The climate niche of the invasive tick species Hyalomma marginatum and Hyalomma rufipes (Ixodidae) with recommendations for modeling exercises

Abstract

AbstractThe finding of immature stages of someHyalommaspp. feeding on migratory birds in Europe is unexceptional. The reports of adults ofHyalommain Europe and British Isles after successful molting from immatures have sharply increased in recent years. The warming of the target territory could favor the persistence of populations of these invasive ticks. While evaluations of the impact on health or measures of adaptation are on their way, the climate niches of these species remain undefined, preventing preventive policies. This study delineates such niche for bothHyalomma marginatum(2,729 collection points) andHyalomma rufipes(2,573 collections) in its distribution area, together with 11,669 points in Europe whereHyalommaspp. is considered to be absent in field surveys. Niche is defined from daily data of temperature, evapotranspiration, soil humidity and air saturation deficit (years 1970–2006). A set of 8 variables (annual/seasonal accumulated temperature and vapor deficit) has the maximum discriminatory power separating the niches of bothHyalommaand the negative dataset, with an accuracy near 100%. The use of accumulated annual temperature as the only variable for predictive purposes is unreliable, as far as values of water in air are excluded.