Seasonal Activity and Metagenomic Analysis of the Introduced Asian Longhorned Tick, Haemaphysalis longicornis, at the United States Military Academy in West Point, New York

The Asian longhorned tick (ALT), Haemaphysalis longicornis Neumann, is an invasive species first discovered at West Point, New York in April 2020. It is a potential disease vector because it transmits several pathogens in its native range. After its initial discovery, weekly surveillance was conducted using the tick drag method to determine the seasonal emergence of its different life stages. Degree days, representing cumulative environmental heating, were calculated for the years 2020 and 2021 based on daily maximum and minimum air temperatures. The degree day model showed when the three life stages emerged each year and was useful for tracking climate change or unusual weather patterns. In the second year, more ticks were collected at more locations indicating populations of ALT were increasing at West Point. A small number of ALT adults and nymphs collected from 2020 were sent to a company for metagenomic analysis to determine the types of bacteria present. No pathogenic bacteria were found. The microbiome of all tick samples was dominated by a Coxiella like endosymbiont (CLE) that is critically important for tick nutrition and behavior. This study reports the initial discovery of ALT at West Point and provides a baseline to understand how this tick may expand and adapt to its new environment. It also highlights the importance of conducting routine tick surveillance on military installations and the need to prevent tick-borne diseases among cadets and soldiers at West Point.