216. Tetrathemis irregularis hyalina Brauer, 1868

Number: 216

Family: Libellulidae

Genus: Tetrathemis

Species: Tetrathemis irregularis hyalina

Common name(s): Elf

Synonyms: N/A

Habitat: Forested ponds

Provinces sighted: Khao Yai NP (Nakhon Ratchasima); Krathing Waterfall (Chantaburi)

Sightings: Uncommon

In flight (that I have seen): July

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 irregularis hyalina. Noppadon agreed. 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 more 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. 

Though I don't have photos of the male to hand, I think I may have seen it but need to look back through my ever-growing number of hard drives. For now, I will just add the female pics.

The female

Here is the female from Chantaburi which I saw last month.

... and here is another female I saw in 2011 just outside Khao Yai (in hand).

I will upload any images of the male (if I have any and if I can find them!)

000. Tetrathemis irregularis hyalina (Brauer, 1868)

Number: 000
Family: Libellulidae
Genus: Tetrathemis
Species: Tetrathemis irregularis hyalina (possibly)
Common name(s): Elf

Thai name(s): 

Habitat: Ponds and lakes on the edge of forests (lowlands)
Province(s) sighted: Below Khao Yai NP (Nakhorn Ratchasima).
Sightings (by me): Uncommon
In flight (that I have seen): July (obviously longer)

The new species just keep on coming! I'm hoping to exceed 150 species before the season is out. The latest addition to my blog, is Tetrathemis irregularis hyalina. I have never seen one before, though I found it difficult to differentiate between this species and T. platyptera. Noppadon Makbun has ID'd the species for me and told me that small spots on the abdomen S2-4 are characteristic of the species.

Interestingly, I also found that T. irregularis and T. platyptera live side by side at this location.

I now doubt this is the correct ID. 

The female

I only saw the female of this species and they were abundant. No idea why I only saw females... it's usually the other way round with most species.

I will be returning to Khao Yao NP in a few weeks and will track down the male, hopefully. Many thanks to Noppadon Makbun for the ID.

87. Tetrathemis platyptera (Selys, 1878)

Number: 87
Family: Libellulidae
Genus: Tetrathemis
Species: Tetrathemis platyptera
Common name(s): Pygmy Skimmer 
Habitat: Forested streams & rivers, as well as ponds on the edge of forests
Province(s) sighted: Phu Wiang NP (KhonKaen); Nam Nao NP/environs (Petchabun); Phu Rua NP (Loei); Widespread (Chiang Mai); Khao Yai (Nakhorn Ratchasima); Koh Chang (Trat).
Sightings (by me): Common, though often overlooked

In flight (that I have seen): April-October

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.

One quick glance at me... and then he was off...

Here's another male I saw in Phu Rua...

In the hand...

A male I caught in Khao Yai NP.

The "very 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.

... and another teneral maleat Nam Nao.

The female

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

A big hand...

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. 

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.