Fig. 1.

A map showing the collection sites and the distribution of BTV serotypes in Australia. The distribution of the BTV serotypes depicts the two BTV epidemiological systems: one in the north of Northern Territory (pale orange) and the other in the eastern states of Queensland and New South Wales (pale blue). The administrative limits of the Australian states and territories are marked with a continuous black line. The BTV serotypes are tagged with their respective distribution zones. The sites of collection of Culicoides are indicated as purple dots. Note the Carpentarian Gap (in blue) located between the two tropical zones of Cape York (northern Queensland) and the Top End (northern NT), at the junction of the BTV serotype distribution zones