Anti-mozzie potions put to ultimate test

By GREGG WYCHERLEY

The irritating high-pitched whine of the mosquito is a sound synonymous with summer, guaranteed to keep even the sleepiest wakefully wide-eyed.

Consumer magazine tested a range of "vaporising" mosquito killers - products you plug in or burn for general use.

The tests, carried out in an independent laboratory in Australia, showed that three of the products worked well, three gave moderate protection and one was ineffective.

Using a volunteer locked in a chamber with 100 hungry mosquitoes, the lab tested how well the products deterred biting, and how effectively they killed mosquitoes.

* The plug-in Mortein Odourless Zapper with mats or liquid and the Raid Portable Mozzie Repeller worked well. The tester received no bites even after eight hours and at least 90 per cent of the mosquitoes in the chamber were killed.

* The Spira and Raid plug-in liquid repellers took longer to kill. After 30 minutes less than 10 per cent of mosquitoes had been killed, but the tester stayed relatively bite-free. After eight hours no bites were attempted and the kill rate was around 80 per cent.

* The Mortein Mosquito Coils deterred biting initially, but became less effective over time. Kill rates were around 40 per cent and the coils stopped burning after seven hours.

* The Raid Citronella Candle did not kill any mosquitoes and on average every female mosquito tried to bite the tester three times.

Colin O'Callaghan, general manager of SC Johnson, Raid's distributors, said the Raid Citronella candles made no claim to kill or repel mosquitoes and he questioned the value of including them in the test.

"Like all of those candles, the only way they are effective is if the mosquito flies into the flame."