Figure 1.

The concept of releasing sterile mosquitoes on a "rolling front" or "rolling carpet". Three phases of a release programme for the same areas are shown. Red mosquitoes represent natural populations, black ones sterile release areas and open boxes disinfested zones. The spatial direction of the releases and the accompanying disinfested areas expansion are indicated by the arrows. This also illustrates the "area-wide control" concept in that there is an increasing disinfested area in return for a continuous level of effort.