A new look at the feeding behavior of hematophagous Diptera: The biting habits of Leptoconops (Megaconops) floridensis Wirth (Diptera: Ceratopogonidae)

Understanding the ecological relationships between species and their pathogens is crucial for comprehending diseases and their risks to human, animal, and environmental health. Some hematophagous species of ceratopogonids feed on birds and can act as vectors for hemoparasites, viruses, and bacteria. However, until now, there have been no reports of these insects feeding on the internal organs of birds. This study aims to describe the unprecedented occurrence of ceratopogonids feeding inside the respiratory system of debilitated gulls and cormorants. As part of the Santos Basin Beach Monitoring Project (PMP-BS Area SC/PR – IBAMA – ABIO 640/2015) we studied the biting midges and coastal hosts rescued in the municipalities of São Francisco do Sul and Itapoá, in the northern region of Santa Catarina State. Approximately 18.2% (31/172) of the gulls and 15.8% (3/19) of the cormorants analyzed were infested internally by Leptoconops (Megaconops) floridensis Wirth and, in sporadic cases, by two species of Culicoides. Gulls accounted for 91.2% of the infested birds (31/34), with the trachea, air sacs, and lungs being the most affected regions of the respiratory system (~83.9%). This is the first recorded occurrence of ceratopogonids feeding in the innermost part of the respiratory system of birds.