Combining transinfected Wolbachia and a genetic sexing strain to control Aedes albopictus in laboratory-controlled conditions

The global expansion of Aedes albopictus has stimulated the development of environmental-friendly methods aiming at controlling disease transmission through the suppression of natural vector populations. Sterile male release programs are currently being deployed worldwide, and are challenged by the availability of an efficient sex separation that can be achieved mechanically at the pupal stage and/or by artificial intelligence at the adult stage, or through genetic sexing, which allows separating males and females at an early development stage. In this study, we combined the genetic sexing strain (GSS) previously established based on the linkage of dieldrin resistance to the male locus with a Wolbachia transinfected line. For this, we introduced either the wPip-I or the wPip-IV strain from Culex pipiens in an asymbiotic-Wolbachia-free Ae. albopictus line. We then measured the penetrance of CI and life history traits of both transinfected lines, selected the wPip-IV line, and combined it with the GSS. Population suppression experiments demonstrated a 90% reduction in population size and a 50% decrease in hatching rate. Presented results showed that such a combination has a high potential in terms of vector control but also highlighted associated fitness costs, which should be reduced before large-scale field assay.