Monday, 28 April 2014

The male of Idionyx carinata

One of the reasons why I went back to Huu Lien, apart from the Gomphids, was to look for the male of Idionyx carinata. I saw several females cruising in the forest and eventually there he was, the male. Always good to find that your earlier identification was correct. The male has a small yellow spot on the anteclypeus like the female and the thorax pattern is the same. The proof of the pudding is in the massive and strange appendages. What do they do with this?

Idionyx carinata, male, such a friendly little chap

That is, until he shows you his "thing" 

Ovipositing female of Orolestes selysi

This weekend when in Huu Lien I observed several females of Orolestes selysi. I previously only saw males, so for the readers interest, here are some pictures. The female started ovipositing in life wood about 2 meters above a shallow and slow moving stream in a bush. Interestingly, she twisted her abdomen so that sometimes the ovipositor faced left, sometimes right.

The female of Orolestes selysi

Ovipositing with twisted abdomen

Sunday, 27 April 2014

Prodasineura croconota - beautiful little critter

At Huu Lien on April 26 I did see something else besides Gomphids and guards. I ran into a beautiful Prodasineura over a heavily forested stream. Within 3 meters or so I saw two males. The would perch on the tips of twigs over the water and close to the surface, or hover close by above the stream, very much like Prodasineura autumnalis does. It was however very brightly colored, as nice change with, let's be honest, the rather boring P. autumnalis. Do Manh Cuong mentions a Prodasineura species (unidentified) from his survey. I do not know if he refers to the same species. It is different from the type specimen (from Taiwan) that has apparently more extensive orange markings on the head, but on the mainland of China this is reduced to two tiny orange spots, exactly as the present species has. The appendages also match well. I am therefore confident it is this species, which is also known from Guangxi, Guangdong, HongKong, Hainan and, according to the IUCN red list information, has recently also been found in Central Vietnam.

Ain't he a handsome fella: Prodasineura croconota, male

Appendages in lateral view

And in latero-dorsal view

Showing the dorsum of the head, with two tiny orange spots

A new species for my Vietnamese list - Gomphidia abbotti

This Saturday at Huu Lien I encountered this smashing large gomphid on two occasions. Identification is quite straightforward, with the double dot on either side on the dorsum of the thorax and the brightly marked orange-yellow and black abdomen. The orange-yellow markings are not always as prominent as in this specimen. Sebastien on his blog mentions the species too, but his sightings are few. He spotted it at Cuc Phuong and in Hoa Binh Province. Hopefully I will have better photos next time.

Gomphidia abbotti abbotti, male

Another new Gomphid at Huu Lien - Asiagomphus sp.

This Saturday, April 26, I was looking for Gomphids at Huu Lien. I paid a price, because today I have a rash on my left arm and a little bit on my left side. Probably a fungal infection from walking in wet cloths all day (very hot, very humid and wading in the streams did not help). Apart from Nihonogomphus cf. liefticki and the Trigomphus sp. I also saw again several of the Gomphid I already mentioned in the Trigomphus entry. I was able to catch a female and take some better pictures of the male. Clearly, it is a large Asiagomphus species, but a few details of the female stand out. The general coloration seems to point to Asiagomphus hainanensis, but details of the female do not match. The lack of longitudinal dorsal lines on the abdomen but rather short perpendicular stripes (not unlike A. acco) do not match any species I have been able to check. What is more, the female has three horns, one on the occipital ridge, and two behind the ocelli. Several species have similar characteristics, but not A. hainanensis or A. pacificus. A. acco has all yellow S1-2, unlike the present species, and a different thorax pattern. The upper appendages from the male seem longer than the inferiors, also present in a few, but only a few, of Asiagomphus species that I have been able to check. If anyone has suggestions as to what this could be?

Photo of the male from quite far away.

Another shot of the same male. Pattern on the thorax very similar to A. hainanensis.

The female Asiagomphus. Note the lack of an antehumeral stripe, only a spot, extensive black on S1-2 and the lack of a second yellow lateral spot on S3. Also, check the shape of the markings on S4-7, perpendicular rather than longitudinal. The vulvar lamina is typical of the genus.

