Orolestes selysi McLachlan, 1895

The genus Orolestes contains some striking species. O. selysi is interesting in that the male comes in two wing forms : hyaline or marked blackish-brown with white patches near the tip.

Male (patch-winged form / October 2012-Cat Ba Island)

Prothorax green. Pterothorax bronzy green above (almost brownish in old individuals), not metallic ; sides with 2 or 3 stripes of different shades of green - more or less bluish in very mature males.
Abdomen bronzed green on dorsum of segments 1 and 2, bronzed black on the remainder, but segments 3 and 4 with a medial bluish area (sometimes only S3) ; margins of segments 7 to 9 minutely spined apically; segment 10 slightly notched. S8, 9 and 10 bluish.
The male comes in two wing forms : hyaline or partly opaque blackish-brown with lacteous patches near the tip. 

Females very similar to males in colour and pattern, but wings always hyaline.

Male (hyaline-winged form / July 2012-Foothills of  Tam Dao)

Male (patch-winged form / October 2012)

Note the greenish labrum and bases of mandibles. 

Anal appendages :  superiors black half as long again as segment 10, slender, regularly curved and forcipate, so that the apices meet; outer border finely spined along apical half ; internally there is a robust basal tooth on inner side and a dilatation which extends along inner border nearly to apex and ends in a triangular, acute tooth.
Dorso-lateral view
Note the margins of S7 to 9 minutely spined apically; S10 slightly notched

Lateral view

A pair at Cat Ba Island (October 2012)

Female insert eggs into tree branch. She choosed a vertically directed plant stem. 
 She performs oviposition accompanied by its mate. 
 Two or three times I spotted the male drive away other males who wanted to mate with the female.

Close-up on the wings. Note the medial bluish areas on S3, 4.

Height of oviposition : 1,70m. The tree (no idea of the species) was in a rather open, muddy area - but certainly under water during the rainy season (from June to September).

The female bent its abdomen, segments 3-4 and 4-5 forming a right angle. Before she started to insert her ovipositor in the plant, she touched the bark with the ovipositor, maybe to provide information leading to a choice of insertion site. Then ovipositor valves protruded and began to move alternately, gradually penetrating into plant tissue. 
During ovipositor insertion, the female rotated its abdomen from side to side. When its cutting valves become entirely inserted in the plant, the female stayed motionless for some seconds ; the egg (eggs?) was probably laid into the prepared hole during this time. Then she removed the cutting valves from the hole, moved a bit around the bark and carried on doing the same process.

The female was carefully guarded by the male throughout the whole procedure - a good boy !

In August 2013, newly emerged tenerals were spotted at a small pond together with their exuviae. 
After checking the area I found many larvae of O. selysi floating motionless near the surface, close to shoreline vegetation or fallen branches, and some of them even starting to climb out of the water.

I stayed there one hour and half with the hope to witness the whole larval emergence process, but without success. I think the emergence occurs at night or at dawn - I was there at 10 a.m., too late probably. 


Close-up on the labial mask.

The mouthparts of nymphs are cleverly modified to form an elongate, prehensile structure known as the mask. This structure is hinged in the middle and bears a pair of terminal claws. The whole arrangement is called the mask because when not in use and folded back under the head, it conceals the rest of the mouthparts. When food is sighted, the mask is thrown forward and the prey is impaled on the claws.

Larvae of O. selysi floating near the surface.

O. selysi larva (August 11, 2013)

A Zygoptera larva is recognizable by the three feather-like gills extending from the tip of its abdomen that the animal uses to "breathe" in its underwater environment (Anisoptera larvae breathe by means of internal rectal hills).  When it does move, it swims much like a fish by making lateral serpentine movements with their abdomens (Anisoptera larvae tend to walk though they can turn on the speed with jet propulsion by expelling water from their anal respiratory orifice).

 This larva chose the wrong support. Emergence is always a risky process...

 Another larva, just bellow the one attacked by ants…

 Newly emerged male.

The pond where these larvae were photographed. A small (less than 20m²) square-shaped, probably man-made pond at the foothills of Tam Dao (alt. 300m a.s.l.), in degraded forest. Other species breeding there include Coeliccia scutellum, Tetrathemis platyptera, Polycanthagyna erythromelas, Orthetrum triangulare, O. chrysis, Zyxomma petiolatum.

O.selysi is known to occur in India (Darjeeling), China (Guangxi, Hainan), Vietnam, Laos and Taiwan.
In Vietnam this species must be either scarce or very local. First published record : 1904, "in Tonkin" (= northern Vietnam) by Martin. Second one in 2004, at Cat Ba Island, Quang Ninh Province, by Dô Manh Cuong. O. selysi is actually known from several localities in northern Vietnam.

