Please cite this article in press as: Kiewra, D., et al., Local-scale spatio-temporal distribution of questing Ixodes rici- nus L. (Acari: Ixodidae)-A case study from a riparian urban forest in Wrocław, SW Poland. Ticks Tick-borne Dis. (2016), http://dx.doi.org/10.1016/j.ttbdis.2016.12.011 ARTICLE IN PRESS G Model TTBDIS-776; No. of Pages 8 Ticks and Tick-borne Diseases xxx (2016) xxx–xxx Contents lists available at ScienceDirect Ticks and Tick-borne Diseases journal homepage: www.elsevier.com/locate/ttbdis Original article Local-scale spatio-temporal distribution of questing Ixodes ricinus L. (Acari: Ixodidae)-A case study from a riparian urban forest in Wrocław, SW Poland Dorota Kiewra a,∗ , Ewa Stefa ´ nska-Krzaczek b , Mariusz Szymanowski c , Anna Szczepa ´ nska a a Department of Microbial Ecology and Environmental Protection, Institute of Genetics and Microbiology, University of Wroclaw, Przybyszewskiego Str. 63/77, 51-148 Wroclaw, Poland b Department of Vegetation Ecology, Institute of Environmental Biology, University of Wroclaw, Przybyszewskiego Str. 63/77, 51-148 Wroclaw, Poland c Department of Geoinformatics and Cartography, Institute of Geography and Regional Development, University of Wroclaw, pl. Uniwersytecki 1, 50-137 Wroclaw, Poland a r t i c l e i n f o Article history: Received 31 August 2016 Received in revised form 20 December 2016 Accepted 22 December 2016 Available online xxx Keywords: Ixodes ricinus Ticks Spatio-temporal distribution Vegetation a b s t r a c t This paper presents the distribution of questing Ixodes ricinus ticks in suburban forest intensively visited by people. The local-scale observations conducted during a 4-year study at 99 plots (of 100 m 2 each) located throughout the entire area of a riparian urban forest, showed a high variation in the density of ticks from year to year. Although I. ricinus is generally permanent in the study area, spatial distribution of sample plots harbouring I. ricinus is variable, i.e. mainly random for adults and larvae, and random or clustered for nymphs. Among the most common plant species in the herb layer, there were not any species which had a statistically significant and constant impact on the occurrence of any of the development stages of I. ricinus. Also relations between the density of tick development stages and vegetation variables, including cover of the herb layer, total species number, species number of the herb layer, and percentage coverage of particular species, as well as ecological indices for light, soil moisture, reaction, and nutrients, did not show any constant and predictable pattern in subsequent years of the study. Only tree and shrub layers were found as variables positively affecting the density of ticks. Although small, suburban forests can be considered as tick-borne risk areas, it is impossible to determine in details areas of tick-borne risk. © 2017 Elsevier GmbH. All rights reserved. 1. Introduction In Europe, Ixodes ricinus ticks are among arthropods of the most significant medical and veterinary importance, primarily due to the transmission of a variety of pathogens. The vector role of I. ricinus is confirmed for several microorganisms, including tick-borne encephalitis virus, Borrelia burgdorferi s.l., Anaplasma phagocytophilum, Rickettsia helvetica, Babesia venatorum, B. diver- gens, B. microti (Gray et al., 1998; Obsomer et al., 2013; Parola et al., 2013; Yabsley and Shock, 2013; Rizzoli et al., 2014; Dugat et al., 2015). The range in abundance, density, and activity of I. ricinus is dependent on a number of environmental factors. Both biotic and abiotic factors remain in their mutual relations and interact with ∗ Corresponding author. E-mail address: dorota.kiewra@uwr.edu.pl (D. Kiewra). ticks multi-dimensionally. Among the abiotic factors a great role is assigned to a high relative humidity in a microhabitat, determining survival of the non-parasitic stage, the air saturation deficit, air tem- perature, photoperiod and solar radiation (Gray et al., 1998; Knap et al., 2009; Estrada-Pe ˜ na and de la Fuente, 2014; Kiewra et al., 2014). The most important biotic factors influencing tick occur- rence are the presence of host and vegetation cover, as those affect the microclimate conditions (Gray et al., 1992; Scharlemann et al., 2008; Ruiz-Fons and Gilbert, 2010; Estrada-Pe ˜ na et al., 2013; James et al., 2013; Estrada-Pe ˜ na and de la Fuente, 2014). The general habitat preferences of I. ricinus are already known. First, they prefer forests to open habitats (Lindström and Jaenson, 2003; Tack et al., 2012). Among various forest types ticks prefer mixed and deciduous forests; however, dry forests like dry pine forests and plantation woods, as well as wetland forests, less fre- quently harbour ticks (Siuda, 1993; Lindström and Jaenson, 2003; Biadu ´ n, 2008; Tack et al., 2012; Kiewra, 2014). Nevertheless, ticks do not limit themselves to optimal habitats (Walker et al., 2001; http://dx.doi.org/10.1016/j.ttbdis.2016.12.011 1877-959X/© 2017 Elsevier GmbH. All rights reserved.