title: Exploiting the behaviour of wild malaria vectors to achieve high infection with fungal biocontrol agents.
abstract: BACKGROUND
  Control of mosquitoes that transmit malaria has been the mainstay in the fight against the disease, but alternative methods are required in view of emerging insecticide resistance. Entomopathogenic fungi are candidate alternatives, but to date, few trials have translated the use of these agents to field-based evaluations of their actual impact on mosquito survival and malaria risk. Mineral oil-formulations of the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were applied using five different techniques that each exploited the behaviour of malaria mosquitoes when entering, host-seeking or resting in experimental huts in a malaria endemic area of rural Tanzania.
  
  
  RESULTS
  Survival of mosquitoes was reduced by 39-57% relative to controls after forcing upward house-entry of mosquitoes through fungus treated baffles attached to the eaves or after application of fungus-treated surfaces around an occupied bed net (bed net strip design). Moreover, 68 to 76% of the treatment mosquitoes showed fungal growth and thus had sufficient contact with fungus treated surfaces. A population dynamic model of malaria-mosquito interactions shows that these infection rates reduce malaria transmission by 75-80% due to the effect of fungal infection on adult mortality alone. The model also demonstrated that even if a high proportion of the mosquitoes exhibits outdoor biting behaviour, malaria transmission was still significantly reduced.
  
  
  CONCLUSIONS
  Entomopathogenic fungi strongly affect mosquito survival and have a high predicted impact on malaria transmission. These entomopathogens represent a viable alternative for malaria control, especially if they are used as part of an integrated vector management strategy.
authors.affiliation: Biomedical and Environmental Group, Ifakara Health Institute, P.O. Box 53, Off Mlabani Passage, Ifakara, Tanzania.
authors.forename: Ladslaus L
authors.initials: LL
authors.lastname: Mnyone
authors.forename: Issa N
authors.initials: IN
authors.lastname: Lyimo
authors.forename: Dickson W
authors.initials: DW
authors.lastname: Lwetoijera
authors.forename: Monica W
authors.initials: MW
authors.lastname: Mpingwa
authors.forename: Nuru
authors.initials: N
authors.lastname: Nchimbi
authors.forename: Penelope A
authors.initials: PA
authors.lastname: Hancock
authors.forename: Tanya L
authors.initials: TL
authors.lastname: Russell
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Kirby
authors.forename: Willem
authors.initials: W
authors.lastname: Takken
authors.forename: Constantianus J M
authors.initials: CJ
authors.lastname: Koenraadt
mesh_terms: D000818:Animals; D000852:Anopheles / Q000382:microbiology / Q000502:physiology; D052982:Beauveria / Q000502:physiology*; D061046:Biological Control Agents; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D007303:Insect Vectors / Q000382:microbiology / Q000502:physiology; D057148:Insecticide-Treated Bednets; D008288:Malaria / Q000635:transmission; D052981:Metarhizium / Q000502:physiology*; D009032:Mosquito Control; D016019:Survival Analysis; D013636:Tanzania
chemical_list: D061046:Biological Control Agents