Sezonske fluktuacije voluharica i miševa (rodentia:muridae) i njihova uloga kao vektora iksodidnih krpelja (acari: ixodidae) / Seasonal fluctuations of voles and mice (Rodentia: Muridae) and their role as vectors of ixodid ticks (Acari: Ixodidae)

The population density and seasonal fluctuations of voles and mice (Rodentia: Muridae) are the most important factors in the diversity, distribution and abundance of ectoparasites. Epidemiological models indicate that an increase in the rodent population density could stimulate an increase in population density of ectoparasites due to the greater variety of preferred habitat (individual hosts). Voles and mice are a group of rodents that have exceptional vector potential for a large number of ixodid ticks species (Acari: Ixodidae), especially tree-host and two-host species. If the densities of the potential host population (voles and mice) are observed as the habitats for ixodid ticks, the qualitative and quantitative differences among them are noticeable, so as different species diversity and population densities of ixodid ticks. Because of the wide ranges of activity, seasonal migrations and population size fluctuations, most rodent species represent a specific type of an "epidemiological bridge" which is responsible for the maintenance of high population density of ticks within certain habitats, but more importantly, the spatial transfer of certain ixodid tick species beyond the boundaries of the certain habitat. Based on the proven vector potential of rodents, the aims of the research were to determine: the seasonal fluctuations and spatial dispersion of voles and mice at selected localities, the dynamics of tick populations collected from nature and obtained from the hosts, vector and ectoparasitic relation between rodents and ticks concerning the type of habitat, meteorological parameters (season), age classes and gender. The four hypotheses will be reviewed: (1) the number of different stages of ticks on the hosts increases with the age group (body mass) of the host, (2) the number of different stages of ticks on the hosts decreases with increasing host population density, (3) a larger number of ticks obtained from the hosts are found on the females than on the males, and (4) the highest number of ticks could be found on the host’s head. The four year study (2008 to 2011) of seasonal dynamics of voles and mice was conducted at four localities: Apatin, Bogojevo, Labudnjača (Kamarište) and Čelarevo. The total of 2.736 rodent specimens were caught. The most numerous species was A. terrestris, followed by: A. agrarius, A . flavicollis, A. sylvaticus and C. glareolus. The total number of identified ticks was 257, belonging to the following species and developmental stages: I. ricinus (larvae and nymphs), I. trianguliceps (larvae), D. marginatus (larvae and nymphs), H. concinna (larvae and nymphs) and R. sanguineus (larvae and nymphs). Within the studied ecosystems, rodents play a significant role in maintaining different species of tick populations, enabling and facilitating transstadial continuity in the life cycles. Furthermore, based on bio-ecological characteristics, especially areal activity during the period of intensive feeding and mating, all observed rodent species were very good vectors of certain ixodid tick species among different types of habitats, providing them spatial and temporal dispersion, which is of great ecological, medical and veterinary importance.