12 April, Melinh Field Station

April 12 was a beautiful day and I headed to Tam Dao to check raptor migration. Nothing flew, so very disappointing. Apart from a lone Chlorogomphus that is, exciting to know they are around already. But without birds, I decided to try Melinh. In a recent publication, Natalia von Ellenrieder et al. mention some interesting species from this area, but I had never been there. So I tried to go and stumbled onto the place without much difficulty. It has basically one major stream that runs through secondary forest and I followed it for quite a bit. Euphaea guerini was probably the commonest species. It is not all that common really, with Xuan Son providing good numbers, but elsewhere it is rare. Here is was common, followed by Mnais mneme, another nice species. And yet another reminder of Xuan Son was Prodasineura croconota, which I know also from Huu Lien. The commonest dragon was Orthetrum sabina, and for once I took some pictures of it. Other interesting species were Protosticta "grandis", a single female, Orolestes selysi, and Mortonagrion aborense, although that species by now is known to occur widely. The only gomphid was Ictinigomphus pertinax. Here are a few photos.

Brachydiplax chalybea flavovittata, a single male on a grassy pond

Handsome Prodasineura croconota, now also known to be widespread

Not a good picture, but it will do, I guess. Mnais mneme, orange-winged male

And because it was too common to ignore: male Orthetrum sabina

It's a male's world (but it would be nothing without females)

Hanging around Pia Oac on April 4 and 5 I bumped into several interesting females that I would like to share here. Plus one interesting copula.

This here is the female of Mnais andersoni, by virtue of its association with a bundle of males

This is a copula of Ischnura carpentieri. The andromorph female it not common at all

Female Trithemis festiva, much more difficult to find than the male

Ovipositing female Anax nigrofasciatus

A different female A. nigrofasciatus, caught hunting over the road on the mountain

Female of Orthetrum triangulare with less clearly marked thorax compared to O. glaucum and dark tip to abdomen

March 28, first trip to Xuan Son of the season

The weather forecast said that west of Hanoi might be sunny in the afternoon, so I decided to drive to Xuan Son today. As is often the case, the forecast was wrong, so a cloudy day. Nevertheless I encountered at least some goodies, although nothing unexpected. Euphaea masoni was already very common and E. guerini was out and about too. In the damselfly department Mnais mneme was common too, and I saw the first Pseudagrion pruinosum of the season. Orolestes selysi was also present in decent numbers at the "Gynacantha puddle".
I was really hoping to see Nihonogomphus schorri, which had been omnipresent in April last year. Cloudy circumstances made it impossible to judge whether it is already common in March, but I saw one male briefly. A first female Macromia flew by. Could not verify the species though, shame. And at the "Gynacantha puddle" a few Cratilla lineata and quite a few adult or semi-adult Gynacantha subinterrupta were huddled in the bushes. All in all not at all bad, given the time of the year and the weather.

Not the best of photos, but anyway, Nihonogomphus schorri, as soon as the sun showed itself, no matter how short.

Female Rhinocypha perforata, quite common

And the male of Rhinocypha perforata. See the lateral thorax pattern. It is the same as in the female, although the forum is very different.

Neurobasis chinensis is a common damsel, but also very pretty, especially when it displays the top side of the hindwing.

The female of Neurobasis chinensis, with the typical double white dot.

Euphaea masoni already very common. This specimen kind enough to keep its wings open, displaying the typical translucent base and tip in the forewing and the reddish brown luster to the inside of the wings.

But the outside is dark blueish

Mnais mneme male, this one already pruinose on the thorax, a feature missing in Mnais andersoni.

The female of Mnais mneme, specimen with reddish veins

Immature (and already missing a pair of legs) Mnais mneme. When there is no pruinosity on the thorax it can be separated from Mnais andersoni through the structure of the penile organ.

Gynacantha subinterrupta with its typical abdominal pattern of oblique light bands. This individual almost adult, but the thorax still not fully green and the face still whitish.

Face of the same individual, showing cream white, not yet yellow.

Different male, this one with yellow face and green thorax, fully mature

A great start of the year

2015 has been very warm in the first few months, so while birding I kept running into unexpected dragons and damsels. But we have been very busy on the field guide project for REGUA, so I have been slow on getting back to the blog. But now it is the middle of March and soon the streams will explode. This weekend Kameliya and I visited Pia Oac for birds and had a great time. But the afternoon of Sunday was sunny and besides almost 300 migrating raptors also enticed several Odonata to venture out. Apart from Pantala flavescens, Palpopleura sexmaculata, Orthetrum pruinosum and O. japonicum internum, plus Ceriagrion fallax and Anax nigrofasciatus, there were quite a few Mnais about. At home the penile organ helped ascertain the species: Mnais andersoni. Although M. mneme becomes pruinose on the thorax whereas this species does not, in early spring M. mneme too is still lacking pruinosity. That is when the penile organ comes in handy (see earlier blog entries).

Male Mnais andersoni

Tying up some loose ends from Yen Bai

There are some loose ends, various interesting (I hope) photos from Yen Bai from the weekend of May 10 and 11 that I would like to share.

For one, I saw a great many Mnais andersoni this time. What is very interesting are two aspects. None of the orange-winged males (many) had a pruinose dorsum to the thorax, quite contrary to what I noticed for M. mneme. On the web there are many photos with pruinosity, but I fail to find ones that also show the penile organ to show the true identity of the species. For the populations here it seems a consistent difference. The other aspect of interest was that the hyaline-winged specimens were far outnumbering the already quite common orange-winged ones. This also is very different from the population of M. mneme in Xuan Son, where the hyaline males are rare.

