Friday 25 November 2022

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

Tuesday 9 February 2021

A new Chlorogomphus for Vietnam

 Preparing to leave Vietnam in the spring and early summer of 2017 was difficult. So much to do still, so many riddles to solve. Late May I had the opportunity to go say goodbye to the Sa Pa area. I had now found a few good spots that were both rather pristine and just outside the National Park, so I could try without the guards looking over my shoulder to look for gomphids and chlorogomphids. On May 29 I worked my way down a slope and heavy brush to the small stream I knew was there inside the forest and stood there by the side of the stream for hours, amusing myself with many Anotogaster chaoi, but little else, until a large dragon fly by. I was able to catch it and stunned to see a large puzzling Chlorogomphid. Sadly it was a female and although it had some striking features, like colored wing bases and thin stripes between the larger ones on the side of the thorax, I could not connect it to a species. That is, until I saw photos of Chlorogomphus miyashitai Karube, 1995 in the bible of Haomiao Zhang on Chinese dragonflies. This properly set me on the path to identification. Chlorogomphus miyashitai was described in 1995 from 'Xien Khang' in northeastern Laos (Karube 1995). I think this refers to Xiang Khouang, a province in northeastern Laos, a region of high mountains, although the description has no other information on the habitat or the altitude of the type location. Haomiao Zhang reports it from the Pu'er region in Yunnan, where it occurs to 1500 m alt. The Laos Province is south of the Sa Pa region, but the Pu'er region borders the Vietnamese Lai Chau province and is thus not that far from Sa Pa. I caught my insect at approximately 1700 m alt. The dorsal pattern of S2, the pattern of the thorax and face, the wing coloration all point to Chlorogomphus miyashitai. Although not recorded from Vietnam previously, it fits well the known distribution, so its occurrence comes as no real surprise.

Female Chlorogomphus miyashitai in hand

Face in frontal view

Sunday 5 January 2020

Overlooked and forgotten - Tholymis tillarga

I realized that a whole genus was missing from my blog. Of course it has only one species, but nonetheless, how is this possible. After all, Tholymis tillarga is a common species that tolerates pretty grim water quality, so it is around even in central Hanoi. It is a typical pond species often found during the day hanging in the underbrush, with females hunting at head height close to dusk, and males starting to patrol the edges of ponds in the hour or so before dark, so from well before sunset. It shares that space with Zyxomma petiolatum. The latter is quite inconspicuous, but Tholymis, or Twister, as it is commonly called, is a bright red insect with white clouds in its wings. Not the female, which is yellowish brown and has yellow patches in the wing. Because it is so common, I rarely took photos of it and when I realized that it was missing from the blog I had a hard time finding some shots of it. I also did not want to search long, so I guess these photos may be somewhat disappointing. So be it, at least it now is on the blog.
Male Tholymis tillage, 1 May 2014 in Huu Lien. I will replace it if I find a better shot. But it is nice and red.
Immature male, but the color in its wing is already starting to show. 4 August 2013, Hanoi City.

Female Tholymis tillage, 13 July 2013, Ba Vi.

Friday 3 January 2020

Anisopleura bipugio - also in central Vietnam

Hämäläinen & Karube described a new Anisopleura species from Lam Dong Prov. in southern Vietnam (technically at the very southern border of the Central Highlands) in 2013. I was never to verify it myself that far south, but in 2016 I ran into it several times. This is my third of fourth species of Anisopleura in Vietnam. In previous entries I introduced A. qingyuanensis and A. yunnanensis and a possible species novum from Pia Oac. The latter has different thorax pattern than A. yunnanensis, but its genital ligula and caudal appendages are seemingly the same and we could find no clear differences in DNA, so eventually decided not to describe it (Phan et al. 2018). Anisopleura is a tricky genus with a lot of look-alike species, so finding one that is remarkably different is pretty thrilling. This is certainly the case for A. bipugio, which has magnificent horns on its prothorax. I observed the species in Bach Ma National Park and nearby Quang Tri and Thua Thien - Hue Provinces. In Bach Ma it occurs together with A. qingyuanensis, which is common further north.

Male Anisopleura bipugio near the top of Bach Ma National Park, August 5, 2016

Close-up of male head, Thua Thien - Hue Prov., June 21, 2016. Females also have these remarkable horns.

