Some interesting gomphids from Quang Nam

On 25-27 September I visited Quang Nam Province around P'rao on the HCM Highway. I ran into quite a few interesting gomphids and I would like to share here some of them. Price for most interesting on the 25th goes to a Leptogomphus species. Recently I had a conversation with Haruki Karube on Leptogomphus uenoi, for which he recently published the male. Before that the species was only known for females and one could argue that the male leads a secretive life. But we concluded that maybe it was just overlooked, as the appendages are rather similar to those of L. perforatus. Well, I caught a Leptogomphus and in hand concluded it was probably L. perforatus, but somehow the ring of the inferior appendages seemed closed and I decided to collect it. Lucky too, for at home it dawned on me this was L. uenoi! The outer edge of the inferiors is straight, but the inside edge curved.

Leptogomphus uenoi male, a typical Leptogomphus species

But look at the appendages! A neat ring and almost straight outer edges.

 On the 26th I bumped into a multitude of interesting species. I was very happy to see quite a few Nepogomphus walli. Males were congregating in a fern at a particular stretch of the stream. I had so far only seen this species in Cao Bang Province.

Nepogomphus walli in hand, with its typical yellowish wollen base of the superiors

One of the males perched, this one not on a fern

Also interesting was the Lamelligomphus sp. that I had seen in spring much further north, in Nghe An Province. It was quite common here.

Lamelligomphus sp., a smallish species with interestingly very dark S2. Some individuals had a small yellow spot posterior of the auricle. It is similar to L. hainanensis, but has no protrusion of the inferiors.

A real surprise was the Nychogomphus flavicaudus on a larger river, where 3 males were hovering in the middle of the day. There were no differences with the specimens from Cao Bang I recorded in spring. Same size and same pattern on the thorax (only an antehumeral spot).

Male Nychogomphus flavicaudus, at least, if flavicaudus is a valid species

The last cool species I want to introduce here is Burmagomphus divaricatus. I had only recorded a freshly emerged specimen in Cao Bang in spring, but here I saw several adult males.

Here is one of the males in hand. The pattern on the dorsal side of the thorax is a little variable.

Another, similar, male perched

And the appendages in dorsal view

Two additional Leptogomphus species

On May 16 I caught a female Leptogomphus in the Tu Le area in Yen Bai Province. On close inspection of the occipital ridge it revealed to smaller lateral horns, protruding backwards, and two central horns bend forward. I was a little baffled and consulted Haruki Karube, who was quick to point out that this was indeed Leptogomphus uenoi, described by Asahina in 1996 and of which the IUCN website says there is doubt it is a valid species, as it was based on a single female. Karube has put that straight, by describing both the male and female this year. The male looks surprisingly like L. perforatus, so it is easy to overlook it, even in the hand. But the female is, at least in hand, distinctive enough. I was happy to find it, of course. It may be widespread, as is indicated by the original specimen being from Sa Pa, the specimens of Karube being from Bach Ma National Park, and my own being from Yen Bai.

On June 17 I caught another female for close inspection on Pia Oac Mountain in Cao Bang Province. This female has two very prominent central horns on the occipital ridge that are both pointing forward and have very thick bases, that touch one another. It misses the backward pointing lateral spikes. I have not been able to match this female with any known species. It may well belong to an as yet undescribed species. Anybody any ideas?

Leptogomphus uenoi, female. Yes, it is a Leptogomphus and yes, other than that it is difficult to tell what species unless you check the occipital ridge.

But if we do so, we see this. 4 horns, to pointing towards the back and to pointed forward in true bull fashion, typical of L. uenoi.

Here at another angle, showing the bull horns

So what it this? It looks exactly the same as the L. uenoi female, although in fact the larger horns are already visible here in lateral view. It is Leptogomphus species incertae.

This is what they look like in frontal view: two thick-set adjoining horns

And here at a different angle you can again see their thick shape, not spike-like, as in many other species, but a water-drop shape. Leptogomphus species incertae.

Two interesting female gomphids from the Nam Bung area.

Saturday July 11 I caught a small female gomphid near Nam Bung. I had never seen it before and studying it in hand revealed a very neat "horn" on the occipital ridge. Now, female gomphids very often have horns on their heads, but the shape of this one, like the tail of a diving whale ("fluking") is extra-ordinary. This pointed me to the genus Sinogomphus. This is, at least for me, really exciting. Last year in early May I had caught Sinogomphus leptocercus in the same general area, but thereafter the species remained elusive, in spite of several searches. I have no description of the female of this species, so I have to exercise some caution here. Nevertheless it is not very likely at all that there is another Sinogomphus species in the area (there are no Sinogomphus species known from Vietnam). So this should be the female of S. leptocercus!

Another female I caught is Leptogomphus divaricatus. This is not at all a rare species, being probably the commonest species in the north of the genus after L. perforatus. But I have not often seen the female and failed so far to take pictures of its distinctive divaricate horns. Glad to put that right!

First the female of Leptogomphus divaricatus, typical as Leptogomphids go.

But they can often be told apart by the horns on the occipital ridge. L. divaricatus has two that bend outward in opposite directions.

