Mitochondrial DNA Intraspecific Variability in Sergentomyia minuta (Diptera: Psychodidae)

Area of Science:

• * Entomology and Parasitology: Focuses on the genetic diversity and phylogeography of sand fly populations.

Background:

• * Limited genetic data exists for the Sergentomyia genus, particularly for Sergentomyia minuta, a species known for morphological variation.
• * Previous hypotheses suggested two subspecies of Sergentomyia minuta based on cibarial teeth count, differing between European and North African populations.

Purpose of the Study:

• * To investigate the genetic structure and phylogeographic patterns of Sergentomyia minuta populations across the Mediterranean basin.
• * To analyze intra- and interpopulation genetic diversity using mitochondrial DNA sequences.

Main Methods:

• * Phylogeographic analysis of 29 Sergentomyia minuta populations from 10 countries.
• * Sequencing of mitochondrial DNA genes: cytochrome b (Cytb) and cytochrome C oxidase subunit I (COI).
• * Bayesian inference was employed to analyze genetic diversity and population structure.

Main Results:

• * Identification of a complex genetic structure within Sergentomyia minuta, comprising four distinct haplogroups.
• * Geographic clustering observed, with North African, Southern European, Balkan/Eastern Mediterranean, and Atlantic Savage Islands populations forming separate groups.
• * One haplogroup exclusively contained North African specimens, while others showed mixed distributions across Southern Europe and the Mediterranean islands.

Conclusions:

• * The genetic findings challenge the traditional subspecies classification of Sergentomyia minuta.
• * Results suggest a complex settlement history of Sergentomyia minuta in the Mediterranean basin, potentially coinciding with other sand fly species like Phlebotomus perniciosus and Phlebotomus ariasi.
• * The unexplained presence of a haplogroup in the Atlantic Savage Islands highlights the need for further research into sand fly dispersal mechanisms.