Bayadera melanopteryx and female Bayadera serrata

On May 25 I bumped into Bayadera melanopteryx for the first time. This is quite an easy species to recognize, courtesy of its darkened wingtips. It is a species that is widely distributed in the southern half of China and known to extend into the north of Vietnam, for instance around Pia Oac in Cao Bang Province and also around Sa Pa. My first encounter was near Sa Pa, but I also saw it several times around Pia Oac. The latest date was June 28.

There are distinct populations of the species in China with consistent differences in the extent of the darkened areas in the wing, so it is possible this is a superspecies, but until that is proved it is best to treat all populations as B. melanopteryx. The Vietnamese specimens all have the apical half of the outer wing blackish.

I know have also found B. serrata in quite a few additional locations to the spot north of Pia Oac where I first saw it last year. Apart from several sites around Pia Oac, it was also rather common close to Tu Le in Yen Bai Province and to my surprise I also ran into a female in Xuan Son National Park. Another addition to the already extensive list of that place. Earliest record this year was May 23 and latest was June 30. Apparently not so rare as thought.

The very dark body of the male of Bayadera melanopteryx

Which becomes very easy to recognize once you see the wingtips. Bayadera hatvan has clearly darkened wingtips and Bayadera hyalina has slightly darkened tips, but never as extensive and clear-cut as in B. melanopteryx

The female of B. melanopteryx has similarly darkened wingtips, although not as dark brown as in the male. The thorax pattern recalls B. hyalina, but see the completely pale metepimeron.

In dorsal view the curved dorsal stripes are also very different

Here is the first of two photographed females of B. serrata. In patterning of the thorax very similar to the male. This one is from Pia Oac.

Whereas this one is the female from Xuan Son, found inside the forest not far from the main stream.

Oviposting Bayadera species!

Saturday July 11 I was checking a stream near Nam Bung in Yen Bai Province. Yes, we know that now from the previous posts. But here I want to relate a special spectacle. In the morning I saw a great many Bayadera. Previously I had seen 3 species along this stream: B. hatvan, B. serrata, and B. hyalina. Of these B. hatvan was by far the commonest. This time I did not see B. serrata, but I saw many copula of the other two species. They could be seen ovipositing here and there in floating logs. But in the canyon there was a large tree that had been cut and toppled down into the stream, where it remained standing up. However, it stood in the middle of a water spray from a waterfall, making it soaking wet. There were a great many (several score) tandems ovipositing on it. Interestingly, the tandems formed single species clusters for some reason undoubtedly instinctively clear to them, but not to me.

Three tandems of Bayadera hatvan out of a great many more. It was not easy keeping my camera sort of dry.

A single tandem of B. hatvan. I lined the camera up with the trunk, but in reality they were almost vertical.

Two tandems of B. hyalina, braving the wetness. They were 20cm lower than the Bayadera hatvan tandems.

Adjusted angle of the same tandems of Bayadera hyalina.

Bayadera species - more confusion

Over the last few weeks I was lucky enough to find at least 5 Bayadera species. I already posted on Bayadera continentalis at Pia Oac. In the meantime I have also been able to capture a female, on May 20.

Interesting pattern with heart-shape laterally and a large elongated spot over the humeral suture. Bayadera continentalis female

Scan of the same female, displaying a distinct brownish wash to the wings

The next species that caught my attention was Bayadera nephelopennis, which apparently is not uncommon in the Sa Pa region. This species can easily be confused with Bayadera bidentata. Both have blackish males with a little pruinosity. B. bidentata is somewhat smaller and the females are in fact rather different in pattern, as I hope to show further on. Anyway, on May 18 I saw both a female and a handful of males in Sa Pa and again several males and a female on May 25.

Female Bayadera nephelopennis in hand

The dorsum of the thorax is quite distinctive. It has broad lines along the dorsal carina, but nothing over the humeral suture.

Another female on May 25

A male on May 18, showing the quite unicolorous appearance

But a pretty face, although this pattern seems shared by many species

 On May 25 I spotted yet another species at Sa Pa that I identified as B. hyalina. However, it does not have dorsal lines on the thorax and several other characteristics of a species. Whether that is an indication of variability or indicates a possible different species needs to be resolved at some stage, preferably through DNA analysis.

Bayadera hyalina (or possibly closely related species?)

Scan of dorsal aspect

 On May 23 weather was cloudy over Pia Oac, so I checked a stream further down and bumped into a whole bunch of Bayadera serrata.  A female in tandem showed herself fleetingly and was quite yellow, but I could not get a photo of her.

Bayadera serrata, male. A beautiful and distinctive species

Brightly coloured thorax and face

And distinctive bird-beak appendages

And finally the last species was Bayadera bidentata. Surprisingly this species showed up with several males and females at Xuan Son on May 30, where we had completely failed to see it previously!

Male Bayadera bidentata, with quite a bit of pruinosity on the thorax contrasting with the black dorsum

The usual pretty face

The female B. bidentata is rather different from B. nephelopennis. It has an irregularly shaped marking over the humeral suture, which is lacking in that species, and reversely misses the lines along the dorsal carina.

 Not to make this posting excessively long, I will publish the differences on the appendages between these species in another post.

Bayadera continentalis - new for Vietnam

Asahina described Bayadera brevicauda continentalis in 1973. On clear consistent differences, both morphological and in colour pattern, Hamalainen in 2004 elevated it to specific status as Bayadera continentalis. It is a species known to occur widely in southern China and thus, as so often, it comes as no surprise that on May 1 I labored my way along a trickle of a stream under dense forest cover on Pia Oac Mountain, quite close to the top at the northern side, that I ran into at least 5 males of this pretty species. It is quite distinctive by virtue of the shape of its appendages, its dark coloration with pruinosity on S8-10 and S1-3, and its smoky brown wings. Other characteristics include the all black labium and the distinct hairy thorax. To my knowledge this is the first record of the species in Vietnam, but it may have been recorded before. If so, I stand corrected.

