A genetic trick known as gene silencing could help wipe out serious farm pests such as the Mediterranean fruit fly and pink bollworm.

The release of sterile males has played a key role in the eradication of some pests, helping eliminate the tsetse fly from Zanzibar, for example. But the method is costly and the radiation used to sterilise the insects can weaken them, so vast numbers must be released to ensure that wild males do not get a chance to mate.

That has led researchers to look at ways of genetically engineering insects to make them sterile or pass on a gene that kills all their offspring. Now Steven Whyard of CSIRO Entomology in Canberra, the insect division of Australia’s national research institute, has shown that gene silencing, or RNA interference, can do the trick.