Dr. Kassai Tibor - Dr. Murai Éva szerk.: Parasitologia Hungarica 6. (Budapest, 1973)
cinus , while in meadows this species is non-inf ested. Another example is given from pastures of Scotland^ where the population density of ticks is very high but the mole is very scarcely infested because it lives in deep layer of humus soil (VARMA, I960). The limited home range of small mammals, such as the common shrew, is one of the factors in maintaining natural foci of infection (NOSEK et al., 1972). Conversely, on the basis of marked animals and their virological and serological examination it is possible to find so called "microfoci" . Birds, as hosts of the ticks or the virus, may be capable of establishing new foci of infection in areas in the same landscape outside the home range of a particular population of small mammals. Birds may also be able to introduce ticks into areas from which ticks have been eradicated or their number greatly reduced. The population density of ticks in an overflowed Danube region regained its normal value in a 4 year period . The population density per 1 hectare of small mammals in the TBE focus Topol'cianky (Tribec Mountain) ,assessed by means of the mark-release-recapture method 7 has been estimated: 1966 1967 1968 Spring 45 50 20 Autumn 75 90 42 The average population density for 1 hectare of ticks,assessed by means of carbon dioxide technique in mid-April 1969, was of 46,000 nymphs and 50,000 adults, while at the beginning of May it was 760,000 larvae, 16,000 nymphs and 3,300 adults only 7 being in indirect correlation with the population density of hosts (MOSEK and KOZUCH, 1970). The protection and preservation of hunting games, such as red deer, roe deer, fallow deer, wild boars, which are usually heavily parasitized by I. ricinus , first of all with adult ticks,