Note the three horns and the all black labrum

Thorax pattern of female seems to be identical for the male

Scan of the female in dorsal view

Differences between Nihonogomphus at Huu Lien and N. schorri at Xuan Son, a case for Nihonogomphus lieftincki

Yesterday, April 26, I visited Huu Lien. The day ended a little weird, when I was questioned by 5 guards demanding so see the insides of my car, the contents of a plastic bag (with Kameliya's rubber boots) and so on. It is of course good they keep an eye on things, so I tried to be cooperative to some extent. But the guy walking by with illegal electric fishing equipment was not even glanced at and the sound of chainsaws from various directions where people were cutting down any larger and accessible trees also did not seem to bother anyone, which made it look like a racial profiling exercise to me. But then again, ecotourism is quite an alien concept here and that anyone would want to take pictures of Odonata, well, weird…

Surprisingly, yesterday was rather sunny and I had another shot at various gomphids. I was able to catch two Nihonogomphus specimens and was struck by the differences with the Nihonogomphus schorri specimen from Xuan Son the other day. I doubt whether the differences are large enough to warrant a discussion of the species level, but it is an interesting case of geographical variation or inter population variability.

First, here is a Xuan Son specimen photographed perched and one from Huu Lien.

Xuan Son, Nihonogomphus schorri, male, April 13

Huu Lien, Nihonogomphus species, male, April 26
Apart from some differences in the coloration, the difference in shape is striking. I only saw one perched in Xuan Son, so it is difficult to generalize. But the difference is born out also by structural differences between the specimens caught. HW shorter and body longer in Huu Lien (BL 47mm against 44mm, HW 34mm against 35mm). (Measurements given by Do & Karube for N. schorri BL 45mm, HW 32.5mm)

The Huu Lien specimen in hand, different from the one perched in the photo

Xuan Son specimen in hand, also different from one perched in photo
An interesting difference, apart from the body shape also evident here, is the black line over the metapleural suture. The Huu Lien specimens all have a thin branch, sharply defined, which is much more diffuse in Xuan Son, giving the impression of a continuous broad black stripe rather than a branch. In the drawings by Do & Karube this branch is completely lacking and the stripe narrows dorsally.

What can already be seen here is the difference in shape of the first segment of the penile organ. Let's pull that close:

Huu Lien Specimen 1, look at the hook directed posteriorly

Huu Lien Specimen 2, identical hook

Xuan Son Specimen, no hook, just pointed straight down
What is interesting is that the shape of the first segment of the penile organ of the Xuan Son specimen is closest to the drawing in Do & Karube, which was of course based on Huu Lien specimens of N. schorri.

Huu Lien Specimen 1, appendages in ventral view. Note the inferior appendage is not spread and although bent upwards, reaches the shoulder of the superiors.

The Xuan Son specimen, spread in a V and falling short clearly off the shoulder  of the superiors

Second Huu Lien specimen, identical to the first specimen
Interestingly again is that the Xuan Son specimen fits well the drawings in Do & Karube, in which the inferior appendage is spread in a V and falls clearly short of the shoulder.
Dorsal view Huu Lien specimen 1

Dorsal view Huu Lien specimen 2

Dorsal view Xuan Son specimen
Note that the shapes and color are consistently different (in the small sample), also given the two in situ photos of life specimens. Both Xuan Son specimens (including the perched specimen) have half of S10 yellow, which is obscured in the Huu Lien specimens, but again clearly illustrated in Do & Karube.

The lamina of the anterior lamina is also drastically different. It is, in short, a completely different structure. And the anterior hamule, with a shoulder in the Xuan Son specimen, as to be expected for N. schorri, only broadens somewhat, without a clear shoulder, in the Huu Lien specimens.

This is a Huu Lien specimen, note the rectangular, but almost square,  lamina at the bottom of the structure

This is the Xuan Son N. schorri. Note the narrow and clearly excavated lamina, which also almost disappears under the adjacent structure. It is very different.
It is clear that the specimens from Huu Lien, the type locality of Nihonogomphus schorri, are a different species. As a matter of fact, shape of appendages and penile organ first segment, shape of anterior and posterior hamuli, measurements, black labrum, all fit very well Nihonogomphus lieftinck, a species from Fujian, Hunan, Hubei and also Guangdong in China. See the drawings in Chao (1954), and in Wilson & Xu (2009), including. The differences in coloration could be geographical variation. With a more thorough study of the type material of N. lieftincki structural differences might become apparent, but for the time being I call this Nihonogomphus cf. lieftincki.

Wednesday, 23 April 2014

A last few photos from Huu Lien* **

*Updated after publication of Paracercion ambiguum
** Updated again after publication of Lyriothemis kameliyae

Here are a last few photos from Huu Lien. It is Wednesday evening, so ready to start thinking of the coming weekend. But for now it is misty, rainy and cloudy, as it has been the last two months. Nevertheless, a few more shots of species seen on April 21. Tetracanthagyna waterhousei is new for the blog.

