Ophiogomphus, Lamelligomphus and Melligomphus

Ophiogomphus longihamulus was described by Karube (2014) from Pia Oac Nature Reserve and I spent a great deal of time looking eagerly for it. Eventually, on July 8, I finally ran into an Ophiogomphus. But it was not to be. It was Ophiogomphus sinicus. In itself a great discovery, and especially interesting because it shares the same habitat and general area with O. longihamulus. That species was observed in May, so maybe O. sinicus appears later. The two species, by the way, can be separated on the basis of, indeed, the length of the hamulus.

Ophiogomphus sinicus, Cao Bang Province, July 8

In hand, the same male

And close-up of the appendages

 Two species of Lamelligomphus were also very common. I saw Lamelligomphus camelus in the provinces Phu Tho, Hoa Binh, Bac Kan, Ha Giang, Yen Bai, Lang Son and Cao Bang. Lamelligomphus hainanensis was much less common. I saw that species in Yen Bai on mountain streams and likewise in Pia Oac Nature Reserve in Cao Bang Province. It is smaller than either L. camelus or L. formosanus and has smooth dorsum to S7-10. Whereas L. camelus is active during the day and at dusk, L. hainanensis seems to be active only during the day.

An obelisking male Lamelligomphus camelus, a common species

Much less common, male Lamelligomphus hainanensis

Another male, right in the act of spraying some liquid from its abdomen. He did this several times. I have no idea what this behavior is.

Lamelligomphus hainanensis, male, in hand. Pattern on S1-2 close to L. formosanus, without the boomerang of L. camelus.

Female Lamelligomphus hainanensis hovering over a stream and preparing to drop egg-ball

A female in hand

Close-up of the female face, showing the double horn on the occipital ridge

 The last species of this posting is Melligomphus ardens. This species too is active at dusk. In fact, although I have saw it during the day at a river in Bac Kan Province, almost all observations this year (at Phu Tho, Cao Bang, and Bac Kan Provinces) were at dusk. At the places where I saw it at dusk, I did not see any during the day.

Melligomphus ardens, male, 26 June, the only male seen in bright day light

An eventful day at Tay Thien - Ophiogomphus sinicus

June 15 I went to Tay Thien again. It was partially cloudy and I was not too happy with that, but it was warmer than yesterday and there eventually were good spells of sun. I ran into several cool species. The first I want to share is another Onychogomphid. Last year, when we were discussing the possibility of several Lamelligomphus species in Vietnam, Sebastien showed a photo of a Gomphid with huge pincers as appendages. Clearly it was not Lamelligomphus, but we did not know what the alternative was. I decided today to first look at the stream where he had seen it. I did not see a lot going up the stream, but on the way back all of a sudden I saw it, sitting on a stone in midstream. I was able to first take some pictures and then to catch it for in hand shots. The stream where I caught it is a low elevation, really bordering the plains, and runs through a relatively open area, although the hills are covered in degraded forest. But later in the day, when I walked the path to the nunnery at Tay Thien (a different stream) I saw two more right next to the nunnery, so in the middle of the forest on the stream at 350m altitude.
Anyway, it is Ophiogomphus sinicus. A rather weird Ophiogomphus at that. It was first included in Onychogomphus as Onychogomphus sinicus, but after studies were done on the larval stages, it was transferred. Well, I guess there are good reasons to do so, but it sure as hell does not look like regular Ophiogomphus species. It is known from a large part of Southern China, although locations are scarce, for instance Guangdong and Guangxi. Not too surprising it occurs in Northern Vietnam.

Ophiogomphus sinicus, male, perched on rock in stream

In hand, the same male

Face of O. sinicus. There is not much difference with Lamelligomphus, really

Appendages in dorsal view

And in ventral view. Note the dorsal tooth at 1/3rd of superior and inferior appendages

And to be complete, ventral view

The shape of the anterior and posterior hamuli