Labrogomphus torvus and Megalogomphus sommeri - more widespread

In November last year we found Labrogomphus torvus in Huu Lien and also in Huu Lien this May Megalogomphus sommeri. L. torvus was a new addition to the Vietnamese list and M. sommeri had been seen by Cuong in Cuc Phuong once. As far as I know, that was it. In the meantime Sebastien recognized L. torvus on photos from an unidentified gomphid from Tam Dao. I also ran into this species in northern Bac Kan Province in late June and early July, where it shared a shallow and 2 meter wide stream along an open agricultural area bordered on one side by degraded forest with Megalogomphus sommeri. Apparently both these large and powerful species have a wider distribution in northern Vietnam. They were both active during the hotter hours of the day, when few other gomphids were out and about. At other moments on the same days at least an additional 9 species visited the same stream (Burmagomphus vermicularis, Stylurus amicus, Asiagomphus auricolor, Lamelligomphus camelus, Merogomphus paviei, Macrogomphus guilinensis, Gomphidia kruegeri, Leptogomphus perforatus, Gomphidia abbotti).

Labrogomphus torvus, male, Bac Kan Province. See also earlier posts both in this blog and on Sebastien's.

Megalogomphus sommeri, widespread in southern China and also more widely distributed in Vietnam than paucity of records seemed to suggest.

The female of Megalogomphus sommeri

Facial pattern of the female

7 december at Huu Lien

We visited Huu Lien on the 7th to find the female of the "Pseudagrion". It was not too warm and not too sunny, but it was a good day. Clearly numbers were dropping and we only saw about 30 species, but hey, it is December. No Atrocalopteryx species, but supercool Labrogomphus torvus was still around. Water levels had dropped and some places had dried up already.

Much nicer sitting like this, than in hand: Labrogomphus torvus, male

The same male, after it chased a butterfly and came back

Labrogomphus torvus - new for Vietnam

I created some confusion with a vague photo of a large Gomphid on the blog over the last few weeks, when posting on Huu Lien. Well, today the riddle was solved. When I arrived at the reservoir Sebastien was already standing by the water's edge holding a Gomphid that had landed on his net! We concluded, based on the long S9, that it should be Marcogomphus, but the appendages did not seem right to me. Later, Sebastien caught a female that was eating another dragonfly. And a second male flew by and landed high in a tree. Obviously, even on December 1, there were still Gomphids around. Back at home a quick check of the literature revealed that indeed it was not a Macrogomphus, but fantastic Labrogomphus torvus, well known from Southern China, Hainan, Taiwan. A huge beast, with long legs with terrible spines on them. And very distinctive appendages. So, I will change the Marcogomphus entry…

Labrogomphus torvus, male

Same male, wing venation

Appendages in dorsal view

Labrogomphus torvus, female