This technology is a transgenic method of controlling arthropod pest and disease vectors such as mosquito populations, by manipulating reproductive viability. Some strains of the intracellular Wolbachia bacterium found naturally in some arthropods can been used to control pest populations by altering reproductive success. The presence of this bacterium in males can lead to the death of offspring, when these males mate with uninfected females. Two of the genes in the Wolbachia bacterium which induce this loss of offspring viability have been identified. Our data reveals that these genes can be directly expressed in arthropods to have a similar effect in the absence of the bacterium. This technology can be used to transgenically target and reduce arthropod populations.