Sterile Insect Technique (SIT) is used to control or eradicate insect pests, usually crop pests or human and animal pests. The target insect is reared in great numbers, than sterilized, usually using gamma radiation. The sterile males are released weekly in high numbers in the target areas. They mate with the wild females which results in infertile eggs being laid. Provided certain other population management activities are properly carried out, the wild population then declines rapidly.
Sterile males compete with the wild males for mating with females. A high ratio of sterile males to wild males is therefore required.
SIT is a proven technique, used in a number of countries to create fruit fly-free areas, and can be very cost-effective. It is an area-wide technique – it must be applied over large areas, usually thousands ha or more. SIT is highly environmentally friendly, making it very acceptable to export markets, which increasingly focus on ecologically compatible, sustainable production techniques. SIT is management intensive – it requires very good coordination, and the cooperation of all the growers in an SIT area.
Sterile Insect Technique (SIT) was initiated by E.F. Knipling and R.C. Bushland (winners of world food prize 1992 for the development of SIT) in the 1930s, when they worked with the screwworm fly, a devastating pest of cattle in North America. The first successful use of SIT to control screwworm was on the island of Curaçao in 1953. Since then SIT has been further developed to suppress more than 20 insect pests, many of them fruit flies and other key agricultural pests.