Fig. 1

Phylogenetic relationships among members of the Anopheles hyrcanus group. Neighbor-joining (NJ) phylogenetic tree was constructed based on partial ITS2 region nucleotide sequences. A distance matrix was calculated using the Kimura 2-parameter evolutionary model and the tree was constructed using the NJ approach in MEGA X version 10.2.2. The scale bar indicates the proportion of sites changing along each branch. The numbers on the internodes indicate percentages of 1000 bootstrap replicates. Bootstrap values  <  70 are not shown in this figure. This phylogenetic tree is a rooted and traditional rectangular tree with An. pullus (AY186792) as an outgroup sequence. All specimens collected in the present study are marked with circles. The closed circles indicate mosquito specimens collected from Hokkaido, Japan, and open circles indicate specimens from the areas outside Hokkaido. Abbreviations of specimen and sequence accession numbers of specimens used in this study are listed in Table 1