The potential for fungal biopesticides to reduce malaria transmission under diverse environmental conditions

Rebecca L. Heinig, Krijn Paaijmans, Penelope A. Hancock, Matthew B. Thomas

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The effectiveness of conventional malaria vector control is being threatened by the spread of insecticide resistance. One promising alternative to chemicals is the use of naturally occurring insect-killing fungi. Numerous laboratory studies have shown that isolates of fungal pathogens such as Beauveria bassiana can infect and kill adult mosquitoes, including those resistant to chemical insecticides. Unlike chemical insecticides, fungi may take up to a week or more to kill mosquitoes following exposure. This slow kill speed can still reduce malaria transmission because the malaria parasite itself takes at least eight days to complete its development within the mosquito. However, both fungal virulence and parasite development rate are strongly temperature-dependent, so it is possible that biopesticide efficacy could vary across different transmission environments. We examined the virulence of a candidate fungal isolate against two key malaria vectors at temperatures from 10 to 34 °C. Regardless of temperature, the fungus killed more than 90% of exposed mosquitoes within the predicted duration of the malarial extrinsic incubation period, a result that was robust to realistic diurnal temperature variation. We then incorporated temperature sensitivities of a suite of mosquito, parasite and fungus life-history traits that are important determinants of malaria transmission into a stage-structured malaria transmission model. The model predicted that, at achievable daily fungal infection rates, fungal biopesticides have the potential to deliver substantial reductions in the density of malaria-infectious mosquitoes across all temperatures representative of malaria transmission environments. Synthesis and applications. Our study combines empirical data and theoretical modelling to prospectively evaluate the potential of fungal biopesticides to control adult malaria vectors. Our results suggest that Beauveria bassiana could be a potent tool for malaria control and support further development of fungal biopesticides to manage infectious disease vectors. Our study combines empirical data and theoretical modelling to prospectively evaluate the potential of fungal biopesticides to control adult malaria vectors. Our results suggest that Beauveria bassiana could be a potent tool for malaria control and support further development of fungal biopesticides to manage infectious disease vectors.

Original languageEnglish (US)
Pages (from-to)1558-1566
Number of pages9
JournalJournal of Applied Ecology
Volume52
Issue number6
DOIs
StatePublished - Dec 1 2015
Externally publishedYes

Fingerprint

biopesticide
malaria
environmental conditions
mosquito
fungus
disease vector
insecticide
parasite
temperature
infectious disease
virulence
life history trait
modeling

Keywords

  • Anopheles stephensi
  • Beauveria bassiana
  • Plasmodium falciparum
  • Plasmodium vivax
  • Anopheles gambiae
  • Biocontrol
  • Extrinsic incubation period
  • Malaria transmission model
  • Temperature

ASJC Scopus subject areas

  • Ecology

Cite this

The potential for fungal biopesticides to reduce malaria transmission under diverse environmental conditions. / Heinig, Rebecca L.; Paaijmans, Krijn; Hancock, Penelope A.; Thomas, Matthew B.

In: Journal of Applied Ecology, Vol. 52, No. 6, 01.12.2015, p. 1558-1566.

Research output: Contribution to journalArticle

Heinig, Rebecca L. ; Paaijmans, Krijn ; Hancock, Penelope A. ; Thomas, Matthew B. / The potential for fungal biopesticides to reduce malaria transmission under diverse environmental conditions. In: Journal of Applied Ecology. 2015 ; Vol. 52, No. 6. pp. 1558-1566.
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