42. Prodasineura sp. [nec. verticalis Selys, 1860]

No: 42 / Family: Platycnemididae / Genus: Prodasineura

Name: Prodasineura sp. [nec. verticalis Selys, 1860] / Orange-bellied Threadtail* 

Habitat: Forested streams
Province(s): Chiang Mai, Trat, Kanchanaburi, Chaiyaphum, Petchabun, Ubon Ratchathani, Sisaket
In flight: March-August / Sightings (by me): Locally common

Easily confused with: N/A

*As there is no common name, I used took the Thai name which fits perfectly.

When I went to Chiang Mai back in March-May 2010, I noticed a species of Prodasineura that I instantly fell in love with. Prodasineura verticalis, known now as the Orange-bellied Threadtail. Since I saw this species for the first time, Noppadon Makbun told me that there are 3 distinct forms of this species; 'Northern', 'Eastern' and 'Western' forms, which I have been lucky enough to spot and photograph. Without Noppadon mentioning this, I would have over-looked the other forms. If you compare the three males, you can see significant differences. Noppadon isn't sure which is the true form of the species. It's a fantastic looking species and is the 3rd Prodasineura damselfly I have added to my blog.

The 'Northern' Male

The male has wonderful red, black and orange stripes on the thorax and the abdomen is completely black except for the caudal appendages which are a greyish colour. This specimen I saw in Chiang Mai.

The 'Teneral' Male

This is a newly emerged northern male, possibly right at the edge of its range and emergence window as I saw this early one morning in Phu Him Rong Kla, Phitsanulok province, in August, 2025. You can see it has narrow reddish bands on the thorax like the specimen above and has whitish appendages.

The 'Eastern' Male

The thoracic dorsal markings are much broader than the 'Northern' specimen. Other markings are slightly different too. Caudal appendages are also black, not greyish (as above). This specimen I saw in Ubon Ratchathani in April, 2022.

This specimen I saw at a small river, Koh Chang (13/04/2011).

The 'Western' Male

Though not the best angle in the world, you can see that the markings on the thorax are different again to the two above (they are slimmer and straigher) and the caudal appendages are black. This one I saw at Kanchanaburi (26/03/2011).

The 'Northern' Female

The female looks similar to all species in the Prodasineura genus, except it has a slightly red tinge to the thoracic markings. Again, this specimen I saw in Chiang Mai.

The 'Eastern' female

Again, even with the female, the thoracic markings are much slimmer than the Northern form. This specimen was ovipositing at a small river, Koh Chang.

The 'Eastern' Copula, Ovipositing

The 'Western' female

This isn't a very good shot and so comparing this specimen is difficult. It was raining and under heavy tree cover, making it really dark. It was also too high up to see dorsally and flew away when it tried to get above it. I will get a better example soon. I saw this female in Kanchanaburi.

41. Prodasineura coerulescens (Fraser, 1932)

No: 41 / Family: Platycnemididae / Genus: Prodasineura

Name: Prodasineura coerulescens / Fork-tipped Threadtail* 

Habitat: Tree-lined river, lowlands
Province(s): Khon Kaen
In flight: November-March / Sightings (by me): Rare

Easily confused with: N/A

*Name made up by me (based on Thai names/existing common names of other species in genus).

The second species of the genus Prodasineura I ever saw, was Prodasineura coerulescens. I was taking photos at the River Chi, Khon Kaen back in December 2008. I thought I had come across another P. autumnulis, but then noticed its azure blue colouration. Then it hit me... it's a new species for me! I have since seen 3-4 males and a female. That said, I haven't spotted this species of damselfly for over 2 years.

The Male

Very similar to a young P. autumnulis in appearance, but has wonderful azure blue stripes on its thorax, end segments and its eyes. It is also fairly easy to get close to and photograph. 

I recently returned to the same area [23.xi.13] and saw about 6-7 and the same numbers of females within a very small area of banking, deep undercover.

