An updated list for my three visits to Phu Quoc in 2015 and 2016

During my stay in Vietnam I was able to visit Phu Quoc island, located off the coast of Cambodia to the west of the Vietnamese Mekong delta, several times. It has a very interesting Odonate fauna compared to the rest of Vietnam, with several rare species, not seen elsewhere in Vietnam. I visited the island from 28 December 2015 to 2 January 2016, again from April 12 and April 15, 2016 and finally from August 19 to 21, 2016. Some species are very local and also occur only in the dry or in the rainy season, so not everything can be seen in any one trip. I already published a list after my first trip. This list is updated here to include all records, to which I added the months in which species were recorded by me in Roman capitals. But first a few photos of good species not published here previously.

Neurothemis intermedia male, 19 August 2016 

A second Neurothemis intermedia male from August 19, 2016

A target species I had been looking for on all my trips, which had been recorded by Bui (2008). Apparently this rare species is a summer species on the island. I only saw a single female, Lyriothemis mortoni.

The fascinating Platylestes platystylus, also on the island of Phu Quoc., August 20, 2016

Immature male of Brachydiplax sobrina, August 20 

And nearby an immature female, much harder to find generally

Monstrous Epophthalmia vittigera, a wonderful male, caught on August 21, 2016

A lovely Ceriagrion calamineum, previously recorded from the island, but misidentified as C. aurantiacum in Bui (2008). Finally found on 21 August 2016.

Agrionoptera insignis male over a dark pool, August 19, 2016. The only specimen I saw on my three visits.

The List:

Lestes praemorsus* VIII

Platylestes platystylus* VIII

Vestalis gracilis I, IV, VIII, XII

Libellago hyalina I, IV, VIII, XII

Heliocypha biforata I, IV, VIII, XII

Euphaea cyanopogon**** I, IV, VIII, XII

Rhinagrion viridatum XII, VIII

Podolestes coomansi***** IV

Aciagrion borneense I, XII

Agriocnemis minima* IV, VIII, XII

A. nana* IV, VIII, XII

A. pygmaea I, VIII, XII

Amphicnemis valentini**** VIII

Archibasis viola I, IV, VIII, XII

Ceriagrion calamineum** VIII

C. cerinorubellum IV, VIII, XII

C. malaisei* VIII

C. olivaceum* I, IV, XII

Ischnura senegalensis I, IV, XII

Mortonagrion falcatum*** I

Onychargia atrocyana IV, VIII

Paracercion calamorum* IV, VIII

Pseudagrion australasiae* IV, VIII, XII

P. microcephalum I, IV, XII

P. rubriceps IV, XII

P. pruinosum I

P. williamsoni I, IV, VIII, XII

Coeliccia kazukoae** I, IV

Coeliccia yamasakii IV

Pseudocopera ciliata* IV, VIII, XII

Copera vittata** I, IV, VIII, XII

Prodasineura verticalis** I, IV, VIII, XII

Anax guttatus I, VIII, XII

Gynacantha basiguttata* I, VIII

G. bayadera* I

G. subinterrupta* I

Heliaeschna crassa*** IV

Ictinigomphus decoratus meleanops I, IV, VIII

Paragomphus capricornis* XII

Epophthalmia frontalis* I

E. vittigera* VIII

Acisoma panorpoides IV, VIII, XII

Agrionoptera insignis* VIII

Brachydiplax chalybea* IV, VIII, XII

B. sobrina* IV, VIII

Brachygonia oculata IV, VIII

Brachythemis contaminata I, VIII, XII

Cratilla lineata IV

Crocothemis servilia I

Diplacodes nebulosa I, IV, VIII, XII

D. trivialis I, IV, XII

Hydrobasileus croceus I, VIII

Indothemis limbata*** I, VIII

Lathrecista asiatica I, IV, VIII

Lyriothemis mortoni VIII

Nannophya pygmaea IV, VIII, XII

Neurothemis fluctuans I, IV, VIII, XII

N. tullia IV, XII

N. fulvia IV, VIII, XII

N. intermedia* IV, VIII, XII

Orchithemis pulcherrima IV, VIII

Orthetrum sabina I, IV, VIII, XII

O. pruinosum* XII

O. chrysis I, IV, VIII, XII

Pantala flavescens I, VIII, XII

Potamarcha congener I, IV, VIII, XII

Pseudothemis jorina** I

Rhodothemis rufa* IV, VIII, XII

Rhyothemis aterrima* IV

R. obsolescens IV, VIII

R. phyllis I, IV, VIII, XII

R. variegata I, IV, XII

R. triangularis IV, VIII

Tetrathemis irregularis IV, XII

Tholymis tillarga I, IV, VIII, XII

Tramea transmarina euryale* I, VIII, XII

Trithemis festiva IV, XII

T. aurora I, IV, VIII, XII

T. pallidinervis I, IV, VIII

Urothemis signata I, IV, VIII

Zygonyx iris I, VIII

Zyxomma petiolatum* IV, VIII, XII

*       Refers to species first recorded on the island, although some are very common

**     Coeliccia kazukoae had already been found by Floris Brekelmans, but is not rare. Prodasineura verticalis had been recorded as Prodasineura sp. Copera vittata had been misidentified previously (as C. marginipes), but is a very common species. Pseudothemis jorina had been recorded but misidentified (presumably) as P. zonata. Ceriagrion calamineum had been misidentified as C. aurantiacum.

***   Refers to species recorded for the first time for Vietnam (as far as I know)

****  Refers to a species novum, but misidentified in previous surveys.

*****Recorded by Flores Brekelmans, not by me, but published on this blog

Two cool species from Cat Tien

Last weekend I visited Cat Tien National Park to spend a few days with James looking for some of his recent discoveries. One of these was a fine female of Zyxomma obtusum. This is a widespread species, occurring from the Indonesian archipelago to the south of Japan, but it was unclear to me how often it has been recorded in Vietnam. I had never seen it, although I keep an eye open for it at dusk all the time, and I know of no other records. Cuong does not mention it in his overview of Vietnamese records. So it was an exciting find when James ran into it; a find that sadly we could not duplicate. But when checking some of his photos we made another discovery. A Ceriagrion he had taken a picture of last July was C. indochinense! This is a species recorded as widespread from Thailand and also from Vietnam, although I have never seen it, so it is maybe not that common. But last July at a grassy swamp there had been many. We went to check the place, but clearly it is not around in February anymore. I am happy to show both species here and look forward to seeing them myself sometime.

A fine male of Ceriagrion indochinense. This species shares a citrine-yellow abdomen and bright green thorax with yellow face with C. fallax, but it has no black at the abdominal tip. Photo courtesy of James Holden.

The female of Zyxomma obtusum. The males are whitish and ghostlike when patrolling as dusk, but the females are less obvious. However, note the dark wing bases and banded abdomen.

The male of Gynacantha basiguttata and a male G. japonica thrown in

November 21 I went to Huu Lien to look for the enigma Planaeschna cf. guentherpetersi again, but did not see it. I did catch an Aeshnid that passed overhead in the forest and was very happy to find it was a splendid male Gynacantha basiguttata. I had caught the female a few weeks back too. Apparently it is not that rare inside the forest. The other cool thing I saw was a communal roost of Cratilla lineata. I had seen that in Potamarcha congener, but this was new knowledge to me. At least 15 bundled together on a hanging twig.

On November 22 I went to Xuan Son and looked for the small pale-faced Planaeschna there. I did see one female, but failed to catch it. It was mostly an uneventful day, but I saw a few Gynacantha japonica and was able to take some pictures. Another unexpected species was Trithemis pallidinervis at the river crossing, which I had not seen this far north. And a fine male Ceriagrion chaoi was another nice one. Not at all that common, although regular at Xuan Son.

Very fine male Gynacantha basiguttata, note the dark wingbases.

Scan of the same male. Note the long and slender epiproct and the wingbases.

Pretty male Ceriagrion chaoi

Gynacantha japonica, note the pale epiproct.

And a surprise female Trithemis pallidinervis

A few hours in Vientiane, Laos and a new species for the Laotian list.