Bayadera continentalis, here under flash the brown of the wings is difficult to ascertain

Here too the colour of the wings is difficult to see

But on this scan it is obvious

Parallel inferior appendages and apically strongly bent uppers in dorsal view

And in lateral view

And just because it is a nice face, the frontal view of the head

Bayadera revisited

About a week ago I met with Phan Quoc Toan, who is working on his thesis in Japan, but happened to be visiting. He has been doing quite a bit of work on the confusing group of Bayadera. I had lent him the few specimens I had and the bad news is that he pointed out several mistakes I had made in my enthusiasm and based on the little correct information there is. Toan has looked at many specimens from collections and it is clear I had to revise some of the blog entries on the genus. Bayadera nephelopennis from Tam Dao is not that species, but is in fact Bayadera bidentata. Coincidentally, Karube had already published that species for Tam Dao. The few Bayadera bidentata I had collected or photographed, from Yen Bai and Sapa, are in fact Bayadera hyalina. And the one fresh specimen from Lai Chau in April might in fact be Bayadera strigata. I am indebted to Toan for sorting this out and today will change the earlier entries. The good news for me is that although I lost one species, I gained two!

Bayadera and Dysphaea

During my trip to Cao Bang Province and from there westward, I ran into an unknown (to me) robust Bayadera perched at a small stream coming from the woods by the road side on June 30 in western Cao Bang Province. It had a dorsal tooth on the superior appendages, something immediately drawing attention. Subsequently, I found out there are two species that share this characteristic: Bayadera serrata, described in 1996 by Davies & Yang from China, and Bayadera kinnara, described recently by Hamalainen from Burma. Based on the shape of the appendages my Bayadera could be identified as B. serrata. This is not the first time the species is reported from northern Vietnam, but records are scarce.

Bayadera serrata, a nice male

Head and thorax up close

The distinctive appendages. Note the dorsal tooth to the superior appendages

Note the serrated edge to the superiors.

Another Bayadera I ran into was Bayadera hyalina, but I saw it only once, which was rather surprising. Two males perched on rocks in the middle of a stream near Sa Pa.

A fine but distant male Bayadera hyalina

Also in Cao Bang Province on June 30 I noticed at the end of the day under a cloudy sky a Dysphaea perched high in a tree, far out of reach of my net, but not of my camera. It seemed to have all dark wings, something that was terribly confusing. I blamed it on the weather that it looked so dark. But the next morning and a swollen river due to the heavy rains of the night before I noticed two more all dark Dysphaea males. One sat in a bush overhanging the river close to the bridge from where I was watching and I judged I could get to it. So I moved into the churning waters, carefully judging whether I would be able to keep my footing. Close to the insect the waters were less deep and less turbulent and I got close enough to it to be able to net it. It tuned out to be Dysphaea haomiao, a species only recently (2011) described, by Hamalainen (thanks for the great work, Matti!).

The first observation, high up in a tree

And the second on July 1, male perched above the churning waters, Dysphaea haomiao.

The same male after capture. Note the many many mites happily sucking away on its belly!

See the horror in close-up, sschlup sschlup

Bayadera bidentata - a nice find at Tam Dao*

*This entry was first published as B. nephelopennis, but this was a mistake. It was adjusted on December 23.

18 May I went to Tay Thien in the Tam Dao mountain range. It was a very hot afternoon and really quite productive. On the way back, between the little shrine in the valley at the foot of the big climb to the temple and the monastery, I noticed a damsel sitting on a twig by the path that in general proportion and cloud reminded me of Devadatta ducatrix, but that species has black wingtips and this one did not. It also had a blue face and in hand the appendages were like Bayadera. It was only later in the year and with the help of Toan that I could settle the ID: Bayadera bidentata. An interesting species with its pruinosity. Although I first thought it was B. nephelopennis, that species has different appendages. The inferiors for instance are quite a bit longer. B. bidentata had been reported from Tam Dao by Karube (1994).

In hand, blackish thorax with pruinosity obscuring yellow lines, black abdomen, blue face

Close-up of blue face

Vaguely smoked brownish wings

Bayadera hatvan and Bayadera hyalina*

*This entry was adjusted on December 23. The ID was adjusted to B. hyalina. It was adjusted again in June 2015 upon publication of Bayadera hatvan.

On May 11 I was checking streams in Yen Bai. Twice I ran into a male Bayadera hyalina. I found them in shaded areas in surroundings with at least heavy shrub cover and rocks. This species was known from only a few localities, although it was thought to be more common. It was known from Thailand and India, but it had not been recorded from Vietnam. But I was very surprised when checking a large rather open stream to find another Bayadera sitting on branches fallen into the stream at the bottom of a cliff. This was a very distinctive species, with dark tips to the wing and in hand with broad superior appendage tips. Although very similar to Bayadera indica, closer inspection revealed that it was in fact different. Earlier claims of B. indica from China (Yunnan) may well refer to this new species, not to B. indica. The species was described in May 2015 by Hamalainen and Kompier as B. hatvan.

Male Bayadera hatvan

Female Bayadera hatvan

Male Bayadera hyalina

Another male in hand

Appendages of B. hyalina in ventral view

Compare ventral view of appendages of B. hatvan

Appendages of B. hyalina in ventral view

And the same for B. hatvan

And finally dorsal view appendages B. hyalina

And similarly, dorsal view appendages of B. hatvan