Ectoparasitic arthropodes, like ticks, confer numerous pathogenic bacterial and viral germs upon human beings and/or animals. Since these vectors are poikilothermic, there is a strong dependence on environmental conditions. Climatic as well as microclimatic conditions play a major role. Against this background, it can be anticipated that climatic changes also influence the bionomics of ticks and of the pathogens conferred by them.