Wednesday, 21 June 2017

Two new Stylogomphus species for science and for Vietnam

Today my paper on two new Stylogomphus species was published in Tombo. And with it two species I had found last year have received a name. The first I found along the Ho Chi Minh Highway just south of Phong Nha - Ke Bang National Park in May 2016 (and again this year) and also a little north of Khe Sanh. The other, a tiny species, I found perched in bright sunlight on a rock in a stream near Bao Loc in Lam Dong Province. Stylogomphus species are notoriously similar in their outward appearance, but have obviously different caudal appendages. That means that it is virtually impossible to separate them by observation or even photos, much like Leptogomphus species. Here are photos of both species.

Stylogomphus delicatus, a species with long and deeply cleft inferiors

Stylogomphus annamensis, a species with short and rounded inferiors

Saturday, 17 June 2017

Macrogomphus matsukii in Cat Tien

James Holden had been reporting Macrogomphus matsukii from Cat Tien NP for a while and I decided to pay him a visit to get to see it in May. Last year I had seen Macrogomphus hovering over a large river at dusk (a habit shared by many gomphids, and certainly M. guilinensis) in Quang Binh Province, but had failed to ascertain beyond reasonable doubt that it was this species. Photos by James from last year had us initially count whether it was M. borikhanensis or M. matsukii, because the lateral pattern on the thorax had only two clear stripes. Facial pattern is very much like M. matsukii though. There seems to be some doubt whether these two species may in fact be conspecific anyway. Just before I went to Cat Tien the rains picked up and the riverbed filled up quickly, so that circumstances had changes considerably when I got there on May 12. Indeed, we saw none, but on the 13th the waters had receded a little and the circumstances the species seems to favor (small trickles over the rocks by the side of the main stream) were restored. And towards dusk: there they were. 3 males hovering over the streams, for a short period joined by a Orientogomphus naninus. That distracted us and therefore I failed to get the stunning pictures I was hoping for. The different individuals had some variability in the extent of the middle lateral stripe, which was absent or represented by a small mark at the dorsal end. Otherwise they seemed perfect for M. matsukii.
This species was described from Thailand and reported also from Lao (IUCN website) and Cambodia (Kosterin, pers. comm.). Not surprising then it also turns up in Vietnam. Here is the best photo.

Male Macrogomphus matsukii, hovering at dusk over stream

Thursday, 15 June 2017

At long last another Lestes

Considering my world Odonata list, Lestes is one of the genera with the most recorded species and that is not surprising, giving the number of described species and the fact they occur around the globe. But irrespective of that, there are not that many species around in Vietnam, apparently. Only three I had been able to find. Lestes praemorsus is the common species, found from the very north to the very south, and Lestes elatus from the southern half of Vietnam. Lastly, I recorded pretty Lestes nodalis from Huu Lien Nature Reserve, to the north of Hanoi. And that was it. Until on May 12 this year I stopped by the road in Lam Dong province, to the northwest of Bao Loc, to check a grassy inundated area in the afternoon. I noticed many Lestes praemorsus, but it dawned on me that some appeared to be larger than others and these all had a reduced pale abdomen tip. This could not be a coincidence. I took photos and collected a few. In the evening I became disappointed. It seemed the appendages were the same, so maybe just variants? But when I returned home several days later and was able to check them under the microscope, it became clear there were in fact differences. Most striking were the differences between the inferior appendages of the species, in addition to the aforementioned differences in coloration. Two species appeared to have this combination of characters, Lestes dorothea Fraser, 1924 and Lestes praecellens Lieftinck, 1937. The former is quite large, a little larger according to the description than mine, which fit better the species described by Lieftinck from Java in size. However, the female I photographed has much more extensive thoracic markings than that species, in line with what is to be expected of L. dorothea. That species is recorded from India, Thailand and Malaysia. Based on the structural characteristics and patterning of the male and patterning of the female I think it is safe to conclude this is L. dorothea as well.
By the way, based on the likeness of the appendages of L. praecellens and L. dorothea one may ask whether these are truly different species. There thoracic markings are also rather similar, if it weren't for the female.

