Figure 3

Challenges for the field release of transgenic mosquitoes. This scheme summarizes the ecological, behavioral and regulatory issues faced by disease control programs based on the release of genetically modified mosquitoes. Ecological requirements are shown in green, behavioral requirements in orange, while regulatory issues are presented in blue. Light-grey sections highlight operational tools that may be used to comply with the requirements. Behavioral requirements include key fitness parameters such as the dispersal ability and mating competitiveness of released males, and can be tested in large laboratory cage trials and then in semi-field settings to select the mosquito strains with the greatest probability of success. Ecological hurdles comprise heterogeneity in the genetics, behavior and natural habitats of vector species (biodiversity), and possible unintended side-effects on non-target species or on the ecosystem. Monitoring of these effects must be constantly in progress in the release phase. The risks, safety and specificity of the engineered strains need to be evaluated by appropriate regulatory agencies, and early public engagement is a priority.