Wednesday, 10 September 2014

Aciagrion borneense - another cool little damsel

Wednesday September 10 I was for work in the city of Danang, visiting some communities on the outskirts. While traversing some former rice fields now covered in grass and puddles I noticed a small and slender blue damsel. A little later I saw several more, interacting in little territorial disputes amongst themselves and with Agriocnemis femina. I could catch one with my fingers and put it in an empty water bottle. In the evening, back at home in Hanoi, I could take some photos and identify it as Aciagrion borneese, a very common and widespread species, that has been recorded before in Vietnam, according to the IUCN information, but apparently recorded only rarely, although given the fact it is common and widely distributed from Indonesia to Thailand and Cambodia in disturbed habitats, it may be also widespread in the south of Vietnam. It is a distinctive species because of the reduced blue on S8 and S10, with blue dorsum to S9. The appendages are a close match with the drawings in Ris (1911), although slightly larger (abdomen 22 mm against 19 mm in the description).

Caught in a trap: Male Aciagrion borneense inside its plastic cage
The scanned insect
Close-up of the thorax and head
Dorsal view of S8-10 and appendages
The same in lateral view

Tuesday, 9 September 2014

A. gigantica. Another Anotogaster!

Sunday September 7 I visited the Yen Bai area and checking a small stream running of the hills alongside QL32 I noticed a large dragonfly cruising. Large, but not extremely large. Nevertheless, when it passed once more it was clearly a Goldenring. It flew up the hillside and hung up in some shrubs. I could take a few record shots and then clambered up the hill until close to it and as this was a lucky day, I could net it. In hand it was immediately obvious from the small size and the yellow mandible bases that this was neither A. sakaii (larger and missing yellow bases), nor A. klossi (larger, although with yellow mandible bases, but different appendages). Indeed, checking the appendages, these were clearly different from what I had seen before, with a very clear large ventral tooth at over one third of the superior appendage, plus another basal one. The top of the frons was black, so later I could rule out A. kuchenbeiseri (which has yellow dorsum to the frons) and A. gregoryi, which has different teeth to the superior appendage. Remains A. gigantica. What is in a name, for a smaller species! But indeed, gigantica is a smaller Anotogaster, if still close to 9 cm. The appendages are rather distinctive, although apparently the specimens from Sapa miss the clear yellow bases to the mandibles. Although the IUCN list only mentions the species from a few old records from Yanmar, Karube (2012) illustrated it as one of 5 species of Anotogaster occurring in Vietnam. It was until now only known from Sapa.
The beautiful Anotogaster up in the shrub. Immediately the very yellow appearance is obvious
And in hand. Note the large yellow lateral markings on the thorax, and broad yellow rings on the abdomen down to S9. The yellow bases to the mandibles are also visible.

Although difficult to capture with my microscopic camera, this shot in the field of the appendages shows the clear ventral tooth almost in the middle of the superior appendage and directed anteriorly, plus a smaller but obvious basal ventral tooth. The epiproct is clearly getting thicker towards its apex and reaches to two thirds of the superiors.
Just short of 9 cm, a full cm smaller than A. klossi and A. sakaii, which is just as well. Those are chunky bulky things, this is a slender beautiful insect.

Typical diverging superiors

Another shot, with the microscopic camera, of the ventral tooth.

Ventral view of appendages 

And lateral view of S1-2. Note the different lamina compared to A. klossi (see that post).

Yen Bai - Aeshnid headache*

Last weekend was great weather, so I decided to drive the Yen Bai and check out the autumn status of things. On Saturday I visited Xuan Son and saw a great many old friends, but nothing I had not seen before. I drove on in the evening to Nghia Lo and stayed in the local hotel, drove on the next morning to the general Yen Bai area. At one of the first stops around 10 AM I caught a beautiful Anotogaster, on which more in the next post. I then around noon checked the trail and stream at the fish farm and motel. There was not really a lot going on, although Anisopleura were plentiful. But in one shaded part of the trail (less shaded all the time because of tree cutting) I saw an Aeshnid that after a short flight over the trail hung up in the trees. With some very careful climbing I was able to get to it without disturbing it. Examining the specimen it appears to be a Cephalaeschna, judging from the venation and the number of cells in the anal triangle. Also, a broad frons. The appendages are blunt, but not rounded, in fact they display a small point. There are quite a few Cephalaeschnids in China, but only a few have been recorded for Vietnam. I am aware of C. aritai and C. asahinai and recently Sebastien caught something close to C. klotsi. The facial markings of my specimen are very close to that described by Karube for C. asahinai, but it has a small apical tooth to the appendages that should be absent in the rounded appendages of C. asahinai. I am still waiting for the article by Asahina (1981) with the exact description of C. needhami, but appendages ( long inferior, slightly pointed superiors) and facial pattern apparently match. It cannot be ruled out this is a completely new species, but for the time being I will consider it C. cf. needhami. Any suggestions more than welcome!

