143. Rhinagrion hainanense (Wilson & Reels, 2001)

Number: 143

Family: Philosinidae

Genus:  Rhinagrion
Species: Rhinagrion hainanense
Common name(s): N/A
Thai name(s): Unknown
Habitat: Heavily tree-covered (extremely low-light) uplands streams
Province(s) sighted: Above Huew Sawat waterfall, Khao Yai NP (Nakhon Ratchasima); Stream at headquarters, Nam Nam Nao NP, (Petchabun)
Sightings (by me): Uncommon
In flight (that I have seen): July-October (though probably longer)

On my last day at Khao Yai, I decided to visit Huew Sawat Waterfall (spelling?). There were millions of tourists and so decided to search above the waterfall, where it was much quieter. Within a few metres of walking, I noticed a  Rhinagrion sp. above me on a tree trunk in almost darkness. I first thought it would be Rhinagrion viridatum. However, it almost flew straight into my face and I noticed just how vivid its blue face was. I waited for him to return to the same spot (as they all seem to do if you are quiet) and he did. I managed to get a few, half-decent photos in almost complete darkness. When I looked at the photos, I noticed that the thoracic markings were different and the colours were very different (especially the bright red underside of the last few segments and the whitish claspers. I closed in silently, until crack!... I stood on a large twig. Amazingly, he flew upwards and then landed on my hand (I was next to his tree). He was on my hand without the camera, so had to work carefully and I managed to catch him.

As it turns out, it's Rhinagrion hainanense, which has been described recently and comes from Vietnam and Laos. First thing I would like to do, is thank Sebastien Delongee for providing information which should have led me to the correct ID, but I was ignorant. It took Oleg Kosterin to believe... thanks to you both... and Noppadon Makbun for your input.  

Since I noticed this first male at Khao Yai, a healthy population of males and 2 females at the stream running through the headquarters, Nam Nao, Petchabun. Here, all the males were perched in extremely darkened areas, about 0.5 metres above the stream. I was lucky enough not only to spot them, but they were willing to let me get some decent photos in their natural positions.

This male decided to set up in the only bright spot along the whole stream.

Here, you can see the more yellow/green markings on the head, as opposed to the bright blue variation at Khao Yai.

Now in the hand ... and playing dead!

Here's the first male I saw at Nam Nao (not fully mature - it's not as dark) ...

The pimped-up BMW of the R. hainanense world - the males arch their abdomens under their thorax to display their bright colours, when a female is around or when another male threatens their territory.

Khao Yai specimen

Here's the male I saw at Khao Yai (July 2011). Almost identical. However, there are a couple of subtle differences (enough to make me think that it could be a sub-species at first). The markings on the head were blue and not green, probably just at a different stage. The caudal appendages are also whitish dorsally, whereas they are blueish on the Nam Nao males.

A shot of the Khao Yai specimen's head. The blue markings had a metallic look to them and really stood out.

The head from a different angle.

The female (Nam Nao) ...

I first saw a female at Nam Nao in October 2011. However, it was too difficult to pinpoint the exact species. Fortunately, since I have now spotted a number of males, I could confidently identify the female. Furthermore, I eventually managed to get half-decent photos of a female ovipositing at the base of a log overhanging the stream at Nam Nao (see below). Fortunately, I was also able to catch her with my fingers once she had finished ovipositing. 

Here's the first thing I saw ... a shadow.

When the flash finally decided to fire, I could see that it was a female and it was ovipositing (you can clearly see the ovipositor protruding in the dark photo).

Unfortunately, she was situated right below the scissors of the trunk and I couldn't get a decent photo. This was the best I could achieve in her natural position.

Here's the log where she oviposited (at the base where it scissors). 

Now in the hand ... I could even be the first person to spot a female, let alone photograph and handle one.

Caudal appendages, close up ...

Once again, many thanks to Sebastian Delongee, Oleg Kosterin and Noppadon Makbun for your tireless work!

