Poster Presentation First Malaria World Congress 2018

The nocturnal biting profile of Anopheles farauti in Far North Queensland, Australia (#257)

Weng K Chow 1 , Robert D Cooper 1 , Lisa M Rigby 1 , Paul Pickering 1 , Matthew Lokhorst 1 , Nigel W Beebe 2
  1. Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Queensland, Australia
  2. The University of Queensland and CSIRO, Brisbane, QLD, Australia

Anopheles farauti is one of the major vectors of malaria in the South West Pacific region and is believed responsible for past outbreaks in Australia. As one of several cryptic species revealed in the 1990s there is limited information available on the biting profile of An. farauti populations where it has never encountered insecticides and their associated selection pressures. We study An. farauti in natural populations in northern Australia to examine its natural biting behaviour using the human landing catch method (HLC) and Encephalitis Virus Surveillance (EVS) traps at the Cowley Beach Military Training Area in Far North Queensland through several seasonal time periods. Mosquitoes were collected hourly using HLC between 1800-0600h and for 24 hours using EVS traps. It was confirmed by EVS that An. farauti did not feed during the day between the times of 0600 and 1800h. The majority of An. farauti biting activity occurred before midnight (76%) with two biting peaks occurring between 1900-2000h (highest) and 2200-2300h. For the first time, we have shown the tight timing consistency of the first and last bite. The standard error for time of first bite and last bite in the dry season (Oct) was 1835h ± 1min (n=26), 0541h ± 4min (n=26) and in the wet season (Apr) was 1836h ± 5min (n=15) and 0609h ± 5min (n=14) respectively. Interestingly, there was a correlation between a reduction in the biting activity of An. farauti with decreasing temperature and increasing humidity. The highest densities of host seeking An. farauti occurred during the wet season and late in the dry season.