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.

Euphaea cyanopogon - an unexpected addition to the Vietnamese list*

*This article was adjusted August 5, 2019, as a result of the publication of a new species Euphaea cyanopogon Hämäläinen, Kosterin & Kompier, 2019. I retain the original text, but the species E. pahyapi is distinct differences with the present species, which now has been described as a new species.

On December 30 I was surveying streams in the forest at the northern side of Phu Quoc island when I noticed a smallish Euphaea species with uniform amber-colored wings. Because E. ochracea had been reported from the island from previous surveys and one of the reports showed a similar amber-colored winged specimen, for the time being I assumed it was this species. But at home checking it against the few specimens that I possess and many photos, both from myself and on the web, the suspicion rose that this really could not be E. ochracea. Not only in outward appearance was it different, but also structurally, like the caudal appendages and the vesicula seminalis. When I caught on to the fact that all adult males of species known from Vietnam have a completely dark face, whereas the Phu Quoc species had whitish-blue markings on the labrum and genae, I became convinced it had too be something else, E. pahyapi. In fact the species was not rare, although also not particularly common, but I saw at least 10 spread over several streams and on January 1 and 2 also noticed it in the forest more centrally to the island.

The species displays some very interesting characteristics. The males I saw (and I only saw males) had facial markings in varying degrees of intensity. A large, but centrally split, spot on the labrum and a large spot on the genae, anteriorly with an incursion of black. The wings were rather straight for the genus and with generally similarly shaped fore wing and hindwing. These were evenly colored from base to apex. Although the discoidal cells of the two specimens I collected are not entire (contra Hamalainen 1985), the cubito-anal space had only 2 cross veins in the fore wing of both specimens and 3 (once 2) in the hindwing, contrary to O. ochracea, which has mostly 4 (or even 5). This fits the description by Hamalainen of E. pahyapi. That species, just like my specimens, has a smooth vesicula seminalis, unlike the grooved vesicula of E. ochracea. The prothorax had vague markings in a few younger specimens, but became all black, contrary to ochracea, which has obvious place areas, and the thorax pattern also was much reduced and less rufous. The abdomen moreover was much darker than in ochracea, again fitting E. pahyapi. The measurements (2 specimens) are an exact fit with those given by Hamalainen for pahyapi, for abdomen, fore wing and hindwing (31-33mm; 29mm; 27mm). Especially fore wing tends to be longer in ochracea. And unlike any of the known species from Vietnam, but in line with E. pahyapi, S3 is adorned with a large area of long hairs. The caudal appendages are rather triangular in outline in lateral view, rather than rectangular.

E. pahyapi was described by Matti Hamalainen in 1985 from peninsular Thailand. Almost immediately afterwards Asahina published E. khaochongensis, which later was synonymized with E. pahyapi as a junior synonym. This is of particular interest, because in the description of Hamalainen the face is completely black, but in that by Asahina the labrum, genae and anteclypeus are all described as dirty blue. As almost all characteristics fit E. pahyapi, it seems quite sufficient to identify it as such. The only obvious difference is the pattern of the face, but given the description of its synonym E. khaochongensis, this is apparently within the range of variability. The other minor difference is that the discoidal cell in both collected specimens has one or two cross veins in all the wings, not entire as was the tendency for Hamalainen's specimens. Of course DNA analysis or further research may still identify the Phu Quoc population as different from that of the Malay Peninsula, but for now the identity of this species as E. pahyapi, not E. ochracea, seems well supported.

IUCN lists E. pahyapi as vulnerable, known from just 3 locations in Thailand and under threat of habitat destruction. As such, its discovery on Phu Quoc in good numbers is very relevant.

Male Euphaea pahyapi. Note the wings of almost similar wit and length, uniformly amber in color. This individual still with yellow-brown spots on prothorax and near ocelli. Also note that dorsal stripes are almost obscured and mesepimeron lacking the stripe bordering the humeral suture.

Another male, with dorsal stripe completely obscured, antehumeral stripe much diminished and mesepimeron with only a reduced stripe along the interpleural suture. This individual with completely black prothorax and cranium.

