Veterinary session

Louse flies are obligate blood-sucking arthropod ectoparasites that can prey on a wide range of warm-blooded animals. The family of louse flies (Hippoboscidae) includes over 200 species, most of which are parasites of birds. Their role as vectors has been known for a long time, they are involved in the transmission of many pathogens, therefore, their animal health significance is unquestionable. As there is currently only limited information available on avian louse flies in Hungary, the aim of our research was to collect the species present in Hungary on a broader scale and to gain a deeper understanding of parasite-host relationships.

In Ócsa, parasites, including louse flies, have been removed from birds that are captured for ringing since 2015. In 2022 the research continued at 7 additional sites: Fenékpuszta, Tömörd, Dávod, Szalon, Lake Kolon, Lajta-Hanság, and Barbacs.

During this time, a total of 236 louse flies were collected from different species of passerines, (Passeriformes), woodpeckers (Piciformes) and owls (Strigiformes), as well as 18 louse fly specimens from the close environment of the birds. The removed parasites belonged to 6 different species. The most common (168 specimens) was Ornithomya avicularia, followed by Ornithoica turdi (24 specimens), then Ornithomya biloba (23 specimens), and Ornithomya fringillina (17 specimens). In addition to these, 3 Ornithomya chloropus and one specimen Ornithoctona laticornis were identified by morphological methods.

To the best of our knowledge, this is the first documented occurrence of the latter species in Hungary. Out of 193 captured birds, a total of 2 different louse fly species were found on the same bird only once. The mean intensity of louse fly infestation in birds was 1.295, while the median intensity of louse fly infestation in birds was 1 louse fly per infested bird.

The captured bird species were classified into four categories according to their habitat: reed, field, forest, and mixed habitat (forest and field) associated birds. Using Fisher's exact test, we found that the difference in host preference of certain louse fly species was highly significant. O. avicularia was much more common in reed birds than O. turdi, which was more common in field and forest birds (p=0.0004). The same difference was not true for O. avicularia and O. fringillina species (p=0.418).