Lester dorothea male. Note the lack of pruinosity on S9.

Male and female of L. dorothea

The female, showing the extensive dark markings on the thorax, unlike L. praemorsus

Another male showing the limited pruinosity on the abdomen tip

A Lestes praemorsus male for comparison. Smaller and with pruinosity on S9.

Sunday, 23 April 2017

Not a Bao Loc specialty - Heliogomphus chaoi

Karate (2004) described Heliogomphus chaoi from Bao Loc in Lam Dong Province in the south of Vietnam. This species is very similar in appearance to Heliogomphus selysi, a species occurring in for instance Thailand. H. chaoi differs especially in the shape of the vulvar scales of the female and the lack of prominent spines on the occipital ridge. In stead it has two small horns behind the lateral ocelli. Karube also notes that the superior appendages have a venture-lateral projection at the midpoint, to separate the male from H. selysi. Indeed, Asahina did not mention this for H. selysi, but I would love to see the holotype to verify this.

Anyway, last year I found this species to be common near Bao Loc at the type locality in early June. But a few days later I bumped into another small Heliogomphus in Gia Lai Province. Outward it was a little different in coloration. Notably, the superior appendages were more extensively white and S7 had a distinct anterior pale yellow ring. With differences between Heliogomphus species often slight, I thought it might be a different species, but checking it under the microscope I cannot but conclude the appendages and vesica spermalis are identical. If so, the slightly different coloration is likely nothing but a geographical variation. I concluded that the Gia Lai specimen is also H. chaoi. That species is therefore much more widespread than previously thought.

Heliogomphus chaoi in Bao Loc. Note it only has on S7 a pale yellow line along the dorsal carina and a lateral basal spot.
Another male at the same location
And the appendages in dorsal view
Heliogomphus chaoi at Gia Lai. Note the small yellow dorsal spot on S8 and the large anterior yellow ring on S7. But structurally it is not different.
The appendages in dorsal view, the white more extensive


Sunday, 16 April 2017

Macrogomphus kerri - wonderful addition to the Vietnamese list*

*adjusted: it also occurs in Cambodia (thank you Oleg).

According to the IUCN website, Macrogomphus kerri may be an endemic to Thailand, where it is widespread, but uncommon. Well, sorry for the Thai, but it is not an endemic after all. 18 June 2016 I visited Gia Lai Province in the Central Highlands of Vietnam. A wonderful small, muddy stream in logged primary forest was a real treasure trove, with 6 species of Macromia flying at the same location, and many other goodies. This large and strikingly beautiful Macrogomphus species, easily recognizable by its bold patterning, was one of those. Not at all rare, I saw quite a few, including ovipositing females. Males tended to sit on or under bushes over the stream. Here are a few photos.

Beautiful male Macrogomphus kerri, perched
Another male, hovering over the stream in a dark place, hence the flash
Male in hand
And the rather similar female



Saturday, 15 April 2017

Amphicnemis gracilis - little critters on Phu Quoc

Last year August I went to Phu Quoc Island to find a few species I had not yet seen there, but that had been recorded from the island. One of these was Amphicnemis gracilis. It turns out it is really localized and frequents swampy forest with lots of ferns. It was not at all easy going, but once I knew how to find them, I saw plenty. They are inconspicuous, sometimes hanging from tips of leaves, but also sitting on twigs and other stuff on the muddy ground. The immature females are pretty, with their red thorax. When maturing they become bluish green. The males are shiny metallic green, with intricate white and very vulnerable appendages. All males had a recurved spike on the prothorax that had not been described for this species, but the caudal appendages are in line with what you would expect of A. gracilis. The genus is, according to Rory Dow, extremely difficult, so I decided to just accept the spike as a local peculiarity. This is the only place in Vietnam where it is known to occur.

A male Amphicnemis gracilis. They hang out in the dark, so it is all flash work.

