Native entomopathogenic Metarhizium spp. from Burkina Faso and their virulence against the malaria vector Anopheles coluzzii and non-target insects

Background: Genetically enhanced Metarhizium pingshaense are being developed for malaria vector control in Burkina Faso. However, not much is known about the local prevalence and pathogenicity of this fungus, so we prospected mosquitoes and plant roots (a common habitat for Metarhizium spp.) for entomopathogenic fungi. Results: Our investigations showed that Metarhizium spp. represented between 29-74% of fungi isolated from plant root rhizospheres in diverse collection sites. At low spore dosages (1 x 10(6) conidia/ml), two mosquito-derived M. pingshaense isolates (Met_S26 and Met_S10) showed greater virulence against Anopheles coluzzii (LT80 of similar to 7 days) than isolates tested in previous studies (LT80 of similar to 10 days). In addition, the local isolates did not cause disease in non-target insects (honeybees and cockroaches). Conclusions: Our work provides promising findings for isolating local Metarhizium strains for application in mosquito biological control and for future transgenic biocontrol strategies in Burkina Faso.