The future of fruit fly Sterile Insect Technique

The aim of the Hex Valley Project was to achieve economical control of fruit flies using an ecologically compatible method. This was largely been achieved. Other fruit production areas have since been included in the SIT programme, viz. the Elgin/Grabouw/Vyeboom and Villiersdorp (EGVV) areas, the Warm Bokkeveld, Wolseley and Tulbagh.

In these areas, approximately 14,000 ha of commercial fruit are being protected by ground releases of sterile male Medflies in strategic localities.

However, the fruit fly suppression programme must be taken to its logical conclusion – eradication. This exercise is very costly, and arguably impossible, when attempted over a relatively small area, as it requires effective quarantine measures to be implemented in the area. Eradication will only become cost-effective when additional fruit production regions are included under the SIT “blanket”. The SIT programme is scheduled to be extended by 2015 to additional fruit production areas in the country, so that about 70% of all plantings will be included.

At present the fruit fly sterile insect technique can only be used for Medflies.