Rhinagrion hainanense Wilson & Reels, 2001

Male, Xuân Son National Park

Wilson and Reels (2001) described Rhinagrion hainanense from a single male collected from Lumu, Hainan, in June 1999. Rhinagrion yokoii Sasamoto, 2003 is a junior synonym of this species (Kalkman and Villanueva, 2011).

All the photos of this post were taken mid-October 2013 at Xuân Son National Park (Phu Tho Prov., northern Vietnam).

The males of the genus Rhinagrion are among the most striking and colourful damselflies. In the field they are easily recognized by having a colourful abdomen with red, blue, orange or pink markings and wings that are hyaline and open at rest.

They perch quite low above the ground and make short flights on the edge of, or within, dense shrubby vegetation along streams.

 Male

Some features of the male Rhinagrion hainanense  : 

Head black with extensive blue-green pattern.
Antehumeral stripe roughly parallel sided, covering about two-thirds length of synthorax. 

Side of synthorax with dark stripe along metapleural suture not connected to dark dorsum of synthorax. 

Male in hand, for better view

Male, facial pattern

Abdomen largely brown-reddish, S3–7 with pale band on posterior half of each segment, S8–10 black with pairs of blue dots on S9–10, superior appendages pale. Sternum of S7–10 brick-red.

Male, tip of abdomen, lateral and dorsal views

During the courtship, this male was hovering in front of the female and arched his abdomen to display the bright brick-red color on ventrum of S7-10 (abdomen was bent downwards at right angles so more bent than the left shot show). The crappy photo in the right show quite well how the tip of abdomen was spread out. And it was not only spread out, it also quivered like a tiny flag!

Female is much less colorful than the male. She show a pale version of the male color pattern, with an apricot ground color. Antehumeral stripe blue-green.

Female

Same, close-up

A male and 2 females at an oviposition spot (muddy banks of a pond)

Ovipositing female 

In his blog thaiodonata, Dennis Farrell photographed a female ovipositing at the base of a log overhanging a stream (see here)

Rhinagrion hainanense is currently known from China (Hainan, Guizhou Prov.), Thailand, Laos (as R. yokoii from Sekong in southeastern Laos), northern and central Vietnam [Xuân Son National Park (Phu Tho Prov.), Cuc Phuong NP (Ninh Binh Prov.), Chu Yang Sin NP (Dak Lak Prov.), Phong Nha-Ke Bang NP (Quang Binh Prov.), Phong Dien Nature Reserve (Thua Thien Huê Prov.), Khanh Hoa Prov.].
The locality at Chu Yang Sin National Park in Vietnam was given as a “sandy forest stream” and that at Phong Dien Nature Reserve as “2m wide and 20 cm deep through disturbed forest”. In Hainan the species is found in dense vegetation beside shady, slow-flowing streams in lowland areas (Kalkman and Villanueva, 2011).
The locality at  Xuân Son National Park - where these photos were taken - is a 30m x 5m pond with clean water, 1 m deep, at the edge of an undisturbed lowland forest.

In August 2013, I also bumped into a male at Tây Thiên (lower slopes of Tam Dao NP), at a tiny pond in degraded secondary forest.

Ten species of Rhinagrion are known. Four are known from continental southeast Asia (hainanense, mima, viridatum, macrocephalum) and the remaining six species from Indonesia, Philippines and North Borneo (Sabah) :

-Rhinagrion borneense Selys, 1886 Brunei, Malaysia (Sarawak, Sabah), Indonesia (Kalimantan)
-Rhinagrion elopurae McLachlan in Selys, 1886 Malaysia (Sabah)
-Rhinagrion hainanense Wilson & Reels, 2001 [syn: Rhinagrion yokoii Sasamoto, 2003] China (Guizhou, Hainan), Laos, Vietnam, Thailand
-Rhinagrion macrocephalum Selys, 1862 Peninsular Malaysia, Indonesia (Sumatra)
-Rhinagrion mima Karsch, 1891 Burma, Indonesia (Sumatra), Thailand, Vietnam
-Rhinagrion reinhardi Kalkman and Villanueva, 2011 Philippines
-Rhinagrion philippinum Selys, 1882 Philippines
-Rhinagrion schneideri Kalkman and Villanueva, 2011 Philippines
-Rhinagrion tricolor Krüger, 1898 Indonesia (Java)
-Rhinagrion viridatum Fraser, 1938 [removed from synonymy of R. mima] Burma, Peninsular Malaysia, Thailand 

Note that R. mima has also been recorded in Vietnam, at Phu Quoc Island (extreme south-west of the country).

