The Bolaven Plateau, in southern is known for its coffee and spectacular waterfalls. Few know that this lush, fertile region –1,000 to 1,350 metres above sea level – also teems with an amazing variety of animal and plant life. I have made several trips to this fascinating area and among the most beautiful insects I have ever seen is the damselfly.
Damselflies are insects classified under the suborder Zygoptera in the order Odonata. They are similar to dragonflies, though certain characteristics set them apart. Damselflies are more slender, with eyes are on either side of the head (dragonfly eyes do not have this gap); and most damselfly species hold their wings up at rest, while dragonflies keep them spread out.
Damselflies have a semi-aquatic life cycle: they lay their eggs on submerged plants or debris. Damselfly larvae are called nymphs and are wingless. After hatching, they spend between two months to three years living in the water and feeding on tadpoles, fish fry, and other small animals. When they are mature, they leave the water and climb onto rocks or plants, typically in the early hours of the morning. The skin moults and the adult damselfly emerges, gradually pumping fluid into its wings and abdomen until they are fully outstretched. Adult damselflies typically feed on other flying insects, although they have been known to eat other small animals as well.
I observed several species on the Bolaven Plateau, all of which were found along clear streams and waterfalls. The rocky, fast-flowing streams and the fact that these damselflies were very skittish made taking noteworthy photographs quite a challenge, but the results were well worth the hours I spent wading through 2-3 feet of water chasing them.
Since I have only seen these species near clear and relatively undisturbed streams, it might be possible to use them as bio-indicators of water quality. However, the current situation of these insects in Laos remains unknown – the first significant study on aquatic insects in Laos was done only in 2012.
The next time you go to a stream or river, keep an eye out for these beautiful creatures, especially among the plants growing along the banks. With a bit of patience, you can get close enough to appreciate their colours and wing patterns. Their behaviour is also very interesting – sometimes even comical – to observe!
The damselflies are found along clear streams and waterfalls of the Bolaven Plateau Could this be a bio-indicator of water quality?
Text & Photos by: Aloke Sahu