Labrogomphus torvus Needham,1931

Female Labrogomphus torvus at Huu Liên Nature Reserve, on December 1, 2014,  
enjoying the first rays of sunshine on a fresh winter morning

Labrogomphus is a monotypic genus erected by Needham (1931) to receive a female specimen of Labrogomphus torvus collected from Hainan. Chao (1954) described the male and larvae specimens collected from Fujian. It is allied to Macrogomphus, with which it agrees in having the 9th abdominal segment more than twice as long as the 8th.  
Labrogomphus torvus is a stunning blackish spiny-legged species, with a thorax handsomely striped, a curved abdomen spotted with bright yellow.  
I was lucky enough to spot both male and female the same day, in December 2013, at Huu Liên, as I wandered along a reservoir's banks.

One of the most impressive Gomphid species I have been privileged to see in Vietnam so far - the very long hind legs armed with extremely long strong spines have probably something to do with this.

... before grabbing few meters away her breakfast, a female Orthetrum pruinosum 

A voracious predator !

This stupid male landed on my net! (I read somewhere that white nets attracts certain groups, namely gomphids. Seems true...) 
Note S9 markedly elongate, S7-9 broadened and the large basal ring on S7.

                             

Male in hand. Hind femur and tibia with very long spines

Female in hand - same stuff on hind legs

Male, head. Note the particular shape of occipital ridge.

Compare with the female :

Male, caudal appendages, lateral, dorsal and ventral views

Labrogomphus torvus is known from southern China including Fujian, Guangdong, Guangxi, Anhui, Hainan Island, Hong Kong. In December 2013, it has been discovered at Huu Liên, first record for Vietnam. In June 2014, I also found it at Tây Thiên (foothills of Tam Dao) along a rather open rocky stream in degraded secondary forest and Tom Kompier recorded it the same month at Ba Be (Bac Kan Province).

According to literature, this Gomphid can inhabit a wide range of stream and river habitats, both in forested and open aspect environments, and even ponds/lakes created by impounding streams - it was the case at Huu Liên.

 

Rhinocypha orea Hämäläinen & Karube, 2001

Two males engage in (prolonged) agonistic flight, 
Tây Thiên - Tam Dao, on May 24, 2014

Rhinocypha orea was described in 2011 by Hämäläinen & Karube, based upon specimens collected at Tam Dao in the 1990's - but without any precise locality indication.

In 2004 and 2005, a large population with more than 50 individuals was observed at a short section of a stream (downstream of Silver waterfall, Thác Bạc, the major touristic attraction at Tam Dao, at ca 900m asl), but one year later, at the same site, only one specimen was found. At this time Rhinocypha orea was only known from this  stream. The portion of forest concerned is partly surrounded by "su su" fields (known in English as christophine or chayote). Those crops are gaining ground year after year (in conjunction with tourism development) and already adjoining the right bank. Vegetation is cleared, changing canopy shading. Located downstream of the Tam Dao Hill Station, the site is also subject to important pollution discharge, especially at the peak tourist season. The stream banks littered with plastic wastes are a very sad and deplorable sight, especially in a so-called "National Park".

After 2006, Rhinocypha orea just disappeared off from local odonatologists radar screens,  despite regular surveys in the area. Some even came to think that it had vanished, victim of changes in water quality and vegetation. But in mid-May 2014, we received a great news from Tom Kompier who found 2 males : one individual not far from the original site (at ca 900m asl) and the other one at only 300m asl, in the area called Tây Thiên – a touristic complex  structured around "spiritual tourism" with many temples, pagodas and monasteries.

Very excited, I quickly arranged a field trip to Tây Thiên to try my luck at finding this rarety! The first individual was seen at noon just in front of the nunnery. Upstream, I spotted 4-5 other males, and the same number 100 meters downstream of the nunnery. So a total of ca 10 males, at a 300 meters section of a heavily forested stream, with big boulders. All the individuals were seen perched on vegetation and rocks along the stream. Almost all were detected in flight – the vibrant golden-colored wings attract the eye,  that is the least one can say.

