Tick Monitoring in Prague Outskirts

The selected area for tick monitoring is located in the southern outskirts of Prague (49°58′43″N; 14°24′52″E; altitude 325 MSL), 4 km from the main observatory station of the Czech Hydrometeorological Institute (CHMI) in Prague-Libuš, one of the best equipped observatories in the Czech Republic (Fig. 1). An adequate size (eg. 600 m²) was required to provide a large enough sample size for registering the spring start and autumn cessation of questing activity when numbers of active ticks are comparatively low. The site comprises eutrophicated, acid oak wood (Quercus robur, 70–100 year-old trees), with patches of younger hornbeam (Carpinus betulus). Most of the stand is evenly dense, with a few small openings. The tree canopy cover is 70 % and the shrub canopy cover (Rubus fruticosa, Sambucus nigra) is <10 %. The herb canopy cover is ~25 %, with prevailing low (<20 cm) sparse grass (mostly Poanemoralis) and patches completely covered with dead leaves or moss. In this vegetation community, considered typical habitat for I. ricinus in Central Europe, three adjacent plots were established each of 200 m² having all the features described, which were consistent year-on-year. Low vegetation of the undergrowth (remaining <20 cm in height throughout the year) in the monitored plots limited the possible bias from seasonal growth of the vegetation on the monitoring of ticks and microclimate. The habitat under study is situated on flat ground completely exposed to sunlight giving homogenous conditions over the whole site. Although the study area is under forestry management, with a controlled population of game (including roe deer), there was no forestry activity on the site or in the surrounding area; the absence of fencing allows free movement of all animals (including humans).Fig. 1

Location and habitat of the monitoring site. Circle indicates location of the Czech Hydrometeorological Institute in Prague-Libuš; circle and arrow indicate location of the monitoring site. Insert shows typical habitat of the monitoring site