Over the past decade, Haemaphysalis longicornis, the Asian longhorned tick, has undergone a geographic range expansion in the United States, from its historical range in east Asia. This tick has been characterized by its frequent parasitism of livestock, an ability to reproduce through parthenogenesis, and its ability to transmit a variety of vector-borne pathogens to livestock, wildlife, and human hosts in its native geographic range. Thus far in the United States, 17 states have reported H. longicornis populations, including 38 counties in Virginia. These numbers come from presence-absence reports provided to the U.S. Department of Agriculture, but little has been reported about this ticks’ seasonality in Virginia or its habitat preferences. Our current study detected H. longicornis populations in seven of the nine surveyed counties in Virginia. Haemaphysalis longicornis were observed in multiple habitat types including mixed hardwood forests and pastures, with abundant H. longicornis populations detected at one particular pasture site in Wythe County. This study also attempted to investigate environmental conditions that may be of importance in predicting tick presence likelihood. While sample size limited the scope of these efforts, habitat type and climatic metrics were found to be important indicators of H. longicornis collection success and abundance for both the nymphal and larval life stages. This current study reports useful surveillance data for monitoring these tick populations as they become established in the western half of Virginia and provides insight into their current distribution and maintenance over a large study region.

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Here we report the first detection and confirmation of Powassan virus (POWV) (family: Flaviridae) in Ixodes scapularis ticks collected from Appalachian Virginia. Ixodes scapularis ticks were collected from vegetation across field sites in eight counties of western Virginia from June 2019 to April 2021. From these collections, one nymph and one adult male I. scapularis were determined to be positive for POWV using real-time RT-PCR and Sanger sequencing. Both positive ticks were collected from Floyd county, VA, at residential sites; the nymph in June 2020 and the adult male in April 2021. The presence of POWV in Virginia in its natural tick vector is crucial knowledge in beginning to understand the movement and transmission of this pathogen into new geographical areas and the risk it poses to medical and veterinary health.

Ticks are susceptible to environmental conditions and, to ensure survival during winter conditions, they adopt a wide variety of physiological and behavioral adaptations including utilization of a suitable niche with insulation (e.g., leaf coverage). To investigate the potential overwintering survival of three tick populations emerging within Appalachian Virginia (Haemaphysalis longicornis, Amblyomma americanum, and Amblyomma maculatum), both a laboratory experiment assessing super-cooling points and a two-factor (elevation and insulation coverage) field experiment assessing overwintering survivability were conducted across a natural southwestern Virginian winter (2020–2021). Dermacentor variabilis adults were included in this study as an example of a well-established species in this region known to overwinter in these conditions. Our study indicated that A. americanum and H. longicornis wintering tolerance is based on life stage rather than external factors such as insulation (e.g., leaf litter) and elevation. Amblyomma maculatum was more likely to survive without insulation. The ability to withstand the extreme temperatures of new regions is a key factor determining the survivability of novel tick species and is useful in assessing the invasion potential of arthropod vectors.