The role of large herbivores in tick-reducing intervention schemes

Of all the stages of the tick Ixodes ricinus, adults are the stage with the lowest numbers in any tick population. The majority of the adult ticks feed on large ungulates like deer, who are generally also in low numbers compared to other important tick hosts like rodents. To reduce tick populations, lowering wild ungulate densities to close to zero or using acaricide applications on them are not really feasible options for large areas in many situations. Since large reductions of wild ungulates in any system will likely conflict with other management objectives, fencing to exclude wild ungulates can be applied in relatively small areas. Many semi-natural systems are being grazed by domestic herbivores. When these herbivores are treated with an acaricide during the tick season for a number of years, tick numbers can be substantially reduced. Short-term applications with treated domestic animals like sheep in small areas are also possible.