Some Nice Stuff Not Far From Hanoi

Nice stream at Tây Thiên 

Below are a few of my recent finds at 3 different sites around Hanoi, all at c. 75km from the city center : Tây Thiên (first slopes of Tam Dao), Mt Ba Vi and Cuu Thac-Tu Son (a tourist area in Hoa Binh Province with nice streams and waterfalls).  

Three amazing places and only 1.5 hrs drive (by scooter) from Hanoi! Not easy to pick up new species for my personal records but always nice photo opportunities - so I am never disappointed. 

Photos taken in May-June.

Periaeschna magdalena, male, Ba Vi
Spotted this species at Ba Vi and Tam Dao, from the lower slopes to 900m

Periaeschna magdalena, female ovipositing at a mossy wall near the road, Ba Vi

Drepanosticta sp., Ba Vi, two males engage in agonistic flight
The brilliant blue patch at the tip of abdomen make this species easy to find in the darkness of the forest

Drepanosticta sp., male, Ba Vi, yet to be described
I bumped the first time into this all-black thorax Drepanosticta in 2011, at Ba Vi, in montane forest (900m asl). Subsequently, I found it at lower elevations (300m) in this mountain but also 50 km further south, at Cuu Thac -Tu Son (Hoa Binh Province), in submontane forest.
Recently, at Ba Vi, Tom Kompier discovered that the very similar Drepanosticta hongkongensis share the same streams that this unknown Drepanosticta (but apparently earlier in the season, before the rainy season), making things more confusing... but more exciting! Drepanosticta hongkongensis (first record for Vietnam) do not show blue markings on prothorax and have different appendages (see Tom's blog entry).

Same, close-up showing the blue markings on protorax (in both sexes). Note also the blue mark at the base of wings

Protosticta satoi, male, Ba Vi

Same, close-up

Protosticta satoi dark morph, male, Tây Thiên 

Leptogomphus sp., Tây Thiên
Copula caught by a robber fly (Asilidae)

The name "robber flies" reflects their notoriously aggressive predatory habits; they feed mainly or exclusively on other insects and as a rule they wait in ambush and catch their prey in flight

Leptogomphus elegans, male, Ba Vi

To my knowledge, in Vietnam, this species is only known from Mt Pia Oac (Cao Bang Prov.) and Mt Ba Vi

Male abdomen tip of 3 Leptogomphus species (from left to right) : L. perforatus, L. divaricatus, L. elegans

Gomphidia kruegeri, copula, Tây Thiên
I saw the female flying above the stream with the abdomen tip bent downward (looked so weird, I thought it was a new species for me!). Then 2-3 males rapidly appeared, loud crashing sounds ensued and the winner grabbed his girl

 Burmagomphus vermicularis, male, Cuu Thac - Tu Son

 Burmagomphus vermicularis, male, Cuu Thac - Tu Son

Paragomphus capricornis, male, Tây Thiên

Paragomphus capricornis, male, nice facial pattern

 Lamelligomphus camelus, male, obilisking in the hot sun, Cuu Thac - Tu Son

 Lamelligomphus camelus, male, tip of abdomen
Two big humps (→ camel(us)...) on S8, dorsal tooth to basal part of superiors

 Lamelligomphus camelus, male, Cuu Thac - Tu Son

.... doing stretching exercises

Lamelligomphus formosanus, male, Tây Thiên
For more details about this species and other Lamelligomphus (+ Ophiogomphus, Melligomphus), see great posts on Tom's blog

 Lamelligomphus formosanus, male, tip of abdomen
 No obvious humps on S8, no dorsal tooth to basal part of superiors, small teeth ventrally on inferiors close to bend

