Wrapping it up at Cat Tien

All in all it has been an amazing time at Cat Tien National Park again, bringing in plenty of new discoveries and showing what a treasure trove Vietnam really is, when it comes to Odonata. I saw about 270 in 2014 and there is definitely no end in sight, but most of my time is spent in the north. So these trips to the south are a rare treat and bring in loads of new experiences. For one, there is no real quiet season. Although in the north even now you can find dragons or damsels (just last week, on the 26th I had a female Megalestes micans in Sa Pa (yes, even at that height they hang on in the cold) that does not compare to the exciting hustle and bustle of the south. Here is a few more damsel pictures to wrap up adventures there.

Male of Argiocnemis rubescens, very common in November

And the immature female of Argiocnemis rubescens

Another species that was surprisingly common this time round was Onychargia atrocyana, here a male

But what was really a surprise was Rhinagrion hainanense. This is a male, although I also saw a female. Very similar R. yokoii has recently been shown to be a junior synonym of this species.

Diplacodes nebulosa - another mystery solved

Where is Diplacodes nebulosa? I asked myself that question often. I had seen it once on a trip to the Mekong Delta in wintertime. That was a work-related trip before we moved to Vietnam and I had never seen it since. Now the riddle was solved. Although the species has apparently been recorded in the north, it certainly has not been seen there by me. Now in Cat Tien I found it present in the dried out and grassy fishponds, where fresh specimens abounded. So, it can be very common in the south, but as a wintertime (dry-season) species. Adult males are grey with dark wingtips, which makes them easy to recognize. The female has a neat black-and-white pattern on the abdomen and thorax. Once known, also easy to recognize.

Female Diplacodes nebulosa with typical broad black dorsal stripe on abdomen and blackish thorax with light stripes.

An adult male, easy to recognize because of small size, blueish-grey colour and dark-brown wingtips.

Another male showing the distinctive wing pattern

And obelisking in the hot sun

Immature male showing the same abdominal pattern as the female, the same thorax pattern too, but the wing tips are already somewhat darkened.

Rhyothemis species from Cat Tien National Park

There are four species of Rhyothemis at Cat Tien, but R. triangularis was sadly absent and I therefore failed to get pictures of that lovely species once again. Other species were less common than they had been in July-August. I saw only a single R. plutonia.

Male Rhyothemis phyllis, a lovely species with reduced black-and-orange pattern on the inner wing.

R. plutonia is a fantastic species that looks pretty much black from a distance, but under close inspection reveals green and purple on the inner wings.

Finally, a female of R. phyllis. Possible to confuse with R. variegata, but black-and-yellow pattern much larger and extending far onto the outer wing on that species.

Neurothemis species at Cat Tien

In the north of Vietnam I bump into Neurothemis fulvia regularly. At Ba Be for instance it is really common. The other Neurothemis here is N. tullia, but I have here in the north only seen it at Van Long. Plus a lonely record of N. intermedia at Cuc Phuong of a single female. But at Cat Tien there are three common species. N. fulvia occurs all over the place. N. tullia is common especially at the fishponds. And Neurothemis fluctuans is a small red-winged species that I have not seen in the north, indeed I am not aware of any records in the north. During my visit in November I also saw a single female (again) of N. intermedia. Although apparently in Thailand for instance this can be a very common species, here I saw just a single specimen at a dried out former pond in open terrain. Maybe she had just sort of happened upon the place, a drifter. Below some shots of the Neurothemis species I took during the trip and a few shots of Brachythemis contaminata. That very common species is a possible pit-fall for female and immature N. fluctuans.

Let's begin with the male of Brachythemis contaminata. The black middle line on the abdomen and the orange wing-pattern, darker near the middle, help identify. 

This is the female of B. contaminata. The blackish line along the dorsum of the abdomen is very obvious and absent in the Neurothemis species.

Female Neurothemis fluctuans. Note the dotted line close to the lateral carina and only a very thin line over the dorsal carina on the abdomen.

In dorsal view, the dotted line located just short of at the very edge of each segment.

