Chlorogomphus nakamurai Karube, 1995

This rare species has only been found in Cuc Phuong and Ba Vi National Parks, Vietnam, from where Haruki Karube described it in 1995. The dragonfly was named after Mr. Nakamura.

It is a beautiful and large-sized dragonfly; the male being deep black with bright yellow markings on the thorax and abdomen. The wings of the males are hyaline with the exception on the tips, while females have remarkable dark marking on their wings.

They are found at shaded, clear streams in the forest. The male usually patrols along the forest stream, looking for females, which only descend from the tree-canopies for mating and eggs laying. Once the female has found a suitable breeding side, the eggs are released directly to the surface of slow-flowing water.

The population of the species is stable in Cuc Phuong now, however no more record of its distribution in Ba Vi National Park, then it was accessed in VU level in IUCN Redlist because the limitation of distributed area.

Male of Chlorogomphus nakamurai, photographed by Cuong Do, Cuc Phuong National Park

Flying female of Chlorogomphus nakamurai, photographed by Cuong Do, Cuc Phuong National Park

Neurobasis chinensis (Linnaeus, 1758)

This is quite common Asian species and is one of the earliest known species of dragonfly. It was named by Linnae based on a picture in book cover of bird. And because in the picture the specimen was drawn with the wings in horizontal position, this species formerly was put in Anisoptera suborder by Linnae. Name of species is specified its locality, from China.

The medium sized damselfly, this species has shining green body and hind-wing is metallic green. The head, thorax and abdomen of the male are metallic green while female has fader green body. The wings of the male distinguish from them of the female. Female’s fore-wing has a white spot at pterosigma position – psedopterostigma, while male’s fore-wings are dust yellowish hyaline and instead of psedopterostigma, there is a white spot at nodus position. The hind-wings of female are shinning colorful, metallic green with an apical black patch on upper side and they are quite dust yellowish hyaline in female.

They are very active damselflies, and live at open swift streams from low to high lands. They never fly far from their breeding habitat; males are strict in territorial defense by showing their flash metallic green hind-wings. Males fly very close to the water surface while females usually perch on vegetations nearby. In courtship flying, males usually keep the hind-wing open in horizontal position to show the flash green upper surface of the wings under sunshine. Sometime males just clap their hind-wings as resting and the action is signal to other males in territorial informing or to coming females for mating. Females insert their eggs into aqua vegetation tissue; in many cases, female sinks in the water during the oviposition while the male around.

Male, photographed by Cuong Do, Ba Vi

Male, photographed by Cuong Do, Pioac Nature Reserve, Cao Bang Province

Male, showing his hind wing in opened position, photographed by Cuong Do, Hon Ba Nature Reserve, Khanh Hoa Province

Euphaea decorata Hagen in Selys, 1853

Medium sized damselfly, the mature form flies during rain season, they have been known as a common species in South East Asia. The teneral form has black synthorax marking with dusk yellow marking but it change into dull black in mature form. The fore-wings of male are hyaline and its hind-wings are hyaline with black spot at 1/3 apex. In female, wings are brownish hyaline.

They found at running clean streams in dark or open forests, they usually perch on stones just above water surface or branch of trees 1-3 m above water level. As perching, they some time open or clap the wings (both pair of wings or just hind wings) in sunshine. The males usually fight each other for protecting their territory and mate with coming females which often rest at higher above.

Male, photo by Cuong Do, Ba Vi National Park

Male in opened wings position, photographed by Cuong Do, Tam Dao National Park

 Male, photographed by Cuong Do, Tam Dao National Park

Aristocypha fenestrella (Rambur, 1842)

Aristocypha fenestrella is one of the odonate species with wide range of altitudinal distribution (0-1700 m). It is one of several common mountain stream damselflies and widespread species.

They are small glittered damselfly with broad violet wings. The body of male is deep black basically with some yellow stripes on thorax and a particular triangular purple marking on dorsal of synthorax. Head is uncoloured black in both male and female with the swollen clypeus as characteristic of the family. Fore wings are narrow, hyaline and some how brownish and hind wings are much broader, with shining violet cell areas insert into dark background. Wings of female just are hyaline or hyaline-brownish. Legs of mature male are very typical with tibia developed to be broader and white coloured. The colours of teneral males usually are fader than it of mature forms.

Those damselflies usually are found in the primary forests, the mature forms fly around their breeding sites which are clear, swift streams. Although they are forest species, this species is quite common, they are widespread species and could be found in whole of the country.

It is one of the most active species of the family with and males are strict territorial individuals. Each male usually appropriates a micro-habitat (a rock, floating timber or a branch of tree..) near the water surface. And when another male enters his territory, rival flying dance will be observed. In courtship flying dance of male and female, or rival flying dance of males, the male usually stay-flies in the air and shows his flash violet hind wing and white tibia of his legs to the partner. A territorial flying between two males take place from some second to many minutes.

Larvae of the species live in sand, gravel swift streams; they are very typical with two long filament gills at the end of abdomen.

Young male, photographed by Cuong Do, Ba Vi National Park

Mature male in full color, photographed by Cuong Do, Hon Ba, Khanh Hoa

Mature male in full color, photographed by Dang Ngoc Tu, Tu Son, Hoa Binh

Female, photographed by Cuong Do, Hon Ba, Khanh Hoa

Devadatta ducatrix Lieftinck, 1969

This species was described by Lieftinck in 1969 based on the holotype collected from Thai Moi, Tonkin (Lang Son Province, North of Vietnam) after he revised R. Martin’s specimen in Paris Museum.

Same to Devadatta cyanocephala, it is a medium-size species, but the colour of body darker and without marking. Whole body species is metallic dark blue or black and uncoloured, The wings are hyaline with particularly apical dark spot, wings always are fold at rest.

Except the distribution, Devadatta ducatrix wide distributed in South East Asia, but it has similar habitat of D. cyanocephala. They usually fly weakly not too far from the streams of their larvae, in shade, humid tropical forests on hight mountains, and some time also found at sun light stream area. 

Male (close wings), photographed by Cuong Do, Ba Vi National Park

Male (opened wings), photographed by Cuong Do, Ba Vi

Female, photographed by Cuong Do, Tam Dao National Park