1. AbstractThis study modelled the changes in the development processes of the health-threatening tick Ixodes acinus in northern Europe as driven by the trends of temperature (1950-2016). I used the ECA&D dataset of temperature interpolated at a resolution of 0.25o as the base data for further calculations, which were based on a previously developed process-driven model of the tick. I used the annual accumulated temperature in the period 1950-2016 to obtain the development rates of the oviposition, incubation, larva-nymph, and nymph-adult molts. Annual values were used to ascertain the trend in development rates of each stage. The ecological division of northern Europe (LANMAP2) was used to summarize results along large regions. The temperature in the years 1950-2016 clearly increased in every area of the target territory. The largest increase was observed for a wide territory eastern to Baltic countries, north-eastern Sweden and northern Finland. The development rates of every tested life cycle process had a trend to being faster throughout the time series. Moderate to high increase of the oviposition rates (70%-100% faster) resulted in central Sweden, Baltic countries, parts of Finland, and adjacent territories of Russia. Faster (70%-90%) incubation and molting rates were consistently observed in the same territories and also in large areas of western Norway. The trend of temperature in the period 1950-2016 shows a consistent inflection point around the year 1990, when the slope of the time series of temperature drastically rose. A comparison between 1950-1990 and 1991-2016 demonstrated that annual accumulated temperature was 86% and 26% higher in the Alpine regions, 7%-8% in the Atlantic and 157%, 10% and 16% in Boreal, Continental, and Nemoral regions, respectively. It is concluded that (i) accumulated annual temperature is clearly increasing in the studied territory, (ii) changes were larger since approximately the year 1990, and (iii) these changes have a deep impact on the life cycle of the tick I. ricinus. Faster development rates could be part of the processes driving the reported spread of the tick in the target area and should be considered as a serious thread to human health.
Preliminary Results on HAT-P-4, TrES-3, XO-2, and GJ 436 from the NASA EPOXI Mission