Like many species in the Prodasinerua genus, they tend to hover for long periods before they settle again (often not until they have caught something to eat).

The Female

The female resembles P. autumnulis. However, I saw a number females roosting along with males. The only difference I can see between the two females is that the abdomen of P. coerulescens seems slightly longer and, like the male, is fairly easy to approach.

This female I saw back in 2009.

I have only spotted this species in Khon Kaen and it is seldom seen even here. It is apparently known along the west of Thailand, but I don't think it is commonly seen.

40. Prodasineura autumnulis (Fraser, 1922)

No: 40 / Family: Platycnemididae / Genus: Prodasineura

Name: Prodasineura autumnulis / Black Threadtail

Habitat: Forested streams
Province(s): Widespread
In flight: Year-round / Sightings (by me): Very common

Easily confused with: Prodasineura humeralis

When I first visited the River Chi, Khon Kaen back in early 2008, I spotted my first ever Prodasineura species - Prodasineura autumnulis. I took a number of photographs of both the male and female. In this area they are in small numbers, but you often see one or two there. For over a year, I thought that the sub-adult male was fully grown. It wasn't until I went  to another place south of Nakhon Sawan that I noticed the adult males are jet black. At first I thought it was a different species, but research proved otherwise.

The Male

The adult male is black on the thorax and abdomen and also becomes slightly pruinosed with age. It is easily frightened and quite hard to photograph. This is the most common stage.

As the male ages, it changes slightly. This specimen, I captured in Nakhorn Nayok, has slight pruinescence to the side of the thorax (photo 28/03/2011 - added 02/04/2011) ... 

... and this one is completely pruinosed save a small greenish-bronze? part of the thorax. I must admit, this is the only specimen I have seen like this. It was at a largish waterfall in Lomsak province, Petchabun (14/07/12). Though it looks right, it acted differently to all the others around it and the colours add to the mystery. Maybe, just maybe, it may be a slightly different form. Can anyone shed light on this?

The Female

The female is almost identical to the sub-adult male, but the abdomen is far more robust. Like the sub-adult male, it tends to hide away and is less commonly seen.

Newly emerged...

The Copula

Not often I see this... I was very happy with it!

A Fresh Emergence...

This male has just emerged and you can still see his exuvia at the base of the stick he has climbed.

39. Coeliccia loogali (Fraser in Laidlaw, 1932)

No: 39 / Family: Platycnemididae / Genus: Coeliccia

Name: Coeliccia loogali / Blue-crescent Sylvan* 

Habitat: Forested streams
Province(s): Petchabun, Loei, Phitsanulok, Chiang Mai
In flight: April-October / Sightings (by me): Locally common

Easily confused with: N/A

*As there is no common name, I based the 'Blue-crested' on the Thai name and 'Sylvan' which is associated with a number of species in the genus.

The 6th (and 7th sort of) damselfly of the Coeliccia species I have seen is Coeliccia loogali as well as Coeliccia c.f. loogali. Both are similar, but the true form (I have seen in Chiang Mai) has a long slim crescent stripe along almost the entire thorax, whereas the close form has a considerably shorter and wider stripe. This form I have seen over a large area spanning Chaiyaphum, Petchabun, Loei and Phitsanulok. It is entirely possible that it is just a slightly different population but only time will tell.

The Male (Close Form)

When I visited Nam Nao National Park in October 2008, I didn't notice this species for a long time. On the 3rd day, I was walking along the pathway which runs along the river at the headquarters and I noticed a tiny little blue blob hovering near the ground. It was Coeliccia. c.f. loogali. Another species for me! Then I noticed many of them. They love extremely dark areas and almost hug foliage on the ground. The marks are pretty easy to distinguish, except for the markings on the end segments of the abdomen which change with age.

The Female (Close Form)

The female is very similar to the true form.

The Male  (True Form)

I saw a true form male on a recent visit to Doi Suthep, Chiang Mai. Here you can see how the thoracic markings are somewhat different. Also the very tips of the caudal appendages are whitish in colour, whereas they remain black on the c.f. specimens.

