Information on the Release of Insects carrying a Dominant Lethal (RIDL) technology

Release of Insects carrying a Dominant Lethal (RIDL) is a method using recombinant DNA technology to create genetically modified insects for biological control. The dominant lethal gene kills the insects but it can be repressed by an external additive, which allows the insects to be reared in manufacturing facilities. This external additive is commonly administered orally, and so can be an additive to the insect food. The insects can also be given genetic markers, such as fluorescence, that make monitoring the progress of eradication easier.

There are potentially several types of RIDL, but the more advanced forms have a female-specific dominant lethal gene. This avoids the need for a separate sex separation step, as the repressor can be withdrawn from the final stage of rearing, leaving only males.

These males are then released in large numbers into the affected region. The released males are not sterile, but any female offspring their mates produce will have the dominant lethal gene expressed, and so will die. The number of females in the wild population will therefore decline, causing the overall population to decline.

Using RIDL means that the males will not have to be sterilized by radiation before release (as done with the "Sterile Insect Technique" (SIT) using radiation), making the males healthier when they need to compete with the wild males for mates.