Fig. 8
Effect of the field-measured temperature on the density of nymphs (DON) is shown for the (a) spring peak and (b) fall peak. The smoother function shows that the DON increases with the field-measured temperature and reaches a maximum at ~ 15 °C and ~ 18 °C for the spring and fall nymphal peaks, respectively. The DON is an estimate of the number of questing I. ricinus nymphs per 100 m2 sampled by the dragging method each month. The field-measured temperature has units of °C and was measured at 60 cm above the ground at the field site on the day of tick sampling. The DON is predicted for the range of field-measured temperatures that occur in the spring and fall. The predicted values were calculated using model 1 in Additional file 1: Table S5. The reference conditions were as follows: site = Low, BM[2,1]  = 1, year = 2004, SNY1 = 150 cm, and calendar days for the Spring and Fall were 15 April and 15 October, respectively