Close-up of S3 with the mass of long hairs on the proximal half

Close-up of the superior caudal appendages, showing their triangular shape, widest close to the base.

Close up of the smooth vesicula seminalis (left in the picture)

Close-up of facial pattern of one male, with extensive bluish white adjacent to the compound eyes, large bluish-white patches on the genae and on the labrum, and paler brown on the anteclypeus.

Another male, in which the markings are much reduced, especially adjacent to the eyes, but also split into two parts now on the labrum.

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

Euphaea ochacea and teneral Euphaea decorata

On April 30 we were looking for dragonflies along the QL32 in Yen Bai Province, just west of Nam Bung, when we ran into several good-looking Euphaea specimens. I was able to take some pictures of the first one, but it flew off before I could get close. Thereafter we saw several other Euphaea specimens, but they differed from the first, in that the first had a dark spot central to the hindwing and hyaline tips. The other males all had much more even coloration of the hindwing and diffusely colored wingtips. These were E. ochracea. Remarkably, when studying the photos, the wing shape for the first specimen also appears somewhat different. The ration between the hindwing length and maximum width is 3.52. For the other specimen photographed it is 3.68. Here is a key, because E. decorata in fact has a different wing shape. It has slightly broader wings that show an S-curve towards the tip. Ochracea generally appears more slender-winged, with an gentle even curve towards the tip. This immature specimen is reminiscent of even broader winged E. ornata of Hainan in coloration. All these species are as far as the appendages go very similar. Under the microscope there are minute differences between E. ochracea and E. decorata, and when comparing the a specimen I caught a week later, but similarly colored and at the same location, to an adult E. decorata I could not find differences, although it is different from E. ochracea. Thus, this colorful specimen is in fact E. decorata, occurring side by side, almost, with E. ochracea. Euphaea ochracea is recorded from various provinces in Vietnam and also in the north, but E. ornata is a Hainan endemic, although it has been claimed from for instance Yunnan and Guangdong. Such records may refer to brightly colored and immature E. decorata, as in fact Matti suggested relating to mine, on the first version of this post, in which I originally suggested the specimen with the darker patch in the wing might be E. ornata.

*I received the Campion paper courtesy of Matti Hamalainen and based on his suggestions went back to Yen Bai and studied the concerned species in hand. Many thanks. The issue is now resolved.

Beautiful male Euphaea ochracea

The female of Euphaea ochracea

The fascinating male Euphaea species displaying  coloration of Euphaea ornata, but in fact immature E. decorata

Euphaea guerini - at last

On 13 April we were birding in Xuan Son, but I also searched for dragonflies. Euphaea masoni was now very common and everywhere on the larger streams, flitting back and forth in constant arial battle, or resting on the stones. But on the small and shaded streams in the forest I also ran into them, and for some reason the ones on the larger streams seemed all dark when flying, but the ones on the small streams showed bright green flashes of their hind wings. Could it be that these were in fact E. guerini, for which I had looked in vain last year? Maybe it was a spring species? Anyway, the easiest way to separate the two species is by taking a look at the base of S9, where E. guerini has a tuft of hair. And indeed, in hand it showed this characteristic nicely. Also the differences in wing darkening (apart from the green flashes, which are more reddish in E. masoni and mind you, the closed wing of both species displays a dark blue shine) were evident, with much darker bases to the front wings and no light tips to the hind wings for E. guerini, although the latter character is somewhat variable in E. masoni and cannot in itself serve to identify. The specimens seemed to also average smaller, evident in the two in below scan, but there appeared to be some variability there too. Nevertheless, a nice addition to the list!

Picture taken in a dark place with flash, Euphaea guerini, male. The green you see is the shine of the topside op the left hind wing. 

The tuft of hair on S9. What will be its purpose, besides to aid identification?

Scan of the two species, E. guerini on top and E. masoni below. E. guerini curled up during preservation. The difference in darkening of the front wing is visible. E. masoni is 52mm in total length, HW 32mm. HW of E. guerini here is 28mm.

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?

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.