Cost factors within the defined cost surfaces for Phlebotomus species.

Factors are surfaces were generated by considering both, spatio-temporal stable and variable environmental conditions within the 21st century. Two cost factors are stable within the 21st century: River valleys are considered as the preferred breeding sites for sandflies [2]. Hence, regions which include river valleys are attributed with costs. Sea as absolute barrier cannot be crossed. Beyond, an altitudinal cost structure was developed in accordance to the preferred elevation of sandflies [2]. Two factors vary in the 21st century: MaxEnt-values of climatic suitability range theoretically from 0 (unfavourable conditions) to 1 (perfect conditions). These values are classified and attributed with costs in accordance to the suitability; the lower the suitability the higher the costs. This factor is species-specific. Cost factors for wind speeds are related to the observations concerning wind-speed dependent flight activity. They are taken from findings of Lane [94] concerning the highest flight activity up to 1.5 m/s; from Quate [95] who observed a reduced flight activity between 1.5–2.5 m/s and Roberts [96] who noticed no flight activity above wind speeds of 3.5 m/s. Climatic suitability and wind speed were averaged over two subsequent time-periods.