138: Idionyx selysi (Fraser, 1926)

Number: 138 / Family: Synthemistidae / Genus:  Idionyx 

Species: Idionyx selysi / N/A
Habitat: Forested Ponds and Streams
Province(s) sighted: Chiang Mai, Petchabun
In flight: July / Sightings (by me): Rare

Species easily confused with: All Idionyx Species

A week had gone by and I returned to the ponds around Nam Nao town. I arrived early to the place I finished at last time, which was 1 kms from the town centre. This time, however, the weather had taken a turn for the worse. Heavy rain the night before, strong winds, heavily overcast, dull and more rain on the way. Worse still, there wasn't a single dragonfly on the water. Last week, there were hundreds. I worked my way through the weeds/marsh and still couldn't find any. I moved on. 

I drove past the town and continued around 4 kms north. I saw a small, but natural pond, surrounded by lots and lots of reeds and bamboo... maybe some will be resting there! It was difficult to get down the steep banking and I slipped a million times. As soon as I got near the bamboo, I noticed a skittish dragonfly, flapping away on a tiny reed, deep under the cover of the bamboo. I set up my camera and, in the windiest conditions in the world, tried my luck, using flash. It was blurred! Worse still, the flash scared the dragonfly and it flew upwards, in a 'bouncy' flight, similar to that of T. pallidinervis. The wind caught it and carried it away. Aaaargh! Gone for good. This photo is the only one I have and it isn't very good. 

This species has now been identified by Noppadon Makbun. He said it is 'likely' to be Idionyx selysi. It has a process pointing upwards on S10, which you can clearly see (unless you are me and didn't see it).

The Male

As you can clearly see (sort of from this terrible photo), there is a protrusion on S10

The Female

I was fortunate to see a number of Idionyx species flying around rapidly when in Chiang Mai with Noppadon Makbun in 2024. Though it was impossible to get any photos, Noppadon did manage to catch a female... and it was really tough to get one!

Many thanks to Noppadon for the ID (even from that terrible photo).

114: Idionyx thailandica (Hämäläinen, 1985)

Number: 114 / Family: Synthemistidae / Genus: Idionyx

Species: Idionyx thailandica / Thai Forest Shadow*
Habitat: Tree-lined Forested Streams
Province(s) sighted: Chiang Main, Nakhon Nayok, Phitsanulok
Sightings (by me): Rare
In flight (that I have seen): March - July

On the way back to Khon Kaen from Kanchanaburi, I made a quick visit to Nakhon Nayok. The first two waterfalls I arrived at were completely dry (then again I shouldn't choose March to hunt for dragonflies!). Finally, I arrived at Nang Rong Waterfall, which had a decent amount of water running through it. Within two minutes, I spotted a small teneral male, which I thought was Tetrathemis platyptera, which I have seen numerous times before. It was only when got closer that I noticed it was something different. It was a slow mover and I was even able to catch it with my fingers, in order to take photos, before I released him safely. I looked on the Internet and thought it was Idionyx thailandica, a new species for me. This was confirmed by Noppadon Makbun. I have since seen this species in Chiang Mai and Phitsanulok, though still don't have good photos!

The Male

The male has distinct black and yellow legs and swirling yellow on black thoracic markings. The caudal appendages are also large in size.

A second male hanging from the underside of a road bridge during rain. This was high up and I even used a 400mm lens just to get these.

The Female

Recently, I managed to get decent a single shot of the female in Chiang Mai... literally one shot... gone.