What are the vectors in European livestock farms? Case studies in Hungary and Spain

Ongoing global changes are strongly impacting the distribution and incidence of vector-borne diseases (VBD) affecting both humans and animals. Livestock production is a cornerstone of the economy and food security of many countries, notably in Europe, and VBD represent a major constraint on its development. Furthermore, domestic animals can serve as reservoirs for zoonotic agents, highlighting the need for a One Health approach to anticipate and control VBD. However, research on livestock-associated vectors in Europe, particularly mosquitoes and stable flies at farm level, remains limited. Although ticks are recognized as the most important vectors in Europe, comparative studies between countries and host animal species are still scarce. On the basis of vector presence, this study assesses the entomological risk for livestock on seven farms located in two European countries, Spain and Hungary, characterized by contrasting climates and husbandry practices.

During spring 2023 and 2024, as well as autumn 2023, three groups of arthropods, mosquitoes, ticks, and stable flies were collected from seven cattle, sheep, and pig farms in Spain and Hungary. Environmental, climatic, and meteorological data, together with information on management practices and animal characteristics, were collected on-site and obtained from local databases.

A total of 1432 mosquitoes, 345 ticks, and 1266 stable flies were collected and identified to species level, representing 37 species in total: 30 mosquito species, 6 tick species, and 1 stable fly species. Among these, 16 species are recognized vectors of pathogens. Hungary consistently exhibited higher arthropod abundance across all groups. Mosquito diversity was also greater in Hungary, with 21 species dominated by Aedes vexans and Culex pipiens pipiens, whereas in Spain, 13 species were recorded, mainly Culex theileri and Anopheles atroparvus. Four tick species were identified in Hungary (Ixodes ricinus, Haemaphysalis concinna, Dermacentor marginatus, Dermacentor reticulatus) while two species were collected in Spain (Hyalomma lusitanicum and Rhipicephalus bursa). The stable flies Stomoxys calcitrans was the only species present in Europe and accounted for all specimens collected, 99% of which were found in Hungary. Seasonal patterns showed spring peaks for mosquitoes and stable flies, and summer/autumn peaks for ticks in Hungary.

The originality of this study lies in its multi-vector description of three arthropod communities associated with three livestock species (cattle, sheep, pigs) on farms located in two European countries with contrasting environments and climates. The study demonstrated the coexistence of 16 arthropod species of veterinary and public health relevance in the surveyed farms. Their diversity and abundance were influenced by geographical contrasts between Mediterranean and Central European climates, as well as environmental characteristics, livestock species, and management practices. These findings provide updated information on the diversity of arthropod vectors present on livestock farms, regardless of production type, and highlighted the need for enhanced vector surveillance in livestock systems, which accounts for environmental, farming, and anthropogenic factors. Such efforts are essential to anticipate VBD emergence driven by invasive vectors and circulating pathogens, mitigate impacts on animal health and productivity, and address interconnected risks to both human and animal populations.