Phenology of Hyalomma marginatum: a longitudinal study in a site of southern France

Hyalomma marginatum tick establishment has been recorded in southern mainland France for around ten years. This two-host species is one of the main vectors of the Crimean-Congo haemorrhagic fever (CCHF) virus. Knowing the phenology of the tick is a prerequisite for a better understanding of its spread and of CCHF virus dispersal. A longitudinal study was carried out between 2016 and 2022 in a horse herd to determine the seasonal variations of H. marginatum infestation. In the study site, adult ticks started infesting their hosts from the beginning of March. Infestation peaked during the first weeks of May. At that period, on average, up to 4 or 5 ticks attached daily to each horse. Then, the