After many years of open discussion and development, the first genetically modified (GM) insect strains are entering field trials. A key engineered trait renders the insects “genetically sterile”, such that some or all of their offspring die; the insects additionally carry a fluorescent marker gene for easy identification. Such “genetic sterility” transgenes (in genetic terms, conditional dominant lethal genes) are not able to establish or spread in the wild due to their high fitness cost; such self-limiting strategies are widely viewed as the lowest risk category.

Vector-borne diseases impose enormous health and economic burdens and additional methods to control vector populations are clearly needed. The Sterile Insect Technique (SIT) has been successful against agricultural pests, but is not in large-scale use for suppressing or eliminating mosquito populations.