Some Xuân Son goodies in the rain

Misty mountains at Xuân Son, after the rain

Back to Xuân Son National Park on July 12th. A typical rainy season day with heat, dark clouds, sun and of course (torrential) rain. At this season, depending of the day, you can have more sun and less rain, or vice versa. A completely unpredictable weather.
The morning was quite sunny but the afternoon the heavens opened and that put paid to my day. The long way back to Hanoi was an epic motorcycle journey...
Below some shots taken during this (too short) session :

Ceriagrion azureum, copula

Found at an open pond in a village. A new species for my personal records. 

In mountain areas I usually ignore open habitats in favour of forest habitats, that's why I overlooked it. 
Under these latitudes, there are often some "bad" bugs (parasitic worms/leeches) in standing water so I always avoid to submerge my butt in ponds. But this time the temptation was too strong!

Matrona taoi, male, well hidden in the forest
A newly (2011) described species, hitherto known from Xuân Son (type locality) and a site in central Vietnam (Quang Binh Province). A Matrona species with metallic green abdomen and brown-reddish wings, lacking any milky coloured reticulation at the wing bases of the male (unlike Matrona basilaris for example).

It was the only Matrona taoi I saw during this short trip. More easy to find in autumn, after the rainy season (October, November & December).

Archineura hetaerinoides, male

That smells like the end of the season for this species, more abundant in April, May and June

Chlorogomphus sachiyoae, male (identified afer in-hand examination, of course)
A typical view of a male Chlorogomphus patrolling up and down a shallow rocky stream, with a slow flight, few dozens of centimeters above water. Found this guy some kilometers before Xuân Son, in a small, incised valley (depth of 15m or so) surrounded by... manioc fields!  Other interesting species there included Coeliccia sasamotoi and Cryptophaea vietnamensis. I have already noticed that interesting forest species can still maintain in very degraded habitats if woody riparian corridors have been conserved.

Euphaea masoni, male & female

Euphaea masoni, male
Note the coppery sheen on upper-side of hind wings (not often visible, generally wings appear all dark). Its close but less common congener E. guerini show an obvious greenish sheen there (see photo below), visible even in bad light conditions; but closed winged of both species show a blue-green metallic sheen. Anyway, the easiest way to separate the two species is by taking a look at the ventral base of S9, where E. guerini has a tuft of long hairs.

Euphaea guerini, male
Note the hairs at the ventral base of S9 

Euphaea decorata, male
A widespread and common species in northern Vietnam and southern China, occurring in both lowland and mountain streams.

A newly emerged male Euphaea decorata

Euphaea ochracea, male
Seems scarce at Xuân Son - only one male spotted. 
Three other Euphaea species are found at Xuân Son (masoni, guerini and decorata), all common.

Lamelligomphus formosanus, male 
Like its congeners, this species is a hovering champion, so it should be easy - in theory - to photograph it in flight. But this little fellow is skittish and quite difficult to approach. 

Lamelligomphus formosanus, female at an oviposition spot

Prodasineura croconota, male