Sterile Insect Technique

The sterile insect technique is a method of biological control, whereby overwhelming numbers of sterile insects are released. The released insects are normally male as it is the female that causes the damage, usually by laying eggs in the crop, or, in the case of mosquitoes, taking a bloodmeal from humans. The sterile males compete with the wild males for female insects. If a female mates with a sterile male then it will have no offspring, thus reducing the next generation's population. Repeated release of insects can eventually wipe out a population, though it is often more useful to consider controlling the population rather than eradicating it.

The technique has successfully been used to eradicate the Screw-worm fly (Cochliomyia hominivorax) in areas of North America. There have also been many successes in controlling species of fruit flies, most particularly the Medfly (Ceratitis capitata), and the Mexican fruit fly (Anastrepha ludens).

Insects are mostly sterilized with radiation, which might weaken the newly sterilized insects, if doses are not correctly applied, making them less able to compete with wild males. However, other sterilization techniques are under development which would not affect the insects' ability to compete for a mate.

The technique was pioneered in the 1950s by American entomologists Dr. Raymond C. Bushland and Dr. Edward F. Knipling. For their achievement, they jointly received the 1992 World Food Prize.