But look at this! Is this remarkable or what? Female Sinogomphus leptocercus. As if mommy bound her baby's hair together into a little palm tree.

Dorsal pattern fits several Sinogomphus species and of course also S. leptocercus.

The whole specimen in lateral view. The lateral pattern of the thorax is a little different from the male (see that entry), but otherwise patterning is similar.

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.

Ba Vi National Park has more to offer

This morning we wandered around Red River Island looking for river breeding gomphids, but we did not find any. Thereafter I drove to Ba Vi to try my luck there. We still have the Drepanosticta enigma to solve. Checking the streams I ran into two new species for my list. Sinorogomphus nasutus is a species I really wanted to see and I am happy I succeeded. Thank you Sebastien for pointing the way! The other species was a Leptogomphus. Haruki Karube showed me the manuscript of his upcoming article for Tombo on Gomphids from Vietnam. In it is also Leptogomphus elegans, which allowed us to identify a Leptogomphid enigma. Sebastien had photos of the appendages of a Leptogomphid that he could not identify, but now we can. I really did not expect to see that same species at Ba Vi. A happy occasion!

Sinorogomphus nasutus, male

Face of male S. nasutus

Lateral view of the appendages of S. nasutus

Dorsal view, normally inferiors would be visible, but S10 bent downwards

Photos in the field failed, so a scan of Leptogomphus elegans, male

The same reason, the same male

Appendages in dorsal view

In lateral view

In ventral view

And the apparatus of S2

Three species of Leptogomphus at Tam Dao

The weekend of 17 and 18 May I spent at Tam Dao. At the lower river stretches around Tay Thien I encountered many Leptogomphus. I already mentioned L. perforatus and a second species, L. divaricatus (now identified thanks to Haruki Karube). Cuong mentions also Leptogomphus gestroi from Tam Dao. And Sebastien has photos of yet another Leptogomphus, likely L. elegans. So, I take care with any Leptogompids I come across. They all look very similar superficially and should be looked at in hand. I thus caught yet another Leptogomphus and saw very different lower appendages. It allowed for easy identification as another species: Leptogomphus tamdaoensis, soon to be published by Haruki Karube (thank you for your comments, Karube-san!).

Here are the three different species. It is immediately clear that these are all rather similar. L. divaricatus is at the top. This is a slightly larger species. L. perforatus is on the left whereas L. tamdaoensis is at the right bottom.

A very sad turn of events was that this nice insect got its jaws entangled in the net and was sadly decapitated. The pattern on the thorax is basically identical to that of L. perforatus.

The difference between these species is thus in the appendages and the apparatus of S2. I already once showed those of L. perforatus and L. divaricatus, but I add them here (of different specimens) once more. They are consistent in their differences. But let's start with Leptogomphus sp. novum.

Very distinctive shape of Leptogomphus tamdaoensis

Compare the stubby boot shape of L. perforatus

And the nicely rounded sock shape of L. divaricatus. Note that this specimen is slightly disfigured, with the left lower appendage bent.

The hamules, with the anterior very long and the posterior not hooked in lateral view, of Leptogomphus tamdaoensis

Those of L. perforatus

And those of L. divaricatus

Three more Gomphids from Yen Bai

Gomphids - I love them! So, when I spent last weekend in Yen Bai, I was a happy man, seeing 6 new species. In fact, one I had seen before, but this is the first time I had an adult in my hands. It is a species of which Sebastien already told me that it was quite common. I have seen it freshly emerged at low altitude in Tam Dao and here it was again higher up in Yen Bai Province. It is a Leptogomphus that looks very closely like L. perforatus, but has inferior appendages smoothly rounded. The hamules are also quite differently shaped, especially the anterior one.

The other two species, well…The first I saw about 6 of. It is an easy species to recognize, or so I thought, and it appears in quite open areas on wet rocky and muddy places, where is sits on the ground, on rocks or on leaves. It was a Heliogomphus and I did identify it as H. scorpio, but subsequently I caught several H. scorpio in Tam Dao and clearly it is a different species. I will come back to this in another posting (this part of text edited May 18). And I saw one interesting gomphid with slender white superior appendages that I subsequently identified as Sinogomphus leptocercus. This is quite a shock, as to my knowledge it is only known from Xizang, Tibet, although close to the Yunnan border. And admittedly the thorax pattern is darker. On the other hand, within Sinogomphus, this species is strange because of the thin and long superior appendages and broad inferiors. Moreover, the penile organ is also a close match. If not this species, than it is something very closely related but as yet undescribed. Unless, of course, someone has a better suggestion.

Sinogomphus leptocercus, male

The penile organ. Compare the drawings in Chao (1990)

The weird appendages in dorsal view

In ventral view

And finally in lateral view

Leptogomphus sp., as far as we have been able to check, undescribed but common.

The appendages in dorsal view, note the smoothly rounded shape

The same in ventral view

The hamules in lateral view, compare with those of L. perforatus below

Hamules of Leptogomphus perforatus for comparison

And finally male Heliogomphus sp.

Perched on a leaf, an easily recognizable species (May 18 edited: not at all that easy, this is not scorpio after all)

The appendages in dorsal view, see also posting on H. scorpio and differences