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!

Sunday, 19 February 2017

Chlorogomphus aritai - another of those magnificent species

Early May last year I was driving along route 14 through Thua Thien - Hue Province, close to the Laotian border. From the corner of my right eye I noticed a large butterfly floating above some bushes by the roadside. But no, a dragonfly! There is very little traffic on route 14 at this point, so I confidently slammed on the brakes and jumped out the car. A magnificent large Chlorogomphid was cruising nearby with colored wings. I was able to catch it and take some in hand shots, before putting it on a bush for some posed photos. Soon after she (it was female) flew off into the nearby forest. What a truly magnificent specimen. I was under the impression it was Chlorogomphus caloptera, but it turned out it was Chlorogomphus aritai, a species described in 2013 by Haruki Karube on the basis of specimens from Bach Ma National Park. Bach Ma centers on mountains close to the sea near Da Nang, but in fact that is not at all far from where I found it, as Vietnam is very narrow at this point. Although the female of C. aritai is superficially similar to the female of C. caloptera, they are not that closely related within the genus. Haruki places C. aritai in the subgenus Nubatamachlorus with C. nakamurai, another species with a female possessing colorful wings, although not nearly as striking as in C. aritai. These species are sought after by insect collectors, and as they are all scarce and under pressure of many negative environmental impacts, this is highly regrettable. I was happy to see her unharmed and hope I will encounter her offspring this year.

Fantastic Chlorogomphus aritai female, posed

The same female in hand before release

Saturday, 18 February 2017

Calicnemia akahara - New to science!

Yesterday was a happy day with the publication of an article on Zootaxa by Phan, Karube and myself on the Calicnemia of Vietnam. It introduced a new species that is in outward appearance very similar to C. miles, but it misses the black abdomen tip of that species. It also has a very different genital ligula, placing it in group 1 (thin flagella), not in group 2 (as C. miles). So, if you are unsure, get out your magnifying glass! Luckily the abdomen tip is a great help and C. miles is restricted to northern Vietnam, with C. akahara, for that is what the new species is called, occurs in central Vietnam. Here are some photos from various encounters with the species last year, between late April and early August.

Calicnemia akahara, male, from Quang Binh Province. Note the completely red abdomen. 
Calicnemia akahara in copula, the female similar to C. miles, but withers dark dorsum to S8-10, but otherwise mostly orangy brown abdomen. This pair from Quang Tri Province.

An aged male in early August from Bach Ma National Park

Sunday, 5 February 2017

Okay, one more: Onychargia priydak

Now that I am at it, let's add this one species also to the blog: Onychargia priydak. This is another species that had just been described by Oleg Kosterin in 2015 from Cambodia. It is similar to Onychargia atrocyana, and the females are indistinguishable, but its caudal appendages are somewhat different. A big difference however is that the males develop beautiful whitish pruinosity. That at least makes them easy to recognize! I was able to get a quick photo before the male disappeared. During subsequent searches I found many immatures and females, but none as nice as this specimen.

Again, this species was found close to Bao Loc. A new species for Vietnam, but not unexpected, given the proximity to the Cambodian border.

Beautiful male Onychargia priydak, with pruinose prothorax, synthorax, femora and S1-2.

A third Aethriamantha species - A. gracilis

Last year I encountered Aethriamantha gracilis in three different provinces in central Vietnam. The first encounter was with several males in a large pool in fields adjacent to a river in Quang Nam Province in early May. The initial enthusiasm, because I considered this a new finding for Vietnam, was dampened a little when already a few weeks later I found it near Bao Loc in some peaty ditches, where it was still present in June. And in September I found it at yet another very different location, at a pond in the forest near K'bang in Gia Lai Province. Clearly this is not a rare species, maybe overlooked because of its similarity to several of the Brachydiplax species? But let's face it, it is a little gem and worth paying attention to.

Male Aethriamantha gracilis, Bao Loc, Lam Dong, June 2016

Another male

Well, they all pretty much look the same, another male.

Euthygomphus schorri - also in Vietnam

Oleg Kosterin published a paper last year in which he tackled some of the problems surrounding the genus Anisogomphus and the genus Merogomphus. Part of the solution was to erect a new genus, Euthygomphus. In the process he also described a new species: Euthygomphus schorri. Now, in the spring of 2016 I had caught some gomphids near Bao Loc in Lam Dong Province that for the moment I considered Merogomphus parvus. Their true identity now became immediately apparent. This too is Euthygomphus schorri. Not surprising really. The location where I caught them abounds in species that have recently been described for Cambodia just across the border, but are new for the Vietnamese Odonate fauna. In this case the shape of the caudal appendages and vesicle spermalis are the give away characters to identify the species, as Euthygomphus species are otherwise confusingly similar in outward appearance. A check in hand or close-up photo is necessary to clinch the ID. The caudal appendages are curved outward in dorsal view and have a distinct upward apical tooth.
This is the third Euthygomphus species found in Vietnam. The others are E. koxingai and E. yunnanensis (formerly thought to be E. parvus).

I refer to Oleg's paper "Reconsideration of the genera Merogomphus Martin, 1904, and Anisogomphus Selys, 1857, including erection of a new genus, with a new species and discussion of addition specimens from Cambodia" in Zootaxa 4171(1):51-76 for the details concerning the identification of these species.

Male Euthygomphus schorri, near Bao Loc, Lam Dong Province, 12 June 2016

Same male at slightly different angle