Before revision:  Hybridisation levelsand release numbers of mosquitoes as a function of intervention duration and target are calculated  .
After revision:  Hybridisation levelsand release numbers of mosquitoes as a function of intervention duration and target are calculated under different hypotheses with regard to the fitness of hybrids and compared with two field studies of actual interventions. The minimal model should serve as a basis for detailed models when the necessary information to construct them is produced. For the time being, the model shows that nature will not clean the non-lethal introgressed genes .