Surveillance of Bactrocera invadens

The surveillance of B. invadens started officially as an Early Warning System project in 2006. The survey is focused mainly on the busiest land border posts (Lebombo, Beitbridge, Ramatlabama, Groblersbrug and Oshoek), airports (OR Tambo, Durban, and Cape Town), seaports (Durban, Cape Town, Port Elizabeth and East London), production areas, fruits and vegetable markets, dumping sites, municipality parks, residential areas, as well as big cities (Durban, Johannesburg, Cape Town and Pretoria) with a total number of 241 traps in 2006.

Due to the recent detection of B. invadens in Mozambique and Namibia, the NPPO of South Africa has decided to intensify surveillance in other areas that pose high risks for introduction of this pest into the country. As a result the number of traps was increased from 241 (in 2006) to 738 (in 2009) with more traps hanged at new trapping areas such as Kosi Bay, Golela, Platjan, Pontdrif and fruit farms.

During the intensive survey at the land borders, transects were identified as the most likely areas through which B. invadens can gain entry into South Africa.

In order to determine the presence/absence of B. invadens in the country, Methyl Eugenol and Biolure (3-component) are used to attract the exotic fruit flies. These lures are mixed and placed on the killing strip (which kills the insect once it enters the trap) which is put inside the Chempak traps. Specimens collected from the traps are sent to taxonomists for identification and verification. To date, no B. invadens have been caught. However, other indigenous fruit flies are regularly caught.

This surveillance project is done with the assistance of officials from the Directorate Agricultural Product Inspection Services, Provincial Departments of Agriculture and fruit industries (Citrus Research Institute, Institute for Subtropical Crops, Deciduous fruit trust, etc).