Burmagomphus magnus - expected in Vietnam

On June 4 Odonatours visited the area of Cao Bang during its tour of northern Vietnam. On this day James Holden joined us from his 'home' in Cat Tien. Together we checked a large stream not far away from the town. While we were pre-occupied with other Odes, James took a photo of what appeared to be an unknown Burmagomphus. Burmagomphus vermicularis and B. divaricatus both occur in the area, but this was clearly different. After a visit to Pia Oac on the 5th, we went back to the stream on the 6th and were lucky enough to relocate this wonderful gomphid. Upon capture the details of the appendages could be verified and the initial suspicion this might be B. intinctus seemed confirmed.
Burmagomphus intinctus is only known from several specimens collected from Fujian in China, which is truly not exactly around the corner. And indeed, further perusal of literature (thank you, James) showed it to be B. magnus, described in 2015 from Hekou district in Yunnan Province in China, which is just over the border from northern Vietnam. It was therefore to be expected.

The original photo by James Holden. What is that?!

Two days later, probably the same individual in hand.

The strong hook on the posterior hamule

And the rounded epiproct and somewhat sinuous superior appendages

Holden - James Holden... James is back in Cat Tien - Microgomphus chelifer

I learned the other day that James is back in Cat Tien National Park. James already spent quite a bit of time there looking for dragonflies in the recent past and now is looking to add more to the list. A few days back he contacted me on an unidentified small gomphid. I was happy to help out and could identify it as Microgomphus chelifer thelyphonus. This species is known from Thailand, but new to the Vietnamese list. There is another Microgomphus species in Vietnam, M. jurzitzai, described by Haruki Karube, also from the south of Vietnam, but that species has quite different appendages. The epiproct for instance is much more "hooked". Here below a few shots of this interesting discovery.
James was also able to take a nice photo of Burmagomphus asahinai, which I also reproduce here. Let's hope he will discover more goodies in the next few months!

Female Microgomphus chelifer thelyphonus, courtesy of James Holden, at Cat Tien NP, 11 Dec 2015

The male of the same species, in hand, same date and place, courtesy of James Holden

Appendages of the male in dorsal view. What looks like two pins extending from the epiproct are in fact two branches originating from the cerci.

And a nice photo of a species already recorded from Cat Tien by James: male Burmagomphus asahinai, photo taken in 22 August 2015, courtesy of James Holden

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 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. 

Lamelligomphus formosanus and Melligomphus ardens

June 8 I visited Xuan Son National Park with the hope of finding the Idionyx male of the enigma species of the week before. Not a single Idionyx crossed my path. But I was intrigued to see that next to Lamelligomphus camelus, which I already spotted last week, there was another Lamelligomphus sharing the same habitat in the same place. It was about as large as L. camelus and had spots on the labrum, unlike the L. hainanensis of Yen Bai. It had more pronounced raised edges to the apical segments, but no humps. In fact, as can be seen from the shape of the appendages, the apical segment of the penis and the thumb-like projection on the anterior hamulus, this was L. formosanus, a species I already had ran into last year. It is the third Lamelligomphus species I see this year and if we count the enigma species of last autumn, the fourth in total. Like L. camelus, it was quite active in the late afternoon, with several males hovering near the third bridge, but also above the concrete path along the river, where L. camelus was also active.

I left the park with the idea of making it to the river nearby to see if anything would fly there at dusk. I saw quite a few Lamelligomphus specimens hovering in the remaining light and because I wanted to know which one it was, I waded into the fast flowing stream. When I finally caught a few, I had a big surprise, because these were not Lamelligomphus, but Melligomphus. And under the microscope they were clearly Melligomphus ardens. The day was made complete by a fine male Burmagomphus vermicularis.

Lamelligomphus formosanus, male. A dark specimen with second and third lateral stripe fused to form almost completely black metepisternum.

A second male with obvious yellow line on metepisternum separating 2nd and 3rd lateral stripe. Note also the pattern on S2. Very different from L. camelus, rather similar to L. hainanensis.

Distinctive appendages of L. formosanus, without dorsal tooth to basal part of superiors, small teeth ventrally on close to bend and highly divergent and long inferiors. Note also the raised edges of S8-9 and the "near" hump, slightly raised middle of S8.

Same appendages in dorsal view

Another close-up of appendages of L. formosanus

The appendages of L. hainanensis for comparison. Very different tips to inferiors.

Facial pattern of L. formosanus

Rather similar facial pattern of male Melligomphus ardens

The complete insect, male Melligomphus ardens. Note the different shape of especially the superior appendages, but not easy to see in flight. Pattern on S2 very similar to L. camelus.

S8 displays minimal humps, not unlike L. formosanus.

The appendages of M. ardens. Note the light tips to the inferior appendages (this being dorso-lateral view) and large lateral tooth on inner surface of superiors at halfway point.

The same appendages in lateral view.

Finally, the small and lovely Burmagomphus vermicularis, hovering above the stream at dusk.

Burmagomphus vermicularis - verified

Haruki Karube mentions Burmagomphus arboreus and B. divaricatus from Vietnam (Karube, 2014). Do Manh Cuong also described B. schneideri in 2011 as a new species and provides description of B. vermicularis from Northern Vietnam. So we know there are at least several species of this genus in Vietnam. Burmagomphus vermicularis was originally described from "Tonkin" by Martin in 1904. It was apparently not recorded until Cuong found it again in 2011, but last year in July in Ba Be National Park we bumped into many emerging Burmagomphus that we thought might be this species. On May 25 I was searching along a bigger, slower stream close to Xuan Son National Park when I found a Burmagomphus in a spider web, freshly emerged, and decided, now that it was caught anyway, to collect it. In its paper envelop it hardened and came out quite nicely colored. I saw several more along the stream, but only took the present specimen. At home it turned out to be B. vermicularis. Maybe it is not a rare species in Vietnam at all. In Southern China it is widespread.

A small, but neat little gomphid. Male Burmagomphus vermicularis, fresh.

Appendages in dorsal view

In dorso-lateral view, showing characteristic notch in upper appendage

In lateral view

Burmagomphus vermicularis - I presume

When in July checking some of the streams in Ba Be National Park that were both not very fast flowing, and with muddy substrate, in open terrain bordered by forested hills, I regularly flushed freshly emerged smallish gomphids with quite interesting markings, like the oblique lines on the dorsum of the synthorax. Although I did not see any mature individuals, clearly this was a Burmagomphus species. Only two Burmagomphus species have been recorded from Vietnam, of which one and is the widespread Burmagomphus vermicularis, known from Southern China, Hainan, Taiwan, Laos and Vietnam. This species inhabits muddy streams in agricultural areas bordered by forested hills. (The other is recently described B. schneideri from southern Vietnam.) Now, it is of course possible that other species of this genus share the preference for this habitat and it is not impossible that more of the at least 24 known species occur in Vietnam, so until I catch a male the identification remains tentative, but it is likely that what I encountered is in fact this rather common species.

Freshly emerged female Burmagomphus vermicularis, presumably

The same individual, at a slightly different angle