Indocnemis ambigua (Asahina, 1997)

Asahina (1997) described the species as Coeliccia ambigua from Tam Dao, Vinh Phuc Province in northern Vietnam, but it has been moved later to the genus Indocnemis.

In his description Asahina pointed out that the venation of ambigua was not consistent with the genus Coeliccia Kirby but with the genus Indocnemis Laidlaw.

In Indocnemis the anal crossing ends on the anal bridge vein (red circle) and not on the wing margin except in one of four specimens examined by Asahina. But, as pointed out by Wilson and Reels (2003) another characteristic of the genus Indocnemis is the presence of four cells between discoidal cell and the nervure descending from the subnode, whereas Coeliccia has just three cells. This species has three cells consistent with the genus Coeliccia. So the term "ambigua" is still appropriate!

Male : the head is mat black, prothorax and synthorax grey (in fact mat black finely pruinosed), the latter with two pale bluish stripes on each side.
The black (not pruinosed) band on the dorsal synthorax contrast with the greyish tint of the rest of the synthorax.
The abdomen is black dorsally, except segments 9-10 bluish tinted.

Caudal appendages also pale bluish ; the superiors much shorter than the inferiors (please note that the photo of appendages was also taken in the field, with the insect alive. With so tiny parts of the body, I can not expect detailed close-ups. Photographing damselflies appendages require other equipment that I don’t have!).

A mating pair

An ovipositing tandem pair
The male remain in tandem with the female while she deposits eggs, termed "contact guarding". Guarding prevents another male from inseminating the female.

This female oviposit into moss at a vertical surface of a rock

I spotted the female very few times. I am not sure that she has been described - not by Asahina at least.

Indocnemis ambigua inhabits montane forest streams. It is known from a limited number of sites in northern Vietnam (Tam Dao only, the type locality) and southern China (Guangxi).
Currently there is only two species recognised in the genus Indocnemis, the other one is I. orang (Förster in Laidlaw, 1907).

Those shots were taken at Tam Dao, along small rocky streams with heavy covert (alt. : 950-1.000 m a.s.l.). Probably the first ones of this species on the internet.

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