Some bugs live in disguise for protection

PUBLISHED : Tuesday, 29 August, 2000, 12:00am
UPDATED : Tuesday, 29 August, 2000, 12:00am

The word 'bug' is commonly used for all insects, but it only really applies to the order Hemiptera (half-winged) and biologists have discovered over 50,000 species up till now. True bugs may live on animals or plants or in water. They have stabbing mouth parts to suck up blood or plant juice.

They are small, ranging from less than one millimetre to over 100 millimetres and are found throughout the world.

Most live on land but some are aquatic, living in water.

Bed bugs, lace bugs, stink bugs and fire bugs live on land. The water boatman and the back swimmer live in water.

Bugs undergo gradual metamorphosis: the eggs hatch into a wingless nymph which slowly turns into an adult. As the nymph feeds and grows, it molts the outer layer of its skeleton several times, changing shape each time until it finally becomes a winged adult. This one is known as complete metamorphosis.

Cicadas are very common in Hong Kong and you can hear them singing loudly in summer. Some bugs protect themselves by looking like something else. Both the ant bug and the treehopper bug mimic ants for protection. The bark bug has a flattened body and projections along its sides- it looks like flaky tree bark.

The stink bug defends itself by releasing a nasty smell. The water boatman has a boat- like body and propels itself forward with oar- like hind legs. It is widely found in Hong Kong's freshwater areas.

WWF HK is a local charity environmental organisation established in 1981 which aims to build a future in which people can live in harmony with nature. For information, call 2526-1011 or visit the Web site at