Atrocalopteryx coomani (Fraser, 1935)

A vibrant turquoise flash in the semi-darkness of the jungle

When you get tired of walking into spider webs, being scratched by branches or biting by dozens of leetchees, the apparition of this little fellow in the middle of nowhere will give you back your courage !

Atrocalopteryx coomani is one of the flying jewels of the last remnants of "pristine" ("relatively untouched" is more appropriate) forest !

I encountered this species in many sites : Tam Dao NP (700m asl, but as low as 200m asl at Tây Thiên), Ba Vi NP and Thuong Tiên Reserve, Huu Lien Natural Reserve..., in virgin-like natural forests but also disturbed (secondary) forests, along clean streams, very frequently into the dense stream-side vegetation. This species is very localized but can be quite abundant in some places. It is common at the end of the rainy season, from July to December, but the first individuals (females) can be seen in May.

It is a perfect subject for a photographer : "photogenic" and not really skittish.

A territorial wing-clapping of a male, which show that most of the surface of forewings is

subhyaline; only the wing tip and costal area are dark.

Male arching his abdomen upward when a female is flying around

Female has brownish abdomen, with a white pseudopterostigmata on both wings.

Two females laying eggs at an oviposition spot defended by a male. All the other males invading this territory were immediately chasing by the owner.

There were no competition at all between those 2 females.
On the contrary, they oviposited in harmony ; a perfect duo !
 



Sometimes, they were also clapping the wings.

One of them had its body half-submerged, and remained like this for at least 20 minutes.

A teneral female, in mid-May

This stunning species is considered as a vietnamese endemic. It is known only from northern Vietnam, in both lowland and montane forests. Its occurrence in Guangxi (China) is expected, but no confirmed records are known (Hämäläinen, 2014).

In Vietnam, it is recorded, at least, from Huu Lien Nature Reserve in Lang Son province; Tam Dao National Park in Vinh Phuc Province; Viet Vinh community, Vi Xuyen district and Tay Con Linh Nature Reserve in Ha Giang Province; Ba Vi National Park in Hanoi and, recently, from Xuan Son National Park in Phu Tho Province (Do & al, 2011). 

Hämäläinen  (2014) transferred Calopteryx coomani to the genus Atrocalopteryx. The other Atrocalopteryx known in Vietnam (North only) are atrocyana, laosica and auco, the latter described in 2014.