Distribution and abundance of Questing ticks in three parks of Emilia-Romagna Region (Italy)

The following study was performed to quantify the presence and abundance of thick in three Emilia Romagna Regional parks, never checked before and usually haunted by family with children. Four sampling site were selected for the investigation. In the “Gessi bolognesi and Calanchi dell’Abbadessa” Regional Park (Bologna province) two sampling site were selected: site A (locality “Ca’ de Mandorli) and site B (locality Ciagnano); another site (C) was localized in the “Monteveglio Abbey Regional Park” (Bologna province) and lastly the site D was localized in the Carnè Park (Ravenna province). In these areas there are naturalistic pathway and picnic areas, intersperse with wood and meadow, that are usually frequented by many people. In these sites, areas or transects were selected and sampled every 15 days for questing ticks from April to October 2010 (from May to October in site D, for the annual closing of the park). Ticks were collected by flagging the upper trail edge line of the or the whole areas with a 1m x 1m white cotton muslin cloth. The ticks were removed every 2 meters to reduce the effect of tick drop-off. Environmental factor considered in each transect or area examined was the dominant vegetation (presence of grass or leaf litter) and the microclimate during each sampling, assessed by measuring the temperature and the percentage of humidity at 5 cm by the soil using a thermo hygrometer (Oregon Scientific). Collected ticks were immediately put into alcohol 70% and afterward identified using identification keys. Ticks species and stage of development were recorded for each transect or areas. Only for I. ricinus, the abundance index (AI) i.e. the number of ticks collected in 100 m2, was calculated for larvae (AIL), nymph (AIN) and adult (AIA), and compared among sites, period of collection, temperature, humidity and dominant vegetation. Kruskall-Wallis test was used to compare the AI in the different sites; non parametric correlation (Spearman Rho) was used to quantify association between the AI and the different temperature or humidity value at the collection time. A total of 8139 questing ticks, mainly larvae (6734), to a lesser degree nymph (1344) and only few adults (33 male and 28 female), were collected. The higher number of ticks were found (4187) in site B, followed by site A (2123), site D (967) and lastly site C (862). Ixodes ricinus was predominant (8080 specimen) but also other few specimens were found such as Dermacentor marginatus (37), Scaphixodes frontalis (13), firstly described in Emilia-Romagna Region, Hyalomma spp. (6) and Ixodes acuminatus (3). In site B there was the major heterogeneity of ticks species. The average AI of I. ricinus was significantly higher in site B both for larvae (215.1 ticks/100 m2, p<0.01) and nymph (29.3 tick/100 m2; p<0.05). The higher AIL was found in July in sites A, B and C, while in August in site D; the higher AIN was found in May in all the sites. The AIL tend to increase, while the AIN and AIA tend to decrease significantly when the temperature increases, instead the AI is not correlated with humidity, even if the larvae were more collected with humidity lower than 35%. The overall AI was higher in transect or areas with leaf litter instead of grass vegetation.