Short report
An extra-domiciliary method of delivering entomopathogenic fungus, Metharizium anisopliae IP 46 for controlling adult populations of the malaria vector, Anopheles arabiensis
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* Corresponding author: Dickson W Lwetoijera dwilson@ihi.or.tz
1 Biomedical and Environmental Thematic Group, Ifakara Health Institute, PO Box 53, Ifakara, Tanzania
2 Department of Zoology and Wildlife Conservation, University of Dar es Salaam, PO Box 35091, Dar es Salaam, Tanzania
3 Pest Management Center, Sokoine University of Agriculture, PO Box 3110, Morogoro, Tanzania
4 Laboratory of Entomology, Wageningen University & Research Centre, PO Box 8031, 6700 EH, Wageningen, The Netherlands
5 Vector Group, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
6 London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E, 7HT, UK
Parasites & Vectors 2010, 3:18 doi:10.1186/1756-3305-3-18
Published: 16 March 2010Abstract
Fungal biopesticides have the potential to significantly reduce densities of malaria vectors as well as associated malaria transmission. In previous field trials, entomopathogenic fungus was delivered from within human dwellings, where its efficacy was limited by low infection rates of target mosquitoes, high costs of spraying fungus inside houses, and potential public health concerns associated with introducing fungal conidia inside houses. Here we have demonstrated that Metarhizium anisopliae IP 46, delivered within an extra-domiciliary odor-baited station (OBS), can infect and slowly-kill a high proportion of the wild adult malaria vector, Anopheles arabiensis which entered and exited the OBS. This study, carried out in rural Tanzania, showed that by using a concentration of 3.9 × 1010 conidia/m2, more than 95% of mosquitoes that flew in and out of the OBS died within 14 days post-exposure. At least 86% infection of mosquito cadavers was recorded with a significant reduction in the probability of daily survival of exposed An. arabiensis in both treatments tested: low quantity of conidia (eave baffles plus one cotton panel; HR = 2.65, P < 0.0001) and high quantity of conidia (eave baffles plus two cotton panels; HR = 2.32, P < 0.0001). We conclude that high infection rates of entomopathogenic fungi on wild malaria vectors and possibly significant disruption of malaria transmission can be achieved if the fungus is delivered using optimally located outdoor odor-baited stations.