99. Hemicordulia tenera donnellyi Kosterin, Karube & Futahashi, 2015

No: 99 / Family: Corduliidae / Genus: Hemicordulia

Name: Hemicordulia tenera donnellyi / Northern Slender-bellied Emerald*

Habitat:  Upland streams

Province(s): Chaiyaphum, Chiang Mai, Loei, Petchabun
In flight: April-December / Sightings (by me): Uncommon

Easily confused with: Hemicordulia tenera

*As there is no common name, I decided upon the first part as the Thai name 'Northern Slender-bellied' and the last part following the name 'Emerald' given to the genus, Helicordulia, so it's the Northern Slender-bellied Emerald.

A new species for me, I saw recently at Phu Kradeung. I was at Sat Anodat Pond and I noticed what I first thought was Zygonyx iris malayana. However, when I got closer I realised it was much smaller and the abdomen was completely different. Also, it was at a pond and nowhere near a waterfall where I always see that species. I sent the photos to Noppadon Makbun and he identified the species as Hemicordulia tenera, though it was later pointed out that it wasn't that species and was currently being described.

Since my post, this has been separated as Hemicordulia tenera donnellyi, a rather long, but very nice title. Since then, I have seen this species quite a few times from Chaiyaphum to Chiang Mai. It can also be common where it resides. However, it rarely seems to land. Instead, it patrols the same area over and over until you become dizzy.

The Male

The abdomen is key to IDing this species. From S-5 it bulges out and also has unique markings. Fortunately, whilst at Phu Khieo Wildlife Sanctuary, Chiayaphum, a strong wind got up, forcing this one to abandon its flight... momentarily anyway and is new for my records at the location.

Close-up of abdomen showing the rather broad middle section of the abdomen. 

The Copula

Once at Phu Luang Wildlife Sanctuary, Loei, I must have seen 20-30 individuals flying over the water's surface. Every corner seemed to house another. But, photographing them was way too tough. Amazingly as I was looking at a common species, a copula landed about 15 ft in front of me. I crept forward, then notcing I was too high up, literally slipped my way down the banking and into the water as quietly as possible only being stopped from going straight in by the tall reeds... and the results were well worth it though it took an age to get out again.

What you normally see...

At Phu Rua NP, I saw a number of males flying continually for extremely long periods to protect their territory (usually an opening in the tree canopy). No idea when or where they rested. I managed to get a couple of half-decent shots, though the lighting was all over the place.