretty species for sure, a lot smaller than most.

And lastly, I ran into a bundle of ovipositing Prodasineura croconota. Interesting I hope are the shots of the female.

Hovering in the dark, not easy, hence not in focus

The female of Prodasineura croconota

And the male, better known

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.

A new species of Anisopleura

There are currently 10 species of Anisopleura known. Recently Zhang & Hamalainen (2014) described a new species from Yunnan (A. pelecyphora), but A. lieftincki was shown to be a junior synonym of A. subplatystyla. Some species are very similar to others. A. yunnanensis is closely related to A. subplatystyla. That species occurs in northern Thailand and Zhang 7 Hamalainen hypothesize that it may also occur in northern Vietnam. However, for now we assume that it is A. yunnanensis that occurs in northern Vietnam. The commonest of Anisopleura in Vietnam appears to be A. qingyuanensis. During the road trip around northern Vietnamese provinces end of June and beginning of July I saw it in Lang Son, Yen Bai and Cao Bang provinces. I did not see A. yunnanensis, which until now I have only seen in Yen Bai. But in Cao bang Province in early July I ran into an Anisopleura that had the general pattern of A. qingyuanensis, but rather different coloration. In hand the appendages were clearly different, more close to A. yunnanensis. It was neither of these two species, the only two known from Vietnam, so I contacted Matti Hamalainen to ask him to please help me out. Matti pointed out that no known species has the combination of characters of my specimen. It is a new species to science and a beautiful one at that, even amongst Anisopleura species.

Anisopleura sp. novum, note the blueish antehumeral and yellow flanks, truly striking

Close-up of dorsum of thorax

Another in hand shot of this stunning insect

Caliphaea confusa and Caliphaea thailandica

In spring of this year I saw both Caliphaea confusa and C. thailandica in Yen Bai. Now during my road trip around the northern provinces I saw both species again. They were still very similar to each other, but completely different from the spring specimens I saw. Now both species had turned into really spectacular copper-red insects that would in the darker recesses of forest streams (thailandica) or more in the open (confusa) act out their territorial disputes. These males with their red bodies and whitish abdominal tips are beautiful to behold indeed. I saw many C. thailandica in Pia Oac Nature Reserve, where they were common along small streams under forest cover. C. confusa on the other hand I saw in Sa Pa at forest edge where they were active in the bright sun. Clearly both species have a long flight period, from early May to July at least.

Female Caliphaea confusa, by association with males

Caliphaea thailandica male in Pia Oac 

Caliphaea confusa male in Sa Pa

Finally, Gynacantha saltatrix

I was for quite a while under the impression that the Gynacantha that I saw repeatedly last year at Huu Lien (apart from G. subinterrupta, which also occurs there) was G. saltatrix. Partly that was because it had been reported from Huu Lien before and I was influenced by the anticipation of seeing it there. However, Wen Chi-Yeh alerted me to the fact that the appendages did not fit that species properly. He also pointed me in the right direction, namely G. japonica. So, I was still waiting to see G. saltatrix. I finally ran into it on June 24 in northern Bac Kan Province, where several started hunting over a stream at dusk. I failed miserably in taking a proper photo of the male, so I went back on July 7 and 8 and on the 8th caught another male, for some proper pictures. This species has almost straight paraprocts and a longer epiproct relatively than G. japonica. In color pattern they are not dissimilar.

Female Gynacantha saltatrix

Male Gynacantha saltatrix, not dissimilar from G. japonica, but that species has less pronounced abdominal pattern

Appendages of male in dorsal view, with epiproct almost half of length of cerci

The same in ventral view. Note how straight the cerci are

And in lateral view

Male frons in dorsal view, with clear T mark

The same for female

Ovipositor in lateral view

Megalestes micans and Megalestes haui

*Adjusted 21 January 2020. Megalestes distans records all refer to M. haui. All entries have been adjusted.

Until now I have seen only two species of Megalestes in northern Vietnam. In April Megalestes micans at Sa Pa and M. haui at Ba Vi National Park. The trip around northern Vietnam brought some new records. Megalestes haui proved common along some streams in Pia Oac Nature Reserve, occurring sometimes in quite high densities, with 20 or so on a 150 m stretch of stream. Megalestes micans was still common and easily found in the Sa Pa region in early July. The one off was a male Megalestes haui at Sa Pa, occurring right by Megalestes micans. Apart from the differences in the appendages, they can also be told apart by the pattern of the prothorax. Megalestes micans has a yellow central line from the anterior lobe right to the posterior lobe. This can easily be seen with binoculars. It is necessary to check the appendages of M. haui carefully because of the possibility of M. distans, but I have not had the pleasure of being able to verify that species yet.