A mature male hyaline-winged form of Mnais andersoni

And the same for the orange-winged form. Note the complete lack of pruinosity on the dorsum of the thorax.

Another interesting aspect these two days was the common appearance of Idionyx carinata. I doubted for a moment that it was this species and not something similar, but the males that I caught were clearly I. carinata. Females were variable, some showing only a small yellow spot on the anteclypeus, but other showing all yellow labrum.

Female Idionyx carinata hanging from a twig

Face of one female Idionyx carinata with only limited yellow and single horn

Another female Idionyx carinata with almost completely yellow labrum and double horn

One of several males caught, clearly I. carinata

As his "thing" shows

Another interesting observation was of a female Devadatta ducatrix. Below a photo:

Female Devadatta ducatrix, more colorful than the male

Mnais mneme, the hyaline winged form

May 3 I was picking up large bags of litter in Xuan Son National Park, a place that is quickly becoming popular with day-trippers, now that a concrete path along the stream and a wide road through the park have been constructed. This may bring economical benefits, but it also brings copious amounts of litter, as many people just drop any wrapping, cans or bottles without thinking twice. This is not a battle I can win, but for the time being I just cannot see the place turn into a rubbish heap and do nothing. The good thing was that some young adults seeing me pick litter came to the rescue and started to help. There is hope.

But, let's go to the topic for this post. Amongst the 100 or so orange-winged males of Mnais mneme I saw a total of 3 hyaline winged males. Until that day I had seen none and already sort of concluded that  the hyaline form does not occur here. Now I know it does, but it is scarce. It differs also in that it has no pruinosity on the dorsum of the thorax. It does appears are quite a different insect and indeed, for a moment I thought it might be. Under the microscope it is however clearly M. mneme.

Mnais mneme, orange-winged male

A younger male in different lighting

A hyaline-winged male Mnais mneme

Scan of both types in lateral view

Scan in dorsal view

Mnais andersoni, that other Mnais

April 30 I was looking for dragonflies in Yen Bai Province. This is no new information, see earlier posts. But amongst the interesting discoveries of that day was also an orange-winged Mnais species. Two species are known from Vietnam, Mnais mneme and M. andersoni. M. mneme is a common occurrence in Xuan Son, where in spring many can be seen in the forest along small streams. This specimen I found however on a relatively open hill side, with ample shrubs but no real forest cover, along a shallow stream. It had no pruinosity on the dorsum of the thorax, but this may well be age related. Under the microscope it displayed the typical penile organ of M. andersoni.

Male Mnais andersoni

Face of the same male

Appendages in lateral view

Appendages in ventral view, compare the entry on M. mneme, decidedly shorter

And the penile organ, with the clear V-shape at the proximal end of the apical segment

Mnais mneme and other Xuan Son goodies

Yes, we are in business! The first real sunny day of the spring in North Vietnam and I found myself in Xuan Son, for birds, but it was rather quiet, but I had good views of a singing Spotted Wren Babbler. But the sun also brought out quite a few dragons. Interestingly, several species were already in copula or ovipositing, so had been around for some time: Orthetrum pruinosum, Copera marginipes, Trithemis festiva, Pantala flavescens, not the rarest of species, but still.

The best species of the day was stunning Mnais mneme. I saw three males, all orange-winged. One I caught and it was very large, abdomen 49 mm, larger than either M. mneme or M. andersoni as described in Asahina's 1975 papers. The appendages pointed to M. andersoni, but the distal segment of the penile organ, as he calls it, is only very shallowly v-shaped, much like his Laos type. Based on this, and helped by the size, I identified it as M. mneme.

Mnais mneme, male orange-winged form

Appendages in ventral view. Tip of inferiors with hook and inferiors well short of superior appendages.

But see the almost t-shape of the distal segment

Another surprise was Ceriagrion azureum, two males in a rice field of all places. I had only seen this beautiful species in Ba Be National Park before. As they were a bit far away and I did not bring the long lens, a record shot only.

Ceriagrion azureum, beautiful species, bad photo

Heliocypha perforata was already common, with many males displaying. Here an immature male and a female.

Heliocypha perforata, female

And H. perforata, immature male, just starting to turn blue on the abdomen

Yet another species already common was Euphaea masoni. Many males were flitting about. Here an almost mature male and a female.

Is she crying, or just shy? Euphaea masoni, female

E. masoni, immature male

Vestalis gracilis was very common in some places, whereas in autumn it is not so easy to find in Xuan Son. I was a bit surprised how common it was already.

Two males Vestalis gracilis, side by side

And the last species I have photos of, Cratilla lineata. This species was also already ovipositing. Here a male.

Cratilla lineata, male

As it is interesting to know what the temporal distribution is of species, here the other species seen today:

Neurobasis chinensis, Aristocypha fenestrella, Agriocnemis femina, Paracercion calamorum, Coeliccia scutellum, Copera marginipes, C. ciliata, Prodasineura autumnalis, Pantala flavescens, Trithemis festiva, Orthetrum pruinosum, O. glaucum, O. triangulare, Brachythemis contaminata.

A total of 20 species, yes, we are in business!