Another Sinorogomphus, but not very different

While visiting the mountains along the Laotian border close to Da Nang in the first week of May I caught a Sinorogomphus that looked very similar to S. sachiyoae. But the lateral pattern on S2 was somewhat different and upon close inspection the shape of the tips of the superior appendages was also different, if not a lot. I thought it had to be S. sachiyoae, but after consultation of the literature it turned out to be a species described already in 1969 by Asahina: Sinorogomphus vietnamensis. A nice and interesting addition to my list. In fact I observed the species in Quang Tri, Quang Nam and Thua Thien - Hue Provinces.

Male Sinorogomphus vietnamensis. Note the pattern on S2 and the fact that the superior appendages seem to touch the inferiors.

The female is even more like S. sachiyoae.

In dorsal view the appendages are quite similar

But in lateral view the tip of the superior appendage is longer and bends downward towards the epiproct.

An exciting new Chlorogomphus and an old acquaintance

When I met Haruki Karube on May 2 at Mau Son mountain he had just explored streams in the Central Highlands in Da Lat. He was kind enough to show me a specimen of the beautiful Chlorogomphus caloptera, which he described as recently as 2013. A female, and that is a beautiful creature.

Never mind the hand, focus on the wonderful wing pattern of this female Chlorogomphus caloptera.

The same female in lateral view

And her face in frontal view

On May 9 I was in Ha Tinh Province, not quite Da Lat, but the south of the north, if you catch my drift. In the lowlands I visited a stream with Toan when we discovered a female Sinorogomphus. In hand I could identify it as S. sachiyoae. This is another species described by Karube, but much longer ago, in 1995. Although originally thought to be restricted in range, it has now been found from Cao Bang Province all the way south to Ha Tinh Province, making it one of the more wide-spread species.

Sinorogomphus sachiyoae female. Note the characteristic pattern on S1-2. They do not always have such extensive basal patches, although it is not abnormal.

Some Chlorogomphids

It was already quite late in the Chlorogomphid season when we started traveling around northern Vietnam, thus we only recorded 6 species from this family, out of 17 mentioned by Karube (2013) as occurring in Vietnam (we now know that Sinorogomphus hiten also occurs in Vietnam, so there are at least 18 species). As Karube mentions, Pia Oac Nature Reserve in Cao Bang Province is a great place for them, with 7 recorded species. The most common species there seems to be Chlorogomphus piaoacensis. We encountered many of them all over the general Pia Oac area, very common at the end of June, but already far less by the second week of July. At the same streams this species was flying, we also caught two similar species that had not yet been recorded from Pia Oac. The first of these, surprisingly, was Chlorogomphus (Sinorogomphus) tunti. This species is known from western China and central Vietnam. It has highly distinctive appendages, the most important clue in the identification of most species. The second was Chlorogomphus (Sinorogomphus) sachiyoae. This species until recently was only known from Tam Dao, but occurs much more widely. Sebastien for in stance was the first to find it at Xuan Son and I found it also in northern Bac Kan Province and thus also at Pia Oac in Cao Bang Province.
The fourth species I was lucky enough to encounter at Pia Oac was Chlorogomphus takakuwai. This species had already been recorded from Pia Oac and is also known from Tam Dao and Lao Cai Province. I saw only one female, ovipositing under forest cover in a shallow stream. The fifth species I saw during the trip was Chlorogomphus auratus, with one female on mount Mau Son and a possible female in Cao Bang Province. Below some photos. And no, these are not all the same species! The thing fascinating about Chlorogomphid species, especially Sinorogomphids) is that they look very much alike, share the same general habitat and behavior. It is truly a mystery why and how so many different species can co-occur in such proximity.

Male Chlorogomphus (Sinorogomphus) piaoacensis, the commonest species in Pia Oac (but nowhere else?). Note the pattern on S1-2 and the highly distinctive appendages (with the tooth-brush shaped superiors, see below).