This Thursday I had a few hours to spare in Vientiane and took a cab to the outskirts of the town. Thank God the surroundings are not close to being as polluted as around Hanoi and I was able to find 38 species in a short time. Vientiane is about as far south as Ha Tinh in Vietnam, which is about the southern edge of my general research area (northern Vietnam). But its species are quite different, much more southern. There was a lot of overlap with the commoner species in Cat Tien National Park, for instance. I was happy to catch a Epophthalmia frontalis male. Yokoi & Souphanthong actually list 31 Macromiidae, 28 of them Macromia. Which is rather astounding. But anyway, I was happy with my frontalis. And I was able to take pictures of male Lestes elatus and female Ceriagrion cerinorubellum. I had seen both these species in Cat Tien, but had not seen these sexes. Below a few pictures. And another very common species in some inundated and apparently deserted rice fields was an Aciagrion. I had to go back to Ris (1911) and Fraser (1933) to find out what may be the differences between Aciagrion occidentale and A. borneese. The appendages look rather similar and the A. borneese I had from Da Nang had been eaten by vermin. But in the end the description of Fraser pointing out that S8 is blue with a black triangle on it in A. occidentale, whereas A. borneese has a broad dorsal black stripe over the whole segment, provided the clue. Photos from India confirm the pattern on A. occidentale, and I therefore conclude that the specimens I saw were A. borneese, on the premise that the pattern is consistent over the complete range of these species. Interestlingly Yokoi & Souphanthong do not list either of these species for Laos. A. borneese is a very common species in Thailand and that country is of course right opposite the river at Vientiane.

Let's start with the addition to the Laotian list, Aciagrion borneese. Note dorsally black S8 and S10, whereas S9 is marked by a thin blackish dorsal line.

Another male with the distinctive pattern

Female Ceriagrion cerinorubellum. Possible to confuse with C. auranticum because of the green eyes and orange-brown cranium. However, S3-7 are blackish above and blue-green laterally, not orange, and S9 misses the clear darker marking.

Lestes elatus female

And the male, which I had failed to find in Cat Tien.

And finally a fine male Epophthalmia frontalis

Ceriagrion species of early April in Pia Oac

4 and 5 April I visited Pia Oac and surroundings. Ceriagrion fallax is a common species here and was already abundant around ponds. But I was thrilled to also find Ceriagrion chaoi, a species I had previously seen only at Xuan Son. And not only did I see it at the "Trigomphus carus" pond on the slopes of Pia Oac, I also saw it at the weak bridge 10km to the south. Clearly it is not rare in the area. I saw C. auranticum there too, only one male, but more thrilling, because it is less common, even scarce, and extremely beautiful, I saw a great many C. azureum. One could almost say it was abundant on the flooding rice fields. Here are some impressions of all but C. auranticum.

To start with a copula of C. azureum

A male, this specimen with some spots on the thorax, likely some kind of damage.

And the greenish female of C. azureum

Copula of Ceriagrion chaoi. Note the yellowish-green eyes and dark dorsum of S9-10 in the male.

Another male C. chaoi

And finally, common but pretty Ceriagrion fallax

A whole lotta Ceriagrion! A new visit to Cat Tien National Park

*Adjusted 21 January 2020 based on discussion with Rory Dow on Ceriagrion chaoi.

12 to 18 November we were guests in the Forest Floor Lodge in Cat Tien and spent all day in the field looking for dragonflies, now under very different conditions than in the wet season. Everyday was filled with sunshine and the forest was already very much drier, with most ponds having disappeared, the Dong Nai River showing expanse of rocks in the rapids, and streams in the forest reduced to trickles. During the wet season I had seen 3 species of Ceriagrion, now we were hoping for a few more. And indeed, we encountered 6, 4 of which I had not seen before. One of the first was a species with bright red abdomen and red face, first seen at the pond in the lodge garden and later also encountered elsewhere. Using Asahina's (1967) summary of Ceriagrion I made a startling discovery. It keys out as, and otherwise also fits very well, C. chaoi. But I had already seen that species, and it was very different in coloration, as far as I knew. So I went back to that species too and checked it once more. In side view the appendages are very much the same, but in dorsolateral view the shape of the superiors is in fact different. The species I had seen in Xuan Son, in the north of Vietnam was C. chaoi. This southern species is clearly different, but has been identified as C. chaoi as well and published through photographs on the web from Singapore. I also found several photos identified as "much redder than usual C. praetermissum" from Thailand. These have a red face and greenish thorax sides, something not present in C. praetermissum. It would appear these and those from Singapore are identical to the Cat Tien species, which is apparently not described currently, mistaken as it is for C. chaoi. I observed it in the park at two locations, both clear water ponds in forested environment with a lot of water plants.

