A type of moth, that causes chaos to the cotton crop in the US, has been genetically modified with a gene from a jellyfish to make it pass on an inherited lethal trait.
Scientists hope to test the moth in a secure location in Arizona. They say there are no problems with the release because the insects are all sterilized and they will be secure in a field cage so cannot escape.
However many people are uncertain about genetically modified animals and plants fearing they may harm the environment and people. In this case though the people involved believe they can show that GM animals are useful.