title: Effects of a new outdoor mosquito control device, the mosquito landing box, on densities and survival of the malaria vector, Anopheles arabiensis, inside controlled semi-field settings.
abstract: BACKGROUND
  The significance of malaria transmission occurring outdoors has risen even in areas where indoor interventions such as long-lasting insecticidal nets and indoor residual spraying are common. The actual contamination rates and effectiveness of recently developed outdoor mosquito control device, the mosquito landing box (MLB), on densities and daily survival of host-seeking laboratory Anopheles arabiensis, which readily bites humans outdoors was demonstrated.
  
  
  METHODS
  Experiments were conducted in large semi-field systems (SFS) with human volunteers inside, to mimic natural ecosystems, and using MLBs baited with natural or synthetic human odours and carbon dioxide. The MLBs were dusted with 10% pyriproxyfen (PPF) or entomopathogenic fungi (Metarhizium anisopliae) spores to mark mosquitoes physically contacting the devices. Each night, 400 laboratory-reared An. arabiensis females were released in one SFS chamber with two MLBs, and another chamber without MLBs (control). Mosquitoes were individually recaptured while attempting to bite volunteers inside SFS or by aspiration from SFS walls. Mosquitoes from chambers with PPF-treated MLBs and respective controls were individually dipped in water-filled cups containing ten conspecific third-instar larvae, whose subsequent development was monitored. Mosquitoes recaptured from chambers with fungi-treated MLBs were observed for fungal hyphal growth on their cadavers. Separately, effects on daily survival were determined by exposing An. arabiensis in chambers having MLBs treated with 5% pirimiphos methyl compared to chambers without MLBs (control), after which the mosquitoes were recaptured and monitored individually until they died.
  
  
  RESULTS
  Up to 63% (152/240) and 43% (92/210) of mosquitoes recaptured inside treatment chambers were contaminated with pyriproxyfen and M. anisopliae, respectively, compared to 8% (19/240) and 0% (0/164) in controls. The mean number of larvae emerging from cups in which adults from chambers with PPF-treated MLBs were dipped was significantly lower [0.75 (0.50-1.01)], than in controls [28.79 (28.32-29.26)], P < 0.001). Daily survival of mosquitoes exposed to 5% pirimiphos methyl was nearly two-fold lower than controls [hazard ratio (HR) = 1.748 (1.551-1.920), P < 0.001].
  
  
  CONCLUSIONS
  High contamination rates in exposed mosquitoes even in presence of humans, demonstrates potential of MLBs for controlling outdoor-biting malaria vectors, either by reducing their survival or directly killing host-seeking mosquitoes. The MLBs also have potential for dispensing filial infanticides, such as PPF, which mosquitoes can transmit to their aquatic habitats for mosquito population control.
authors.affiliation: Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania. ammbando@ihi.or.tz.
authors.forename: Arnold S
authors.initials: AS
authors.lastname: Mmbando
authors.affiliation: Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania. fredros@ihi.or.tz.|Faculty of Health Sciences, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa. fredros@ihi.or.tz.
authors.forename: Fredros O
authors.initials: FO
authors.lastname: Okumu
authors.affiliation: Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania. jmgando@ihi.or.tz.
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Mgando
authors.affiliation: Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania. rsumaye@ihi.or.tz.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Sumaye
authors.affiliation: Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania. nstephen@ihi.or.tz.|Faculty of Health Sciences, School of Pathology, University of the Witwatersrand, Johannesburg, South Africa. nstephen@ihi.or.tz.
authors.forename: Nancy S
authors.initials: NS
authors.lastname: Matowo
authors.affiliation: Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania. emadumla@ihi.or.tz.
authors.forename: Edith
authors.initials: E
authors.lastname: Madumla
authors.affiliation: Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania. ekaindoa@ihi.or.tz.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Kaindoa
authors.affiliation: Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania. skiware@ihi.or.tz.|Department of Mathematics, Statistics and Computer Science, Marquette University, Milwaukee, WI, USA. skiware@ihi.or.tz.
authors.forename: Samson S
authors.initials: SS
authors.lastname: Kiware
authors.affiliation: Environmental Health and Ecological Sciences Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania. dwilson@ihi.or.tz.|Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK. dwilson@ihi.or.tz.
authors.forename: Dickson W
authors.initials: DW
authors.lastname: Lwetoijera
mesh_terms: D000328:Adult; D000818:Animals; D000852:Anopheles / Q000254:growth & development*; D005260:Female; D006801:Humans; D007303:Insect Vectors; D007306:Insecticides / Q000494:pharmacology; D008297:Male; D052981:Metarhizium / Q000254:growth & development; D009032:Mosquito Control / Q000295:instrumentation* / Q000379:methods*; D016019:Survival Analysis
chemical_list: D007306:Insecticides