This study examined whether Aedes aegypti extends its human blood seeking activity into night hours. Human landing catches (HLC) were conducted hourly from early morning (04:30) to late evening (21:30) in urban and rural sites in Kisumu County in western Kenya, and in Kwale County at the coast. Out of 842 female Ae. aegypti mosquitoes, 71 (8.5%) were collected at night (nocturnal), 151 (17.9%) at twilight (crepuscular), and 620 (73.6%) during the day (diurnal). Three-fold and significantly more Ae. aegypti female mosquitoes were collected during the twilight (crepuscular) hours than night (nocturnal) hours. Significantly more Ae. aegypti female mosquitoes were collected during daytime (diurnal) than night time (nocturnal). In general, the number of mosquitoes collected reduced as darkness increased. Extended time into the night to seek for blood meals enhances chances for Ae. aegypti to contact humans and transmit arboviruses diseases.
Address correspondence to Bryson Alberto Ndenga, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya. E-mail: email@example.com
Financial support: This study was funded by a program award RO1 AI102918 from the National Institutes of Health, Bethesda, MD to A. D. L.
Authors’ addresses: Bryson Alberto Ndenga and Joel Omari Mbakaya, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya, E-mails: firstname.lastname@example.org and email@example.com. Francis Maluki Mutuku, Department of Environment and Health Sciences, Technical University of Mombasa, Mombasa, Kenya, E-mail: firstname.lastname@example.org. Harun Njenga Ngugi, Department of Biological Sciences, Chuka University, Chuka, Kenya, E-mail: email@example.com. Dunstan Mukoko, Vector Borne Disease Control Unit, Nairobi, Kenya, E-mail: firstname.lastname@example.org. Uriel Kitron, Department of Environmental Sciences, Emory University, Atlanta, GA, E-mail: email@example.com. Angelle Desiree LaBeaud, Department of Pediatrics, Stanford University, Stanford, CA, E-mail: firstname.lastname@example.org.