Reverse genetics systems provide the opportunity to manipulate viral genomes and have been widely used to study RNA viruses and to develop new antiviral compounds and vaccine strategies. The recently described method called ISA (Infectious Subgenomic Amplicons) gives the possibility to rescue RNA viruses in days. We demonstrated in cell culture that the use of the ISA method led to a higher genetic diversity of viral populations than that observed using infectious clone technology. However, no replicative fitness difference was observed. In the present study, we used the chikungunya virus as a model to compare in Aedes aegypti and Aedes albopictus mosquitoes the genotypic and phenotypic characteristics of viruses produced either from an infectious clone or using the ISA method. We confirmed the results found in cellulo corroborating that the use of the ISA method was associated with higher genetic diversity of viral populations in mosquitoes but did not affect the vector competence validating its use for in vivo experiments.