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!

December 8, Xuan Son in the winter sun

This Sunday, I drove to Xuan Son, to see what has changed since I last visited. Like in Huu Lien, water level had dropped, but the good streams were still good. Here too about 30 species for the day, but numbers for most were down. Coeliccia sasamotoi was the exception, being very much in evidence all over the place. What is interesting is that several species recorded for Huu Lien in summer, but completely absent during all our visits this November / December were still commonly flying at Xuan Son. Aristocypha fenestrella and Matrona basilaris were easily found. Also Euphaea masoni, only seen during our first visit to Huu Lien a month ago and not since, was still about in small numbers. What makes them stay on here?

I bumped into the following species: Matrona basilaris, M. taoi, Vestalis gracilis, Neurobasis chinensis, Atrocalopteryx coomani, Vestalaria miao, Noguchiphaea yoshikoae, Heliocypha perforata, Aristocypha fenestrella, R. "arguta" (I took pictures of several in hand, with hardly any orange on S9-10 to quite a bit), Euphaea masoni, Agriocnemis femina, Ceriagrion auranticum, C. fallax, Pseudagrion pruinosum, Coeliccia onoi, C. scutellum, C. sasamotoi, Indocnemis orang, Copera marginipes, C. vittata (I must have overlooked it before), Boyeria karubei, Orthetrum sabina, O. pruinosum, O. glaucum, Diplacodes trivialis, Neurothemis fulvia, Palpopleura sexmaculata, Crocothemis servilia, Trithemis festiva, T. aurora.

Old male Euphaea masoni

Another male with hole in wing

Matrona basilaris, male, was still common

Matrona basilaris, female

Atrocalopteryx coomani, male

Matrona taoi, male, only one and damaged male around

Pretty Coeliccia sasamotoi, male

Ceriagrion fallax, male

One of several captured Rhinocypha cf. arguta, with at least some orange on S9-10.

Very nice male Copera vittata, overlooked previously?

A few cool jewels from Huu Lien

We encountered 4 species of Jewel at Huu Lien, Heliocypha perforata, Rhinocypha biforata, aforementioned Rhinocypha cf. drusilla group and Libellago lineata. These are lovely damsels, brilliantly colored, and especially Libellago, tiny. All were very common in places, apart from the drusilla type, of which we saw only one. Here are a few impressions.

Beautiful Rhinocypha biforata, male

Rhinocypha biforata, female

Stunning Libellago lineata, male

An immature male Libellago lineata

And the female Libellago lineata

Heliocypha perforata, male

Rhinocypha arguta* and Heliocypha perforata

Xuan Son National Park is home to at least 4 species of Jewels. One of the targets for going there however was Rhinocypha arguta, a reddish Jewel of shallow forest streams with gravel bottoms. Apparently a late season species I was happy to find it was relatively abundant in its choice habitat, where I saw many scores of them. The stream where I found it was heavily vegetated with large emergents and the species commonly sat on the leaves.

* See also the blog entry on R. huai and the drusilla group of Rhinocypha.

Rhinocypha arguta, male

Another male, slighly more orangy

An immature male, with stigmata still largely whitish and colours still dull

Rhinocypha arguta, female, with prominent yellow horizontal streak on thorax, like male

And a copula

Nearby the dam connecting Coi and Lap villages there were also many specimens of Heliocypha perforata, a species I already introduced. Here I use the opportunity to also publish the female, which has a relatively striking thorax pattern.

Another copula, this time of Heliocypha perforata

Heliocypha perforata, male

Heliocypha perforata, female, with longitudinal stripe on abdomen and antehumeral stripe with parallel stripe over side of thorax on mesepimeron

Xuan Son outing, other records

The visit to Xuan Son was intended to search for some late season stream species. As we approached the National Park from the east and not from the north, we ended up at the wrong entrance. Wrong, because we could not find some essential streams in primary forest. Nevertheless we had quite a good time, but convinced we were in the wrong place we decided to try to approach from a different direction. Quite a challenge without a detailed map of the area and none of the villages mentioned. But we were successful in that we made it late in the afternoon to Lap Village. That was a fantastic place. The trial and error driving around route 32 brought us the already mentioned Lamelligomphus sp. and a Lesser Emperor, Anax parthenope junius. This is a species recorded as a vagrant from Vietnam, but it is likely it is more common. We saw a male over a pond by the road side, but it did not allow pictures. However, its small size, brownish abdomen with extensive light markings pointed away from A. guttatus and to this species. I guess we need a little more definite proof next time. In Lap Village one of the last dragonflies of the day was a smashing Matrona taoi, described from Xuan Son only two years ago. And because we were so late we sat a bit on a bridge at dusk before returning to Hanoi (a three and a half hour drive after all), when all of a sudden in the last light of the day the already mentioned Boyeria karubei started swarming. Not at all a bad October day, with 35 Odonate species. Besides the aforementioned goodies Onychothemis testacea also still put in an appearance. Below some of the stream damsels for which this is such a good area.

Matrona basilaris, male. We only saw one, but it is still early in the season

There were already quite a few Vestalis gracilis about, here a male

And here a teneral male. We saw several freshly emerged.

Copula of Vestalis gracilis

One of the targets: Matrona taoi, male, in all its splendor

Pretty Neurobasis chinensis, here the male, was common

Neurobasis chinensis, female

Euphaea decorata, female

Euphaea masoni, couple side by side

Heliocypha perforata, male. One of at least 5 species occurring in the area, of which we saw also R. biforata and Aristocypha fenestrella.

Jewelry

Some 10 Chlorocyphidae have been recorded in Vietnam. To date I have seen 4. A trip to Ba Be National Park in late July produced all these. Aristocypha fenestrella fenestrella is also found along rapid forest streams in Tam Dao and Ba Vi, so closer to Ha Noi. Rhinocypha biforata apparently is a common species, but to date I have only seen it along a small roadside stream on the way to Ba Be. Heliocypha perforata was common on streams near Ba Be, with an apparent preference for somewhat less rapid streams than A. fenestrella, often occurring in close proximity, but A. fenestrella in steeper and more forested sections. Libellago lineata occurred in very different habitat, slow streaming more murky rivers and lakes, like Ba Be lake itself, where males could be observed on floating bits of rotting wood, the same stuff that females oviposit in. To date (14 September) at least A. fenestrella is still common in the right habitat around Ba Vi.

Rhinocypha biforata, male

Libellago lineata, male

Aristocypha fenestrella, immature male

Aristocypha fenestrella, male

Heliocypha perforata, male

Identifying the females is challenging. Content for a later blog entry. And obviously I cannot wait to see  the other members of the Vietnamese Jewels. Seeing these brilliant insects battle it out over the rapids to impress the females, wings flashing, legs outstretched (in for instance A. fenestrella the white front femurs are a striking feature in display) is a treat!