Engaging an Interdisciplinary Team to Map the Current and Future Distribution of the Asian Longhorned Tick ( Haemaphysalis longicornis ) in North America: A One Health Approach to Risk Mapping and the Added Value of Citizen Science

Summary The Asian longhorned tick (ALHT) ( Haemaphysalis longicornis Neumann, 1901) is a vector for many pathogenic micro-organisms of veterinary and public health importance. The ALHT is native to east Asia but was accidentally introduced into New Zealand and Australia in the early 1990s/late 1880s, respectively. It is now well established in these countries and it is a competent vector for Theileria orientalis Ikeda, which can cause significant livestock morbidity and mortality. Recently, this tick was introduced into North America. It was first formally detected on sheep in New Jersey in 2017, although it is now thought that it may have been present in the USA since 2010 but was initially misidentified as the morphologically similar rabbit tick H. leporispalustris (Packard, 1869). As of August 2022, this tick has been reported in 17 US eastern states. In this case study, we illustrate how we engaged an interdisciplinary team to examine the habitat suitability for the ALHT across North America under current and future climatic conditions. Using a transdisciplinary approach, we also considered potential routes of entry into Canada from the north-eastern states of the USA. Using published and current surveillance data, we generated habitat suitability models to predict the most likely areas in North America for the geographic expansion of the ALHT. Following discussions with climate change experts and entomologists, models were also developed to examine future habitat suitability under selected climate change scenarios. Interviews with experts and government colleagues suggest that likely routes of entry into Canada include cross-border movement of infested terrestrial wildlife and livestock, dog importations and the movement of migratory birds. Enhanced tick surveillance, including the use of citizen science, is required to gain a better understanding of how this tick might spread in the future. The logo of T C C dash 3 W. A map is depicted and the bottom-left part of the map is highlighted. The logo of the University of Calgary Faculty of Veterinary Medicine. The logo of the Canadian Animal Health Surveillance System or C A H S S.