First record of Haemaphysalis concinna (Acari: Ixodidae) tick in the Khalkh Numrug basin of Eastern Mongolia.

Haemaphysalis (Acari: Ixodidae) ticks remain poorly studied in Mongolia. Here, we report the first confirmed record of Haemaphysalis concinna Koch, 1844 in the Numrug Strictly Protected Area, Dornod Province, eastern Mongolia, based on both morphological characteristics and molecular analyses. This region lies along the Mongolia-China border within the forest-steppe and steppe zones of the western Greater Khingan Mountains. Tick sampling was conducted at six sites (lakeshores, riverbanks, and marshy forests) between early April and mid-August over a three-year period. A total of 1014 H concinna specimens were collected, of which 148 (including two nymphs) were selected for DNA extraction. PCR amplifications targeting the mitochondrial 16S rRNA (∼455 bp) and Cox1 (∼820 bp) genes were performed. Eight samples were sequenced, with three 16S and two Cox1 sequences meeting quality thresholds. The sequences of both genes exhibited 99.8 % and 100 % identity, respectively, to H. concinna sequences from Russia (Cox1: PP851089.1, PP851095.1; 16S rRNA: KP866207.1) and China (Cox1: KR108863.1; 16S rRNA: ON097130.1) available in GenBank. This high level of sequence identity strongly supports the identification of the Mongolian samples as H. concinna. Species identification was further supported by morphological characteristics consistent with published descriptions of adult ticks. This record from the Khalkh Numrug basin represents the first verified occurrence of H. concinna in eastern Mongolia. These findings underscore the need for further research on the species' ecology, host range, and potential public health significance in the region.