Field Trials with a Translocation Homozygote in Aedes aegypti for Population Replacement1

Abstract

Translocation homozygote strains of the yellowfever mosquito carrying several genetic markers were released in villages near Mombasa on the Kenya coast in an attempt to replace the indigenous populations by the introduced strains. A translocation strain marked with red eye was recovered in very low numbers after releases. However, when a strain marked with wild-type eye color was released, it readily entered houses and laid eggs in ovitraps. Translocation progeny were rarely obtained from natural breeding containers and none of the translocation strains became established in the field. Fitness studies conducted in the field and the laboratory showed that the translocation strains were deficient in fertility, larval development time, larval and adult survival, and mating competitiveness. Experiments also demonstrated that, when a choice was offered, native females laid 90% of their eggs in natural breeding sites while females carrying the translocation preferred ovitraps, laying 62% of their eggs in these sampling containers.