The Copula

I was also lucky enough to spot a copula while at Phu Rua NP, though it was seriously difficult to get anywhere near them so I am happy with this photo.

Coming soon...

The 'Young' Male (True Form)

This is the only true C. loogali I have spotted, when I visited Doi Inthanon, Chiang Mai last April. It is a young male that will change significantly in colour as it ages. You can also see how the thoracic markings are much slimmer and longer than the different form of the mature adult above.

The Female (True Form)

Here is a true form old female I also saw in Chiang Mai at the same time as the sub-adult above. It is identifiable as it has a kind of cross-shape dorsally at the end segments.

Here is a younger female from Nan.

Here is a old female from Chiang Mai.

I am not sure how common the undescribed C. c.f. loogali is, or its distribution (Chaiyaphum, Petchabun, Loei, Phitsanulok so far). But if you visit Nam Nao National Park, if you look very carefully in the darkened areas, you are sure to find this species.

38. Coeliccia chromothorax (Selys, 1891)

No: 38 / Family: Platycnemididae / Genus: Coeliccia

Name: Coeliccia chromothorax / Yellow-throated Sylvan* 

Habitat: Forested streams
Province(s): Chaiyaphum, Phitsanulok, Petchabun, Loei, Chiang Mai, Trat
In flight: April-December / Sightings (by me): Locally common

Easily confused with: N/A

*Name made up by me (based on Thai names/existing common names of other species in genus).

The fifth damselfly from the Coeliccia genus I have added to my blog, is Coeliccia chromothorax. This was the 2nd Coeliccia species I ever saw and again it was at Nam Nao National Park in October 2008. Since then, I have seen it at quite a few upland streams and seems to be quite abundant when you see it.

The male

The male is easy to spot as it not only has striking yellow/orange and black colouration to the thorax and abdomen, it also likes to perch on branches and leaves in the sunshine.

Another male I spotted at Nam Nao National Park.

Male, in the hand ... and playing dead. Something I have seen a lot with this genus. He flew away unharmed moments later.

The Female

The female is much more difficult to identify as it is similar to other females from the Coeliccia genus. The adult female has two separate white marks on the end segments of the abdomen and is also seen close to the male, but often in darker areas.

If you visit Nam Nao National Park you are sure to see this species if you walk along the river near the headquarters.

37. Ceriagrion olivaceum olivaceum (Laidlaw, 1914)

No: 37 / Family: Coenagrionidae / Genus: Ceriagrion

Name: Ceriagrion o. olivaceum / Rusty Marsh Dart

Habitat: Lowlands marshland and ponds
Province(s): Chaiyaphum, Petchabun, Kalasin, Khon Kaen, Chantaburi
In flight: November-February / Sightings (by me): Uncommon

Easily confused with: N/A 

I saw a female of this species about two years ago in Khon Kaen, but I never seen one since. When I visited Khao Soi Dao National Park last December, however, I saw several! Near the entrance there was a small pond that had a number of species. Just away from the water's edge in the grasses, I saw a Ceriagrion species and soon realised that it was Ceriagrion olivaceum. A new species for me! There were a number of females, but I only saw one male. Since then, I have spotted males at a small number of other places, though I am yet to spot another female.

The Male

Both sexes are very similar, but the male has a little more yellow/brown colouration to the abdomen. That said, I have now seen many specimens and the colours seem to vary slightly, especially on the abdomen.

This male from Phu Khieo WS, has a reddish upper abdomen and is almost white on the underside.

 

Another from Nam Nao NP, with a more uniform brownish abdomen.

The Female

The female is paler in colour but both sexes have a distinct 'olive' coloured thorax, which I presume gives it its name.

Here is the first female I saw at Khao Soi Dao NP.

It seems to be more common than I first thought and that it may easily be overlooked. It is quite difficult to spot and tends to hide away in the long grasses.