Systems and breeding methods for pest control

A method for controlling population of a wild biological species, the method comprising:

• releasing into a wild population of the wild biological species a system for controlling the population of the wild biological species, the system comprising:
• a population of genetically-modified individuals of the biological species, the population comprising a first sex and a second sex, the genetically-modified individuals comprising:
• a repressible genetic mutation that results in:
• death of a juvenile individual of the first sex when the juvenile individual of the first sex comprises the repressible lethal mutation and is reared in the absence of a repressor;
• or
• sterility of an individual of the first sex when the individual of the first sex comprises the repressible lethal mutation and is reared in the absence of a repressor;
• and
• an underdominant genetic mutation so that:
• offspring of a mating between a member of the system and a wild-type member of the biological species are nonviable;
• and
• offspring of a mating between two members of the system results in viable offspring only of the second sex;
• and
• allowing members of the system subpopulations mate with wild members of the biological species in the absence of the repressor.