This is a male Prodasineura autumnalis, a rather common species

And this is a beautiful male Lyriothemis kameliyae

This is the Paracercion ambiguum male, a new species to science. 

And finally a female Tetracantagyna waterhousei. This bulky mama flew up higher into the trees, so I could not get better shots. It is a monster of a dragonfly.

Some additional species at Huu Lien from April 21

The two Copera species of Huu Lien and the one Pseudocopera were already common and easily found. Here are the males of P. ciliata and C. marginipes in their full glory.

Pseudocopera ciliata is the easy one, large, and white when mature

Here a male Copera marginipes with its simple, but large superior appendages

A somewhat messier C. marginipes. C. vittata normally has much less white on the last segments.
A remarkable and large species was Orolestes selysi. The dark-winged form and the hyaline form occurred side by side.

A fantastic dark-winged specimen of Orolestes selysi

The somewhat less striking, sorry to say, hyaline version.
I also had the opportunity to take a better look at some immature Orthetrum glaucum.

First, a female Orthetrum glaucum.

A fresh, still less pronounced, female

The interesting immature male. The striking pattern is later completely obscured by pruinosity.

Tuesday, 22 April 2014

Idionyx carinata at Huu Lien

April 21 I was checking for dragonflies inside the forest in Huu Lien Nature Reserve in the afternoon under a cloudy sky. My attention was drawn by a dragonfly cruising up and down a slight opening over the trail. Caught, it appeared to be a female Cordulid. Checking at home it became quickly apparent this is an Idionyx species. Karube (2011) described 3 species for Vietnam, Idionyx victor, I. carinata and I. asahinai. The latter two have the same thoracic markings are my female and the double horn on the vertex points to I. carinata. A further difference with I. asahinai is the facial pattern, with a small yellow spot on the center of the anteclypeus, whereas in I. asahinai the whole labrum is also yellow.  

I. carinata is widely distributed in Southern China and apparently also in Northern Vietnam, as Karube mentions specimens from Tam Dao, from Cuc Phuong and also from Cao Bang Province. By the way province is the province west of Lang Son, in which Huu Lien is located. 

Fraser (1924) mentions I. optata as very similar to I. carinata, but states for instance that the anal loop of carinata has less cells (4-6 cells in carinata and 12 in optata). However, this was based on only one female and one male specimen. The photo of I. carinata in Karube show around 12 cells in the loop. My specimen also has 12 cells. Of course I will be happy to see a male next time!

Idionyx carinata, female, scan of dorsal side

Same female in ventral view. Note the straight yellow stripe and the extensively yellow metepimeron, yellow extending onto metepisternum.

Note the double horn on the vertex and the small yellow spot on the anteclypeus (and extending marginally onto the labrum)

Huu Lien Gomphid enigma*

*Adjusted after publication of the Tombo May 2015 issue, in which Haruki Karube published Trigomphus kompieri.

Yesterday, April 21, I visited Huu Lien Nature Reserve and ran into 4 Gomphid species. Nihonogomphus schorri, after all it is the type location, and Ictinogomphus pertinax will not raise eyebrows. A small gomphid of which I saw 4 individuals should. It appears to be a Trigomphus species, a genus not recorded from Vietnam, although it has been recorded with several species from southern China. It has appendages close to those of T. succumbens, but the thorax markings and facial markings are rather different. Especially the thick black line along the metapleural suture, the so-called third lateral stripe, is strange. If correct, this species awaits description. Please see the below photos and if you know what it is, tell me. (It was subsequently established that this is a new species of Trigomphus, described as T. kompieri (Karube, 2015)

Besides, I also saw another, large, Asiagomphus. I was able to take some photos, but these do not show the abdomen tip. I doubt anyone will have the audacity to identify it on basis of the photo, but I add it at the bottom nonetheless.

The very, for a Trigomphus, blackish male of T. kompieri.

At about 45 mm not a large insect, for a Gomphid

Appendages in ventral view

More striking, because of the white color of the superior appendages, in dorsal view

Close-up in lateral view, of course upside down. This is the right side. The superior appendages have a large ventral tooth at 2/5th and a serrated distal edge, inferiors smoothly curved.

The left side, lateral view, this one uppers up and lowers down.

The right superior appendages in dorsal close-up. Ventral tooth also visible as lateral tooth, but it is one and the same.
The other, large, enigmatic Asiagomphus. Note the narrow lateral yellow stripe.