The first to emerge is Agrionoptera insignis (Grenadier). The larva was completely out of water for up to three days. During this time, it explored various spots on the driftwood, usually resting at a spot (blue arrows) for a few hours before moving on. In those three days, it seemed to be selecting an emergence spot meticulously. Either that or some parts of the larva was still undergoing changes to adulthood and so not yet ready for emergence.
Next up is a close relative from the same genus: Agrionoptera sexlineata (Handsome Grenadier). For this larva, the emergence was quick and straightforward. I spotted it out of water at early evening and by the next morning, the fine-looking adult male has emerged.
Its interesting how two similar and related larvae assumed different pre-emergence behaviour. But this is just a one-off observation and thus can’t constitute any concrete conclusion. Hopefully future larvae studies by other odonatologists can provide clearer understandings. The larvae emergence of both species is captured beautifully by Dr. Choong here:
Corbet, P. S., 1999. Dragonflies: Behaviour and Ecology of Odonata. Cornell University Press, New York.
Tang, H. B., L. K. Wang & M. Hämäläinen, 2010. A Photographic Guide to the Dragonflies of Singapore. Raffles Museum of Biodiversity Research, Singapore.