Veterinary importance and integrated management of Brachycera flies in dairy farms

Adult Brachycera can affect dairy cattle through their feeding behaviour. The main famil ies of veterinary importance are Tabanidae, Athericidae, Rhagionidae, Muscidae, Glossi nidae and Hippoboscidae. Non-biting flies such as house flies and face flies ingest liq uids from animal tissues using sponging mouthparts, whereas biting flies such as tabanids, sta ble flies and tsetse flies take blood from hosts using piercing-sucking mouth parts. Thus, Brachycera flies may impact livestock through both direct effects (nuisance, skin injuries, blood losses) and indirect effects (pathogen transport or transmission), contributing to economic losses for dairy production. Nonbiting flies are mainly mechanical carriers of pathogens, especially bacteria (e.g. Escherichia coli, Moraxella bovis, Staphylococcus aureus). Tabanids and biting muscid flies are mainly mechanical vectors of pathogens including bacteria (e.g. Bacillus anthracis, Anaplasma marginale), protozoa (e.g. Besnoitia besnoiti, Trypanosoma spp.) and viruses (e.g. lumpy skin disease virus), whereas tsetse flies are biological vectors of trypanosomes causing African Animal Trypanosomosis. Brachycera flies are also developmental vectors of several nematodes (Thelazia spp., Parafilaria bovicola, Stephanofilaria stilesi). Today, several control methods are available for the integrated management of flies inside livestock facilities and in pastures, including environmental methods (sanitation), biological methods (parasitoids, entomopathogenic fungi), chemical methods (insect growth regulators, insecticides) and mechanical methods (traps, targets). Facing the growing concern of increasing fly populations related to changing climate and land use, there is a crucial need to better assess their direct impact and their role in the epidemiology of (re)emerging flyborne pathogens and to improve the effectiveness and sustainability of control methods.