Expanded range of Haemagogus leucocelaenus in yellow fever hotspots: new findings from Santa Catarina State, southern Brazil.

Abstract

Background: The Haemagogus genus includes nine mosquito species reported in Brazil, each with distinct distribution patterns. Haemagogus leucocelaenus, a major yellow fever vector, is widely distributed throughout the country, while Haemagogus leucophoebus, a morphologically similar species, has only been identified in Acre State.

Objectives: This study evaluated the presence of Haemagogus species in southern Brazil by comparing their morphological and molecular characteristics.

Methods: Mosquitoes were collected from five municipalities in southern Santa Catarina State, Brazil. Each specimen was identified morphologically and photographed. Genomic DNA was extracted, and a Cytochrome C Oxidase Subunit I (COI) gene fragment was amplified using polymerase chain reaction (PCR). The positive amplicons were sequenced for molecular identification.

Findings: New records of Hg. leucocelaenus were found in Santa Rosa de Lima, Rio Fortuna, Braço do Norte, São Martinho, and Pedras Grandes, located at the southern edge of the Atlantic Forest. This study expands the known distribution of Hg. leucocelaenus, the only Haemagogus species identified in the area, with 91 specimens collected. Although some specimens exhibited morphological variations that might lead to misidentification as Hg. leucophoebus, molecular identification confirmed that all were Hg. leucocelaenus.

Main conclusions: This study is the first to report Hg. leucocelaenus in Santa Catarina, Brazil, and provides DNA barcoding sequences from southern Brazil. This method offers a reliable alternative for species identification, especially when combined with morphological analysis. Further molecular studies are needed to determine whether the morphological variations observed indicate intraspecific differences.