Dragonflies

Dragonflies, a group of fascinating insects in the order Odonata, are generally familiar to the wider public due to their colorfulness, relatively large size compared to most other insects, flight capabilities, and presence around human-modified landscapes. Even though commonly referred to as ‘dragonflies,’ order Odonata includes two suborders: the dragonflies of suborder Anisoptera and the damselflies of suborder Zygoptera. These suborders are different from each other in multiple characteristics, including the general body shape. These insects have an amphibious life cycle consisting of three life stages: the egg, larvae, and the adult. The larvae are exclusively aquatic, while the adults are terrestrial insects capable of flight.

There are over 6,400 known species of dragonflies around the world at present, and many more species are discovered every year. Sri Lanka has 132 species of dragonflies as of 2024. Among the reported diversity of Sri Lankan dragonflies, 59 species and an additional eight subspecies are endemic to the country, indicating 51% total endemism.

Dragonflies are found throughout the country, from the coastal belt to the mountain peaks. However, the highest diversity and the highest endemism are reported in association with wet zone rainforest habitats and lower montane forests.

Being carnivorous animals, both larvae and adult dragonflies act as apex predators among the invertebrate communities in their habitats and thus help maintain the population of other insects, including economically harmful species such as pests and disease vectors. Dragonflies are also considered among the top indicator species in aquatic habitats. The presence of some species of dragonflies in a habitat provides hints on the water quality and the overall health of the ecosystem. This has led dragonflies to be recognized as "Guardians of the Watersheds" across the globe and considered a flagship group of insects in the conservation movement.