Coeliccia cyanomelas and its synonyms

Recently a paper was published by Yu et al. in IJO (2019) on Coeliccia cyanomelas. Before that, Steinhoff & Uhl (2015) had already shown that C. onoi was a junior synonym of C. cyanomelas. Now, Yu et al. showed that C. wilsoni, C. sexmaculata and C. mingxiensis were also junior synonyms of C. cyanomelas. And, if you have been following these pages, you will be aware that I had reported C. mingxiensis too. It had first been recorded by Do in 2009 from Tam Dao. Because it looks strikingly different from all other species in the region, I never stopped to properly think when I saw similar specimens and assumed they were C. mingxiensis. I should have known better, because the color of the eyes and the weakness of their bodies indicated that these are immature specimens. Coeliccia cyanomelas is just an extreme example of changes in coloration during various stages of maturity as often observed in the genus. Here are a few photos showing different stages.

Here a fresh C. cyanomelas with the typical reddish shoulders, white-pink appendages and comma shaped antehumerals. This is what we used to call C. mingxiensis
This is the same specimen with the thorax in close-up. The color of the eyes is clearly immature.

This is a somewhat more mature male. The thorax is much darker above, with the antehumerals reduced to short lines, but the shoulder is still reddish. The abdomen tip is now white, not pink, and the eyes coloring properly too.

Here the reddish shoulders are gone and blue tones are evident.

This is just a variant, with additional small spots close to the wing base.

And thrown in: an adult female. Females similarly go through pale yellow stages first, but eventually turn blue like the mature males.

Thursday 2 January 2020

Asiagomphus mayhem - Vietnam is the place to be

August 2018 I finally was able to publish the results of 4 years of chasing Asiagomphus species in Vietnam. The paper that appeared in Zootaxa that year provided information on 8 species from this diverse genus. Asiagomphus acco is one of the easy species to recognize and had been recorded from Vietnam before. It is widespread and I published it on the blog long ago. Another species that is, at least in hand, easy to recognize is Asiagomphus reinhardti, which had only recently been described from neighboring Cambodia. The male has highly distinctive appendages, quite different from all other species in SE Asia. I found it both in Lam Dong Province and in Gia Lai Province. Here is an example in hand.

Male Asiagomphus reinhardti, caught May 17, 2016, near Bao Loc
As pointed out elsewhere in the blog, the most widespread species of Asiagomphus in northern Vietnam is probably A. auricolor. The original description by Fraser was based on a female and it had been hard to match it with its female. In my paper I give a first description of the male and provide further information on the female. Photos of this species are included already on this blog in past entries.

In neighboring Thailand Asiagomphus xanthenatus occurs and I was able to verify the occurrence of this species in central Vietnam, where I one lucky day ran into three males. Here is a photo of one of these.

Asiagomphus xanthenatus male, May 15, 2016 from Quang Nam Province.
Near Da Lat in Lam Dong Province, not that far actually from where I collected A. reinhardti (Bao Loc), I found a new species to science, Asiagomphus kosterini, which I reported already in this blog. 

That leaves us with 3 more species. One of these is a species with longitudinal stripes on the abdomen, different from all other species in Vietnam, although this pattern occurs on many of the northern species. This is Asiagomphus pacificus, which I found in Cao Bang Province and Bac Kan Province in the north. I reported this species already previously within this blog.

Which leaves us with two tricky species that I also already showed on the blog. Both turned out to be new to science and both are rather similar to some of the other species shown in this entry. These are Asiagomphus superciliaris and Asiagomphus monticola. Here are examples of both.

Male Asiagomphus monticola, Yen Bai Province, June 1, 2014

Asiagomphus monticola male, Xuan Son NP, May 31, 2014

And finally Asiagomphus superciliaris, Huu Lien Nature Reserve, May 24, 2014
Comparing the photos of these last three species, all similar to A. auricolor too, may leave the casual observer somewhat bewildered. Indeed, these species are rather difficult, if not impossible, to identify in the field without in-hand inspection. The details of the caudal appendages and secondary genitalia provide good clues. If you carry a copy of my Zootaxa paper, which provides these clues, you should be able to identify them and release them again.

Saturday 27 October 2018

Euphaea sanguinea, a new species for science

It has been busy. Busy with work, busy in the field here in the Netherlands, busy writing up some papers and before you know it, time is slipping without blog posts. So much so, that I have even failed to publish on the blog new species described from Vietnam in which I had some part. But here it is, a nice photo of a male of the newly described Euphaea sanguinea Kompier & Hayashi, 2018, published earlier this year in Zootaxa (Phan, Kompier, Karube & Hayashi 2018). This is a species localized in south central Vietnam and across the border in Cambodia (Kosterin 2016). It had been overlooked until now, because it is rather similar to E. ochracea, although, once you know it, it is actually obviously different, not only because of its appendages, but also by the very clear-cut red on S2-6. Below is a photo of a male from Bao Loc, Lam Dong Province, not far north from Ho Chi Minh City.

The newly described Euphaea sanguinea, a pretty male.