Locomotor activity of adult Dermacentor reticulatus ticks (Ixodida: Ixodidae) in natural conditions

Introduction and objective. Expansion into new areas and the great epidemiological significance of the D. reticulatus tick in Europe prompts investigations of its ethology. Therefore, the locomotor activity of D. reticulatus adult stages in an optimal habitat during the spring and autumn activity periods was analysed. Materials and method. Marked D. reticulatus adults were placed at the central point of each experimental plot. At regular time intervals, specimens attached to the cloth used in the flagging method were collected, and the distance covered by the ticks was measured. In each collection round, the temperature and humidity level in the habitat was also measured. Results. Within 7 weeks, adult D. reticulatus ticks can cover an average distance of 60.71 +/- 44 cm. The locomotor activity of adult stages is greater during the spring than the autumn activity period. Questing, females cover a greater distance (66.35 +/- 100 cm) than male ticks (54.85 +/- 45 cm). Adult stages are characterised by greater aggressiveness 24 hours after being released, i.e. 30% of females and 19% of males attempt to attach to host skin. The locomotor activity in adult ticks depends on the humidity of the habitat (Z=-1.198; p=0.050). The temperature does not affect tick walking. Conclusions. Given the low rates of horizontal locomotion of adult D. reticulatus ticks, the prevalence of the species in nature is determined by the presence of their hosts and humidity conditions ensuring their further development and survival. The dependence of D. reticulatus locomotor activity and aggressiveness on the humidity level implies an increased risk of host attacks in locations and periods that offer favourable humidity conditions for this species.