214: Tetrathemis hyalina Kirby, 1889

Number: 214 / Family: Libellulidae / Genus: Tetrathemis

Species: Tetrathemis hyalina / Elf

Habitat: Forested Swampy Ponds

Provinces sighted: Chantaburi, Phuket, Narathiwat

Sightings: Uncommon

In flight (that I have seen): July-August

Species easily confused with: Tetrathemis platyptera

Well, I think I can finally put this species into the 'seen' bank. Going all the way back to 2011, I saw what I thought was Tetrathemis hyalina. However, I think I actually got the two species (T. platyptera) as they were living side by side. In fact, I was so confused that I actually decided to not count it as a record, especially as I didn't think it could be found as high up as Khao Yai. That is until I saw it again seven years later in Chantaburi. Now, I am convinced it is in fact the same species and I should have had more faith in Noppadon's ID (he is never wrong haha).

It is very similar in appearance to its common cousin but there are subtle differences. The easy way to separate them is through the almost clear (or hyaline) wings as well as the reduced size of the markings on the abdomen of the Elf. Since then, I have managed to spot a female in Phuket and also a small number of males at a swampy pond in Narathiwat... though they were a bugger to get anywhere near.

The Male

Super skittish and took me an age to get these (very happy with them). The abdomen of the male is much slimmer than that of the common species, which is the easiest way to split them. Of course, the lack of enfumed wings is also a feature, though not all T. platyptera do have yellowish wing bases, so it isn't a guarantee.

The Female

Here is the female from Chantaburi.

I am pretty sure that this is also a female of this species from Phuket (though it has puffed out its abdomen), but has significantly reduced markings along the abdomen. Let me know if I am wrong.

87. Tetrathemis platyptera (Selys, 1878)

No: 87 / Family: Libellulidae / Genus: Tetrathemis

Name: Tetrathemis platyptera / Pygmy Skimmer 

Habitat: Forested Ponds, Marshland & Slow-moving Streams

Province(s): Widespread
In flight: April-October / Sightings (by me): Locally Common

Easily confused with: Phyllothemis eltoni, Tetrathemis hyalina

Tetrathemis platyptera is a small dragonfly that I have seen on several occasions at different water sources, from large rivers to small farm ponds under lots of tree cover. It is easily confused with T. irregularis,  but one of the easiest ways to distinguish the two species, is that T. irregularis has clear wings (apparently) and T. platyptera has yellow/orange colouration to the base of the wings. Also, I have never even seen T. irregularis (I believe it is very much a southern species).

The adult male

This adult male has distinct yellow and black markings and its vivid turquoise eyes. the yellow base of the hind wings can clearly be seen, which distinguishes the species.

In the hand...

A male I caught in Khao Yai NP.

The "Old" Male

This is a very old male that has lost lots of its colour. You can still make out the markings on its thorax and abdomen.

The 'Teneral' Male

I saw this teneral male when I visited Nam Nao National Park in October 2010. It has all the markings of the adult, but the wings are still colourless and the eyes haven't yet developed that dazzling metallic sheen.

Another teneral male I saw at Khao Yai.

The Female

The female is very much like the male, but the markings are a little different and the abdomen is much more robust.

This photo gives good indication of just how small this species is. Also, it shows up the markings on the thorax very well indeed, as well as the yellow base of the wings. I managed to catch this female by hand. It was sheltering under trees in a darkened area just after a heavy storm at Phu Wiang National Park last October. 

The 'Teneral' Female...

This female I saw recently at a stream next to Nam Nao town, Petchabun, has very prominent colouration to the wings. Something I rarely see in this area, especially as a teneral specimen.

The Copula

This is the first copula (wheel) I have seen of this species (it lasted about 5 seconds).

Another copula I saw (again very briefly)...