Molecular identification of Pharyngomyia picta (Meigen, 1824) (Diptera: Oestridae) in sambar deer (Rusa unicolor) from Kerala, India

Abstract Nasopharyngeal myiasis caused by bot fly larvae of the family Oestridae is an important parasitic condition affecting both wild and domestic mammals. Pharyngomyia picta ( P. picta ), an obligate parasite of cervids, is predominantly reported from the Holarctic region. Although molecular data on P. picta are available from various regions across the world, information from Indian wildlife hosts, especially protected sambar deer ( Rusa unicolor ), remains scarce. The present study reports the morphological and molecular identification of bot fly larvae recovered from a fatal case of nasopharyngeal myiasis in a sambar deer from Kerala, India. Postmortem findings indicated acute respiratory failure and circulatory collapse, along with nasopharyngeal myiasis. Morphological features suggested the recovered maggots to be P. picta . Further molecular confirmation of the species was achieved by amplifying and sequencing a 640 bp fragment of the mitochondrial COI gene. Phylogenetic analysis revealed that the Kerala isolate clustered closely with a Spanish isolate with strong bootstrap support, forming a distinct monophyletic clade. These findings suggest the reliability of the COI gene for accurate species-level identification and the need for surveillance of the impact of nasal bots on the health of wildlife.