THE BIOLOGY AND MONITORING OF THE INVASIVE ASIAN LONGHORNED TICK, HAEMAPHYSALIS LONGICORNIS NEUMANN, 1901 (IXODIDA: IXODIDAE) IN THE UNITED STATES
The Asian longhorned tick (Haemaphysalis longicornis) is a newly introduced, invasive species in the United States. Since the earliest record of its presence in West Virginia in 2010, H. longicornis has been collected from twelve states in the US. It is known to transmit disease pathogens, including the severe fever with thrombocytopenia syndrome virus (SFTSV), Theileria sp., Babesia sp. and Rickettsia sp. These pathogens infect livestock and humans, causing economic losses and substantial rates of morbidity. In addition, H. longicornis is capable of being infected with pathogens that already exist in the US, namely, Borrelia sp. and Ehrlichia sp., which compounds the associated health risks. Management and control of this emerging tick requires knowledge of its biology, ecology, and distribution. This research addresses the current need for a standardized and effective collection method, which is important for defining potential tick exposure and disease risks as well as ecological factors relating to the tick distribution. Average ticks collected using three check distances (5 m, 10 m, and 20 m) and three collection methods (drag sampling, sweeping, and CO2 traps) were compared to determine the optimal collection technique. Field collections were conducted from June through August 2019, in Westchester County, New York, and ticks were grouped by life stages to assess the collection method efficiency. Results indicated that implementing shorter check distances, using the drag sampling method were ideal for adult collections. Shorter check distances were still the most effective for collecting nymphs. In contrast to the adult collections, the difference between drag sampling and sweeping methods were not statistically significant for nymphs. CO2 traps attracted H. longicornis, but additional research is necessary to devise an effective tick retaining method before CO2 traps can be implemented in the field. Results are presented to inform and support H. longicornis surveillance and control programs across the nation.