Anisogomphus maacki - new for Vietnam

June 18 I noticed a rocky stream next to the road that runs just north of Pia Oac and connects Cao Bang to Ha Giang. I decided to climb down to it and give it a go. After a short while surveying I noticed a gomphid perched on the rocks in the stream that first reminded me of Stylurus, because of the wide expansion of S8-9 and the markings on it. But in hand I noticed the typical Anisogomphus spines on the femora. A bit at a loss I checked Chao and found out that it was just that. Anisogomphus maacki, a species that years ago I had also seen in Japan.

This is noteworthy, its occurrence in Vietnam, because its occurrence in the south of China, although reported, has been questioned. The species has a wide distribution, ranging from Nepal to Japan, but generally is believed to be a more northern type of gomphid.

That is why it was an even larger surprise that I ran into it again on June 23 just below Sa Pa in Lao Cai. Which means that it cannot be that rare and must be rather widespread. Here too I found it at a rocky stream in relatively open terrain. At least 7 males were present.

There are several Anisogomphus species in Vietnam. Besides the relatively uncommon Anisogomphus koxingai that also includes Anisogomphus tamdaoensis, which was placed in the wrong, but closely related genus Merogomphus originally, but now placed in Anisogomphus. In fact, it would not surprise me if it would turn out to be a junior synonym of Anisogomphus pinratani from Thailand. The two species are very similar, to say the least. Anisogomphus tamdaoensis is a widespread and common species. And then there is the Anisogomphus sp. novum that I first saw at Pia Oac. As a matter of fact I saw a female at the same place as where I first saw Anisogomphus maacki. That location is actually not that far from where I saw this unknown species first (about 40-50km).

Male Anisogomphus maacki, with widely expanded S7-9 and big yellow markings, although quite reduced on S9.

Another shot of the same individual from Cao Bang

Close-up of the thorax and head of a different specimen

S7-10 and appendages in dorsal view. This specimen even less yellow on S9

Face of the same second specimen from Cao Bang

One of the males from Lao Cai. Note the large spines on the distal part of the femur of the last pair of legs.

S7-10 and appendages in dorsal view, this specimen clearly with more yellow on S9

Scan of the Lao Cai specimen

A new Anisogomphus species?*

*May 20, 2016, this species was published as Anisogomphus neptunus Karube & Kompier, 2016

August 31 I visited Pia Oac and on the way there along the TL212 already caught a male
Anisogomphus tamdaoensis. I had caught a female of A. tamdaoensis at Pia Oac already late June and was happy to confirm a male about 7 km from the reserve. It was a little smaller than other males I have caught at Ba Vi and Tam Dao, but the appendages are identical. We can now safely assume this species to have a wide range in northern Vietnam.

However, when I visited the "illegal gold miners stream" in the reserve, where I had caught several and saw many Anisogomphus sp. in June and July, it was cloudy and nothing happened, apart from one Macromia moorei. So I went to the pass and, as we know from earlier posts, caught Anotogaster klossi. Then I decided to give the stream another go, now that the weather was a little better. When waiting there a gomphid of medium size dropped from the sky. It seemed to be another A. tamdaoensis, but flew off chasing an insect before I could get to it. A little later a similar, if not the same, gomphid perched on some leaves. I wanted to make sure, so caught it and before checking the appendages already had a thrill. It had a large yellow dorsal spot on S7, something absent in A. tamdaoensis, but something the females of June/July had all displayed. Indeed, this was an Anisogomphus species! So, likely the male of my mystery species.

I could find 20 species of Anisogomphus in the literature (including A. tamdaoensis). None fit the present species, although I have not been able to find the description of A. jinggangshanus Liu, 1991. The appendages are somewhat similar to A. anderi Lieftinck, 1948, but obviously different. For the moment it looks like this is a new and rather distinctive species!

Anisogomphus sp. novum (Anisogomphus neptunus). The indicator for the genus are the large spines on the femur

Note the large yellow spot on S7. The weird appendages are already visible.

In dorsal view. The superiors seem fused into a plate with three distinct parts.

The superiors have a large process that seems fused with the process of the other , so the appearance is created of a third central process.

Lateral view

And ventral view

This is the A. tamdaoensis, nice to verify the male. Compare general structure and spines on femur.

A. tamdaoensis in dorsal view. Typical appendages (although shared with A. chaoi and A. pinratani) and only narrow line on dorsal carina on S7.

Anisogomphus tamdaoensis - range expansion

Anisogomphus tamdaoensis was described by Karube (as Merogomphus tamdaoensis) from Tam Dao in 2001. We have found it since in Hoa Binh province and in Cao Bang Province. Today (August 16) I caught two females on Mt Mau Son in Lang Son Province. Clearly this species occurs over a wide range in Vietnam. Although these are females, I find no differences with several other females of A. tamdaoensis in my possession.

