At long last another Lestes

Considering my world Odonata list, Lestes is one of the genera with the most recorded species and that is not surprising, giving the number of described species and the fact they occur around the globe. But irrespective of that, there are not that many species around in Vietnam, apparently. Only three I had been able to find. Lestes praemorsus is the common species, found from the very north to the very south, and Lestes elatus from the southern half of Vietnam. Lastly, I recorded pretty Lestes nodalis from Huu Lien Nature Reserve, to the north of Hanoi. And that was it. Until on May 12 this year I stopped by the road in Lam Dong province, to the northwest of Bao Loc, to check a grassy inundated area in the afternoon. I noticed many Lestes praemorsus, but it dawned on me that some appeared to be larger than others and these all had a reduced pale abdomen tip. This could not be a coincidence. I took photos and collected a few. In the evening I became disappointed. It seemed the appendages were the same, so maybe just variants? But when I returned home several days later and was able to check them under the microscope, it became clear there were in fact differences. Most striking were the differences between the inferior appendages of the species, in addition to the aforementioned differences in coloration. Two species appeared to have this combination of characters, Lestes dorothea Fraser, 1924 and Lestes praecellens Lieftinck, 1937. The former is quite large, a little larger according to the description than mine, which fit better the species described by Lieftinck from Java in size. However, the female I photographed has much more extensive thoracic markings than that species, in line with what is to be expected of L. dorothea. That species is recorded from India, Thailand and Malaysia. Based on the structural characteristics and patterning of the male and patterning of the female I think it is safe to conclude this is L. dorothea as well.
By the way, based on the likeness of the appendages of L. praecellens and L. dorothea one may ask whether these are truly different species. There thoracic markings are also rather similar, if it weren't for the female.

Lester dorothea male. Note the lack of pruinosity on S9.

Male and female of L. dorothea

The female, showing the extensive dark markings on the thorax, unlike L. praemorsus

Another male showing the limited pruinosity on the abdomen tip

A Lestes praemorsus male for comparison. Smaller and with pruinosity on S9.

A few hours in Vientiane, Laos and a new species for the Laotian list.

This Thursday I had a few hours to spare in Vientiane and took a cab to the outskirts of the town. Thank God the surroundings are not close to being as polluted as around Hanoi and I was able to find 38 species in a short time. Vientiane is about as far south as Ha Tinh in Vietnam, which is about the southern edge of my general research area (northern Vietnam). But its species are quite different, much more southern. There was a lot of overlap with the commoner species in Cat Tien National Park, for instance. I was happy to catch a Epophthalmia frontalis male. Yokoi & Souphanthong actually list 31 Macromiidae, 28 of them Macromia. Which is rather astounding. But anyway, I was happy with my frontalis. And I was able to take pictures of male Lestes elatus and female Ceriagrion cerinorubellum. I had seen both these species in Cat Tien, but had not seen these sexes. Below a few pictures. And another very common species in some inundated and apparently deserted rice fields was an Aciagrion. I had to go back to Ris (1911) and Fraser (1933) to find out what may be the differences between Aciagrion occidentale and A. borneese. The appendages look rather similar and the A. borneese I had from Da Nang had been eaten by vermin. But in the end the description of Fraser pointing out that S8 is blue with a black triangle on it in A. occidentale, whereas A. borneese has a broad dorsal black stripe over the whole segment, provided the clue. Photos from India confirm the pattern on A. occidentale, and I therefore conclude that the specimens I saw were A. borneese, on the premise that the pattern is consistent over the complete range of these species. Interestlingly Yokoi & Souphanthong do not list either of these species for Laos. A. borneese is a very common species in Thailand and that country is of course right opposite the river at Vientiane.

Let's start with the addition to the Laotian list, Aciagrion borneese. Note dorsally black S8 and S10, whereas S9 is marked by a thin blackish dorsal line.

Another male with the distinctive pattern

Female Ceriagrion cerinorubellum. Possible to confuse with C. auranticum because of the green eyes and orange-brown cranium. However, S3-7 are blackish above and blue-green laterally, not orange, and S9 misses the clear darker marking.

Lestes elatus female

And the male, which I had failed to find in Cat Tien.

And finally a fine male Epophthalmia frontalis

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)

Lestes nodalis - a weird Lestes!

April 21 was Easter Monday and thus a holiday for me. After two days in cloudy Hanoi I just had to go somewhere, but the weather was not appealing at all. I decided to go for it anyway and drove to Huu Lien Nature Reserve. Huu Lien is a brilliant place for dragonflies, still, but there is always the sound of chainsaws in the background and I dread seeing cut down trees left and right in the last decent patches of the forest. Also, the water quality is deteriorating. All in all I hope that we will be able to enjoy the bounty of the place also in years to come. Anyway, I had nearly 50 species on a mostly cloudy day in April, not bad at all. I saw two Gomphids I had not seen before, one of which I could catch. More on that later.

When checking a field laid bare with some weeds near a shallow stream that dries out in winter, bordering agricultural lands, I noticed a weirdly colored Lestes. I was able to take some pictures and catch it, but afterwards I saw nearly 10 more, both males and females. Checking the literature at home it turned out to be Lestes nodalis (Selys, 1891). A species known from Thailand, Myanmar, India, and bordering China (Guangxi, Yunnan), so it is maybe not surprising it also occurs here in Vietnam, but it had not been recorded before, so another addition to the Vietnamese list!

The coloration of both the male and the female is rather peculiar, lacking the metallic shine so often seen in the genus. The appendages are very typical and the pterostigma is dark with a light border all around.

Lestes nodalis, male

Another male, showing off its fabulous colors

Close-up of head and thorax

The female is not less weird in color, maybe more so

Another female, note also the darker trailing edge of the slightly amber wings

Appendages of the male in dorsal view. Superior appendages with distally pointed projection, mostly pale yellowish with black tips.

Lestes praemorsus

Until recently I had 18 species of Lestes spreadwings seen around the world. Then Lestes viridis was changed into Chalcolestes viridian and I had only 17. And then the lucky day came that I found a little pond with grassy verges on the border of Ba Be National Park and so two male Lestes that could quite straightforward be identified as Lestes praemorsus, based on the distinctive appendages. It is a very nice Lestes, even if sometimes I do not get overly enthusiastic about some members of the genus.

Lestes praemorsus, male

Distinctive appendages in lateral view taken through microscope