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

Lamelligomphus formosanus and Melligomphus ardens

June 8 I visited Xuan Son National Park with the hope of finding the Idionyx male of the enigma species of the week before. Not a single Idionyx crossed my path. But I was intrigued to see that next to Lamelligomphus camelus, which I already spotted last week, there was another Lamelligomphus sharing the same habitat in the same place. It was about as large as L. camelus and had spots on the labrum, unlike the L. hainanensis of Yen Bai. It had more pronounced raised edges to the apical segments, but no humps. In fact, as can be seen from the shape of the appendages, the apical segment of the penis and the thumb-like projection on the anterior hamulus, this was L. formosanus, a species I already had ran into last year. It is the third Lamelligomphus species I see this year and if we count the enigma species of last autumn, the fourth in total. Like L. camelus, it was quite active in the late afternoon, with several males hovering near the third bridge, but also above the concrete path along the river, where L. camelus was also active.

I left the park with the idea of making it to the river nearby to see if anything would fly there at dusk. I saw quite a few Lamelligomphus specimens hovering in the remaining light and because I wanted to know which one it was, I waded into the fast flowing stream. When I finally caught a few, I had a big surprise, because these were not Lamelligomphus, but Melligomphus. And under the microscope they were clearly Melligomphus ardens. The day was made complete by a fine male Burmagomphus vermicularis.

Lamelligomphus formosanus, male. A dark specimen with second and third lateral stripe fused to form almost completely black metepisternum.

A second male with obvious yellow line on metepisternum separating 2nd and 3rd lateral stripe. Note also the pattern on S2. Very different from L. camelus, rather similar to L. hainanensis.

Distinctive appendages of L. formosanus, without dorsal tooth to basal part of superiors, small teeth ventrally on close to bend and highly divergent and long inferiors. Note also the raised edges of S8-9 and the "near" hump, slightly raised middle of S8.

Same appendages in dorsal view

Another close-up of appendages of L. formosanus

The appendages of L. hainanensis for comparison. Very different tips to inferiors.

Facial pattern of L. formosanus

Rather similar facial pattern of male Melligomphus ardens

The complete insect, male Melligomphus ardens. Note the different shape of especially the superior appendages, but not easy to see in flight. Pattern on S2 very similar to L. camelus.

S8 displays minimal humps, not unlike L. formosanus.

The appendages of M. ardens. Note the light tips to the inferior appendages (this being dorso-lateral view) and large lateral tooth on inner surface of superiors at halfway point.

The same appendages in lateral view.

Finally, the small and lovely Burmagomphus vermicularis, hovering above the stream at dusk.

Melligomphus sp. nov. ?

On July 23, as is known by now, I found myself in Ba Be National Park, happily checking a stream with gomphids left and right. There were several Lamelligomphus camels, or so I thought, hovering above the stream, a bit like some Phyllocycla species do in Rio de Janeiro, but that is another story. I caught one specimen and made some record shots in hand. Now, working on the photos, I had another look and lo' and behold, it did not look like Lamelligomphus at all, so I checked it against another specimen I collected in Tay Thien, and lo' and behold indeed, it was different. What is more, that species was a Lamelligomphus, but not L. camelus either. The plot thickens...
The Ba Be specimen was Melligomphus ardens, or was it? As can be seen on the photos S8 does not have a pair of humps, it only has a tuft of hairs centrally on the dorsum of the segment. And now we come to think of it, the metepisternum should have a stripe, but it is reduced to just two tiny yellow elongated spots. This could be individual variation. Wilson & Xu 2009 also give an elongated 5th cel in the anal triangle, absent in this specimen and there seem other differences in the appendages too. Enough to raise an eyebrow! Better go back next year.

As a postscript, the other Melligomphus species all seem to have the antehumeral stripes separated from the collar, unlike M. ardens. Chao does not give the 5th cell in the triangle.

Melligomphus sp. nov. , male

The appendages, but note the dorsum of S8, a tuft of hair, but no humps!

Another view of the last segments