Sterile Insect Technique

The Sterile Insect Technique, best known by its acronym SIT and also identified as the Sterile Insect Release Method (SIRM), is a biologically-based method for the management of key insect pests of agricultural and medical/veterinary importance. In the FAO glossary, the Sterile Insect Technique is defined as "a method of pest control using area-wide inundative releases of sterile insects to reduce reproduction in a field population of the same species". It is therefore a type of "birth control" in which wild female insects of the pest population do not reproduce when they are inseminated by released, radiation-sterilized males. Sterilization is induced through the effects of irradiation on the reproductive cells of the insects. SIT does not involve the release of insects modified through transgenic (genetic engineering) processes. In this type of autocidal control, sequential releases of the sterilized insects in adequate sterile to wild male overflooding ratio's lead to a reduction in pest population numbers. Effective control using sterile insects is achieved when part of area-wide integrated pest management (AW-IPM) programmes.

Under the International Standard for Phytosanitary Measures No. 3 of the International Plant Protection Convention, sterile insects are categorized as beneficial organisms as the Sterile Insect Technique is among the most environment-friendly insect pest control methods ever developed. It differs from classical biological control, which involves the introduction of non-native biological control agents, in the following ways:

→ Sterile insects are not self-replicating and therefore cannot become established in the environment
→ Autocidal control is by definition species-specific or intra-specific, and
→ SIT does not introduce non-native species into an ecosystem

The Sterile Insect Technique was first developed in the USA, and it has been used for 50 years. It is currently applied on six continents, and the four strategic options in which sterile insects are being deployed as a component of AW-IPM for insect pest control are: suppression, eradication, containment and prevention.

For over four decades the sterile insect technique has been a major subject of the Joint FAO/IAEA Programme on Nuclear Techniques in Food and Agriculture, involving both Applied Research to improve the technique and to develop it for new pest insects and the transfer of the SIT package to Member States through Field Projects so that they can benefit from improved plant, animal and human health, cleaner environments, increased crop and animal production in agricultural systems, and accelerated economic development. SIT has been applied to a number of species of fruit flies, moths, mosquitoes, tsetse flies and screwworm flies.

Numerous publications related to the development of the Sterile Insect Technique have resulted from applied R&D, coordinated research projects, symposia and meetings, and training activities. These have provided much information to researchers, pest-control practitioners, programme managers, plant protection and animal health officers, and policy makers.

A major reference on the principles, practice, and global application of the Sterile Insect Technique is the book "Sterile Insect Technique. Principles and practice in area-wide integrated pest management". Fifty subject experts from 19 countries contributed to develop this SIT textbook.