Tuesday, March 1, 2011

53. Orthetrum triangulare triangulare (Selys, 1878)

Number: 53
Family: Libellulidae
Genus: Orthetrum 
Species: Orthetrum triangulare triangulare
Common name(s): Blue-tailed Forest Hawk, Triangle Skimmer, Lesser Blue Skimmer
Thai name(s): แมลงปอบ้านเสือสามเหลี่ยม
Habitat: Exposed ponds & seepage, forested streams and rivers (uplands)
Province(s) sighted: Nam Nao NP/environs (Petchabun); Phu Kradueng NP (Loei); Doi Suthep, Doi Inthanon (Chiang Mai); Khao Soi Dao (Chantaburi).
Sightings (by me): Fairly common at Phu Kradeung NP
In flight (that I have seen): March-December (probably all year)

The sixth species of Orthetrum I have added to the blog (and the last I have spotted so far) is Orthetrum triangulare triangulare. I am still looking for 3 species of Orthetrum in Thailand. I have seen this at a number of upland streams and rivers, especially in Chiang Mai, Phu Kradeung National Park and Nam Nao environs. The tend to live alongside other Orthetrum species and tend to like hot, sunny weather. The males are common at the water's edge, but I have only spotted one female. 

The male
The male is easy to recognise as it has a large blue section to the abdomen and the rest of it is completely black. They like to hang right over the water's edge on branches and twigs.

A copula
The only time I have ever seen a female of the this species, was part of a copula at the small pond right next to the headquarters of Doi Inthanon, Chiang Mai. This demonstrates that they are as happy by ponds as they are alongside rivers.

Here's another male and female. The female is ovipositing with the male guarding above. I was this pair late afternoon at the same location as the copula above. This went on for several minutes.


  1. This comment has been removed by the author.

  2. Dennis, I love your blog. It has been a great, fun resource for helping me identify dragonflies in Asia. Maybe you have seen more by now but if you haven't, I found some images of a female that I captured and took some photos of. They are here http://www.inaturalist.org/observations/3157881. Hope they are of some use!!