The Suppression of the False Codling Moth in South Africa Using an AW-IPM Approach with a Sit Component

Abstract

The false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is native to sub-Saharan Africa, where it infests various commercial, and wild, fruit-bearing plants. This major pest is not present in the Americas, Europe, and Asia, and therefore has phytosanitary implications, which impose severe limitations on potential South African exports. Consequently, this pest represents a severe threat to the fruit industry of South Africa, in terms of socio-economic impacts on both fruit production and job security. Although the pest can be managed to some extent with insecticides, mating disruption, and orchard sanitation, a long-term environment-friendly solution was needed. This became more evident as T. leucotreta developed resistance to available insecticides, while stricter quarantine measures were enforced by importers of African citrus. In 2002, research commenced on an area-wide integrated pest management (AW-IPM) programme in conjunction with the development of the Sterile Insect Technique (SIT) for the false codling moth. Commercial sterile insect releases started in the 2007-2008 season over 1500 ha of citrus orchards in Citrusdal, Western Cape Province, but by 2017-2018 had gradually expanded to almost 19 000 ha in three different citrus producing regions of South Africa. The programme is currently owned by the Citrus Growers Association (CGA) that have contributed to the steady growth of the SIT programme in the citrus industry. Over the past ten years the status of T. leucotreta as a pest threat was systematically reduced in areas where the SIT was practiced on an area-wide basis, compared to non-release areas.