A FITNESS ADVANTAGE FOR AEDES-AEGYPTI AND THE VIRUSES IT TRANSMITS WHEN FEMALES FEED ONLY ON HUMAN BLOOD

Literature on arthropod-borne diseases has traditionally supported the notion that mosquito vectors maintain a feeding duality that includes vertebrate blood meals for egg development and sugar meals from plant s for the synthesis of flight and survival energy reserves. Aedes aegy pti was found to deviate from that feeding pattern by obtaining a repr oductive advantage when feeding only on human blood. Female mosquitoes fed human blood alone had a greater net replacement rate and intrinsi c rate of growth during all phases of their reproductive Life than con specifics fed human blood plus sucrose. Feeding frequently on human ho sts during each gonotrophic cycle is necessary to avoid death due to s tarvation and increases exponentially the spread of Ae. aegypti-borne disease. Our results help explain why Ae. aegypti is such an unusually efficient vector of human disease; frequent biting of humans results in a high reproductive rate for vectors as well as the viruses they tr ansmit.