125: Brachydiplax sobrina (Rambur, 1842)

Number: 125 / Family: Libellulidae / Genus: Brachydiplax

Species:  Brachydiplax sobrina / Little Blue Marsh Hawk

Habitat: Large, Exposed Rivers, Small Lowland Forested Ponds

Province(s) sighted: Lomsak), Khon Kaen, Udon Thani 

In flight: July-October / Sightings (by me): Uncommon

Species easily confused with: Brachydiplax farinosa; Brachydiplax chalybea; Aethriamanta gracilis

A really difficult genus to ID is Brachydiplax. However, with the help of Noppadon Makbun and Oleg Kosterin, I am now able to ID species in the field (hopefully). With Brachydiplax sobrina I am leaning towards their preferred habitat being large exposed rivers, as opposed to marshy/weedy ponds preferred by other species in the genus - though I could be completely wrong, especially as its common name is the Little Blue Marsh Hawk.

(Yes, I am wrong ... I have seen this species thriving at small farmer's ponds.)

The male

The male is almost identical to other species in the genus. However, it can be identified by its antenodal crossveins. This species has 7 as opposed to 8-9 of B. farinosa. I first saw this species back in 2008, I saw it again briefly in 2011 and then recently in Udon Thani province where it seemed fairly abundant, though mature males were hard to approach.

The Young Male

Similar to the above but devoid of pruinescence. That will come later.

An unfortunate ending ...

The best way to separate this species ... 

The Female

Compared to the male, the female is very rare. In fact, since I saw my first ever male in 2008, I have only seen two females and one of them almost escaped my lens... well, it may have well as done as the shot was so poor. Roll onto 2021 at the River Chi in Khon Kaen with Andrew Pierce while looking for a very rare butterfly I had once seen there and boom... there was a female! As clear as day and got loads of great shots. It was like finding a new species... no, better! And here she is:

124: Orolestes octomaculatus (Martin, 1902)

Number: 124 / Family: Lestidae / Genus: Orolestes

Species: Orolestes octomaculatus / Large Eight-spotted Spreadwing*

Habitat: Forested Ponds (Mostly lowlands)
Province(s) sighted: Chaiyaphum, Khon Kaen, Nakhon Nayok, Petchabun, Udon Thani

Sightings (by me): Common
In flight (that I have seen): Year-round

*As it didn't have a common name, I based the name on the Thai name 'Large Eight-spotted' and the common name for Lestidae 'Spreadwings', so the 'Large Eight-spotted Spreadwing'.

A spreadwing that is widespread (that's a mouthful!), and quite common and had eluded me until now, is Orolestes octomaculatus, now known as the Large Eight-spotted Spreadwing. I saw a male for the first time on June 11, 2011. However, today (June 18, 2011) I returned to find the female. Where I had seen three males at Tad Fah Waterfall, this time there was only one and I thought my luck was out. So I decided to visit Phu Wiang National Park itself about 20 kms away from the waterfall. About 300 metres inside the entrance there was a tiny and muddy clay pool to my left with a few bushes and trees overhanging and I thought I may as well have a look, seeing as though I was there already. To my amazement, there were around 20 male O. octomaculatus resting out of the sun under the leaves of a small tree. I managed to improve my photos from the previous week (though it took a long time as they fly high up into the tree the moment you even breathe) and then tried to take even more shots (sometimes I'll take hundreds of photos of the same individual just to make sure it's OK). As I was about to shoot again, I noticed something above it on the same branch... I took a photo just to see what it was and it turned out to be a female! Yet, it was in the strangest position I have ever seen. Watching her for about 20 minutes, I discovered she was ovipositing into the bark of the tree that overhung the pond. Since then, I have seen this species many times at numerous different locations and it appears to be around the whole year.

The Male

It is easy to distinguish because of its beautiful wings, blue/green eyes and S9-10 are bright blue and it has large claspers. It is also large for a damselfly.

Here's looking at you ... 

The 'Hyaline' Male

A small number of males never develop black spots on their wings (and young males too) and are known as hyaline specimens. This is not commonly seen.

The 'Young' Male

This is a very young male...

...and this one has literally just emerged...

The Female
The female is fairly dull in comparison, but she does have a blue dorsal patch at the end of the abdomen.

This female is ovipositing into a branch. Something I see quite a lot with this species.

And here is another...

The 'Teneral' Female

You rarely see then at this stage but then suddenly they will emerge en masse.

Another emergence very early and still attached to her exuvia. Don't know why but this is right up their for favourite shots. I captured this well in the early morning light, even if I may say so myself.

The Copula

It took me a long time to get this and it is rarely seem! I was very happy with it, but somehow I much prefer the shot after where they are both resting momentarily. There is just something about this I love.

The Tandem

The Courtship/Mating Behaviour

Here, I just managed to get a blurry photo as the male grabs a female.

He now has her firmly.

Let the mating begin...

Once split, she starts to use her ovipositor to gouge out small holes in the branches and lay single eggs into each hole... all the while, the male is guarding his prize.

A second male appeared, and shortly (off camera, the first male attacks the second and it disappears.

123: Pseudagrion australasiae Selys, 1876

Number: 123 / Family: Coenagrionidae / Genus: Pseudagrion

Species: Pseudagrion australasiae / Look-alike Sprite

Habitat: Exposed Ponds, Lakes & Slow-moving Streams (Uplands & Lowlands)
Province(s) sighted: Widespread
Sightings (by me): Common
In flight (that I have seen): April-December
Species easily confused with: Pseudagrion microcephalum; Cercion malayanum;

One species that I'm sure I have seen a number of times is Pseudagrion australasiae. However, unless you are very, very close to it, it is hard to tell the difference between P. australasiae and P. microcephalum. Having studied photos for a long time, one difference I have noticed (I think) is that P. microcephalum is a brighter, more vivid blue. Whereas P. australasiae is a slightly more muted blue. Also, P. australasiae is slightly bigger but has shorter caudal appendages compared to that of P. microcephalum. 

The Male

As mentioned above, the male is very similar to the male of P. microcephalum. If you see two together, it is easier to compare as P. australasiae is duller in colouration and is also larger. Also, P. microcephalum is far more common in Khon Kaen and the surrounding areas. 

  

The 'Young' Male

This one hasn't quite developed that shimmering blue colour.

...and he needs a haircut!

P. australasiae is slightly larger than P. microcephalum (a good way of IDing if seen together)

The superior (top) appendages are shorter than those of P. microcephalum

dorsal view ...

The Female...

The female is very similar to other females in the genus. However, for me, I was lucky recently. At at large, shallow lake I saw recently at Khao Yai, Nakhon Ratchasima province, I spotted many males and females, including the female at all stages. P. microcephalum wasn't present, making identification much easier. Though this specimen is old.

The adult female is blue in colour.

The 'mid-stage' female...

Here, we have a mid-stage female, which is just showing signs of blue on the thorax.

The 'Young' Female...

This is a young female, which is brown in colour. There were many of these early in the morning. However, once the sun came up, they all vanished into the bushes and trees.