Chrysomya albiceps (Diptera: Calliphoridae) associated with cutaneous myiasis in sheep from Uruguay: Molecular evidence supporting a potential primary role

Cutaneous myiasis is a major parasitic condition affecting sheep production worldwide. In Uruguay, it has traditionally been attributed to Cochliomyia hominivorax as the obligate primary agent, whereas Chrysomya albiceps has been regarded as a secondary species. The aim of this study was to report two cases of cutaneous myiasis associated with Chrysomya albiceps in sheep in Uruguay, supported by morphological identification and representing the first molecular confirmation of this species in ovine myiasis in the country, and to discuss its potential role as a primary agent. Larvae were collected from lesions in two affected sheep from different locations and identified as C. albiceps using morphological keys. Molecular confirmation was obtained by amplification and sequencing of a 658 bp fragment of the mitochondrial COI gene, followed by BLASTn and phylogenetic analysis. BLASTn comparisons showed >99% identity with the reference sequences of C. albiceps. Phylogenetic analysis grouped the Uruguayan sequences together with sequences of C. albiceps from other regions, with high bootstrap support. Monospecific infestations and concordant morphological and molecular evidence support the potential role of C. albiceps as a primary agent of cutaneous myiasis in sheep in Uruguay. These findings highlight the need for further surveillance to clarify the epidemiology and impact of this species.