Questing tick densities
All the ticks collected were identified as Ixodes ricinusspecies. Overall, questing I. ricinus nymphs and adults were found on vegetation in all the sampled months with a unimodal pattern (Figure 2). The main period of activity for both nymphs and adults occurred between April/May and early July. Questing larvae were found from April to October and in higher numbers from May to early July, suggesting a synchronous activity with nymphs.
Questing nymph densities varied significantly between years (Mann-Whitney U test, p-value<0.001). The annual cumulative DON was higher in 2011 and 2013 (respectively 500 and 575 nymphs/100 m² with a maximum density per month of 270 and 350 nymphs/100 m²) than in 2012 and 2014 (respectively 120 and 240 nymphs/100 m² with a maximum density per month of 110 and 150 nymphs/100 m²) (Figures 2 and 3). The annual cumulative density of questing adults fluctuated in line with the annual cumulative DON, although the annual variations were lower than for the nymphs. It varied from 12-18 adults/100 m² in 2012 and 2014 to 25-28 adults/100 m² in 2011 and 2013.