Birth Control for Insects: The Sterile Insect Technique (SIT) for Controlling Fruit Fly (Tephritidae: Diptera) by Releasing Sterile Males

The aim of this technical brief is to summarize the results obtained from the laboratory and field trials conducted on birth control for insects in minimizing the impacts of fruit flies on horticulture. Several species of fruit flies belonging to Tephritidae family have a greater impact on global agriculture specially horticulture trade than almost any other pest. The introduction of fruit fly pests in an area pose a major risk to horticulture in affected countries due to the larvae damage to plant tissues before their harvest. One efficient, cost-effective and biologically-based fruit fly’s control technology in use of the Sterile Insect Technique (SIT) that unlike to chemical control tactics is friendly to the environment and does not pose any health concern. The sterile insect technique is widely used in integrated programs against tephritid fruit fly pests, and it involves the massrearing and subsequent sterilization of large numbers of male insects of the target pest. The sterilized male insects are then released repeatedly over the infested areas, where these mate with the fertile wild females that consequently produce no offspring. The wild pest population can be effectively suppressed if the sterile males outnumber the wild males. The sterile flies are good fliers and marked sterile males have been recovered up to 24 miles away from their release point, and these are very transient throughout their life. Furthermore, it is important that operational programs implementing the SIT need continuous routinely revising and updating of all protocols to ensure increased efficiency, while two-way feedback is essential between the mass rearing facility and field operations. Finally, it is necessary to point out that this series of studies also cover all the aspects of total quality management for fruit fly rearing, sterilization, shipment, holding, and release as it relates to the SIT application to support rapid progress. A variety of studies have developed protocols to assess strain compatibility and to improve colonization procedures and strain management. Specific studies have also addressed issues related to insect nutrition, irradiation protocols, field dispersal and survival, field cage behavior assessments, and enhancement of mating competitiveness. In special situations of isolation, if the pest population is treated systematically on an area-wide basis with sterile males, complete eradication of pest flies can be achieved as sterile males can invariably seek out and mate with any remaining females of the target pest population, a feat that is difficult to achieve using insecticides.