Researchers have created plants that kill insects by initiating a gene-silencing response called RNA interference that targets particular genes in particular insects, and may be safer and less likely to have unintended effects than other genetically modified plants.

Others warn that it is too early to make such predictions and that the plants should be carefully tested to ensure that they do not pose environmental problems.

Monsanto is developing genetically modified plants that use RNA interference to kill the insects that eat them.