Résumé
Accumulating evidence suggests that the diet of mosquitoes, particularly those derived from plants, may significantly impact their biology. These meals can influence various aspects of mosquito fitness, such as survival and fecundity, as well as their vector competence for pathogens. However, the precise mechanisms underlying the plant-mediated effects on vector capacity to transmit pathogens remain unknown.In light of global changes and the shifting spread of arboviruses in Europe, including the south of France, where autochthonous cases of chikungunya and dengue are on the rise, we hypothesize that specific plants growing in Occitanie (South of France) could influence the vector competence of Aedes albopictus.To test this hypothesis, we exposed newly emerged Ae. albopictus females for 5 days to different plant species (Lavandula angustifolia, Perovskia atriplicifolia, Scabiosa atropurpurea), and to water and sucrose solution as controls. Females were then subsequently challenged with chikungunya (CHIKV) and dengue (DENV) viruses using oral experimental infection procedures. Females that ingested a complete infectious blood meal (composed of viruses and blood erythrocytes) were then incubated for 7 and 14 days post infection (dpi). At each time point post-infection, 20-30 per condition were analysed using qPCR to detect and quantify viral genomes in their bodies (abdomen+thorax) and heads, respectively, to approximate the infection (IR) and the dissemination (DR) rates as proxies of the vector competence. Our initial results showed significant effects of mosquito diet on the vector competence, depending on the time points (7 vs. 14 dpi), the virus (DENV vs. CHIKV) and the tissue (body vs. head), but will need to be repeated to confirm them. These preliminary results suggest that plant species in Occitanie might have an impact on the vector competence of Ae. albopictus, which could warrant further investigation before considering implications for managing local arboviral transmission.