I bumped into this species at 4 lowland sites : a small marsh partially wooded surrounded by forest (Cat Ba NP), a small (less than 20m²) pond in heavily degraded forest (foothills of  Mount Tam Dao) and 2 tiny pools along rocky, forest brooks (foothills ot Tam Dao, Cuc Phuong NP).
Orolestes selysi is a forest dweller but certainly does not need good forest habitats.

In southern Vietnam occurs an another Orolestes : O. octomaculatus (Martin, 1902), a stunning Lestid characterized (the male) by 2 dark spots on each wings. 


Sympetrum hypomelas (Selys, 1884)

Many tour groups and independent tourists travel from Hanoi to Sa Pa (Lao Cai Province, northwestern Vietnam), principally to visit this picturesque mountain town (at 1650m a.s.l.) and its bustling market, where many of minority ethnic groups gather.

From a naturalist’s point of view, however, the journey’s highlight is a chance to visit the Hoang Lien National Park, which covers 25.000 ha in the Hoang Lien Son Range. This granite formation is the southeasternmost extension of the Himalaya Range. Much of it lies above 2000m, with a number of peaks reaching 2500-3000m, including the Mount Fan Xi Pan, the tallest mountain in Vietnam - and even in Indochina - at 3143m.

In this area, fauna and flora show Sino-Himalayan affinities - the Himalayan Libellulid Sympetrum hypomelas is a good example.

A pair at an ovipositing spot. The male flies above the female and drives away 
other males who may want to mate with her.

These shots of Sympetrum hypomelas were taken at Hoang Lien National Park in August, at 1900m, at a small marsh surrounded by forest.
This is a handsome black, yellow and red Libellulid - a very striking colour combination!

A pair in tandem

Male with labrum, face, frons suffused with bright red. Pterothorax reddish on dorsum, with a broad black humeral stripe; laterally two broad bright citron-yellow stripes separated by a broad black stripe. Wings hyaline, with extreme bases amber-yellow. 

 A resting male
Abdomen bright reddish above, black beneath, this colour overlapping on to sides from segments 2, 3, or 4 and very broadly so from segments 6 to 10.  

Female adult
Female closely resembling the male, but pterothorax golden-brown on dorsum, face amber and markings of abdomen very different than those of male : there is an additional subdorsal broad black stripe extending from base of segment 2 to segment 7, where it becomes confluent with the black of underside and enclose a yellow stripe.

Female not fully mature : abdomen not yet reddish above

A newly emerged female

Sympetrum hypomelas is a widespread species found in eastern India, Nepal, China (Tibet), northern Thailand (Loei, Chiang Mai), Myanmar and Bangladesh.

To my knowledge, this attractive Libellulid is a new record for the Vietnamese fauna.
The site where these shots were taken. The other species spotted in this area include, amongst others, Ceriagrion fallax and the rare Cordulid Somatochlora dido - the latter at the edge of the swamp forest (on the right).

 Sa Pa (1650 a.s.l.), in the North-West Vietnam highlands. This  hill-station town lies in the Hoang Lien Son Range, southeasternmost extension of the Himalaya Range. 
This area is made up of mid- and high-elevation forests, scrub and grasslands.

In this area, the avifauna also shows strong Sino-Himalayan affinities.
Photo : a stunning male Green-tailed Sunbird (Aethopyga nipalensis).


Megalestes micans Needham, 1930

M. micans is small for members of this genus. It is found in montane forests, amongst the vegetation along streams. The adult is a weak flyer, though it is well camouflaged at rest. 

These shots were taken at Hoang Lien National Park (Sa Pa, Lao Cai Province) in August, at 1800m a.s.l. Males were quite common along shaded brooks and streams with gritty bottom (but no females seen).

Prothorax dull metallic green with anterior and posterior lobes, and middle of mid-lobe pale yellow. Synthorax metallic emerald-green on dorsum. Sides dull green with a yellow stripe on each side of the mesepimeron, whole of metepimeron yellow.

"in hand" shot for better view of the thorax

Abdomen very long and slender, yellowish ventrally. S1-2 metallic green on dorsum, S3-7 dull reddish with greenish tinge at intersegmental sutures. S8 dull green. S9-10 whitish-grey pruinescent on dorsum.

Anal appendages blackish ; superiors slightly longer than segment 10, forcipate, broad at base with, on the inner side, a short, robust, quadrate process. Inferior appendages much shorter, rudimentary, tipped with stiff yellowish hairs, without obvious spine(s) in lateral view (unlike M. haui and M. distans, the 2 other Megalestes known in Vietnam).
 Dorso-lateral view

 Lateral view

 Dorsal view

 Ventral view

M. micans is known from China (Sichuan, Yunnan), northwestern Vietnam and northeastern India (Assam).
In Vietnam, this species has been recorded at only a handful of sites in Lao Cai and Lai Chau Provinces.