Leading Article: Controversy in the cabbage patch

SINCE the release of Jurassic Park, the use of genetic engineering to create new kinds of living things has had a bad name. In fact, this new kind of science is both more mundane and less threatening than the madcap scheme that went so badly wrong in Steven Spielberg's film. One example of its use, in which Britain leads the world, is in pesticides.

If science can use viruses to kill plant pests instead of today's poisons, the result will be not only cheaper and better crops but also less harm to the environment and less health risk to the people who eat those plants. So it is puzzling that a dispute should have broken out in Oxford about a programme of research into this field.

The proposed experiments that have created the controversy involve Autographa californica NPV, a virus that kills cabbage-eating caterpillars. Scientists have found a way of injecting into the virus a scorpion poison gene whose presence helps it to kill caterpillars much more quickly. They have planted a cabbage patch on the Oxford University farms on which to try out the new virus.

Those who object to the forthcoming experiments have three complaints. They say the scientists have taken insufficient precautions to stop the virus escaping. If the fencing around the plot were vandalised, they fear, birds could then carry infected caterpillars into the outside world, where the virus could then mutate into something fatal to other forms of life. They say that the farms, which are close to the prized Wytham Woods, are the wrong place for the experiment. And they contend that far too little is known about the new virus to risk letting it loose on the natural world.

On the first point, they are probably right; it is only prudent to be careful beyond the call of scientific duty when releasing such an unusual man-made living thing. There are also good grounds for concern about Wytham, which is an unspoilt area whose environment should be treated with special care.

The complaint that it is fundamentally imprudent to unleash an artificially mutated virus on the world per se is more serious. There is certainly a risk, albeit a slight one, that the virus might wipe out more caterpillars of different kinds than the researchers expect.

But the abolition of chemical pesticides, which this research could eventually make possible, would do enormous good to the environment - and Professor David Bishop, who has been leading research on the subject, has an unrivalled reputation in his field. The precautions should be improved. More should be done to reassure the public, but the research should continue.