Guardians of the watershed : global status of dragonflies : critical species, threat and conservation

Dragonflies, those beautiful and colourful creatures which can often be seen hovering above water, pre-date dinosaurs. Today, some 5,000 species have been described and many more await discovery and description. The value of dragonflies lies in their beauty and distinctive colours which make them valuable subjects for research on insect behaviour, both for ecology and art; the fact that their larvae are aquatic makes them a good indicator of water quality; and because they are predators, they are particularly useful in the control of mosquitoes which pass on diseases to human beings.