Clearly not the same species! Chlorogomphus (Sinorogomphus) tunti, male.

Obviously the same species as directly above, another Chlorogomphus (Sinorogomphus) tunti male.

Chlorogomphus (Sinorogomphus) sachiyoae. Clearly different from the two previous species. Note pattern of S1-2 and lack of apical spot on S7. This one captured in Bac Kan Province.

Another Chlorogomphus (Sinorogomphus) sachiyoae, this one captured in Pia Oac Nature Reserve on same stream as C. piaoacensis and C. tunti.

A very different specimen and not just because it is a female. Chlorogomphus (Petaliorogomphus) takakuwai. Note orange wing bases and distinctive marking on S1-2.

Highly distinctive rounded superior appendages without branches of C. piaoacensis.

And in dorsolateral view, showing distinctive toothbrush shape

And in even more detail

The same for C. sachiyoae. Rounded, but with clear branch at halfway point

Appendages of C. sachiyoae in lateral view, showing distinctive shape of apex.

Dorsal view of the deeply forked superior appendages of C. tunti

The same in lateral view, showing the downward angle in the stem of the superior appendage

Eventful day at Tay Thien, a few more goodies

This weekend (June 15-16) proved pretty productive at Tay Thien. Apart from the species already described, I encountered about 50 more. Here are a few other highlights

The first was this beautify male Polycanthagyna erythromelas. I saw several females flying about, but this male resting for a short while in a nearby bush was a treat.

And in the lower river stretches were several Lamelligomphus formosanus active. Once you know the species, it is not so confusing anymore.

Another species present in good numbers, towards the evening in the open and during the day in dark clearings, was Macromidia rapida. I was lucky with a male that perched nearby.

The female of Sinorogomphus sachiyoae. Very much like the male in appearance. After these shots she happily continued ovipositing.

Another cool female, Heliogomphus scorpio. The male was active nearby as she was ovipositing near the nunnery. Like the male, very pale (white) metepimeron, unlike Heliogomphus sp., which occurred at the same stretch, but is much yellower.

Here a close-up of her pretty face. Note the horn on the occipital ridge.

There was something else I did not expect, Drepanosticta hongkongensis. I noticed a male at 350m asl beyond the nunnery. Under the microscope it is identical to the specimens from Ba Vi. I thought the species there was known only from that location in Vietnam, but when this is D. hongkongensis, well, in that case it is not surprising it occurs elsewhere. Although the caudal appendages are identical, the anterior lobe of the prothorax is all black, as it should be for D. hongkongensis, unlike the specimens from Ba Vi.

The penile organ, identical

As are the caudal appendages

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

Sinorogomphus sachiyoae

18 May I found myself checking the streams around Tay Thien. At the end of the day I saw a slender and large dragon cruising over a stream at about 300m asl. It was not difficult to catch and in hand it was obviously a Sinorogomphus species. Although very similar in outward appearance to other Sinorogomphus species, the typical appendages allowed for identification as S. sachiyoae, a species known from Tam Dao and recently also recorded from Xuan Son by Sebastien.

Like all Chlorogomphids, a very attractive species! Sinorogomphus sachiyoae, male

Note the notch in the tip of the superior appendages. These also have a large lateral tooth, but that is difficult to see in this picture.

In dorsal view the lateral tooth of the superior appendages is visible. Note the deep V in the epiproct.

Sinorogomphus hiten - new for Vietnam

On May 11 in Yen Bai Province I caught two male Chlorogomphus specimens. I kept one and took a few extra photos of the other. Sebastien was of great help in providing me with the article on Sinorogomphus hiten by Sasamoto et al (2011). They described that species for Laos. In the recent overview of all species of Chlorogomphids in Vietnam by Haruki Karube this species is still missing.

A beautiful and slender Sinorogomphus hiten.

Another male of the same species

The appendages in dorsal view

The same in lateral view

And finally in ventral view