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.



Friday, 17 August 2018

Two new Rhipidolestes for Vietnam

Currently 25 species of the genus Rhipidolestes are known. Many are very similar. Wilson and Xu (2007) provided a key to the known species, a great many of which occur in China. It has been a frustration for me that I had until now only been able to find Rhipidolestes owadai in northern Vietnam, where it is quite widespread and sometimes locally very common. How could there be no other species around, with directly across the border so many others? But frustrating as it might be, during 4 years in Vietnam I never found anything else.
It was with this knowledge that this spring I accompanied Phil Benstead and a fine group of people to the north of Vietnam on a two-week tour. Of course we encountered R. owadai. And I explained again and again that this is strangely enough the only species of the genus in Vietnam. Until on June 12 we spent a morning in the pouring rain at the Love Waterfall in Sa Pa at approximately 2000m altitude. I found a completely drenched somewhat smallish Rhipidolestes, virtually dead, in the mist and rain. The altitude was way higher than any R. owadai I had ever seen, so I paid close attention. It was a new species for Vietnam! Checking the details, it is close to identical to the detailed description of R. jucundus Lieftinck, 1948, a high altitude species from Fujian Province in China. That is far away from Sa Pa, but at least the altitude is similar. Possibly the cone on S9 is larger than in the type, but Lieftinck did not draw it and although the specimen is kept at Naturalis, the collection is currently closed. Also, Lieftinck described only one row of cells between CuA (his Cu2) and the wing margin in all wings. In my specimen there are two rows in the hindwing. However, otherwise everything fits exactly. I am confident this is indeed R. jucundus.
But things turned stranger after returning home and checking a R. owadai, or so I thought, I had collected in comparison. I did not properly note the location, but I probably took it in Cao Bang, at Pia Oac. looking at it again, it was immediately obvious it had a blue face, quite unlike R. owadai. Further study pointed to R. cyanoflavus Wilson, 2000. This species at least was described from nearby Guangdong Province in China. I am quite embarrassed not having recognized it in the field, but anyway, a third Rhipidolestes found to occur in Vietnam!

Many thanks to Keith Wilson and Martin Schorr, who provided some of the papers I needed.

Rhipidolestes jucundus in the rain at Love Waterfall
Its bright orange face
The rather distinctive appendages in dorsal view, although similar to those of R. malaisei from Myanmar. Apologies for the faeces visible.
The appendages in lateral view, with the upward pointed tooth of the inferiors clearly visible.
Not even a proper picture. Rhipidolestes cyanoflavus, from northern Vietnam, probably Pia Oac.
I have to admit, it is not clear how I missed noticing the face is blue.

The superior appendages, clearly different from R. owadai.







Tuesday, 19 June 2018

Burmagomphus magnus - expected in Vietnam

On June 4 Odonatours visited the area of Cao Bang during its tour of northern Vietnam. On this day James Holden joined us from his 'home' in Cat Tien. Together we checked a large stream not far away from the town. While we were pre-occupied with other Odes, James took a photo of what appeared to be an unknown Burmagomphus. Burmagomphus vermicularis and B. divaricatus both occur in the area, but this was clearly different. After a visit to Pia Oac on the 5th, we went back to the stream on the 6th and were lucky enough to relocate this wonderful gomphid. Upon capture the details of the appendages could be verified and the initial suspicion this might be B. intinctus seemed confirmed.
Burmagomphus intinctus is only known from several specimens collected from Fujian in China, which is truly not exactly around the corner. And indeed, further perusal of literature (thank you, James) showed it to be B. magnus, described in 2015 from Hekou district in Yunnan Province in China, which is just over the border from northern Vietnam. It was therefore to be expected.

The original photo by James Holden. What is that?!
Two days later, probably the same individual in hand.

The strong hook on the posterior hamule

And the rounded epiproct and somewhat sinuous superior appendages