Male Ceriagrion sp, note red face, bright red abdomen, greenish flanks and brownish dorsum

Another male

Another male, showing the bicolored thorax and red face

Appendages of Ceriagrion sp in lateral view. Very similar to C. chaoi.

But see the triangular subapical process to the superiors in dorsolateral view, rather different

The second species I ran into was very small Ceriagrion praetermissum. The male of this species also has red abdomen and red face, but has otherwise pale brownish tones. This appears to be a dry season species, that now was very common around the larger lakes, like Crocodile Lake and Bird Lake. There were still many fresh individuals in the forest or hiding in the grass. It may well be abundant in a little while. The appendages of the male and female are quite distinctive. The female has a long ovipositor and the male has a characteristically forked inferior appendage. Apparently C. praetermissum was not yet known from Vietnam, but it is common in neighboring countries.

Male Ceriagrion praetermissum with brownish thorax, but orange-red abdomen and red eyes.

Another male

Female C. praetermissum, with long ovipositor and red eyes.

Very characteristic inferior appendages of C. praetermissum

The next new species I ran into was the long-bodied Ceriagrion olivaceum. This species is as big as C. praetermissum is minute. I only saw three fresh individuals, all males, but as this is also a dry season species, it may likely become more common a little later in the season. This species has rather pale eyes and the abdomen does not become reddish.

Long-bodied male Ceriagrion olivaceum with greenish eyes and only marginally orange-brown abdomen.

Another fresh male.

The appendages of the male

The last, and a very spectacular, new species was Ceriagrion cerinorubellum. This is a beautiful green and orange species, rather large, with characteristically long inferior appendages. Not that this plays a role in its identification, its size and coloration rule out other species at a glance. I saw only two in a drying out pond with extensive rush-fields.

Spectacular Ceriagrion cerinorubellum, striking and beautiful.

Another male, with a dark spot on the thorax.

The two other species I encountered were C. malaisei, of which I saw a single male at Crocodile Lake that I could not take a picture of, and C. aurantiacum, which too I saw at Crocodile Lake, but in somewhat larger numbers, and at the fishponds.

Green-eyed Ceriagrion aurantiacum

Another male in dorsal view

And the lateral view of the appendages, with the relatively long and straight inferiors

Pia Oac in October - continued

I had a fascinating day at Xuan Son this weekend, with a plethora of Planaeschnids. That is a mixed blessing, as writing up is going to be a headache. So first a few goodies from Pia Oac on October 18. Amongst the few damsels that I saw while looking for Aeshnids I took photos of a few.

First to show is this wonderful male Ceriagrion fallax, a common species at this altitude, but always beautiful and more so with the bit of moisture clinging to it.

Then I was lucky enough to bump into a copula of Noguchiphaea yoshikoae. No idea what the function of the horns is on their prothorax. In close-up they run parallel to the male paraprocts holding her, but apparently without interaction.

And finally this well mature female of Ischnura carpentieri.

Ceriagrion calamineum, new for Vietnam

I have been lucky so far with Ceriagrion species. I really like this genus of robust and colorful damsels. In Cat Tien in the first week of August I encountered 3 orange-yellow species. Just a few C. auranticum, generally a common and certainly a widespread species, C. malaisei, which I had seen before in Bac Kan Province and in Ba Be National Park in the north, but also occurring, evidently, in the south. But the third was the price. Ceriagrion calamineum is a species known to occur eastward to central Thailand. Like Brachydiplax sobrina and quite a few other additions to Vietnam I found in Cat Tien, it belongs to a complex of southern species that occurs widely in Thailand and apparently extends further eastward. I found them in a corner of inundated grassland near the fishponds next to the guard station.

The beautiful male Ceriagrion calamineum

The paler female, hiding in the grass

A second male

Typical appendages in close-up