Descriptive and Geometric Morphometry of the Wings of Phlebotomus sergenti Populations in Central Morocco.

Background: Phlebotomus sergenti, the proven vector of Leishmania tropica, the causative agent of anthroponotic cutaneous leishmaniasis, is widely distributed in Morocco. Previous works using molecular markers (Internal Transcribed Spacer 2 rDNA and Cytochrome B mtDNA) hypothesized the existence of multiple closely related populations of sand fly species (cryptic species) that would exhibit distinct vectorial capacities. This work studies morphotypic diversity using traditional and geometric morphometry analyses carried out on Ph. sergenti's wings from central Morocco, where active L. tropica transmission occurs for 30 years. Methods: Descriptive characteristics (size and shape) of the right wings were measured in Ph. sergenti's specimens collected from fourteen stations in central Morocco. Both traditional and geometric morphometry methods were used to analyse geographic variations in Ph. sergenti wing's size and shape. Results: These analyses support the existence of distinct Ph. sergenti populations, enlightening significant phenotypic variations of Ph. sergenti's wings, regarding their size and shape, depending on geographic origin. In addition, traditional and geometric morphometric analyses of the wing's length, centroid size, β, ɵ, and γ distances allowed clear discrimination of Ph. sergenti sub-populations. Conclusion: These data pinpoint the adaptative ability of Ph. sergenti to local environmental conditions. Additional studies are now required to further shed light on the genetic structure of Ph. sergenti populations in Morocco.