Scalmogomphus guizhouensis in Yen Bai

The weekend of 10 and 11 May I visited Yen Bai Province looking for dragonflies and escaping the hot (41 C) weather in Hanoi. The Saturday was mostly cloudy, but around Nam Bung and further on along the QL32 it was still great exploring. I ran into about 15 quite colorful gomphids that I could not identify. Both males and females were common and quite easily approached. At home, after some searching, I finally identified it as Scalmogomphus guizhouensis. In fact, to be fair, I identified it as S. wenshanensis. The latter was described in 2005 by Zhou, Zhou & Li. The former in 2000 by Zhou & Li. Scalmogomphus guizhouensis was redescribed based on a collected individual from Sa Pa by Do Manh Cuong (2008). I found almost no difference between the two species when comparing the drawings. Interestingly, Zhou, Zhou & Li make no mention of S. guizhouensis, even if one of the authors also described that species. They only compare it to S. falcatus and the grounds on which they do so (second tooth apically on inferior appendage, bifurcate anterior hamule) are shared between both species. Only the green stripe on the frons is cut in two by black line in the middle in S. wenshanensis. Be that as it may, the species is identical with the redescription by Do.

Male Scalmogomphus guizhouensis

The same, female

Another male S. guizhouensis

Another male

The female in the field

Apart from the bifurcate anterior hamule, also the appendages are typical, with the strongly downward hooked superiors and the inferiors with two teeth, one at basal third and one close to the tip

Periaeschna magdalena - until proven otherwise

When checking a small stream just west of Nam Bung in Yen Bai Province on April 30, Kameliya spotted an Aeschnid hanging in a bush by the stream. I was able to take a few record shots, but failed miserably in catching it, as it was hanging smack in the middle of a thorn bush. There was a lot of cursing going on, but today I studied the venation of the wings and was able to pin down the genus as Periaeschna. Only one species is known from Vietnam, but 5 occur in China, so it is quite likely that other species will also occur in Vietnam, besides the known P. magdalena. The pattern of the abdomen, the all dark legs, the brownish frons, the small brown basal spots to all wings however all fit P. magdalena nicely. Asahina (1981) produced descriptions of the species that proved helpful and newly described species from Southern China (by Wilson and by Xu) do not fit. But I am open to suggestions.

Male Periaeschna magdalena with its very dense wing venation typical of the genus (median space with many crossveins)

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

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

4 species of Calicnemia*

*Adjusted after C. mortoni was re-identified as C. haksik.

Asahina (1997) mentions 4 species of Calicnemia for Vietnam, C. miles, C. uenoi, C. erythromelas and C. eximia. A fifth species (C. mortoni, although this record likely refers to C. haksik, which had not yet been described at the time) was recorded at Tam Dao in 1975 (Pritykina in Do & Dang, 2007). On top of this, Sebastien Delonglee in May 2013 found another species at Ba Vi that looked very much like C. soccifera. He did not collect it and could not get shots of the penile organ to be absolutely certain. But be that as it may, at least 6 species of Calicnemia occur in Northern Vietnam.

On April 30 we followed the QL32 into Yen Bai Province in search of good weather. There was a promise of clear skies in the west. It all ended in mist, but first we had some good spells just west of Nam Bung. There on the rocks along the road where small streams run down we found many Calicnemia. A few C. miles, large numbers of C. eximia and quite a few C. soccifera. Indeed identical to the shots on Sebastien's blog, but we also got shots of the penile organ to ascertain the identity. Interestingly, this species was described as recent as 2013.

On May 2 at Tam Dao we also found, in rainy weather, several C. haksik. I am happy to introduce all 4 species here, although C. miles and C. haksik were already featured before.

Calicnemia eximia, male

C. eximia, female

Another C. eximia male

Beautiful Calicnemia miles, a male

Copula of Calicnemia haksik

Calicnemia haksik, a male

Calicnemia soccifera, male, not at all rare in Vietnam, apparently

The female of Calicnemia soccifera

An immature male, thorax stripes still yellow

The typical penile organ of C. soccifera

And the distinctive appendages, with double tooth on the venter of the superior appendage

Philosina buchi - Another addition to the Vietnamese list

May 1, Labour Day, I was working the streams of Huu Lien looking for Asiagomphus (amongst other things), when my attention was drawn by a large whitish insect with red on the abdomen. It turned out to be a fantastic spreadwing damselfly. I had seen it on photos, but did not immediately know what it was. Checking at home made quickly clear that it was Philosina buchi, a species widespread in Southern China, also in Guangxi and Guangdong, and as in so many other cases, it is not withheld by political borders. Its occurrence in Northern Vietnam is thus not unexpected. Here a photo of this fantastic damsel.

Male Philosina buchi, a stunning damselfly.