Up in the tree, Cephalaeschna. Note the greenish markings and the reddish femurs. 
In hand, reddish legs obvious, as is the long epiproct.

In dorsal view, note 5 celled anal triangle and small pterostigmata

Facial pattern with yellowish-red labrum, greenish yellow postclypeus, antefrons dark reddish brown with greenish lower margin.

Appendages in dorsal view. Note that they are not rounded, if blunt, with angular corner,. Epiproct two-thirds of superiors. 

Lateral view of the same
Ventral view. Again the corners not rounded.

Penis in lateral view. Flagella longer than apical segment, double

Penile organ in ventral view
*Haomiao Zhang commented that this species is indeed close to C. needhami (and C. klotsi), but that it is neither. It could well be a new species.

Tuesday, 2 September 2014

Lamelligomphus sp. - a new species after all?*

*This entry slightly adjusted now that the Lamelligomphus sp. has been described by Karube (2015) as L. vietnamensis.

Last year in October I caught a Lamelligomphus (see the entry) that until now I have not been able to identify. Sebastien also had photos of similar specimens, but only recently did we see it again. In August Sebastien informed me he had seen several in northern Vietnam and this weekend when visiting northern Bac Kan Province I too caught up with it again. I had a single male hovering over a clear stream that I could catch. Superficially it is like L. hainanensis. It has similar penile head shape, similar anterior hamule shape, no humps on S8, small teeth on the interior of the superior appendages. Indeed, I had thought previously this was L. hainanensis, until I found it earlier this year. But what I call L. hainanensis has a continuous green-yellow stripe over the top of the frons, even if it is slightly incised. The Lamelligomphus sp. (now Lamelligomphus vietnamensis) has the stripe clean cut into two parts. Also, L. hainanensis has all black or only slightly marked labrum, whereas the present Lamelligomphus has two clear yellow spots on the labrum. The inferior appendages are more blunt and do not project at all beyond the superiors. In dorsal and ventral view there are also small differences. And where L. hainanensis is a smaller species, with abdomen 41-42 mm, in the present species it is 47-48 mm. It is clearly a common species, has undoubtedly been overlooked (like L. formosanus), but I cannot fit it onto any known Chinese species. It is close enough in structure to L. hainanensis, but there cannot be two species with the same name, obviously.
Lamelligomphus vietnamensis. Typical as the genus goes.
Compare this photo of an earlier L. hainanensis. Very similar in overall patterning, but longer overlap of inferiors, which also clearly protrude.
Dorsal view of Lamelligomphus vietnamensis.

This is the face of  Lamelligomphus vietnamensis. Note the broken line over the frons and the large oval spots on the labrum. The yellow over the anteclypeus is, I think, normally continuous.

I already published this photo of face of L. hainanensis with continuous stripe over frons and all black labrum. Sometimes there are small yellow spots  near the sides (actually also in this specimen). 

Dorsal view of appendages
Ventral view
And lateral view. The short inferiors that do not protrude at all typical

Penile organ by the looks of it similar to L. hainanensis

A new Anisogomphus species?*

*May 20, 2016, this species was published as Anisogomphus neptunus Karube & Kompier, 2016

August 31 I visited Pia Oac and on the way there along the TL212 already caught a male
Anisogomphus tamdaoensis. I had caught a female of A. tamdaoensis at Pia Oac already late June and was happy to confirm a male about 7 km from the reserve. It was a little smaller than other males I have caught at Ba Vi and Tam Dao, but the appendages are identical. We can now safely assume this species to have a wide range in northern Vietnam.

