| Title: | Competitive Plant-Mediated and Intraguild Predation Interactions of the Invasive Spodoptera frugiperda and Resident Stemborers Busseola fusca and Chilo partellus in Maize Cropping Systems in Kenya |
| Author(s): | Mutua JM; Mutyambai DM; Asudi GO; Khamis F; Niassy S; Jalloh AA; Salifu D; Magara HJO; Calatayud PA; Subramanian S; |
| Address: | "International Centre of Insect Physiology and Ecology, Nairobi P.O. Box 30772-00100, Kenya. Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, Nairobi P.O. Box 43844-00100, Kenya. CNRS, IRD, UMR Evolution, Genomes, Comportement et Ecologie, Universite Paris-Saclay, 91198 Paris, France" |
| ISSN/ISBN: | 2075-4450 (Print) 2075-4450 (Electronic) 2075-4450 (Linking) |
| Abstract: | "Following its recent invasion of African countries, fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), now co-exists with resident stemborers such as Busseola fusca (Lepidoptera: Noctuidae) and Chilo partellus (Lepidoptera: Crambidae) causing severe damage to maize crops. Due to niche overlap, interspecific interactions occur among the three species, but the mechanisms and degree remain unclear. In this study, we assessed plant-mediated intraspecific and interspecific interactions, predation in laboratory and semi-field settings, and larval field occurrence of S. frugiperda and the two stemborer species. Larval feeding assays to evaluate competitive plant-mediated interactions demonstrated that initial S. frugiperda feeding negatively affected subsequent stemborer larval feeding and survival, suggesting induction of herbivore-induced mechanisms by S. frugiperda, which deters establishment and survival of competing species. Predation assays showed that, at different developmental larval stages, second-sixth instars of S. frugiperda preyed on larvae of both B. fusca and C. partellus. Predation rates of S. frugiperda on stemborers was significantly higher than cannibalism of S. frugiperda and its conspecifics (p < 0.001). Cannibalism of S. frugiperda in the presence of stemborers was significantly lower than in the presence of conspecifics (p = 0.04). Field surveys showed a significantly higher number of S. frugiperda larvae than stemborers across three altitudinally different agroecological zones (p < 0.001). In conclusion, this study showed that the invasive S. frugiperda exhibited a clear competitive advantage over resident stemborers within maize cropping systems in Kenya. Our findings reveal some of the possible mechanisms employed by S. frugiperda to outcompete resident stemborers and provide crucial information for developing pest management strategies for these lepidopteran pests" |
| Keywords: | ecological niche fall armyworm plant-mediated competition population dynamics predation stemborers; |
| Notes: | "PubMed-not-MEDLINEMutua, Johnstone Mutiso Mutyambai, Daniel Munyao Asudi, George Ochieng' Khamis, Fathiya Niassy, Saliou Jalloh, Abdul A Salifu, Daisy Magara, Henlay J O Calatayud, Paul-Andre Subramanian, Sevgan eng Grant No. DCI-FOOD/2017//European Union/ CBFAMFEW II, Project ID; 720FDA20IO00133/ Agency for International Development/ Switzerland 2022/09/23 Insects. 2022 Aug 31; 13(9):790. doi: 10.3390/insects13090790" |
