Friday, March 11, 2011

000. Unknown Species

I have now added all the species I have photographed so far (except for Pseudagrion australasiae which I do have photos, but the are very poor and will wait for better examples). However, there are a few species that I haven't yet identified and hopefully anyone looking at this blog may be able to help. I have sent the images to Noppadon Makbun but he hasn't been successful, though I thank him so much for his unrelenting patience with my questions and thirst for knowledge about odonata! 

Here are the species I can't identify. If you know, please comment on my blog or email me 

1. Aciagrion sp. (location: Phu Kradeung National Park, 17/10/08)
This damselfly from the Aciagrion genus I thought was A. occidentale. It was only when I looked at the markings on the end segments that I realised it may be an undescribed sub-species. 

Oleg Kosterin commented: "The marking in your Aciagrion is curious indeed (isn't it a female?) but I would not exclude an aberration of A. borneense" He could well be right... even it being a female!

2. Species unknown (location: Huay Kaew Waterfall, Chiang Mai, 29/03/2010)
I saw this dragonfly floating in the river at the base of the waterfall where all the kids swim. I have no idea what it is, especially as it is partly decomposed. Probably in too bad a condition to ID.

If you could help with identification in any way that would be great. 

108. Pseudothemis jorina (Förster, 1904)

Number: 108
Family: Libellulidae
Genus: Pseudothemis
Species: Pseudothemis jorina
Common name(s): Yellow-banded Skimmer, Banded Skimmer
Thai name(s): แมลงปอบ้านโคนท้องขาว
Habitat: Exposed, mostly tree-lined weedy ponds and lakes (uplands & lowlands)
Province(s) sighted: Widespread (Khon Kaen); Nam Nao NP/environs (Petchabun); Widespread (Chiang Rai); Khao Yai (Nakhorn Ratchasima); small pond, Kabin Buri.
Sightings (by me): Very common, but to get a decent photo ... ultra rare!
In flight (that I have seen): February-October

A widespread species from the Libellulidae family that I have seen many times, but really struggled to get good photos of, is Pseudothemis jorina. It is instantly recognisable with its white band on the abdomen and white face. The rest of it is black. It also has minor black colouration to the base of the hindwings. 
The male
The adult male is black with a white band on S1-3. The face is also white. The young males are more yellow than white.

Fortunately (for me not the dragonfly), I saw a dead one when I visited a waterfall in Chiang Rai early one morning. The ants had just got to it, but I managed to get a good photo of it before it was devoured (if you look closely, you can see an ant at the terminal segments). 
Male in flight
This was the best photo of a male before finding the dead one. They are rarely seen in Khon Kaen and the ones I have seen, never seem to land.

Teneral male
I finally found a teneral male hiding deep in some bushes at Nam Nao Helicopter Pad recently. It made me really happy to finally see one. It's similar to the male, but has a yellow band and is more of a brown colour. It will become white and black with age.

The teneral female
What's more, there was a young female close by. This is the first female I have managed to photograph successfully... all the other times are attempts at photographing her ovipositing with the male close by... not a chance! The teneral female is very similar to that of the adult.

This teneral female was caught in a web ... fortunately for her, I spotted and released her (after a photograph, of course)

I managed to catch her carefully with my fingers and then carefully release her.

You can see this species at many, many locations throughout Thailand, especially established, weedy lakes and ponds, but the adults can be seriously difficult to get close to.

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.

106. Agriocnemis femina femina (Brauer, 1868)

Number: 106
Family: Coenagrionidae
Genus: Agriocnemis 
Species: Agriocnemis femina femina
Common name(s): White-backed Wisp, Pinhead Midget, Pinhead Wisp, Variable Wisp
Thai name: แมลงปอเข็มเล็กขนเทา
Habitat: Generally open, small to medium sized ponds, surrounded by tall grasses
Province(s) sighted: Nam Nao NP/environs (Petchabun);  Phu Kradueng, Phu Rua NP/environs (Loei); Widespread (Chiang Mai); Widespread (Chiang Rai); Khao Yai (Nakhorn Ratchasima); Khao Soi Dao (Chantaburi).
Sightings (by me): Very common (but I've still never seen one in Khon Kaen)
In flight (that I have seen): All year
Species, easily confused with: Agriocnemis minima; Agriocnemis pygmaea
Another microscopic species that belongs to the Agriocnemis genus, is Agriocnemis femina femina. I have overlooked this species for long periods of time, basically because I used to think that a pruinosed Agriocnemis pygmaea was in fact this species (yes, I had a lot to learn back then!). I then learned that this species wasn't actually even present in Khon Kaen and the surrounding areas. Well, in over a year of searching I have only come across A. pygmaea (No. 18 on my blog) and A. minima (No. 17 on my blog). I eventually saw a male in Chiang Mai, but didn't really take much notice of it. It was only when I visited Khao Soi Dao NP that I noticed a small ditch early in the morning just outside the entrance. I had a quick look and noticed Agriocnemis was present. I managed to get a good photo of a pruinosed male and YES! it was A. femina (I have to take a photo to tell the species apart as they are so small). That was the only Agriocnemis species present at that ditch. Since then, I have seen this species at many locations.

The 'mature' male
At certain times of the year (seems to be late in the year), there are hundreds of these little fellows seemingly floating around like little bits of fluff. I think they look great close up. Can be identified by its anal appendages.

