Sterile insect technique

Sterile Insect Technique (SIT) is a method of biological insect control, whereby overwhelming numbers of sterile insects are released into the wild. The released insects are preferably male, as this is more cost-effective and the females may in some situations cause damage by laying eggs in the crop, or, in the case of mosquitoes, taking blood from humans. These sterile males compete with wild males to mate with females in the wild. As they cannot produce offspring, the population of the species declines. This technique has successfully been used to eradicate the Screwworm and the Mediterranean fruit fly.

History

The Sterile Insect Technique was first developed by Edward F. Knipling and Raymond C. Bushland in the 1930s. The first large-scale test was carried out in 1954 against the screwworm fly in the island of Curacao. The test was successful and the technique has since been used to eradicate the screwworm from all of North and Central America.

Method

The insects are sterilized through a process of radiation. This is usually done using gamma rays, but X-rays or high-energy electrons can also be used. The radiation dose must be carefully controlled to ensure that the insects are sterile but still competitive in mating.

Applications

SIT has been used against a number of insect pests, including the Mediterranean fruit fly, the Mexican fruit fly, the Pink bollworm, and the Mosquito. It is currently being tested against the Tsetse fly in Africa.

Advantages and Disadvantages

The main advantage of SIT is that it is species-specific and does not harm other insects or the environment. However, it is expensive and requires a high level of organization and management.

See also

• Biological pest control
• Radiation sterilization
• Insect ecology

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  Cochliomyia hominivorax
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  Edward F. Knipling, Entomologist
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  Cochliomyia hominivorax distribution