Natural occurrence of entomopathogenic fungi in Burkina Faso and use in Spodoptera frugiperda biocontrol

The fall armyworm (FAW), Spodoptera frugiperda, a devastating invasive pest of maize and other crops, was first detected in Burkina Faso in 2017. Its rapid spread and the severe yield losses it causes have forced farmers to rely heavily on broad-spectrum chemical insecticides. This dependence raises serious concerns about environmental contamination, human health risks, insecticide resistance, and the disruption of natural pest regulation. Consequently, there is an urgent need to develop sustainable, environmentally benign integrated pest management strategies. The present study aimed to isolate and identify indigenous entomopathogenic fungi from FAW cadavers, with the ultimate goal of establishing a biological control strategy against this major pest within the context of a circular economy. FAW cadavers were collected from maize fields across several localities in Burkina Faso. The fungi were isolated on appropriate culture media and the recovered isolates were screened for pathogenicity against FAW larvae. The Isolates revealed fungi belonging to the genera Aspergillus, Penicillium, Fusarium, Cladosporium, Rhizopus, Macrophomina, Beauveria, and Metarhizium. Following pathogenicity screening, only isolates of the hypocrealean entomopathogens Beauveria and Metarhizium were retained due to their significant lethality against FAW larvae. Bioassays confirmed their efficacy, enabling the selection of the most potent isolates for further development. These isolates represent promising candidates for the development of a mycobiopesticide within a circular economy model. Future research should focus on the mass production, formulation, and field efficacy of the selected strains, as well as investigating their endophytic potential in crops and their activity against other key agricultural pests.