Aedes unalom sp. nov. in Cambodia, a new Stegomyia species close to Aedes albopictus (Diptera, Culicidae)

Abstract

Preliminary genetic analysis of cytochrome c oxidase subunit 1 (COI) gene of specimens initially assigned to the mosquito Aedes albopictus based on morphology revealed two clusters. This observation led to further genetic and morphological analysis: a total of 86 Stegomyia specimens identified morphologically as Ae. (Stegomyia) albopictus, were collected between 2017 and 2019 in Cambodia. Their mitochondrial DNA COI gene and 5.8S-ITS2 rDNA were sequenced for molecular characterization and genetic analysis as well as Wolbachia presence/type. In 2022, additional Stegomyia specimens were collected for COI sequencing and morphological characterization. Of the 86 Stegomyia specimens, 14 specimens had divergent COI and 5.8S-ITS2 sequences compared to other Stegomyia species, and were negative for the presence of Wolbachia, unlike Ae. albopictus specimens which carried wAlbA and/or wAlbA B types. Additional trapping in 2022 resulted in the colletion of 11 specimens with similar divergent COI and 5.8S-ITS2 sequences. Sequence blast results did not match these COI and 5.8S-ITS2 sequences, neither within Stegomyia taxa nor other organisms. Lastly, after morphological examinations, specific characters were observed in adult mosquitoes and male genitalia, allowing the specimens to be described as a new Stegomyia species named Aedes unalom Maquart & Hide, sp. nov. This species lives in sympatry with other Stegomyia species such as Ae. albopictus or Ae. aegypti and does not carry Wolbachia. This new species should be considered as a potential arbovirus vector.