Male Megalestes haui, with dark prothorax (and of course different appendages)

Male Megalestes micans, showing the yellow line over the prothorax

Another, showing the same characteristic

And a third, for whoever was not convinced yet

Ophiogomphus, Lamelligomphus and Melligomphus

Ophiogomphus longihamulus was described by Karube (2014) from Pia Oac Nature Reserve and I spent a great deal of time looking eagerly for it. Eventually, on July 8, I finally ran into an Ophiogomphus. But it was not to be. It was Ophiogomphus sinicus. In itself a great discovery, and especially interesting because it shares the same habitat and general area with O. longihamulus. That species was observed in May, so maybe O. sinicus appears later. The two species, by the way, can be separated on the basis of, indeed, the length of the hamulus.

Ophiogomphus sinicus, Cao Bang Province, July 8

In hand, the same male

And close-up of the appendages

 Two species of Lamelligomphus were also very common. I saw Lamelligomphus camelus in the provinces Phu Tho, Hoa Binh, Bac Kan, Ha Giang, Yen Bai, Lang Son and Cao Bang. Lamelligomphus hainanensis was much less common. I saw that species in Yen Bai on mountain streams and likewise in Pia Oac Nature Reserve in Cao Bang Province. It is smaller than either L. camelus or L. formosanus and has smooth dorsum to S7-10. Whereas L. camelus is active during the day and at dusk, L. hainanensis seems to be active only during the day.

An obelisking male Lamelligomphus camelus, a common species

Much less common, male Lamelligomphus hainanensis

Another male, right in the act of spraying some liquid from its abdomen. He did this several times. I have no idea what this behavior is.

Lamelligomphus hainanensis, male, in hand. Pattern on S1-2 close to L. formosanus, without the boomerang of L. camelus.

Female Lamelligomphus hainanensis hovering over a stream and preparing to drop egg-ball

A female in hand

Close-up of the female face, showing the double horn on the occipital ridge

 The last species of this posting is Melligomphus ardens. This species too is active at dusk. In fact, although I have saw it during the day at a river in Bac Kan Province, almost all observations this year (at Phu Tho, Cao Bang, and Bac Kan Provinces) were at dusk. At the places where I saw it at dusk, I did not see any during the day.

Melligomphus ardens, male, 26 June, the only male seen in bright day light

Nihonogomphus - more widespread

To my not small amazement I caught a male Nihonogomphus schorri in Bac Kan Province on June 21. This species was described from Huu Lien, where it co-occurs with Nihonogomphus thomassoni. In early spring it was also very much in evidence in Xuan Son National Park. To my knowledge, Bac Kan is the third province in which this species is verified. Clearly the species has a distribution in northern Vietnam much larger than just Huu Lien in Lang Son Province.

Male Nihonogomphus schorri from Bac Kan Province

Some proof, appendages in dorsal view

In lateral view

In ventral view

And the distinctive shape of the lobe

 The other Vietnamese Nihonogomphus species was also very much present in northern Bac Kan Province. I am still not sure whether this taxon is Nihonogomphus lieftincki or N. thomassoni. In communication with various scholars the question has been raised whether these two species are really distinct. But for now let's go with the fact that N. thomassoni is the taxon said to occur in Vietnam. There was something peculiar about the really large number of specimens I saw in northern Bac Kan Province. Although I had seen this species in at midday in Huu Lien and on other streams in Lang Son Province, I think I saw it only once in Bac Kan during the day. One stream where it was very common I visited during the day half a dozen times, not to see any. But in the last 30 minutes or so before darkness it would appear in good numbers, with at least one every 25 meters or so and often several in close proximity, flying rapidly just above the surface chasing each other, or sitting on low hanging branches and shrubs over the water. They would still be there when it was almost too dark to see them. This seems at variance with their behavior in Lang Son, although I have not spent a lot of time there at dusk. Nevertheless, very peculiar. I also caught a female. Please compare to the female of the Nihonogomphus entry from Xuan Son. The lateral pattern on S3 is different.

Nihonogomphus thomassoni, female, Bac Kan Province

A very green male perched in almost complete darkness, but photographed with flash

Another male Nihonogomphus thomassoni in hand