The successful establishment of an exotic species in a newly colonised region is not only dependent on temperature. Factors like availability of unoccupied ecological niches and avoidance of competition due to temporal segregation of oviposition [35, 64] were hypothesised to play a role in the Asian bush mosquito’s invasion success. Also, the colonisation dynamics of Ae. j. japonicus on the over-regional scale likely depends on passive transport which is thought to play a major role in its long-distance dispersal as inferred by genetic population structure . While probably not relevant for the demographic dynamics of an established species, inherently unpredictable passive transport may play a crucial role for initial colonisations and the sudden and ephemeral occurrence of populations (e.g. Berchtesgaden in ). Information on the dispersal mode, other non-thermal factors, and their impact on distribution need to be integrated into predictions of the occurrence of Ae. j. japonicus. However, thermal conditions set the limits of possible occurrence and thus determine the probability of long-term population establishment.