105. Rhinagrion viridatum Fraser, 1938

Number: 105

Family: Philosinidae

Genus: Rhinagrion

Species: Rhinagrion viridatum
Common name(s): N/A
Thai name(s): N/A
Habitat: Heavily forested streams, lowlands & uplands
Province(s) sighted: Sai Thong NP (Chaiyaphum); Nam Nao NP (Petchabun); Phu Kradueng NP (Loei); Khao Yai (Nakhorn Ratchasima); Khao Kitchakut NP (Chantaburi); Koh Chang (Trat).
Sightings (by me): Fairly common, but small numbers
In flight (that I have seen): April-December

In my opinion, Rhinagrion viridatum is one of most stunning damselflies that I have ever seen. Firstly, I saw a male at Khao Kitchakut NP. I also saw 2 males and a female at two different stream locations on Koh Chang. Most recently was at Khao Yai NP (more since then). The ones I have seen, all like deep, dark alcoves (some with almost no light) above a deep cut out of the river that is almost still (probably to make it hard for idiots like me to get near them). I originally thought this was R. mima. However, it is now confirmed as R. viridatum. Primarily because of the location (R. mima is only found in a small number of places in the west of Thailand). R. viridatum is found elsewhere. Secondly, The prominent greenish-blue marks on the abdomen differ to that of R. mima.

Since then, I have spotted another solitary male at Phu Kradueng NP. Oddly, this male was basking in glorious sunshine, unlike the other specimens I have seen which seem to like darkened areas.

The male

The male is a medium-sized damselfly but instantly recognisable. Its thorax boasts vivid greenish-blue stripes on black. The abdomen also has greenish-blue dorsal markings and it also has amazingly colourful orange end segments, which you can see from a good distance. 

Since I wrote this, I recently spotted several males at a very quiet stream at Sai Thong NP, Chaiyaphum province [24.v.14]. Though it is nothing new for me to spot this species, I was suprised to see 4-5 males in one short trip (usually solitary sightings) and they rested around 6 inches above the water, along the steep banking and in close proximity to each other, instead of perching around 1 1/2 metres above the water in the trees (and then higher as soon as you approach them). They were also fairly easy to approach, unlike earlier specimens which fly away at the slightest movement (though I did have to sit fully in the stream up to my chest in order to get good shots). Worth every squelching sound from my boots and underpants as I walked afterwards! Anyway, I think it is impossible not to fall in love with this species.

Here's the male I spotted at Nam Nao (and the only male that loved the brightest sunshine in the world).

Here's a close-up in the brightest sunshine in the world. Still, makes a nice backdrop, I think.

Appendages (lateral view). Note the tuft of hair at the end of the superior appendages.

Appendages (dorsal view). Note the two orange dots which are characteristic of this species. It also has whitish tips to the superior appendages.

Teneral male

This is a newly emerged male, which I saw at a heavily tree-covered pond, Khao Yai National Park. Note how the wings are parallel to the abdomen. They will open out in time. Also... look how S7-10 segments are crushed flat.... er... that was me! It landed in front of me and a spider pounced on it... I pulled it away just in time, but damaged its abdomen in the process. I hope he survives!

Here, you can see where the spider had him by the abdomen (S1-2), dorsally. It's wings were also damaged. I suppose me squashing its abdomen trying to save it didn't help matters... still, I tried!

The female

When I visited a number of waterfalls in Koh Chang (13/04/2011), I was surprised to see this species. I saw 2 males and, in a deep, dark alcove which contained a tiny bit of water at the bottom, I saw my first female. I couldn't even hardly see her it was that dark and I had to take a photo to ID her (using flash of course). I managed to get a few shots of her, before she flew straight up and out of the alcove through a tiny hole at the top.

Ovipositing

I also observed her ovipositing into slightly damp, mossy vegetation, which was growing on a vertical bank, about 1.5 metres above a tiny pool at the edge of the stream.

... and if you look closely, I think that is an egg, but I could be wrong.

The teneral female ...

Here is a young female I saw at Khao Yai, Nakhorn Ratchasima

Although they always seem to be in small numbers, I think this species may be more common than first thought, because they are easily missed... not many people look into dark holes along riverbanks. Other people may think they are crazy!
Many thanks to Noppadon Makbun for the information and confirmation of ID.