Sunday, 18 October 2015

Gynacantha basiguttata in Huu Lien

Today I visited Huu Lien to try once again for the Planaeschna cf. guentherpetersi, but I failed to see it (although I saw two possibles hunting at tree top level in the late afternoon). But when I made my way back through the forest at dusk I saw quite a few Gynacantha. Most were immature G. subinterrupta, but one larger species whizzed by and was netted with a little luck. To my large surprise it had extensive dark basal patches to the wings: Gynacantha basiguttata. I had seen this species in the south, in Cat Tien National Park, but did not expect it at all this far north. After all, Huu Lien is almost in China. This is a large species. The female I caught was 76mm without the (broken) appendages.

Female Gynacantha basiguttata, a large species, easily recognizable by the dark wingbases.

Monday, 12 October 2015

So does Planaeschna guentherpetersi occur in Huu Lien or not?

On December 1, 2014, I caught a female Planaeschna in Huu Lien that seemed to be a P. guentherpetersi, complete with the typical dorsal and lateral pattern on S2. Please see the concerned post. The facial pattern however was much more vivid than anything I have ever seen in Xuan Son, where the species is quite common. So, when I discussed with Haruki Karube a little while back we decided that it was not likely these two were in fact the same species. But I had no material from Huu Lien for comparison (I may have released the specimen at the time, or it was eaten by vermin, anyway, I do not have it), so it was/is undetermined. I had a single specimen last year that flew off. Finally yesterday I noticed an Aeshnid in the dark of the forest flying about. It hung from a twig, but I could not get to it, so decided to make some pictures with flash. These made it clear is was a male, and that it was a Planaeschna for sure. It also has the same dorsal pattern as the female on S2. Interestingly, the pattern on the remainder of the abdomen and on the lateral side of S2 is the same as in P. guentherpetersi. The shape of the appendages, insofar as can be judged from the pictures is not at variance with that of P. guentherpetersi either. Although the fact remains that the female has quite a more pronounced facial pattern, it seems for the time better to assume this is a local variant than enough grounds to claim this is a different species. But of course, I will try to catch it at the next occasion. It would be great to sample the populations for DNA.

The enlightened photo of the Huu Lien specimen, showing the typical dorsal pattern of S2 and remainder of the abdominal pattern. Compare with the below scan of the Xuan Son male.
The Xuan Son male. Planaeschna species have a lot of variation in the pattern of S2 or the abdomen, so for these specimens to very similar is likely too much of a coincidence.

The Huu Lien male at a different angle, showing the intense green and black thorax pattern and the lateral pattern of S2, with the yellow auricle and two spots on the distal edge.  This is very much the same pattern as can be seen in the scan below.
See the pattern of S2 on this male from Xuan Son. No other species in Vietnam, out of the other 9 or so I have found, has a similar pattern, but the specimen from Huu Lien has it. See also the heel on the ventral side of the superior appendages, visible in both the scan and the photo. For what it is worth, of course.

Sunday, 11 October 2015

Finally Matticnemis doi

In 2012 Matti Hamalainen published Platycnemis doi as a new species from Huu Lien Nature Reserve. In 2013 K-D Dijkstra, on the basis of both molecular and morphological evidence, moved the species to a new genus, Matticnemis. Matticnemis doi is the sole species in this genus. Obviously Matticnemis takes it name from Matti. The "doi" species name honors Do Manh Cuong.

I had been frustrated quite a bit that over the many visits a did to Huu Lien I had failed to connect with the species and this year around the end of June I spent several boiling hot days looking for it (Matti had collected the species on June 22). Huu Lien is still illegally logged and the area where the species occurs is opening up, which causes the forest to dry. Only very small sections of the streams are still covered by forest. Although I knew the exact place where Matti and Cuong had seen the species, it could not be found and I feared it had already gone extinct.

But today I went to Huu Lien to look for the possible Planaeschna species novum there and to my not small surprise I found two males close to the waterfall, perched on twigs on the forest floor along puddles from where the stream had resided. I was very happy. Of course I had not expected it in October, but apparently it has a long flight season. To my even larger surprise I later in the day found another 4 males and 2 females at the original location at the other side of the hills between the village and the waterfall. This means the species is in less immediate danger, as it occurs in several places, although these are both under a lot of pressure.

The first male Matticnemis doi close to the waterfall. A highly inconspicuous species, due to its dark colors. It is about the same size at Copera marginipes and C. vittata.

Another male, this one at the type location

The female has mostly the same pattern, but misses the swollen tibia of the last two pairs of legs. 

Saturday, 10 October 2015

A few hours in Vientiane, Laos and a new species for the Laotian list.

