Study on Diptera Hippoboscidae of the genus Lipoptena, parasites of ungulates, and morphological and bioecological investigations on L. fortisetosa, a new species for Italy

This research explored different aspects of two hippoboscid species: Lipoptena cervi (Linnaeus, 1758) and L. fortisetosa Maa, 1965, which are hematophagous ectoparasites infesting mainly cervids and occasionally biting humans. Investigations aimed at enlarging the general knowledge on these species particularly renowned for their possible role in human and animal health implications. To achieve the research goal several studies groupable into five sections have been conducted. In the first section an overview on the Hippoboscoidea superfamily has been presented in order to show the scenario in which the studied hippoboscids are included. The second section regards morphological investigations that allowed to underline the peculiar body characters discriminating L. cervi and L. fortisetosa which are commonly mistaken. Additionally, several morphological adaptations that some hippoboscid species differently evolved to efficiently live together with their hosts have been shown. The process by which ectoparasites locate the victims has been carefully discussed in the third section. This topic has been assessed by examining L. fortisetosa colour attraction trough an experiment conducted in field. This trial allowed to prove that the fly is able to discriminate colours and uses visual stimuli to find hosts. Besides, observations on the antennae of different hippoboscid species have been performed using scanning and transmission electron microscopes approaches. Morphological studies provided a detailed description of the conformation of these structures with a particular focus on the sensory pattern. Sensilla have been mapping and typing, and, thanks to ultrastructure performed on L. fortisetosa, the involvement of chemoreception played by basiconic and coeloconic sensilla, as well as by other antennal features, has been hypothesized. The four section includes the core data of the PhD program. It deals with the diffusion of the two studied Lipoptena spp. in central Italy and is focused on the relation these insects established with their main cervid hosts. Parasitism dynamics and infestation preference, in terms of species, sex, and age classes of hosts, have been investigated comparing the results of the two hippoboscid species. Further, phylogenetic analyses on L. fortisetosa have been performed with the purpose of giving information useful to trace the route this ectoparasite travelled from the native country Japan to Europe, probably carried around by its original host, Cervus nippon. Finally, the last section reports the results obtained by the characterization of the bacterial community of L. fortisetosa. This research proved that the fly harbours several pathogens of medical interest confirming that it represents a possible risk for human health as carriers of microorganisms potentially responsible of diseases.