Two new genetic-sexing strains of Anopheles albimanus Wiedemann are described and compared to previously existing strains. Each of the genetic-sexing systems was synthesized by organizing propoxur resistance, a T (Y;2R) translocation, and an In (2R) inversion in an aberration complex that pseudolinks resistance to the Y chromosome and suppresses recombination during meiosis in the male. A discussion of the genetic sexing of mosquitoes is included which details the prerequisites for developing a genetic sexing system, the essential steps for maintaining such a system, and genetic phenomena that could cause problems for the genetic sexing system.