Another male
And yet another
These fleshy things are the caudal appendages
And here you can see the recurved spike from the posterior lobe of the prothorax
The really pretty immature female

And this is what she looks like all grown-up and ready for action. You might think it is a different species, but no.


Monday, 10 April 2017

Orthetrum internum headaches

Last Thursday I was in Sa Pa and as usual this time of the year Orthetrum internum was already out in good numbers. Wen-Chi Yeh had responded to my posting of the species in 2014, but I had overlooked the significance of his comment. Basically he said that my photos looked different from what he was used to for O. internum. I had noticed that lack of pruinosity on the  dorsal side of the thorax, but in my posting mentioned this as one of the characteristics of O. internum. How wrong can you be?

Yesterday I visited Pia Oac in Cao Bang and ran into O. internum is several places. This in itself is strange, because I had never seen it there before. But even more strange was the fact that they were clearly pruinose and much more black-and-yellow. These were true O. internum! But if so, then what is the species in Sa Pa?

Structurally the two are identical. I am not sure if there are structural differences visible to us between O. internum and O. japonicum. These two were considered subspecies of O. japonicum in the past, until DNA sequencing made it clear they were in fact separate species. So, the lack of structural differences does not necessarily mean that the Sa Pa species is O. internum, nor does it support the other option, of course. But in coloration it is very different. The labium and labrum are pale orange, not black. The frons lacks black edges dorsally. The venter is not nearly as black, with the hamulus pale brown with only the tooth darker brown, but it is black-and-white in O. internum. And the thorax ground colour is black or dark brown in O. internum, with clear yellow on the prothorax (especially posterior lobe). In the Sa Pa species the ground colour if brown with pale markings, and there is no yellow on the prothorax, just pale areas. And most interestingly, there never is any pruinosity on the dorsum of the thorax!

From Sa Pa, note orange labium and labrum, brown color of thorax, no pruinosity, pale thoracic markings. Photo taken in 2014
Last Thursday. Note some characteristics. 
But this is a very black O. internum. Note also black labium and labrum, black on top of frons, pruinosity on the thorax, from Pia Oac
In dorsal view
A slightly less black male from Pia Oac. Note also the clarity and extent of the yellow markings on the thorax.
Note the yellow posterior lobe of the prothorax.



Friday, 7 April 2017

Lyriothemis kameliyae published in Zootaxa

Yesterday Lyriothemis kameliyae was published in Zootaxa. This is not at all a difficult species to recognize once you realize that it is actually different from L. bivittata. Problem is that all Lyriothemis species flying around in southeast Asia with a double yellow lateral marking on the otherwise brown thorax and with a red abdomen, plus dark streaks at the wing bases, had been lumped together under L. bivittata. In fact, there are at least several species involved. L. kameliyae occurs together with L. bivittata in northern Vietnam. Xin Yu already wrote to me he had collected L. kameliyae in China. Undoubtedly it is quite widespread. As beautiful as it is, it remained anonymous, until now!
Male L. bivittata (top) and male L. kameliyae (bottom). Spot the differences!

Sunday, 2 April 2017

April 2 - Huu Lien and first gomphids

April 2 was a nice spring day to look for the first gomphids of the season in Huu Lien Nature Reserve. As always, the first impression was of clearance progressing, but like last year end of March, Trigomphus kompieri was about at various locations. The first I bumped into was a female, but like last year, I could not catch it and did not get a picture! Trigomphus is genus of early gomphids. Paragomphus may actually be year round, although rare in the winter, I think they may be around. Anyway, there was a male about too, interacting with the Trigomphus. I also saw quite a few Paracercion melanotum and fully mature Gynacantha subinterrupta. Below a few photos.

The first male Trigomphus kompieri of the day, a little difficult to get a clear shot.
And the third. Somewhat easier. The second eluded the camera.

Paragomphus capricornis against a muddy stream background.

