Plague of fire ants the latest Hong Kong alien invasion - and boy, do they sting
Venomous ants from South America join the indestructible apple snail and river fish on a long list of foreign species to have made Hong Kong home, writes Sarah Lazarus
Tony Lee was looking at a tree when the attack occurred.
"I felt a red hot burning sensation on my lower leg," says the 64-year-old.
A keen amateur botanist, Lee had been studying plants growing near his home in Tseung Kwan O when he accidentally trod on a nest of red fire ants. The ants swarmed over his shoes, scaled his socks, ran up his trouser legs - and stung.
Zombie ants, viruses and a parasite - how US fights insect invaders
Red fire ants are notorious for their aggression. They bite victims with their jaws to get a good grip then inject venom from their stingers. Unlike honeybees, which lose their stingers, the ants can sting repeatedly. In most cases, the venom causes a pink spot that itches and burns, forming a white blister a few days later. Some people develop chest pains and nausea. In rare cases, the venom triggers anaphylactic shock, which can be fatal. Fortunately for Lee, he did not suffer a bad reaction.
Red fire ants are not a Hong Kong species - they come from South America. Throughout the territory's long history as a trading hub, alien plants and animals have arrived in droves from other parts of the world. Some, such as the pinewood nematode and brown rat, are brought in accidentally, as stowaways on ships or cargo planes, lurking in soil or attached to clothing and shoes; others have been transported here deliberately, as farm animals, pets, crops or ornamentals, or to control alien populations that preceded them. Some new arrivals perish shortly after they land, others persist but cause no harm, and a few run out of control. These invasive species can wreak havoc, decimating native wildlife, damaging the economy and harming human health. The International Union for Conservation of Nature (IUCN) has identified the "world's 100 worst invasive alien species". Red fire ants are on the list.
