As the New Scientist article Flotilla of designer insects is new weapon in pest control explains, large numbers of genetically modified insects could be released in Spain in an attempt to control olive tree pests.
A similar trial was conducted seven years ago in the U.S. to test a technique for tackling cotton pests. The results reported safety and effectiveness, and did not report any unexpected problems.
The principle is simple: "send out an army of male flies equipped with genes that prevent any offspring, male or female, from reaching breeding age," and the olive pest population is finished.
Scientists who support this method believe it has the potential to provide a better and more precise tool to combat agricultural pests and insects that spread human diseases. Opponents of genetic modification disagree.
Who knows what the long-term effects could be?