First record of Culex (Culex) acharistus Root, 1927 (Diptera: Culicidae) in Bolivia: morphological and molecular confirmation across contrasting Andean environments

Abstract

This study reports the first record of Culex (Culex) acharistus Root, 1927 in Bolivia, based on an integrative approach combining larval morphology and molecular identification using a fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Specimens were collected from 4 localities representing contrasting environmental settings: La Paz (urban environment, approximately 3,600 m a.s.l.), El Alto (urban environment, approximately 4,000 m a.s.l.), Cochabamba (urban and peri-urban environments, approximately 2,600 m a.s.l.), and Licoma, a rural locality in the Yungas region (approximately 1,900 m a.s.l.). Fourth-instar larvae were morphologically examined using diagnostic characters and preserved for molecular analyses. The 6 analyzed specimens shared an identical COI haplotype, showing more than 99% sequence identity with available Cx. acharistus sequences in GenBank. Maximum likelihood phylogenetic analysis placed the Bolivian haplotype within the Cx. acharistus clade. These results provide morphological and molecular evidence for the occurrence of Cx. acharistus in Bolivia, extend its known distribution in South America, and document the species at its highest elevation reported to date, at approximately 4,000 m a.s.l. in El Alto. This study highlights the value of integrating morphological and molecular approaches for reliable identification of Neotropical Culex species.