Lyriothemis bivittata (Rambur, 1842)

Lyriothemis bivittata is a robust and medium-sized libellulid, characterized by a dark brown synthorax with 2 broad markings at the sides and a reddish abdomen. Wings hyaline, only very slightly darkened in the basal one or two cells.

The male has a red abdomen and a striking white face (labrum, anteclypeus/postclypeus, frons). Top of antefrons shining blue-green.

Male, from Cuc Phuong NP.

 Male, head, from Tam Dao NP.

 Same male, from Tam Dao.

Wing venation, male.

The female (photos from the foothills of Tam Dao National Park, along a slow flowing streem in disturbed forest) has a broad orange yellow abdomen, changing reddish brown in old individuals. Face blackish. Wings smoked pale brown in aged insects.

Before this little fellow grabbed its lunch (a tiny butterfly), it was difficult to get near.

Lyriothemis bivittata is known from India, Nepal, Myanmar, Thailand, Vietnam and Laos, but seems to be scarce everywhere. Indeed, this species is not often recorded, Hämäläinen and Pinratana (1999) describe it as a “rare forest species”. It breeds (at least sometimes) in water filled tree holes and is likely to be under-recorded.


Archineura hetaerinoides (Fraser, 1933)

In June 2012, I was very surprised to find this stonking species  - a new one for me - along a stream already prospected two times in 2011. But it was in mid-september, and the only large sized calopterygid that I had spotted at that time was Calopteryx coomani. 

With the large white patches at each wing base - which do not cover more than 30% of the wing -, the male Archineura hetaerinoides is unmistakable.

A wary species, metallic green Calopterygid of gigantic proportions with white basal wing colouration. A spectacular sight!

Dramatic backlighting...

Territorial dispute
With no female yet present, I saw two males vying for territory. The perched male - the happy owner of a big rock - raised and arched his abdomen (photo below; the other male is above, outside the frame), whilst fluttering his wings, showing the four white patches.

The female has bright orange wings. The first one I spotted was really skittish and flew away at the slightest movement.

After 30 minutes playing hide-and-seek, I only got distant shots (3-4 meters, too far for my 100 mm lens, even for a such big guy). Really difficult to get close to. As I was thinking "Arrgh..., what a pity that I didn't bring my 400 mm lens !" - the one I use for birds -, this nice damselfly landed on a leaf one meter away, right in front of me !

Continuing downstream I encountered an another female, this one not shy at all, and I could approach quite closely.

Wing-clapping just after landing

I should try more backlit shots; with odonata, the detail in the wings catching the light is always lovely. The backlit and bright conditions were a little tricky photographically, but I'm quite pleased with these!

Archineura hetaerinoides is known from Laos, Vietnam and southern China, in both lowland and upland sites, but is very localized. 
This rare species is one of the largest Caloptera, equaled only by Archineura incarnata (Karsh, 1892) from China and Echo maxima Martin, 1904 from northern Vietnam - the latter not recorded since its description in 1904 !

In Vietnam, Archineura hetaerinoides has been found in the north, center and south of the country: Sa Pa (Lao Cai Province), Cao Bang town and Thanh Cong community (Cao Bang Province), Mau Son mountain (Lang Son Province), Tam Dao National Park (Vinh Phuc Province), Son Kim community (Ha Tinh Province), Kon Ka Kinh National Park (Gia Lai Province), Xuân Son National Park (Phu Tho Province)...

Those photos were taken at the feet of the Tam Dao mountain range, along a swift, open rocky stream with many boulders, in a secondary forest area (alt. 250m a.s.l, photo below).

A good range of open and rocky lotic habitat species was encountered there included Zygonyx iris, Lamelligomphus camelus, Gomphidia kruegeri, Paragomphus capricornis, Euphaea decorata, E. masoni, E. guerini, Aristocypha fenestrella, Onychothemis testacea...


Tetracanthagyna waterhousei McLachlan, 1898

A female resting under a large leaf, at Ba Vi NP. A perfect umbrella.

Tetracanthagyna waterhousei is a dragonfly of great size and robust build, equalling in this respect the largest known living dragonflies. It is known to be crepuscular, coming out in forest after sunset – as many Aeshnids. But all the females I spotted were well active during the day. The male have hitherto eluded me. 

Female, Tam Dao.

T. waterhousei is one of the 4 Aeshnids I encountered the most in the Hanoi area (sensu lato, i.e. within a 60-70 km radius) - with Gynacantha subinterrupta, Anax guttatus and Polycanthagyna erythromelas. As the latter, T. waterhousei is a strict forest stream dweller. 

The two sexes are similar in appearance. Both have dark reddish-brown abdomen and thorax, the latter marked with bright citron-yellow as follows : oblique narrow antehumeral stripes converging strongly on mid-dorsal carina, two rather broad stripes on each side, the anterior close to the humeral suture, the posterior traversing the middle of metepimeron and broadest of the two. 

Note the head very massive, globular, the eyes very broadly contiguous, the face warm brown, the frons not elevated and blackish on upper surface.

Female have a short, cylindrical, very robust abdomen, but tapering very gradually towards the anal end. Segments 2 to 7 with very narrow yellowish apical annules, narrowly interrupted on mid-dorsum; S8-10 unmarked. 

End of abdomen, female.

Ovipositor is very massive, extending nearly to end of abdomen ; segment 9 with the apical dorsal spine more robust than in the male; segment 10 prolonged into a 4-spined dentigerous plate below, the two medial spines longer than the others.

This dentigerous plate is an adaptation to enable the insect to oviposit in dry soil, the robust pitchfork-shaped organ being employed to scoop holes or to fix the end of the abdomen whilst the ovipositor is driven home in the ground. This habit is shared by many other Aeshnids. 
The female deposits her eggs in mud or dry soil along streams. I also spotted it ovipositing in branches.

A female resting after ovipositing.

Female ovipositing in a (dead?) branch, 5-6 meters above a stream (you can clearly see the ovipositor protruding).

T. waterhousei is widely distributed in tropical and subtropical mainland Asia, with records from eastern India to Laos, Vietnam and southern China.

I encountered this gorgeous species in both pristine forest (Cuc Phuong NP) and degraded secondary forest (first slopes of Mount Ba Vi and Tam Dao); it don't seem too fussy.