Macromidia rapida Martin, 1907

Macromidia rapida, male, Huu Liên, June 2014

Martin (1907) erected the genus Macromidia to include the type species M. rapida Martin (from “Tonkin”, i.e. North Vietnam).

Another male, from Tam Dao

(remark: this photo has been taken after quite a long examination in hand, 
that’s why position of the wings looks unnatural - they should lie flat)

In 3 years, I bumped into M. rapida only 3 times, at rocky streams of Ba Vi and Tam Dao’s foothills, running through secondary forests. It is certainly not scarce but just inconspicuous - spend the great part of the day hiding in the vegetation.  

Two times, I found M. rapida resting at eye level amongst bushes, along moderate to fast flowing open/partially shaded rocky streams - one time inside willow-like shrubs in the middle of the stream.

The third time, an individual was netted as it was zigzagging low over a tiny, shallow pool at the margin of a stream, just before rain. Cat-like reflexes are needed to catch this little fellow!

(same remark as photo above)

Abdomen black, yellowish striped on the middorsal line.

Head largely dark reddish brown; frons dark metallic green, labium pale brownish. Narrow yellow stripe on the anteclypeus.
Synthorax shining metallic green and yellow laterally; dorsum (mesepisternum) metallic green with lower portion reddish brown.

 "Oh my god what happen to me !"

Tip of abdomen, dorsal.

Caudal appendages of typical Macromidia type, the superior yellowish with dark base and apex.

Tip of abdomen, lateral.

I didn’t spot the female, but according to Asahina (1988), head and thorax patterned as those of the male insect. Cerci yellowish with black type.

M. rapida is found in southern China, Thailand, Cambodia and Vietnam. This species inhabits streams of lowland/mid-elevation forests, even degraded ones (young secondary forest for example, as I saw at Ba Vi).

Macromidia genialis shanensis (Fraser, 1927)

Last May, during a field trip in the foothills of Mount Ba Vi, I bumped into a cordulid dragonfly tucked away deep in the bushes. After some shots, I caught it for closer examination of caudal appendages, and identified a male Macromidia. I first thought it was M. rapida, a species I had seen along the same stream, but I noticed some obvious differences: cerci black (pale yellowish and black-tipped in rapida), face largely dark green, large yellow spot dorsally on S6. 

Later, with the help of some documents (Fraser, Asahina), I confidently identified it as Macromidia genialis shanensis.

Macromidia species are crepuscular in nature and rest in dense vegetation near streams during day. They become active as rain threatens or dusk approaches, circling and zigzagging low over streams.

Head metallic dark green, except yellow labium and yellow anteclypeus.

Synthorax marked on sides with 2 broad, green metallic stripes, enclosing a citron-yellow area; beneath (lower part of metepimeron) also citron-yellow. 
Wings hyaline tinged with yellow at the base. 
Abdomen black, with S7-9 inflated; S2 with a dorsal spot; S3-5 with a middorsal yellow longitudinal line; S6 with a large oval-shaped dorsal spot. 

Anal appendages wholly black, of nearly the same shape as in M. rapida.

Tip of abdomen, dorsal

Male basal abdomen with secondary genitalia, lateral (M. rapida on the right for comparison). Note the shape of genital lobe: triangular in M. g. shanensis and rounded in rapida 

               Male head (right, M. rapida)

                      Male abdomen, dorsal (right, M. rapida)

The genus Macromidia is purely oriental in distribution and contains a dozen of species, among them 2 has been recorded in Vietnam: M. genialis and M. rapida.

A number of subspecies of M. genialis have been described. Macromidia g. genialis is known from Peninsular Malaysia, M. g. erratica from Java, Sumatra and Sarawak, M. g. shanensis from Myanmar, Thailand, Laos, Vietnam (+China?).

The first record of M. g. shanensis in Vietnam is recent (in 2011, by Karube). Its inconspicuous nature may at least in part account for the paucity of records. 

I found this male at a partially shaded, 3 meters wide rocky stream with well vegetated banks, but running through an open, heavily logged forest at the foothills of Mount Ba Vi. This suggests that this species do not require high quality habitats and therefore should be more common.

Somatochlora dido Needham, 1930

Somatochlora dido, male, Sa Pa, Sept. 2013

I spotted this stunning species in mid-August 2012 and September 2013, at Sa Pa (Lao Cai Prov., northern Vietnam), within the Hoang Lien National Park boundaries, a bit below Tram Tôn Pass (Đèo Trạm Tôn), at ca 1900m a.s.l.

I had great fun taking some photos of males in fly

In October 1995, Syoziro Asahina also vouchered a male in the same area ("Deo Tram Ton"). It was the second record of this species after its original description in 1930 (type locality is Sichuan) !

I used a part of his description publish in « Records of the Northern Vietnamese Odonata taken by the expedition members from the National Science Museum, Tokyo, 1996. Part III : Aeschnidae, Corduliidae, Libellulidae” for writing this post.

The males were flying slowly, hovering a lot

Male, in hand

Thorax shining metallic green with broad yellowish bands on the sides.

Abdomen entirely metallic black, except some yellow markings on S2 and S3 as follows : S2 with a lateral yellow spot and a yellow edge along the posterior margin; two proximal spots laterally on S3.

Male, facial pattern

Male, tip of abdomen, dorsal and lateral views

Caudal appendages black, the superiors with apex recurved and pointed,  with two small tooth on the lateral sides. The inferiors more than ½ the length of the superior.

The female is almost silimar to male in colour and pattern

Female, facial pattern

Somatochlora dido has an extremely broad and fragmented distribution from northern Vietnam through southwestern and southern China (Guangdong, Guangxi and Sichuan) and Hainan. All confirmed records have been obtained from high altitude in remote locations. Only a few scattered locations are currently known, but the species is probably under-recorded.

Members of the genus, the largest in the Corduliidae, are predominantly Holarctic and they are found as far north as Odonata exist. When found in the subtropics these species has been usually found at high altitude in excess of 1000 m up to 2290 m (source : http://www.iucnredlist.org).

At Sa Pa, I found this species at an acidic wooded swamp in a small valley.