Long-Term Monitoring of the Numbers of Ixodid Ticks (Acari: Ixodinae) in St. Petersburg and Leningrad Province

Changes in the distribution and abundance of ixodid ticks Ixodes persulcatus and I. ricinus in St. Petersburg and Leningrad Province over the period of 1970–2018 are analyzed. As compared with the data of the 1970s, the abundance of ticks has decreased by 6–9 times in the city parks and suburbs and by 1.5–10 times in Leningrad Province. With the increasing anthropogenic impact caused by the population growth and seasonal migration of people in the territories of Leningrad Province bordering the city, contacts of people with ixodid ticks have become more frequent, increasing the number of tick bites and complicating the epidemic situation of tick-borne infections.