Distribution of Aedes aegypti and Aedes albopictus in Turkey, determination of vector status and population genetics

Aedes aegypti (L., 1762) and Aedes albopictus (Skuse, 1895) (Diptera: Culicidae) are important vectors of arboviruses. In Turkey, Ae. albopictus was first identified in 2011 in the Thrace region of northwest part of Turkey. Resident populations of Ae. albopictus were revealed in the Black Sea region in 2015 and in the Aegean region in 2018. Ae. aegypti was re-reported in northeastern Turkey. In this thesis, the current distribution areas of these species were determined by both field and literature surveys, possible invasion routes of these species, possible origins and current vector status of these species were investigated by using population genetic parameters. For this purpose, the locations reported in the field studies and previous studies were used. Collected samples were identified morphologically and by band sizes obtained from the gel. The mitochondrial COI gene region for Ae. albopictus was used to detect possible invasion routes of the species and to reveal population genetics. For Ae. aegypti, due to limited samples, the genomic ITS2 gene region and two mitochondrial COI, one ND4 and one ND5 gene regions were used. In the results obtained, three haplotypes were determined for the Ae. albopictus COI gene region (Hap_1, Hap_2 and Hap_3) and Hap_1 was the most dominant haplotype and its presence was determined in all regions. Hap_2 was found only in Black Sea and Marmara samples, while Hap_3 was found only in Aegean samples. Significant differences were determined between Aegean, Marmara and Black Sea populations in the AMOVA test performed to test three possible invasions. The Fst test performed greatly supported the results of the AMOVA test. In the results made using world samples, it was determined that the possible origin of the Black Sea and Marmara lineages was determined as temperate lineage, while the possible origin of the Aegean region lineages was determined to be a mixture of temperate and tropical lineages. According to the AMOVA test results in studies conducted for Ae. aegypti species, no significant difference was observed between Turkey and Georgia samples. This situation revealed that the species in Turkey is a lineage of Georgian origin and that it is not a new invasion for Turkey. The data obtained showed that the genetic variation of the species decreased from east to west. It has been determined that some haplotypes are characterized only in the Black Sea and Caucasus regions. In the phylogenetic trees, Ae. aegypti lineages in the Black Sea region did not cluster with samples belonging to a specific region for each gene region. These results may indicate that the Ae. aegypti lineage in the Black Sea region may be a lineage dating back to the 1950s. In the studies conducted to investigate the possible vector status of the species, the presence of Rize and Çayeli West Nile virus and Ae. filavivirus in Artvin Hopa were detected for 2018. In 2019, the presence of West Nile virus was detected in Çayeli, Fındıklı, Arhavi Istanbul islands and Kırklareli samples, Ae. filavivirus in Fındıklı and Istanbul islands samples, and Cell fusing agent in Hopa samples.