Current geographical distribution
Hyalomma marginatum is widely distributed in North Africa and Asia where it is reported from: Algeria, Armenia, Azerbaijan, Egypt, Ethiopia, Georgia, Iran, Iraq, Israel, Morocco, Sudan, Syria, Tunisia and Turkey (Hoogstraal, 1979; Latif & Walker, 2004; EFSA, 2010).
In Europe it is present in Southern and Eastern Europe having been recorded from: Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, France, Greece, Italy, Kosovo, Former Republic of Macedonia, Moldova, Montenegro, Portugal, Romania, Russia, Serbia, Spain and Ukraine. Several sporadic records have also been reported on imported animals, humans, and migratory birds in: Germany, Finland, Netherlands and the United Kingdom but do not represent established populations.
Potential for future spread
Ectoparasites such as ticks by themselves have relatively little mobility, even Hyalomma marginatum. However, they can be transported over vast distances by their vertebrate hosts in particular migratory birds and ungulates. Once attached to the skin of a host they may feed for a period of up to thirty days. It is the duration of attachment which enhances their ability for dispersal. Livestock in particular pose a particularly high risk of importing ticks as they can support high infestations and it is not uncommon for up to 100 Hyalomma marginatum ticks to be found on one animal.
Degradation of agricultural land leading to scrub encroachment has been identified as a risk factor for population explosions particularly when the land was previously cattle pasture.
Populations in the Mediterranean basin (Southern Europe and North Africa) are currently considered to be regulated by rainfall and evapo-transpiration in summer. A decrease in both of these would likely impact on the available habitat for the tick and facilitate its spread towards northern latitudes, whereas populations in Eastern Europe and the Caucasus are regulated by the minimum temperatures in late autumn. The low temperatures in late autumn force nymphs to overwinter engorged with subsequent high mortality rate. Whereas in regions where they currently survive, warmer autumns allow for the moulting of nymphs to adults decreasing the mortality of the population and allowing for gradual spread into suitable neighbouring territories.