Wing morphology variations in Culicoides circumscriptus from France

Area of Science:

• Entomology
• Ecology
• Evolutionary Biology

Background:

• Culicoides circumscriptus is a widespread European vector of avian malaria and a potential vector for Akabane and Bluetongue viruses.
• This midge species inhabits diverse environments with significant seasonal changes.
• Understanding its phenotypic variation is crucial for assessing disease transmission dynamics.

Purpose of the Study:

• To investigate phenotypic variation in Culicoides circumscriptus populations across three French departments (Corsica, Moselle, Var).
• To determine if environmental factors influence the observed phenotypic differences in C. circumscriptus.

Main Methods:

• Geometric morphometrics was employed to analyze wing phenotypes using anatomical landmarks and outlines.
• Dendrogram analysis based on landmarks and specific wing outline sets (outlines-2) revealed population separation.
• Comparison with a different wing outline set (outlines-1) showed alternative clustering patterns.

Main Results:

• Wing phenotype analysis using geometric morphometrics revealed distinct variations among Culicoides circumscriptus populations.
• Dendrograms indicated population differentiation based on wing morphology, particularly with the outlines-2 dataset.
• The study identified environmental and ecological pressures contributing to the observed phenotypic variation.

Conclusions:

• Phenotypic variation in Culicoides circumscriptus populations suggests adaptation to local environmental conditions.
• The findings support the presence of phenotypic plasticity in this biting midge species.
• This plasticity may influence the vector competence and distribution of diseases transmitted by C. circumscriptus.