Comparative morphology of the deer ked Lipoptena fortisetosa first recorded from Italy

Hippoboscidae flies parasitize various animal species. Knowledge about these insects remains sparse, although they are known to cause stress and damage to their hosts, and they can also accidentally infest humans, causing different sanitary risks. Research conducted in Tuscany assessing the biology and the distribution of Lipoptena cervi (Linnaeus, 1758) (Diptera:Hippoboscidae), the most common ectoparasite of ungulates in Italy, revealed the presence of Lipoptena fortisetosa (Maa, 1965) in Italy for the first time. This study includes a morphological comparative description of L. cervi and L. fortisetosa, emphasizing the peculiar differences between the two species to facilitate their accurate identification. The most pertinent morphological differences between the two species have been highlighted, such as the external features of the antennae, distribution of bristles, and different features in the external genitalia. In both species, scanning electron microscopy investigations on mouthparts revealed strong adaptive convergence in the feeding apparatus. Modified palps and a very thin proboscis are described in relation to feeding behaviour.