This Thursday I had a few hours to spare in Vientiane and took a cab to the outskirts of the town. Thank God the surroundings are not close to being as polluted as around Hanoi and I was able to find 38 species in a short time. Vientiane is about as far south as Ha Tinh in Vietnam, which is about the southern edge of my general research area (northern Vietnam). But its species are quite different, much more southern. There was a lot of overlap with the commoner species in Cat Tien National Park, for instance. I was happy to catch a Epophthalmia frontalis male. Yokoi & Souphanthong actually list 31 Macromiidae, 28 of them Macromia. Which is rather astounding. But anyway, I was happy with my frontalis. And I was able to take pictures of male Lestes elatus and female Ceriagrion cerinorubellum. I had seen both these species in Cat Tien, but had not seen these sexes. Below a few pictures. And another very common species in some inundated and apparently deserted rice fields was an Aciagrion. I had to go back to Ris (1911) and Fraser (1933) to find out what may be the differences between Aciagrion occidentale and A. borneese. The appendages look rather similar and the A. borneese I had from Da Nang had been eaten by vermin. But in the end the description of Fraser pointing out that S8 is blue with a black triangle on it in A. occidentale, whereas A. borneese has a broad dorsal black stripe over the whole segment, provided the clue. Photos from India confirm the pattern on A. occidentale, and I therefore conclude that the specimens I saw were A. borneese, on the premise that the pattern is consistent over the complete range of these species. Interestlingly Yokoi & Souphanthong do not list either of these species for Laos. A. borneese is a very common species in Thailand and that country is of course right opposite the river at Vientiane.

Let's start with the addition to the Laotian list, Aciagrion borneese. Note dorsally black S8 and S10, whereas S9 is marked by a thin blackish dorsal line.
Another male with the distinctive pattern

Female Ceriagrion cerinorubellum. Possible to confuse with C. auranticum because of the green eyes and orange-brown cranium. However, S3-7 are blackish above and blue-green laterally, not orange, and S9 misses the clear darker marking.

Lestes elatus female

And the male, which I had failed to find in Cat Tien.

And finally a fine male Epophthalmia frontalis

Tuesday, 6 October 2015

Some interesting gomphids from Quang Nam

On 25-27 September I visited Quang Nam Province around P'rao on the HCM Highway. I ran into quite a few interesting gomphids and I would like to share here some of them. Price for most interesting on the 25th goes to a Leptogomphus species. Recently I had a conversation with Haruki Karube on Leptogomphus uenoi, for which he recently published the male. Before that the species was only known for females and one could argue that the male leads a secretive life. But we concluded that maybe it was just overlooked, as the appendages are rather similar to those of L. perforatus. Well, I caught a Leptogomphus and in hand concluded it was probably L. perforatus, but somehow the ring of the inferior appendages seemed closed and I decided to collect it. Lucky too, for at home it dawned on me this was L. uenoi! The outer edge of the inferiors is straight, but the inside edge curved.

Leptogomphus uenoi male, a typical Leptogomphus species

But look at the appendages! A neat ring and almost straight outer edges.
 On the 26th I bumped into a multitude of interesting species. I was very happy to see quite a few Nepogomphus walli. Males were congregating in a fern at a particular stretch of the stream. I had so far only seen this species in Cao Bang Province.

Nepogomphus walli in hand, with its typical yellowish wollen base of the superiors

One of the males perched, this one not on a fern

Also interesting was the Lamelligomphus sp. that I had seen in spring much further north, in Nghe An Province. It was quite common here.

Lamelligomphus sp., a smallish species with interestingly very dark S2. Some individuals had a small yellow spot posterior of the auricle. It is similar to L. hainanensis, but has no protrusion of the inferiors.
A real surprise was the Nychogomphus flavicaudus on a larger river, where 3 males were hovering in the middle of the day. There were no differences with the specimens from Cao Bang I recorded in spring. Same size and same pattern on the thorax (only an antehumeral spot).

Male Nychogomphus flavicaudus, at least, if flavicaudus is a valid species
The last cool species I want to introduce here is Burmagomphus divaricatus. I had only recorded a freshly emerged specimen in Cao Bang in spring, but here I saw several adult males.

Here is one of the males in hand. The pattern on the dorsal side of the thorax is a little variable.

Another, similar, male perched

And the appendages in dorsal view

Sunday, 4 October 2015

Anax immaculifrons - the fourth Anax

Driving from Da Nang to P'rao, just in Quang Nam Province, I finally caught up with what is in Europe sort of a legendary species, or at least greatly appreciated. And likewise, in fact, in Vietnam. Ana immaculifrons, a beautiful Anax species. Interestingly, I have not seen it in northern Vietnam, nor am I aware of any records here, but it apparently occurs both on Hainan and in Guangdong in China. In Vietnam is is known from the area around Da Nang, so in that respect it was not strange that I saw several on September 25. All where observed along clear mountain streams, where there where shallow pools. I did not see any females.

This was the first specimen I saw. It would perch for prolonged periods before going back to patrol flights.

The same male, but posed after I had captured it to take shots of the appendages

And this is what they look like in dorsal view

Another male, this one not posed, but posing of its own free will