Ecological effects on underdominance threshold drives for vector control.

•Two engineered underominance systems for mosquito control are investigated.•Male-only releases must be larger than bi-sex releases to trigger the gene drive.•Female-specific lethality averts more disease cases than bi-sex lethality.•Genetic lethality efficiency is less important than ambient transgene fitness cost.•Mating success and longevity of engineered insects strongly governs drive success.