Agriocnemis femina, close up - cleaning his appendages (explained to me by Noppadon Makbun)

Agriocnemis femina, close up - now showing a strange appendage near his genitalia

A semi-mature male
Still has slightly red end segments, but is only half pruinosed 

The young male
The young male is the most common of all and is almost identical to Agriocnemis pygmaea, except for the caudal appendages. It is also possible to identify as A. femina as S7 has more of a physical change from black to orange, whereas S7 on A. pygmaea is more of a gradual change from black to orange.

Caudal appendages
Agriocnemis femina, male (caudal appendages) - the easy way to differentiate this species. Looks a bit like a character from the Muppets, I think. 

The 'old' female
This very old female I can only correctly identify, as it was the only Agriocnemis species present at a small ditch in Chantaburi. It's the easy way to tell! If both species were present, I'm not sure I could tell the difference at this stage.

The sub-adult female
The young female can be identified by having prominent black marks on the pronotum (neck). 

The 'green' female

The copula
Here's a young male with a very young female.

Not the best angle in the world, as they sat really low down in a ditch and I couldn't get anywhere near low enough. This is an old male with a very young female... this would be deemed illegal in the human world!

105. Rhinagrion viridatum Fraser, 1938

Number: 105
Family: Philosinidae
Genus: Rhinagrion
Species: Rhinagrion viridatum
Common name(s): N/A
Thai name(s): N/A
Habitat: Heavily forested streams, lowlands & uplands
Province(s) sighted: Sai Thong NP (Chaiyaphum); Nam Nao NP (Petchabun); Phu Kradueng NP (Loei); Khao Yai (Nakhorn Ratchasima); Khao Kitchakut NP (Chantaburi); Koh Chang (Trat).
Sightings (by me): Fairly common, but small numbers
In flight (that I have seen): April-December
In my opinion, Rhinagrion viridatum is one of most stunning damselflies that I have ever seen. Firstly, I saw a male at Khao Kitchakut NP. I also saw 2 males and a female at two different stream locations on Koh Chang. Most recently was at Khao Yai NP (more since then). The ones I have seen, all like deep, dark alcoves (some with almost no light) above a deep cut out of the river that is almost still (probably to make it hard for idiots like me to get near them). I originally thought this was R. mima. However, it is now confirmed as R. viridatum. Primarily because of the location (R. mima is only found in a small number of places in the west of Thailand). R. viridatum is found elsewhere. Secondly, The prominent greenish-blue marks on the abdomen differ to that of R. mima.

Since then, I have spotted another solitary male at Phu Kradueng NP. Oddly, this male was basking in glorious sunshine, unlike the other specimens I have seen which seem to like darkened areas.
The male
The male is a medium-sized damselfly but instantly recognisable. Its thorax boasts vivid greenish-blue stripes on black. The abdomen also has greenish-blue dorsal markings and it also has amazingly colourful orange end segments, which you can see from a good distance. 

Since I wrote this, I recently spotted several males at a very quiet stream at Sai Thong NP, Chaiyaphum province [24.v.14]. Though it is nothing new for me to spot this species, I was suprised to see 4-5 males in one short trip (usually solitary sightings) and they rested around 6 inches above the water, along the steep banking and in close proximity to each other, instead of perching around 1 1/2 metres above the water in the trees (and then higher as soon as you approach them). They were also fairly easy to approach, unlike earlier specimens which fly away at the slightest movement (though I did have to sit fully in the stream up to my chest in order to get good shots). Worth every squelching sound from my boots and underpants as I walked afterwards! Anyway, I think it is impossible not to fall in love with this species.

Here's the male I spotted at Nam Nao (and the only male that loved the brightest sunshine in the world).

Here's a close-up in the brightest sunshine in the world. Still, makes a nice backdrop, I think.

Appendages (lateral view). Note the tuft of hair at the end of the superior appendages.

Appendages (dorsal view). Note the two orange dots which are characteristic of this species. It also has whitish tips to the superior appendages.

Teneral male
This is a newly emerged male, which I saw at a heavily tree-covered pond, Khao Yai National Park. Note how the wings are parallel to the abdomen. They will open out in time. Also... look how S7-10 segments are crushed flat.... er... that was me! It landed in front of me and a spider pounced on it... I pulled it away just in time, but damaged its abdomen in the process. I hope he survives!

Here, you can see where the spider had him by the abdomen (S1-2), dorsally. It's wings were also damaged. I suppose me squashing its abdomen trying to save it didn't help matters... still, I tried!

The female
When I visited a number of waterfalls in Koh Chang (13/04/2011), I was surprised to see this species. I saw 2 males and, in a deep, dark alcove which contained a tiny bit of water at the bottom, I saw my first female. I couldn't even hardly see her it was that dark and I had to take a photo to ID her (using flash of course). I managed to get a few shots of her, before she flew straight up and out of the alcove through a tiny hole at the top.

I also observed her ovipositing into slightly damp, mossy vegetation, which was growing on a vertical bank, about 1.5 metres above a tiny pool at the edge of the stream.

... and if you look closely, I think that is an egg, but I could be wrong.

The teneral female ...
Here is a young female I saw at Khao Yai, Nakhorn Ratchasima

Although they always seem to be in small numbers, I think this species may be more common than first thought, because they are easily missed... not many people look into dark holes along riverbanks. Other people may think they are crazy!
Many thanks to Noppadon Makbun for the information and confirmation of ID.