Table 1.
Summary of the haplotype and Rickettsia infection rates among the 7 ixodid tick species obtained in the Niigata Prefecture, Japan.
Fig 1.
Median-joining network of the 59 cox1 haplotype sequences of Rickettsia positive and negative I. ovatus.
Haplotype groups are indicated by numbers (1 to 4).
Fig 2.
The influence of altitude on the habitat distribution of I. ovatus.
The points indicate the sampling sites of the collected individuals per I. ovatus haplotype group (n = 3) in the haplotype network (Fig 1). The map shows the elevation level across the sampling area, with Niigata Prefecture Japan depicted as a color gradation. Group 4, not shown in this figure, with haplotypes 54 and 55 was found on Sado island, which is encircled in black in box 3.
Fig 3.
The relationship between the mean altitude of Rickettsia positive (n = 46) and negative (n = 300) I. ovatus.
Welch t-tests revealed a significant difference in the mean altitude between Rickettsia-infected and non-infected I. ovatus at p < 0.05. Populations with combined sites are labeled A to H.
Fig 4.
An unweighted pair group method with the arithmetic mean (UPGMA) dendrogram of I. ovatus based on the pairwise genetic distance (FST) of cox1 among the 7 populations across Niigata Prefecture, Japan.
We excluded one population due to the limited number of samples.
Table 2.
The differences in Rickettsia infection rates and mean altitude in I. ovatus haplotype groups and cluster dendrogram groups.
The table shows the distribution of Rickettsia-infected and uninfected I. ovatus and the mean altitude in each of the haplotype groups as shown in Fig 1 (I. ovatus haplotype network) and the cluster dendrogram in Fig 4 (I. ovatus cluster dendrogram). The z-score test showed a significant difference at p < 0.05 between the Rickettsia detection rates in haplotype groups 1 and 2 (indicated by ab) and in cluster dendrogram groups 1 and 2. The Welch t-test at p < 0.05 revealed a significant difference in the mean altitude of haplotype groups 1 and 3 and cluster dendrogram groups 1 and 2 indicated by ab. Haplotype group 4 was not included in the analysis due to its low sample size.