Fig. 1

Sampling sites of I. ricinus in the Netherlands. Pools of nymphs from eight forest sites (triangles) were used for 16S rRNA amplicon sequencing analysis. Individual nymphs from these and 11 other forest sites (points) were tested by qPCR for the presence of tick microorganisms and used for co-infection analyses. A box marks the sampling site by two letters, and a linear colour gradient represents longitude. Full coordinates, habitat, vegetation cover, tick density, and the number of vertebrate species per location are provided in Additional file 1: Table S1