However, when I visited the "illegal gold miners stream" in the reserve, where I had caught several and saw many Anisogomphus sp. in June and July, it was cloudy and nothing happened, apart from one Macromia moorei. So I went to the pass and, as we know from earlier posts, caught Anotogaster klossi. Then I decided to give the stream another go, now that the weather was a little better. When waiting there a gomphid of medium size dropped from the sky. It seemed to be another A. tamdaoensis, but flew off chasing an insect before I could get to it. A little later a similar, if not the same, gomphid perched on some leaves. I wanted to make sure, so caught it and before checking the appendages already had a thrill. It had a large yellow dorsal spot on S7, something absent in A. tamdaoensis, but something the females of June/July had all displayed. Indeed, this was an Anisogomphus species! So, likely the male of my mystery species.

I could find 20 species of Anisogomphus in the literature (including A. tamdaoensis). None fit the present species, although I have not been able to find the description of A. jinggangshanus Liu, 1991. The appendages are somewhat similar to A. anderi Lieftinck, 1948, but obviously different. For the moment it looks like this is a new and rather distinctive species!

Anisogomphus sp. novum (Anisogomphus neptunus). The indicator for the genus are the large spines on the femur
Note the large yellow spot on S7. The weird appendages are already visible.
In dorsal view. The superiors seem fused into a plate with three distinct parts.
The superiors have a large process that seems fused with the process of the other , so the appearance is created of a third central process.
Lateral view
And ventral view
This is the A. tamdaoensis, nice to verify the male. Compare general structure and spines on femur.
A. tamdaoensis in dorsal view. Typical appendages (although shared with A. chaoi and A. pinratani) and only narrow line on dorsal carina on S7.

A few interesting Calopterygids from Bac Kan and Cao Bang Provinces

I know this stream along the TL257 in Bac Kan, at Km 58, that has some really interesting Gomphids in spring. So on August 30 I paid it a visit. And not in vain. The price of the day went to Matrona taoi, a rare endemic Matrona species, recently described from Xuan Son and apparently also known from Quang Binh Province in Central Vietnam. It may be more widespread. The stream I visited is not special, running along a clearing with cultivated fields and degraded forest on one side. It is not particularly wide either, 2 meters or less in most places. But along the stretch of about 400m I counted 4 males of this wonderful species. A few Matrona basilaris were also present, and many Vestalis gracilis.

The next day along the TL212 in Cao Bang I visited a small stream by the road side in a pocket of rice fields and houses. This stream also seems like nothing special, but it had 4-5 males of Atrocalopteryx coomani. This is a relatively widespread, but definitely scarce species. In Pia Oac I found another Matrona basilaris. Clearly the advent of autumn is bringing other species!

Male Matrona taoi, a beautiful and rare damsel

Showing the wing pattern, with lighter outer thirds

Scan of male Atrocalopteryx coomani, with also a very interesting wing pattern

Which is not visible in the perched insect, apart from the short moments it will flash its wings

Monday, 1 September 2014

Anotogaster klossi - another Goldenring

On August 30 I drove to just north of Ba Be, stayed the night at a local hotel in Cho Ra and drove on the next morning to Pia Oac. As usual the skies were clear until I got near the top, which invariably is covered in cloud. But I was in luck, as the shifting winds caused it to clear up now and then for longer spells of sun in the afternoon. Visiting the little swamp and the stream that feeds it close to the pass, I noticed a large dragonfly cruising along the opening. Goldenring! This was exactly the same spot where two months ago I observed several Anotogaster sakaii and the size fitted. But as it passed I could catch it and noticed the clear yellow markings on the bases of the mandibles. In A. sakaii these are unmarked orange-brown. A different species of Anotogaster! Using the paper by Karube (2012) the appendages and the shape of the lamina matched very well with Anotogaster klossi, the only species in the paper with clear yellow bases to the mandibles. It is large for that species, but just at the top of the range given by Karube. The length of the abdomen was 76 mm and total length 10 cm. Anotogaster klossi has been recorded in southern, central and northern Vietnam. In fact, Asahina recorded it from Pia Oac. No cool range extension thus, but nevertheless, a very exciting find. Those records are from May and I was surprised to find this species this late in the season. I saw 2 more Anotogaster, but not close enough to verify these too were A. klossi.

Scan of Anotogaster klossi, male. 

The male A. klossi in hand. Note the clear yellow bases to the mandibles. The head is hanging almost detached, that explains the awkward position.

Note the yellow mandible patches and the deeply excavated frons.

Very long superior appendages and thin epiproct.

Dorsal view of appendages, showing superiors twice as long as epiproct in dorsal view
Ventral view with slight excavation of epiproct

Typical shape of lamina in lateral view