Nasopharyngeal myiasis in red deer has never been studied in Portugal. For this reason, from December 2015 to February 2016 a study was derived on hunted red deer in Idanha-a-Nova county to evaluate the Diptera larvae presence. During the initial examination on the spot, the larvae was analysed at the nasopharynx. When present, larvae were collected for further species identification. The infestation prevalence was 50.6 ± 7.61% (CI 95%), and the mean parasitism intensity was 11.38 larvae per affected host. Two larvae species were found, Pharyngomyia picta and Cephenemyia auribarbis, both on single or concomitant infection, with the first species having a higher prevalence and mean infestation intensity than the second. The larvae's prevalence was significantly higher (X2 = 4.35; p = 0.0370) in males (62.16 ± 11.05%) than in females (41.30 ± 10.06%). Within age groups, younger animals showed a higher prevalence. This study shows the presence of P. picta and C. auribarbis larvae in the wild red deer population in Portugal for the first time. The high parasitic prevalence and mean intensity highlight the importance of this parasitosis in this wild species. For this reason, more scientific research is required to accurately assess its prevalence in other geographic areas, and evaluate the risk factors as well effects of this parasitosis on the deer population.
Keywords: Cephenemyia auribarbis; Cervus elaphus; Pharyngomyia picta; nasopharyngeal myiases; oestrosis; red deer.