Both females, the older one on top, scanned under a kitchen plate, explaining the patterns around them.

The younger of the two, identical to the specimens of A. tamdaoensis, although some have yellowish wing bases.

A more aged female, the other found today

Merogomphus, Anisogomphus and Euthygomphus* **

*Updated on June 1, 2016 after publication of Anisogomphus neptunus
**Updates on December 15, 2016 after publication of the genus Euthygomphus Kosterin, 2016


There is one species of Merogomphus known from Vietnam. Merogomphus pavici is a large species, with distinctive appendages and markings. Euthygomphus parvus is a small southern species recorded from southern Vietnam that formerly was also included in Merogomphus. Then there is Anisogomphus tamdaoensis, described from Tam Dao, but at least also present at Ba Vi NP and in Hoa Binh Province and also originally included in Merogomphus.

During our travels at the end of June and beginning of July we observed Merogomphus pavici in Phu Tho Province (Xuan Son NP), in northern Bac Kan Province and in southern Cao Bang Province. This comes as no surprise, it is a widespread species.

Merogomphus pavici, male, from Bac Kan Province. Long legs indeed.

Another species we encountered was Anisogomphus tamdaoensis. A male was observed in Hoa Binh Province at Cuu Thac - Tu Son and what is very likely the female of this species was caught freshly emerged in Pia Oac Nature Reserve. It is safe to conclude that this species is much more widely spread than the rather restricted range of Tam Dao and Ba Vi.

Male Anisogomphus tamdaoensis from Hoa Binh Province, June 27

And its distinctive appendages in dorsal view

Female of presumably Anisogomphus tamdaoensis from Pia Oac, June 23.

However, now things get a little more complicated. In northern Bac Kan Province (and on June 28 also in Lang Son Province) we encountered several smallish male gomphids that at first glance seemed Euthygomphus parvus. Even at a second glance they did. It was only at a much later stage (today) that I realized they were in fact something else, namely Euthygomphus koxingai, a species known from southern China of which its occurrence in northern Vietnam is not at all surprising. It is uncannily close in outward appearance to E. parvus, which has a different penile organ. Also, in that species the antehumeral stripes are confluent with the collar. The appendages appear identical (see for instance the entry on E. parvus in the blog of Dennis Farrell). In his table of Anisogomphus Zhao (1990) uses the all black labrum of A. koxingai to distinguish it from other species, but as Wilson has pointed out, mainland China A. koxingai has in fact transverse yellow marks on the labrum (at the time of publication of their articles this species was still included in Anisogomphus).

Euthygomphus koxingai, male, late June Bac Kan Province

Another male Euthygomphus koxingai in the field

Appendages in dorsal view

In lateral view

And in ventral view

And finally, in Pia Oac I observed many Anisogomphus females that came to drop balls of eggs, almost always at the very same location and sometimes several females at the same time. They all came to a little sandy shallow area right under a rock, would drop eggs, fly up to perch on a nearby fern and produce another egg-ball to fly down and dip it and so on. These all shared extensive yellow both dorsally and laterally on the abdomen. They also had rather long vulvar lamina. I noticed photos on the web of seemingly identical female Anisogomphus from Thailand. Wilson (2005) mentions an Anisogomphus sp female from Guangxi that may also be closely related. For now, I can only treat this as Anisogomphus sp, unless anyone recognizes the species or until we can find a male. Strangely, although at least 20 females came to oviposit over the days I was in Pia Oac, no male was ever seen.

Female Anisogomphus neptunus in hand, Pia Oac Nature Reserve, early July

Another female preparing egg ball, this time not on a fern, but perched on a rock.

Close-up of abdomen, showing the extensive amount of yellow, both dorsally and laterally

Close-up of vulvar lamina

Anisogomphus tamdaoensis

Karube described a new species of Merogomphus from Tam Dao in 2001. Specimens were collected between May and early August. Subsequently the species was also found at Ba Vi. See also the blog entry on the blog of Sebastien Delonglee. Recently it was transferred to Anisogomphus. I was lucky enough to see a male on August 11 and a female on August 18, the male near Tam Dao Resort and the female along the stream at Tay Thien, also in Tam Dao National Park. The male and female both are reminiscent of the Leptogomphus species that are around (at least Leptogomphus perforatus, but seemingly more than one species is involved) and quite common, but the dorsal stripes are touching the collar, whereas in the Leptogomphus species they are not attached. Also, of course the male appendages are different and the appendages of the female or blackish, whereas they are whitish in the female Leptogomphus species. Also, the labrum of A. tamdaoensis is black, but it has two yellow spots in L. perforatus. Lastly, A. tamdaoensis has yellowish suffusion on the bases to the wings.

Anisogomphus tamdaoensis, male, eluding capture

The female, not so clever