Rhyothemis triangularis Kirby, 1889

ID SOURCE #1 : http://www.asia-dragonfly.net
ID SOURCE #2 : http://www.fx.fudan.edu.cn

Found in China, Guandong, Hong Kong, Indonesia, India, Sri Lanka, Myanmar, Malaysia, Philippines, Peninsular Malaysia, Thailand, Taiwan, Viet Nam

Genus : Rhyothemis

Super-Family: LIBELLULOIDEA Family: LIBELLULIDAE

 

English  |  Traditional Chinese  |

One of the most  striking dragonflies is Rhyothemis triangularis, aptly named due to the deep metallic blue triangular patch (black for female) on its hind wings. Dragonflies from the genus Rhyothemis characteristically have short abdomens with broad hind wings.

Common in open countries or streams in swampy forest. R. triangularis is common and widespread in Asia.


Rhyothemis triangularis hw 24 mm. An unmistakable species, rapid in flight, perching low over water. Lakes, ponds and sluggish streams in swampy forest. Larva squat; sprawled amongst bottom leaf trash in shallow water. Widespread in Sundaland and mainland tropical Asia.
 

R. triangularis is another small species. Solid colour on the wings is limited to deep, metallic-blue basal patches. It inhabits the edges of lakes and drains from the lowlands up to about 600 m. Males often hover over the breeding site and are quite swift in flight. Unlike some other members of the genus they are rarely found together in large numbers and seldom stray far from the water. It is only moderately common in Borneo but is widespread in Asia.

 


Female color is less bright. The wing color is deep purple and less metallic then the male’s deep metallic-blue.

This female length is 23mm.
Hind wing is 21mm
Hind wing span is 44mm

This female was found laying eggs at the edge of a weedy pond. Segment 9 has a segment full of jelly-like eggs. The eggs are bright yellow though in this image some eggs look dark because of light reflection.

A sticky substance surrounds the eggs that keep the egg together in an egg mass and holds the eggs to an anchor.

But there is one egg (see arrow) has something in it that looks like a developed embryo.

The Larval exoskeleton of Rhyothemis triangularis (Kirby, 1889)  is 27mm in length.

The whole skeleton is covered with sandy mud.  This larval exoskeleton found on 16 December 2006 at the drainage of main entrance to Tawau Sport Complex.


A Female Rhyothemis triangularis (Kirby, 1889)

Above lone female Rhyothemis triangularis spotted on 8 Oct 2006 at Sabah forest reserve.  No male around.  Disappeared in the grasses after a few snap shoots.

 A Male Rhyothemis triangularis (Kirby, 1889).  Rhyothemis triangularis is another attractive dragonfly with  a bright enamel blue.


 

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