The Influence of Southwestern Virginia Environmental Conditions on the Potential Ability of Haemaphysalis longicornis, Amblyomma americanum, and Amblyomma maculatum to Overwinter in the Region

Abstract

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.

Seasonal Dynamics of Tick Species in the Ecotone of Parks and Recreational Areas in Middlesex County (New Jersey, USA)

“…This phenomenon has been described in Asia [ 38 , 42 , 43 ], Oceania [ 36 ], and, recently, in the USA [ 23 ]. The development stage sequence (nymph → adult → larva) is observed throughout the year with nymphs (spring) followed by adults (summer) and larvae (late summer and early fall), which suggests that the nymphal stage may be the main overwintering stage in NJ, as it was proposed recently for Virginia populations [ 44 ].…”

Heartland Virus: An Evolving Story of an Emerging Zoonotic and Vector-Borne Disease

“…Though field studies have so far failed to find any evidence of natural HRTV infection in this species [55], these ticks have been found to be experimentally susceptible and competent vectors, capable of horizontal transmission to mice (as evidenced by seroconversion), as well as transovarial transmission [56]. Like A. americanum, H. longicornis is a multi-host tick capable of overwintering under appropriate conditions [57] and thus should continue to be considered as a potential vector for HRTV.…”