Heliogomphus unidentified (yet to be described ?) 
Looks superficially like H. scorpio but sides of thorax yellower and caudal appendages very different. Both species share the same habitat at Tây Thiên. I also found this mysterious Heliogomphus at Ba Vi, at higher elevations (900m)

Heliogomphus scorpio (left) and Heliogomphus sp. side by side (caught at Tây Thiên along the same stream, same day). Note in scorpio the paler thoracic stripes, especially metepimeron 

Ventral view of  caudal appendages of males Heliogomphus scorpio (left) and Heliogomphus sp. The latter shows lateral spine of superior appendages much shorter, with 2 tooth at apex

Fukienogomphus promineus, male, Tây Thiên, + tip of abdomen (dorsal view)

Known from southeastern China and at least 2 mountain localities in Tonkin (northern Vietnam) : Mount Mau Son/Lang Son Prov. (first country record, in 2010, by Do Manh Cuong) and Tam Dao/Vinh Phuc Prov.. It was the first time I spotted this species on the lower slopes of Tam Dao, at only 350m asl. 
Vietnamese specimens show reduced lateral thoracic markings along the metepisternum compare to Chinese specimens (Do Manh Cuong, 2011).

Chlorogomphus sachiyoae, male, + tip of abdomen (dorsal view)
Quite common at Tây Thiên, even along open rocky stream in degraded secondary forest

Sinorogomphus nasutus, male, + tip of abdomen (dorsal view)

Caught at Ba Vi

Chlorogomphus auratus, male, + tip of abdomen (lateral view)
Seen at Cuu Thac-Tu Son (submontane forest) and Ba Vi (montane forest). At Ba Vi, in some streams, co-occurs with Sinorogomphus nasutus

Asiagomphus sp., male, Ba Vi

Found last year at the lower slopes of Ba Vi and some specimens were collected this summer. Without any doubt this is the same unknown Asiagomphus species found in Lang Son (Huu Liên) and Yên Bai Provinces (called “species 1 or A” in Tom’s blog), on the basis of the following features : antehumeral spot (sometimes absent in some specimens), large posterior hamulus, second lateral stripe, lots of yellow on S1-2, shape of inferior appendages in ventral view. 

Like “species 1”, the female is "tri-horned" : two over the lateral ocelli and one on the occipital ridge.

Same place, same species, male, but no antehumeral spot

Asiagomphus sp., male, Ba Vi, tip of abdomen
In ventral view, inferiors very widely separated in broad basin like U-shape

Asiagomphus sp., male, Ba Vi, in hand

Asiagomphus sp., female, Ba Vi, in hand
Note the strikingly broad expanse of yellow at base of abdomen

Tri-horned female : two horns over the lateral ocelli and one on the occipital ridge

According to Tom Kompier (pers. comm.), this species is probably the mysterious Asiagomphus auricolor described by Fraser in 1926 based from one single female specimen collected in "Tonkin, Ngai Tio" (i.e. northern Vietnam, exact location remain obscure - maybe Ngai Thâu in Lao Cai Prov.), and never recorded since then! 

But let's wait and see Tom's conclusions on his blog.

Polycanthagyna erythromelas, female, Tây Thiên 
One of the commonest jungle Aeshnids... without being a common sight – far from it

Same female, in hand. Just gorgeous...

Archineura hetaerinoides, male, Tây Thiên

Still many individuals observed mid-June, along the well-shaded stretch of the main stream around the nunnery but also downstream in much open habitat - but with dense riparian vegetation

 Archineura hetaerinoides, female, Tây Thiên

Archineura hetaerinoides, male in hand
Specimens from Vietnam have larger milky white maculation on both fore and hind wings - geographical variation (Karube, 2002d)

Orolestes selysi, male hyaline-winged form, Tây Thiên 

The 2 forms (patch- and hyaline-winged) share the same tiny pond at Tây Thiên

Orolestes selysi larva near the water surface, Tây Thiên

This larva crawls up onto a stem emerging from the water and will begin soon its transformation, Tây Thiên