Can natural enemies control the fall armyworm in West Africa?
Besmer régis Ahissou1, Wendnéyidé Mathieu Sawadogo2, Schémaéza Bonzi3, Kossi Hugues BaÏmey4, Aimé H. Bokonon-Ganta5, Irénée Somda3, François Verheggen1
1University of Liège, Gembloux Agro-Bio Tech., Belgium
The fall armyworm Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is a major polyphagous pest native to the tropical Americas. Since its arrival in sub-Saharan Africa in 2016, it has threatened food security through damage to maize and other crops of economic importance. Knowledge about natural enemies and their potential to control this new pest in Africa is still limited. In this study, we aimed to identify local natural enemies that control this pest in Burkina Faso and to evaluate the predation potential of earwigs in the laboratory. Through surveys conducted in about 50 maize fields naturally infested by the pest in the provinces of Houet and Kadiogo, we collected eggs, larvae and predatory arthropods of the pest. Parasitoids, larval parasites and predators collected in the field were identified using various identification keys and databases from GBIF (Global Biodiversity Information Facility) and CABI (Centre for Agricultural Bioscience International). We identified 12 natural enemy species associated with the fall armyworm in Burkina Faso. Nematodes (Mermithidae) were the most frequent parasites (73.2% of parasitized larvae). Parasitoids included Coccygidium luteum (Brullé), Chelonus bifoveolatus (Szépligeti) and Drino sp. Among predators, Carabidae (Calleida sp.), Coccinellidae (Cheilomenes sulphurea (Olivier)), Forficulidae (Diaperasticus erythrocephalus (Olivier), Forficula senegalensis (Serville)), Formicidae (Pheidole megacephala (Fabricius) and others), Mantidae, Pentatomidae, Reduviidae (Rhynocoris sp.) have been encountered. Among the predators, earwigs were the most abundant (51%) in untreated maize fields. An adult consumed an average of 71.6 ± 23.4 eggs and 36.5 ± 8.7 L1 larvae of S. frugiperda per day. In this context, the training of producers on the recognition of natural enemies and cultural practices likely to preserve them is an option to develop conservation biological control against this pest.
Keywords: Biological control, entomopathogenic nematode, parasitoids, predation potential, Spodoptera frugiperda
Contact Address: Besmer régis Ahissou, University of Liège, Gembloux Agro-Bio Tech., Liège, Belgium, e-mail: besmernicgmail.com