Thursday, August 28, 2008

Drepanosticta quadrata

Damselflies from the family Platystictidae usually need close examination in particular the wings venation and anal appendages to identify the species confidently. Platysticids generally occurs in primary forests near small streams and the larvae have a distinctive disproportionately large head.
Within this family, the genus Drepanosticta is represented by eight species in Peninsular Malaysia. They usually fly close to streams, flitting within the forest understory. Both males and females typically have a blue spot at the abdomen base in which the shape of the spot can serve to identify some of the species from Peninsular Malaysia. Drepanosticta quadrata has a blue spot with a triangular pointed tip. This species was described from Singapore and according to references is known only from Singapore. This would thus make this damselfly a Singapore endemic. Even so, the website
http://www.asia-dragonfly.net/ has this species as also occurring in China and Myanmar and has pictures of females from Johor. More work is perhaps needed to shed light on the true distribution of this damselfly as Albert Orr himself noted Drepanosticta spp. as data deficient with many species needing identity clarification.




Pictures taken at: Central Catchment Nature Reserve, August 2008

Update 2010Jan19th:
The blue marking on abdominal segments S8-9 is variable among species of this genus. D. quadrata is not endemic to S'pore. In fact, it is believed that D. quadrata and D. fontinalis could be the same species. (thanks Dr. Ian Choong)


References:

Orr, A. G., 2003. A Guide to the Dragonflies of Borneo. Their Identification and Biology, Natural History Publications (Borneo) Sdn. Bhd, Malaysia.

Orr, A. G., 2004. ‘Critical species of Odonata in Malaysia, Indonesia, Singapore and Brunei’, in Guardians of the Watershed. Global status of dragonflies: critical species, threat and conservation, eds, V. Clausnitzer & R. Jodicke, International Journal of Odonatology, vol 7(2), pp. 371-384.

Orr, A. G., 2005. Dragonflies of Peninsular Malaysia and Singapore, Natural History Publications (Borneo) Sdn. Bhd, Malaysia

3 comments:

C.Y. Choong said...

Hello there,

I'm quite attracted to Drepanosticta quadrata...... according to Orr (2005), quadrata is only recorded in Singapore. On the other hand, D. fontinalis (very similar to quadrata) is found in Peninsular Malaysia. I had caught some fontinalis, and the blue marking on the tail is quite resemble quadrata..... but Orr still insists that they are fontinalis due to its bright strips on the sides of thorax. Do you think you could catch some quadrata specimens and send them to me? I need close inspection....

spookydragonfly said...

Beautiful photography...you've captured every delicate detail!

Anonymous said...

Hello, Would you do me a favor? I am doing research about Drepanosticta in North Sulawesi. Could you kindly provide me with the references mentioned in this page? Thank you. (trinatallei at yahoo dot com).