Area-wide integrated pest control operation in Thailand: Two interacting closely related species, Bactrocera dorsalis sensu stricto and Bactrocera correcta, with potential of species complexity

Full text: Since 1987, we have set up a pilot project initially for the control of the Oriental fruit fly (OFF), Bactrocera dorsalis (Handel), and recently also for control of the Guava fruit fly (GFF), Bactrocera correcta. In doing so, we integrated the SIT with other monitoring and control methods in the Rajburi province (south) as well as recently in Phichit province (north). These two area-wide control programmes are operated with different management schemes integrating various stakeholders such as crop growers, local field operators, producers of the sterile insects, politicians, activists, reporters, exporters, scientific experts, and researchers from academies and research institutes. Regular feed back information systems of the field monitoring have been set-up with geographical positioning system (GPS) with the support of IAEA. Thus, most trapping sites and infested fruits collection sites from both the control areas have been geo-referenced and have become valuable resources for the population dynamic studies regarding the effectiveness of the area-wide control programme. Recent research is investigating the impact of the presence of two different but conceivably interacting closely related species, B. dorsalis and B. correcta, which are sympatric polyphagous species with highly overlapping commodity host ranges. However, their degree of host preferences is somewhat different. Crop growers and area-wide control experts require that our effective area-wide control programme needs to be tailored so that population suppression for both species is achieved. Besides, there were several (unpublished) reports indirectly suggesting mating interactions between the two species. This presentation reports initial analysis of mating tests between these two fruit fly species, comparison of their natural history, and the demographic data from our area-wide control areas and from general agricultural areas. We also addressed the use of established molecular genetic markers for genotyping fruit fly species for the field operations. These DNA markers may be used for the analyses of the genetic structure of the population and estimate the degree of genetic diversity and relationships at the intraspecific and interspecific level. The data may also be useful for the understanding of the potential species complexity issues within the region. (author)