131. Rhyothemis obsolescens (Kirby, 1889)

Number: 131

Family: Libellulidae

Genus: Rhyothemis

Species: Rhyothemis obsolescens

Common Name(s): Variegated Plain Skimmer, Dusky Flutterer, Bronze Flutterer
Thai name(s): แมลงปอบ้านไร่ลายเลือน, แมลงปอบ้านไร่ขีดใส, แมลงปอบ้านปีกลายเลือน
Habitat: Exposed upland rivers
Province(s) sighted: Khao Yai NP (Nakhorn Ratchasima)
Sightings (by me): Uncommon
In flight (that I have seen): June-July (longer, I'm sure)

I have just returned from a 2-day trip to Khao Yai Nationl Park. I visited there for the first time, back in April and it was rather quiet, although I did manage to spot one or two new species. This time, however, I faired rather better. Torrential rain, armies of hungry leeches, heavily swollen rivers and inaccessible areas I had previously visited, didn't put me off (though my girlfriend stayed in the rented car most of the time). And it was worth it. I managed to spot a few more specimens, as well as a lot of non-odonata related things and I had a great time. 

I had been driving around Khao Yai National Park all day and right at the death, I noticed a slow-moving, but swollen river about 900 metres up or so. I chanced my arm and drove towards it. I then noticed it was part of a campsite I hadn't even noticed before. There was a beautiful river that ran though it, shrouded by tall, large lilly pads. I saw a few species and decided I needed a full day there and so planned to camp there with my girlfriend in the next few weeks. As I walked back, I noticed something that looked a little like Neurothemis fulvia. Then I realised... it was a species I had been after for a long time, Rhyothemis obsolescens. I followed the male for long periods, trying to get close to it, but it fluttered further along the lilly pads every time. I followed it about 40 metres downstream and then noticed that there were a few more specimens. Almost waist-deep in mud, I managed to get close enough to get a few half-decent photos, much to the amusement of the camping Thais, and the embarrassment of my girlfriend. So, there you have it... all 5 species in the Rhyothemis genus! I couldn't be happier.


Since then, I have returned and found both male and female!

The male

From a distance, the male looks much more boring than its cousins. However, on closer inspection, its a vivid bronze with lots of dazzling variants in colour and patterns on its wings. It really is a truly magnificent creature.

In the hand...

I managed to capture a young male. As you can see, they are small, but no less beautiful.

The female...
Early one morning, I ventured out to the river while my girlfriend was still in the tent. I was glad that I did, as I saw not one, but two females! As with all species in the genus, the females usually hide far away from the water's edge.


The female is identical to the male, except its abdomen is more robust. This one has a damaged forewing.

Here's another female, which I also managed to capture with my little net (it's really handy!)

Now in the hand...

This shows just how similar the female is to the male.

107. Zyxomma petiolatum (Rambur, 1842)

Number: 107

Family: Libellulidae

Genus: Zyxomma 

Species: Zyxomma petiolatum
Common name(s): Brown Dusk Hawk, Dingy Duskflyer, 
Dingy Duskdarter, Long-tailed Duskdarter, Slender Duskdarter
Thai name(s): แมลงปอบ้านคล้ายยักษ์, แมลงปอบ้านก้านยาว

Habitat: Heavily tree-lined ditches, drains, ponds and lakes (uplands & lowlands)
Province(s) sighted: Widespread (Khon Kaen); Nam Nao NP (Petchabun);  Huay Gairo waterfall (Chiang Mai); Khao Yai (Nakhorn Ratchasima).
Sightings (by me): Fairly common
In flight (that I have seen): February-July

Another species from the Libellulidae family that I have spotted on a few occasions, is Zyxomma petiolatum. It is not easy to spot as it tends to hide away in the bushes close to water and is very well disguised.  

The male

The male is easy to identify because of the bulbous S1 of the abdomen. It has green eyes and the rest of the thorax/abdomen are a yellow ochre. It also has black rings on each segment of the abdomen.  The tips of the wings darken as it matures.

Here is the same specimen dorsally.

The teneral male...

This young male is much lighter in colour compared to that of the mature adult. The wings were also clear (top two photos @ Nam Nao, third @ Chiang Mai).

The female

The female has an even more bulbous abdomen than the male... she almost looks pregnant. Otherwise, it is the same. This specimen flew into my bungalow in Khao Yai at night attracted by the light. I left her there for the night as it was pouring with rain. She flew away in the morning.

Here she perched happily on the edge of the very net I tried to catch her with!

You can see just how dull she is. The wings have a distinct brown tinge to them.

Here it shows just how prominent and almost abnormal looking S1 of her abdomen is.

I am not sure how common this species is, but I have seen it in many times in Khon Kaen (especially in the school corridors), as well as in Khao Yai and Chiang Mai, so think it must be widespread. Also, I have seen it in February-July though it could be in flight all year.