Amphigomphus nakamurai

On August 10 last year I caught a male Amphigomphus nakamurai at Tam Dao. This species was described by Karube in 2001. It has since been recorded from Laos, and it was also recorded from Pia Oac in Cao Bang Province. It is therefore categorized as Least Concern by IUCN. Indeed, I ran into it several times in early July in the Pia Oac area, both inside the reserve and just outside, both in relatively pristine environment, the stream somewhat disturbed by gold mining, and in generally deforested areas in the hills with some remaining riparian corridors. Here are some photos of both the male and the female. The female could be confused with Nihonogomphus species, for instance given the green frons and green antehumeral stripes, but has much smaller abdominal markings.

Male Amphigomphus nakamurai, with its impressive appendages. The green markings on the thorax and the green frons may lead to confusion with Nihonogomphus, but the appendages are very different.

The female of Amphigomphus nakamurai, with similar pattern to the male. It has largely blackish abdomen, baring the lateral yellow markings on S1-3.

Appendages of the male in lateral view

And in ventral view, showing also the forked epiproct