Another female showing the typical dotted line on the abdomen. This specimen also with darkened wingtips.

The immature male showing the same, but somewhat more pronounced abdominal pattern and the wing pattern of the adult male in orange brown.

The mature male, with abdominal pattern obscured by dark reddish colour and now deep red wings, with the transparent tips to the hind wings extending along the posterior edge towards the middle.

In comparison, male N. fulvia, with transparent tips reduced to the apex of the wing only, not extending along the posterior edge.

Another male N. fulvia. The transparent apex starts halfway the pterostigma.

Female N. intermedia, with typical broad uninterrupted lateral line and dark humeral stripe

Female N. tullia, smallish species with dark brown and white wing pattern.

The male of which has extensive black on inner wings and whitish-grey outer wings.

Prodasineura coerulescens - another Prodasineura

One species that was on the Cat Tien list already, but that we just could not find, was Prodasineura coerulescens. On November 18 I decided that before we were going home I should at least give the Dong Nai river a closer look. Until that time we had largely ignored it. Yes, I know, silly. So, when a blue damselfly hovered just above the surface in typical Prodasineura fashion I knew that mystery was solved. Prodasineura coerulescens does occur at Cat Tien and it favors the rapid parts of the main river. It is a very nice damsel, as most Prodasineura in fact are. And a cool new species. It is known from both Thailand and southern Vietnam, apparently absent from Lao DPR and Cambodia, but maybe it is just awaiting discovery. I saw about 4 males. P. laidlawi is also known from Vietnam and similarly blue, but it has more extensive blue on S9 and a different pattern on the top of the head and the prothorax.

Prodasineura coerulescens, male, perched above the river

And another, hovering above the current

Heliaeschna uninervulata - Swarming at Cat Tien

On November 17 we were checking the road from the lodge to the fishponds in an open, disturbed, area, with some forest and shrub cover. Close to dusk, we were looking for Gynacantha. As luck would have it, a species appeared in good numbers, with several score dancing around. But not so lucky, they stayed quite high. Kameliya discovered a place where they were flying somewhat lower and I was able to net two females. In hand, they had very broad leaf-like appendages. But my mind was set on Gynacantha, so it did not occur to me this could be something else. It was only after Oleg Kosterin (thank you Oleg!) responded to a later email by me, that it dawned on me that this was a Heliaeschna. Venation in the wing made it clear it was H. uninervulata, a species that had been reported from Vietnam before (1953, Lieftinck), but otherwise apparently had gone unnoticed. It occurs widely over south-east Asia, so it probably occurs more commonly.

Heliaeschna uninervulata, female. In coloration and appearance rather Gynacantha-like. Note the single cross-vein in the median space.

Dorsal view of the frons

Facial pattern, rather simple

The distinctive leaf-shaped appendages

Two more Lestidae from Cat Tien

During my little excursion to Cat Tien, I was able to finally find Orolestes octomaculatus. That was very welcome. James had found one in the lodge, but I had not been able to replicate that record and felt hopelessly left out. This time round I was more lucky. First we found a freshly emerged female in the flooded excavations on the way to the fishponds. Then I found a female smack in the middle of the forest, and finally several males at ponds close to the bird lake trail. It is an easy species to recognize. The female in hand by the 5-6 large teeth on the ovipositor and the male by the 8 spots on the wing.

The other Lestidae I ran into, was a female Lestes elatus, which I found at the fishponds. Luckily an easy species to recognize on account of its patterning. Also apparently common in all sorts of disturbed habitats. I found only one, but at least we know it is there. Hopefully also males next time.

Lestes elatus, a female photographed from some distance

The same female in hand. I am sorry about the prominent finger, but if you check the print, you can see it is me. The pattern on S8-9 is very typical.

Orolestes octomaculatus, not a good photo and with flash, but you can see the typical double-dot pattern on all wings.

Another male, again a little hasty when taking the picture

Female of Orolestes octomaculatus, note the rather different, plain, coloration of S8-9 when compared to female O. selysi (see that post)

Note the large teeth on the ovipositor (same female as in previous picture)