How much better it would be to have a kinder, gentler form of pest control, one that renders female mice infertile, preventing plagues before they start and leaving native wildlife untouched.

And that is just what the Pest Animal Control-Cooperative Research Centre (PAC-CRC) in Canberra hopes it has created. Its agent could be undergoing contained field trials in Australia within two years, and be commercially available within five.

But there's a catch. The agent in question is a genetically modified virus designed to replicate and spread. It is a new, man-made disease, one of several being developed (see "On the drawing board", opposite). Once released, they will be as hard to control as any other wildlife disease. Like natural diseases, they could be accidentally or deliberately taken to other countries. They could mutate or recombine with other viruses. They could jump species. The consequences could be disastrous.

The European house mouse may be an exotic pest in Australia, for instance, but in many countries it is a native animal and a key part of the food chain. Nor is the mouse virus the only "disseminating" or transmissible genetically modified organism with the potential to spark international conflict. A team in New Zealand is modifying a parasitic nematode to sterilise brushtail possums- a devastating pest in New Zealand but a protected species in Australia. "Once you've let it go, you can't get it back," admits Warwick Grant, head of the team at AgResearch in Upper Hutt. "Biological control has a chequered history. The stakes are pretty high and you don't want to get it wrong." '"/>

Contact: Claire Bowles
claire.bowles@rbi.co.uk
44-207-331-2751
New Scientist
27-Aug-2003