Asiagomphus, two different new species?*

*This entry was adjusted on January 1, 2020. In August 2018 I published an article on Asiagomphus species in Vietnam in Zootaxa. By then I had verified 8 species of Asiagomphus in Vietnam, several of which were new to science and others were not previously recorded from the country. I did not want to change the 'historic' entry below that reflects my first ramblings when confronted with specimens of this tricky genus in Vietnam, so I left it as it is, but added the proper scientific names for the species involved between block-marks. (These are Asiagomphus auricolor and A. superciliaris.)

I already posted on an Asiagomphus species occurring at Huu Lien Nature Reserve. Until now I only had a female in hand. Useful, because the horn on the occiput immediately helped to eliminate most possible species. It was however pretty much impossible to say more on the specific identity.

On May 1 I went again to Huu Lien with the objective of catching the male. I saw a great many (15+), but this is a wary and large insect and I was clumsy too, so it took a while before I finally was able to catch one.

Later that morning I ran into another Asiagomphus male, perched on a stone in the stream, something the other Asiagomphus had not done, always sitting on leaves and branches over the water or hovering and patrolling above the stream. It seemed smaller and darker. And luckily this one specimen was not as difficult, to I was not that clumsy, or both. Anyway, I was able to catch it.

With this, trouble only started. It is clearly another species, but which one? Interestingly, both males share the pattern on the abdomen with transverse yellow lines at the sutures between the segments, and do not have longitudinal lines. The also lack a antehumeral stripe, and the second male even a spot. This is a pattern shared with A. xanthenatus acco [= Asiagomphus acco], which otherwise of course is very different, with a ventral tooth to the upper appendages and largely yellow S1-2. For now, I am at a loss. There seems to be no direct hit with any of the known species in the larger region. The occipital pattern of the female rules out most species for species 1 and species 2 is so dark, it is also different from any others. Of course, most species display quite a bit of geographical variation, or in the details of the appendages. This does not make things easier, but my hope is that scholars with experience of many of the Chinese species may be able to say something on the subject. My gut feeling however is that these are both undescribed species.

Possible species in the area include A. auricolor (Fraser 1926, only one female known, I do not have the description, but it is apparently from "Tonkin")*, A. hainanensis, A. pacificus, A. pacatus, A. perlaetus, A. septimus, A. takashii, A. giza, A. xanthenatus acco and A. x. xanthenatus. I have no match. Suggestions are very welcome.

Measurements:
Species 1 TL 63mm, Abdomen (+app) 47mm, HW 39mm
Species 2 TL 57mm, Abdomen (+app) 41mm, HW 33mm

* I received a copy of Fraser courtesy of Matti Hamalainen. The synthorax pattern of the female in the description is reminiscent of species 1, but lacks the antehumeral spot. The measurements are also off (abdomen length 45mm, mine 50mm). It has all yellow S1-2. Therefore species 1 is not A. auricolor [subsequently I could establish that it is].

To fresh up our memory, the female of Asiagomphus species 1 [=A. auricolor], with two horns over the lateral ocelli and one on the occipital ridge

The vulvar lamina of the female Asiagomphus species 1 [=A. auricolor]

Asiagomphus species 1 [=A. auricolor], with antehumeral spot, large posterior hamulus, second lateral stripe, lots of yellow on S1-2

Asiagomphus species 2 [=A. superciliaris], no antehumeral spot, no second lateral stripe, small posterior hamule, S1-2 dark dorsally

Here the two species scanned in dorsal view. Species 1 [=auricolor] is on the top left.

Species 1 [=auricolor] appendages in dorsal view

Species 2 [=superciliaris] appendages in dorsal view

Species 1 [=auricolor] secondary genitalia, note especially posterior hamule

Species 2 [=superciliaris] secondary genitalia, much smaller posterior hamule with inconspicuous hook

Species 1 [=auricolor] appendages in ventral view, very widely separated inferiors in broad basin like U-shape

Very different inferior appendages, shallowly cut in V-shape [=superciliaris]

Species 1 with stump superior appendages [=auricolor]

Species 2 with sharp point to superiors [=superciliaris]

Species 1 [=auricolor], black labrum. Note the flat area between the two bumps behind the ocelli

Species 2 [=superciliaris], black labrum. Note the gentle V-shape between the two bumps behind the ocelli and the hump on the occiput

The problem with penises. They all look alike. Species 1 [=auricolor], distal segment

Species 2 [=superciliaris], distal segment

A new species of Gomphidictinus*

*Adjusted June 1, 2016. This species now published by Karube as Gomphidictinus kompieri. I am really happy with this massive species.

In 1942 Fraser, and right now I do not have the article, so if you have it please send it to me, erected Gomphidictinus for a species in the Gomphidia group with a spine at the base of the apical segment of the penis. Otherwise Gomphidictinus wheeleri, later identified as a junior synonym of G. perakensis, is very much Gomphidia like, although it is very large.

Last year I mentioned a weird Gomphidia from Tam Dao that lived deep in the forest. May 3 I was lucky enough to encounter at least 6 in Xuan Son National Park, all on a stretch of a shallow clear stream under heavy forest cover. I was even more lucky in that I observed 2 females of which I collected one.

Under the microscope the male has the spine of Gomphidictinus, interesting, as G. perakensis is a deep forest species too. It has many differences in color pattern, however, and the female is strikingly different (in G. perakensis S2 is completely yellow, for starters).

It is also a massive insect. Asahina gives abdomen (including appendages) 52-56mm for males G. perakensis, and female 51-52mm. Laidlaw (1902) gives total body length 78mm, already very large. However, my specimens from Xuan Son have the following measurements: Male (2) TL 86-88mm, Abdomen (+app) 64-66mm, HW 57mm, Pterostigma HW 7.5mm. Female (1) TL 90mm, Abdomen 64.5mm, HW 63mm, Pterostigma HW 8mm.
(The Tam Dao specimen was more moderate, with 82mm TL and HW 52mm)

As you can see in the accompanying scan, it dwarfs G. kruegeri, already a large dragonfly. What is further interesting is that it is very pale, not yellow, and that it is very dark. The postclypeus is completely dark, differing from G. perakensis and the female has interestingly a completely unexpected shape to the occipital ridge.

On the left Gomphidia kruegeri, a large dragonfly, and the right the Gomphidictinus species novum, a truly ginormous dragonfly

The male face, with all black postclypeus and labrum

The female face, similar to the male, but note the occipital ridge, quite the opposite of G. perakensis

Note the spine at the base if the apical segment, typical of Gomphidictinus (if a valid genus)

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

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