Study on the dispersal of Bactrocera tryoni
Understanding the dispersal behaviour of pests is important in the development of scientifically justified trade restrictions and when delimiting regulated areas. The available scientific data on the dispersal potential of Bactrocera tryoni (Diptera: Tephritidae – EPPO A1 List) has been recently reviewed by Dominiak (2012) and used in different predictive models. Most studies reviewed concluded that the lifetime dispersal distance of B. tryoni rarely exceeded 1 km, although it was recognized in that longer dispersal distances for a small number of individuals may occasionally occur. As a result of this study, the following 5 distances were proposed to delimit ‘quarantine areas’ in Australian conditions:
- a radius of 1.2 km when the dispersal of B. tryoni remains within 200 m of an outbreak epicentre (i.e. all fruit flies are caught within this 200 m radius zone).
- a radius of 2.4 km – for a dispersal within 400 m of the outbreak epicentre.
- a radius of 6 km – for a dispersal within 1 km of the outbreak epicentre.
- a radius of 10 km – for a dispersal within 1.6 km of the outbreak epicentre.
- a radius of 15 km – for a dispersal within 2.5 km of the outbreak epicentre.
It is planned to apply the above proposals in the field and to review them after 5 years of operational experience in Australia.
Sources
Dominiak BC (2012) Review of dispersal survival and establishment of Bactrocera tryoni (Diptera: Tephritidae) for quarantine purposes. Annals of the Entomological Society of America 105(3), 434-446.