Paracercion melanotum male

And Gynacantha subinterrupta showing well

Monday, 27 March 2017

Coeliccia mientrung - a splendid new species

Today a new species of Coeliccia was published: Coeliccia mientrung. This is a species that looks quite a bit like Coeliccia pyriformis, but it differs actually in quite a few details of its coloration. The yellow on the abdomen tip is restricted in comparison, the antehumerals are much shorter, the eyes are colored differently, to name a few. Of course, the genital ligula is somewhat different too, and the shape of the superior appendages are also different. This may sound like a lot, but in fact many it is still rather similar. In Phong Nha - Ke Bang the two species occur side by side. To the north apparently only C. pyriformis occurs and to the south C. mientrung. For details and additional information, please see the Zootaxa article.

Female of Coeliccia mientrung.

The male of C. mientrung, with three-colored eyes, short antehumerals and reduced yellow on the abdomen tip.

Its look-alike, C. pyriformis. Note the blue eyes of the mal, the banana-shaped antehumerals and the large yellow abdomen tip.


Thursday, 2 March 2017

The world of Protosticta revisited

To my dismay I noticed that I had not yet published here on the blog 4 species of Protosticta found in the course of last year. To be more precise, one had been published by Jan van Tol in 2008, P. linnaei. Another had been known for a while, but was considered a dark form of P. satoi. It was published last year, by me, as P. nigra. A third species I found in a small touristic area with wet forest near Bao Loc. This was P. proboscis. And lastly I ran into yet another new species, that occurred side by side with P. satoi in Xuan Son National Park: P. albifrons, also described last year. All this just goes to show that you really need to give these little critters a close look. For let's be honest, they do look alike a lot. It is really in many cases only possible to tell them apart by a close look at their tiny caudal appendages. See below for photos of all species, but if you are interested in their diagnostic features, please read up on them in Phan & Kompier, 2016 and Kompier, 2016.

Female of P. albifrons. Note the large white spot on S9, the thin black metapleural line and the pattern on the prothorax.

The male of P. albifrons. Similar thin black line and prothorax pattern. The true and straightforward feature is of course the shape of the caudal appendages, but that is impossible to see here.

The male of P. linnaei. Note the pattern of the prothorax. Again, the appendages would be the give-away feature, but you need a microscope.

The handsome female P. linnaei. Note the lack of a white spot on S9.

Now, this handsome devil is more easy to identify, thanks to the black thorax. This is P. nigra.

Yes, and this fellow is again rather similar to the previous ones, before P. nigra. It is P. proboscis, its name coined after the drooping central lobe at the apex of the appendages. Anyone that can identify it from a distance is a true connoisseur. 

Tuesday, 28 February 2017

Just around the corner - Lao PDR

On February 21 I had to go to Luang Prabang in Lao PDR for a meeting. In between reading papers for the meeting I popped into the woods close to the hotel. It was smack in the dry season, but I managed to find two species that I had not seen before, not in Vietnam and not anywhere else. The first was pretty Coeliccia dydima. This species might be confused with the similar C. cyanomelas. C. dydima is a common species in Thailand and Lao PDR, but has not been found yet in Vietnam. And maybe that is because it does not occur there. But I will keep on looking. It was nice to get some experience with it in neighboring Lao. I saw at least 10.
The other species was Aciagrion pallidum. This species  has been reported also from Vietnam, although I have not been able to find it yet, so likely it is localized and/or rare in there. It appears to be a dry season species, when it hides in dry forest and waits for the rains. The rufous abdomen is a good character. I saw only the one male.
Lastly, I also saw few Coeliccia poungyi poungyi, always a nice species to bump into. Here are a few record shots.

Here is the male of Coeliccia dydima. Note the limited extent of the blue on the abdomen tip and the large anterior dorsal markings on the thorax (in comparison to C. cyanomelas)

Here is the female. The pattern on S9 is a good feature.

And an immature male (note the color of the eyes). It is very yellow, not blue, and the dorsal markings on the form a pair of somewhat C. mingxiensis like spots, not yet separated into two sets of two (meaning 4 separated spots in total). 

How about this? Beautiful, but inconspicuous, male Aciagrion pallidum.

Finally, Coeliccia poungyi poungyi, a female. Note the solid yellow abdomen tip.

And the exquisite male!