Poster Presentation First Malaria World Congress 2018

On the origins and spread of differences in human host preference in a group of malaria transmitting mosquitoes (#223)

Luke Ambrose 1 , Daniel Ortiz-Barrientos 1 , Tom Burkot 2 , Tanya Russell 2 , Neil F Lobo 3 , Robert D Cooper 4 , Nigel W Beebe 1
  1. The University of Queensland, Saint Lucia, QUEENSLAND, Australia
  2. James Cook University, Cairns, Queensland, Australia
  3. Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
  4. Army Malaria Institute, Brisbane, Queensland, Australia

Host preference is a trait that varies widely between species of mosquitoes, and is an important factor contributing to their capacity to transmit human disease. Anopheles hinesorum (formally An. farauti 2) is a mosquito species that has population level differences in its ability to detect humans as hosts. Throughout most of its range An. hinesorum bites humans, and the use of humans as is believed to be an ancestral trait. However, some populations in the Solomon Archipelago  have evolved to be non-human biting. Specifically, there are two highly divergent mitochondrial lineages, both of which exhibit non-human biting in different parts of the Solomon Archipelago. We explore the possibility that this derived non-human biting trait has been transferred between these lineages via gene flow rather than it evolving independently as has been previously suggested. We use microsatellite data and assess genetic relationships between populations of the species from throughout its range, including between the non-human biting populations from these divergent mitochondrial lineages. We also examine genetic relationships between a previously unstudied human biting Solomon Island Western Province population and the rest of the species. Based on the data presented, we propose that there has been human mediated transport of females from PNG (where An. hinesorum is human feeding), into the Solomon Island Western Province population. This introduction has likely resulted in the human biting trait becoming established in this part of the Solomon Islands. If this localized human biting trait spreads through the Solomon Islands, An. hinesorum, with its larval site selection plasticity, may emerge as a new malaria vector in this region.