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