Dragon of the insect kingdom

Glenda Chong Channel NewsAsia 24 Jun 11;

SINGAPORE: They have been around for about 300 million years; are carnivorous, with voracious appetites; and they start their day with a shot of sunlight.

Odonata, better known as dragonflies, are commonly found in wetlands. And the presence of these winged insects are significant.

Robin Ngiam, Senior Biodiversity Officer with NParks, said: "Because dragonflies are top predators in the insect world. So if you imagine lions and tigers in the animal kingdom, in the insect world, dragonflies fulfil that role.

"Being top predators, they hunt all sorts of insects, insects pests, mites including mosquitoes. So having a good population of dragonflies at a pond for example, helps to suppress the insects pests population from exploding."

Dragonflies living in tropical climate like Singapore have a lifespan of about a year and they spend one-third of that as adults to mate and reproduce. So the presence of a dragonfly is a very good indication of the health and diversity of your water garden ecosystem.

That is because dragonflies only dwell in clean and unpolluted water.

Mr Ngiam said: "In some countries like South Africa, which are more advanced in dragonfly research, scientists actually monitor dragonfly population to tell them whether a river or stream is polluted. So once that particular stream or river is polluted, the dragonfly population decrease is an indicator to them that something is wrong, let's do something about it."

As you can see, dragonflies play an important role in the ecosystem. Singapore has recorded eight to nine new species of the winged-insect in the past four years. There are about 125 different species of dragonflies on the island, more than any temperate country in Europe.

-CNA/ac