Discovering 'insect technology'

Shobana Kesava, Straits Times 28 Jun 08;

INSECTS could be the inspiration for new tools to aid humans, with help from the latest DNA technology. Some projects here include:

# Dragonfly alert system

The humble dragonfly nymph could soon be the aquatic version of the canary in a coalmine.

Just like how the singing birds were used by miners to warn them of foul air, the dragonfly young, which live in ponds and reservoirs, could alert humans to water pollution.

National University of Singapore (NUS) postgraduate researcher Nanthinee Jeevanandam, 28, hopes to use their genetic fingerprint to help organisations like national water agency PUB determine the level of cleanliness of reservoir water.

Different dragonfly species have varied tolerance to pollutants such as lead and sulphate, and some require cleaner water or more oxygen.

So, looking at which species is thriving in the water would be a quick and chemical-free method of assessing water quality, she explained.

DNA barcoding would be used to tell the nymphs apart as they look virtually identical.

Miss Jeevanandam has already collected DNA sequences for about a quarter of Singapore's 110 or so dragonfly species.

One day, they could all be on a DNA chip used in a portable kit.

# Military fly spy

A tiny fly that feeds on frog blood could one day help hone sophisticated military spyware.

The 2mm fly, discovered by NUS postgraduate student Gwynne Lim, 24, feeds on the blood of a tree-dwelling frog which lives in local and regional forests.

'Despite its size, it manages to hear in stereo to locate the frog call in the cacophony of the forest.

'If we find out how it does this, it could have applications for generating better hearing aids or military surveillance systems,' she said.

The blood-sucker was among 15 lookalike species related to the sandfly, which Miss Lim identified through DNA barcoding.

Before she did so, only one species had been identified in the region - in 1930.

Such applications could be a decade away.

For now, Miss Lim is planning to study the flexible membranes which are flies' equivalent of 'ears', and how the insects respond to different sounds.