Identification of sympatric cryptic species of Aedes albopictus subgroup in Vietnam: new perspectives in phylosymbiosis of insect vector

The Aedes (Stegomyia) albopictus subgroup includes 11 cryptic species of which Ae. albopictus is the most widely distributed. Its global expansion associated with a documented vector competence for several currently emerging arboviruses raise obvious concerns in the recently colonized regions. While several studies have provided important insights regarding the biology, biogeography and medical importance of Ae. albopicus species, the investigations of the several other sibling species are scarse. In Asia, distinct indigenous populations within the Ae. albopictus subgroup can be found in sympatry. Based on morphological structure of the cibarial armarture, we identify a cryptic species in the protected forest national park at Bù Gia Mập in South-Eastern region at the province of Binh Phuoc, South of Vietnam. Analysis of nuclear (ITS1-5.8S-ITS2) and mitochondrial (CO1, ND5) markers confirmed the divergence of the two species. Analysis of midgut bacterial microbiota revealed a strong similarity among the two species with a notable difference; contrary to Ae. albopictus, the cryptic species did not harbour any Wolbachia infection. These results could reflect either a recent invasion of Wolbachia in Ae. albopictus species or alternatively a loss of this symbiont in the cryptic species. We argue that neglected species of the Ae. albopictus subgroup are of main importance in order to estimate variation of host-symbionts interactions across evolution.