Who’s biting the woylie and what are they transmitting?

Prior to European settlement, the Woylie (or brush-tailed bettong) Bettongia penicillata, had a distribution over much of Australia. Over the next 180 years, the woylie distribution was reduced and became restricted to three principal areas in south-west Australia, namely Upper Warren, Tatanning and Dryandra. As part of the recovery plan, fox control and woylie relocations were initiated and by 1996 the woylie became the first Australian mammal to have its conservation status downgraded. However, since 2001 the number of woylies has declined rapidly, with capture rates indicating a 70–80% reduction in population sizes over a 5 year period. During the investigation into the recent decline, a distinct species of Trypanosoma was identified at high prevalence and studies have shown a correlation between parasite prevalence, high parasitaemia and woylie decline. In efforts to further understand this vector-borne parasite, sampling of haematophagic arthropods has focused on Tabanids, Sandflies, Fleas, Ticks and Midges in the Upper Warren and Karakamia regions. It is hoped that this understanding of the vector and its distribution will provide baseline data for future woylie relocation programs, safe-guarding against the inadvertent introduction of disease into naive populations or naive animals into infected populations, thus increasing the chances for success