This little population inhabit a rather well preserved stream, I wrote “rather” because there are some permanent human activities in link with the nunnery. I don’t know which impact on the water quality  this small religious community may have. I noticed that the (Buddhist) nuns burn all kind of waste at the stream banks (even plastics) and wastewater is discharged directly into the stream. But they do not cut down trees, that’s a very good point - and they even blamed me to catch odonates! Upstream of the nunnery, human activity is almost nonexistent.

male, with flash
Very dark damselfly, but with a surprise well hidden!

in natural light

Forewings hyaline; hindwings with 2 different pattern : oustide black with green sheen at tip, inside (the "surprise") golden and reddish (dark reddish at tip)

Photo in natural light, like all the other images in flight presented here

Rhinocypha orea is only known from Tam Dao National Park in northern Vietnam. It is currently classed as Endangered by the IUCN, on account of its limited range and the paucity of records.

Nychogomphus lui Zhou, Zhou & Lu, 2005

Male Nychogomphus lui, Hanoi, on June 15, 2011

An enigma finally resolved thanks to Tom Kompier who recently sent me an email with a link to a Chinese website, with these words: “have a look at the photo with caption Nychogomphus lui”. I opened the link and immediately recognized a familiar Gomphid, one of the 3 mysterious Gomphids species I encountered 1,5 km from downtown Hanoi in 2011 and 2012. An unidentified species that not only puzzled me but also experienced odonatologists.

Just after receiving Tom’s email, I checked the original description by Zhou & al., 2005, which confirmed its identity.

But let’s go back to mid-June 2011 : during a noon stroll at Hanoi, I bumped into a medium-sized male Onychogomphine resting on leaves 50cm above the ground, in a tiny wooded area surrounding a small pond. A very polluted pond I must say, located 1,5 km from the city center and 400m from the Red River – the large river that runs along the city. At that time, I was interesting by Odonata for only few months – so a complete novice. After some shots in hand, I released it (big mistake...), convinced that in such a place it could not be something else than a very common species, easy to identify. If I had known that it was a new species for the country, the story would have been very different! 

Some of the pictures displayed here are quite bad, I apologize for that. They were taken 3 years ago with my first camera.

Some features of the male Nychogomphus lui : 

-head well marked (labrum with pair of elongated yellow spots, anteclypeus, base of mandibles  yellow, split yellow line over frons).

-synthorax black with a yellow dorsal stripe  connected to the collar stripe to form a broad 7-shaped mark, superior yellow antehumeral spot, sides of synthorax marked with broad yellow stripes.
-basal part of abdominal segments 4-7 all ringed completely [broader basal ring on S7], S7-9 broadly expanded.
-superior appendages whitish, brownish-tipped, the apical half curved downwards, slightly longer than the inferiors, the latter undulant curved, bifid almost to base, the two branches very closely apposed, curved strongly up to meet the superior appendages. 

Male, frontal view showing the broad dorsal 7-shaped marks on the synthorax. 

Tip of abdomen, lateral & ventral views, showing the superiors curved downwards, the inferiors undulant curved, bifid almost to base, the two branches very closely apposed.

I also did manage some record shots of the female. She display a similar color pattern to the male.

The female. Note the basal part of abdominal segments 4-7 all ringed 

completely (broader ring on S7) as the male.

Nychogomphus lui has been described in 2005 from Yunnan. As far as I know, this record from Hanoi is the first one outside China. According to Dr Haomiao Zhang (pers. comm.), Nychogomphus lui breed in rivers and streams. So the specimens I encountered came certainly from the Red River (about 700-800m wide at Hanoi) and it is probably the case of the 2 other unknown Gomphids found at the same polluted pond – among them a female Stylurus sp., members of this genus in Asia generally prefer broad, deep, slow flowing rivers. 

The most interesting thing in all this story, it is not really the fact that Nychogomphus lui is a new record for Vietnam. No, the most exciting - and puzzling - thing for me is that it passed unnoticed (in Vietnam but also in China – remember, it has only been described in 2005!) despite the fact it can live in the most unlikely of urban or suburban settings.
And believe me, Hanoi is far from being a “green city”!...