VietOdonata: juin 2015

Flock of Pantala flavescens in front of Tam Dao and its three characteristics pics

I know I've been neglecting this blog lately. But the truth is, I've been very busy!

I’m back in the field now, when the sun shines, and hope to make up for lost time a bit. Below are some of my best photos from recent trips in May and June along the foothills of Tam Dao (Tây Thiên and Mê Linh) and a bit of blurb.

These trips yielded some new species to my ever-growing Tam Dao species list. The best were 3 Macromia species and Heliogomphus retroflexus, all captured along a stream at Mê Linh. Four new species for me along a single stream in secondary forest, very unexpected... I also spotted there Labrogomphus torvus, which might be the first record for Tam Dao.

At Tây Thiên I checked the spot of the extremely localized Rhinocypha orea (around the nunnery) and found 5 males.

Many species were buzzing around everywhere... but I am too lazy to write a list!

This male Macromia katae was found patrolling up and down a short, well-shaded stretch of stream at Mê Linh, Tam Dao (mid-May). Like Macromia pinratani vietnamica or Macromia malleifera, flight slowly on a quite rectilinear trajectory.

Stretch of stream at Mê Linh where 4-5 males of Macromia katae were seen at 2 different visits.

Stream of stony and gravel bed running through secondary forest, thickets and orchards, but with woody riparian corridor well conserved. Dragonflies are well-known to be sensitive to light conditions, with the species having a range of light conditions that they prefer. When these conditions are changed, such as by human removal of the tree canopy, the odonata assemblage changes accordingly, with forest species being replaced by species preferring sunlit habitats. Riparian corridors help to maintain odonata assemblages, even when the surrounding habitats are severely degraded – this is the case at Mê Linh.

In a recent publication, Natalia von Ellenrieder et al. mention some interesting species from Mê Linh, among them Macromia katae, 1st record for Vietnam.

This species has been described from Hong Kong in 1993. It is so far only known from few localities within lowland secondary forest in China (Guangdong and Hainan) and Hong Kong, in Laos near the Vietnam border (Yokoi 2003), and now from Vietnam, and it has been assessed as Vulnerable by the IUCN Red List (Wilson 2013).

Macromia katae in hand
All Macromia species can not be reliably identified without capture and closer examination

Macromia katae, male, distinctive facial pattern

Macromia katae, male, caudal appendages, lateral and dorso-lateral views : note the spine-like process on S10

Another interesting Macromia species I found recently at Mê Linh is Macromia urania. It is much smaller than M. katae and its flight is quite erratic.

Macromia urania, male, Mê Linh
Note the expansion of S7-9 and the 2 dorsal spots on S8

Macromia urania, male, Mê Linh

Close-up on the male secondary genital apparatus

note the wavy outline of the hamule

Blackish face with yellow postclypeus

Macromia urania, male, caudal appendages, lateral and dorso-lateral views

The third Macromia species I recorded at Mê Linh is M. cupricincta. It was sharing with M. urania the same short, open stream stretch - at the difference of M. katae which was caught in a well-shaded stretch. These three Macromia species were active at midday.

Macromia cupricincta, male, Mê Linh
Described from India (1924), subsequently found in Malay Peninsula, Laos, Myanmar and Thailand. First record in Vietnam from the South (Karube, 2011), but also presence in the North as shown by this record and the one (the ones?) of Tom Kompier.

Identified as cupricincta based on the combination of brown-reddish face, extreme curve of the wing at the anal triangle and long acuminate spine on the dorsum of S10. Note also the coppery-brown wash on tip of abdomen, on S4-6 (ventral half).

Brown-reddish face

Macromia cupricincta, male, caudal appendages, lateral view (left) / dorsal view of abdomen (right)

The 50m open stretch at Mê Linh where Macromia cupricincta and M. urania were caught.
Males Labrogomphus torvus were also spotted there, perched on stones. I was astonished by this spot (very ordinary, I always thought these species were a bit picky habitat-wise). These species where found nowhere else along the 700m of stream surveyed (4 times).

I also add here a fourth Macromia, a very common one this one, photographed at Tây Thiên : Macromia pinratani vietnamica.

Macromia pinratani vietnamica, male, roosting 30m away from the water (Tây Thiên)
A widespread and very common Macromia, but a roosting individual is quite a rare sight

Another male photographed at a greater distance with a 400 mm telephoto lens- the one I use for birds

Macromia pinratani vietnamica in flight when patrolling a small brook in forest.
Males consistently patrol a few dozen of centimeters above the water, slowly, on a rectilinear trajectory.

Rhinocypha orea, Tây Thiên, a typical view of a male perched few meters above the stream on leaves

I spotted 5 males Rhinocypha orea around the nunnery in mid-May 2015, all detected in flight – the vibrant golden-colored wings attract the eye. Described in 2011 from Tam Dao, this damselfly has never been recorded elsewhere.

Rhinocypha orea, male, Tây Thiên

Forewings hyaline, hindwings with 2 different pattern : oustide black with green sheen at tip, inside golden and dark reddish at tip.

Euphaea guerini, male and female, Mê Linh

Euphaea masoni, copula, Tây Thiên

Euphaea masoni, female crawling down a plant stem to get under the surface for submerged oviposition

Archineura hetaerinoides, male, Tây Thiên

Euphaea decorata, teneral male, Mê Linh

The exuvae it has just crawled out of

Libellago lineata, male, Mê Linh- still one of my favourite little damsels

The first time I have ever seen this species at Tam Dao

Lamelligomphus formosanus, Tây Thiên, a male obelisking at midday (to minimize solar radiation falling on it)

Ophiogomphus sinicus, male, Tây Tiên

Merogomphus paviei, male, Mê Linh

The first time I encountered this species at Tam Dao

Labrogomphus torvus, male, Mê Linh

A recent addition (2013, Huu Liên, Lang Son Prov.) to the Vietnamese fauna. According to Tom's blog, quite widespread in northern Vietnam, but certainly not common.

In 2012 near the Tam Dao Bear Rescue Center, I photographed an unknown gomphid which I identified 2 years later as Labrogomphus torvus. This new record confirm its presence within the massif.

Gomphidia kruegeri, male, Mê Linh

Gomphidia kruegeri, a male obelisking, Mê Linh

Gomphidia kruegeri, male, Mê Linh

Gomphidia abbotti, male, Mê Linh

Gomphidia abbotti, female, Mê Linh

Asiagomphus auricolor, male, Mê Linh

Asiagomphus auricolor, male, Mê Linh

A quite different pattern (less yellow on S1-2, complete humeral stripe) but I could not find any structural differences

Philoganga vetusta, female, Tây Thiên

Tetracanthagyna waterhousei, female, Mê Linh
This common Aeshnid prefers well-shaded stream with steep banks

Macromidia rapida, female, Mê Linh

A rather common species at the foothills of Tam Dao.

Macromidia rapida, female, Mê Linh

Tetrathemis platyptera, male, Tây Thiên

Trithemis aurora, male, Tây Thiên

Cratillea lineata, male, Tây Thiên

I feel that, every now and again, it’s worth taking a moment to pause and ponder how beautiful the world around us is. Scenes like this:

Zygonyx iris, male, Mê Linh

… really help me center myself and relax. That might be a very common dragonfly, one that I see throughout the season in my area, but the sight of them never grows old.

They remind me how amazing our world is, and how many things I’ve yet to experience. Do any of you get the same feeling in nature?