[Range and ecology of Dermacentor reticulatus (Fabricius, 1794) in Mazuria focus. II. Seasonal activity patterns of the adults].

In the spring and fall of three consecutive years (1997, 1998 and 1999), a study of the seasonal activity patterns in hungry adult forms of Dermacentor reticulatus was conducted on experimental sites, supplemented by field observations beyond the sites in 2000 and 2001. The studies confirmed two periods of activity (spring and fall). The ticks' activity depended mostly on the average daily temperature of the environment, and was observed in temperatures ranging between +4 degrees C and +13 degrees C. Factors diminishing the ticks' activity also included day length and relative air humidity; no active ticks were observed during days longer than 16 hours, or in average relative air humidity lower than 65%.