Difference in susceptibility of small rodent host species to infestation by Ixodes ricinus larvae.

In a laboratory experiment (repeated eight times) individuals of six small rodent species were mixed with 500 Ixodes ricinus larvae for 24 h, than over a 3-day-long observation period engorged ticks fallen from individually kept rodents were counted. Forty engorged larvae fell from the hosts, 25% from striped field mice, 32.5% from house mice, 22.5% from common voles, 10% from bank voles, while wood mouse and steppe mouse proved to be almost free of successfully infesting ticks (both 5%). Statistical analysis indicated, that tick burden differed significantly among host species. Similarly significant differences were shown between sensitivity of two related species, house mouse and steppe mouse, and more ticks were collected on the second observation day compared to the first day. The difference in susceptibility of hosts to Ixodes infestation could be due to various anti-tick behavior habits of hosts, or difference in preference of the ticks between host species.