Combining temperature-dependent life table data into Insect Life Cycle Model to forecast fall armyworm Spodoptera frugiperda (JE Smith) distribution in maize agro-ecological zones in Africa

• Published in: PloS one Vol. 19; no. 5; p. e0299154
• Main Authors: Adan, Marian, Tonnang, Henri E Z, Kassa, Cojdo E F, Greve, Klaus, Borgemeister, Christian, Goergen, Georg
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06-05-2024; Public Library of Science (PLoS)
• Subjects: Africa; Agricultural production; Agricultural research; Agriculture; Animals; Army-worms; Biology and Life Sciences; Climate; Climate change; Climate change mitigation; Climate policy; Corn; Crop yield; Crops; Diseases and pests; Distribution; Earth Sciences; Environmental aspects; Fecundity; Female; Food security; Future climates; Insects; Larva - growth & development; Larva - physiology; Larvae; Life Cycle Stages; Life cycles; Life history; Life Tables; People and Places; Permanent establishment; Pest control; Pests; Phenology; Physiological aspects; Precipitation; Productivity; Rain; Spodoptera - growth & development; Spodoptera - physiology; Spodoptera frugiperda; Temperature; Temperature dependence; Zea mays - growth & development; Zea mays - parasitology; Africa; Benin
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0299154

The fall armyworm (FAW), Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), an invasive agricultural pest, has significantly impacted crop yields across Africa. This study investigated the relationship between temperature and FAW life history traits, employing life cycle modeling at temperatures of 20, 25, 28, 30, and 32°C. The development time for eggs, larvae, and pupae varied from 0-3 days, 10-18 days, and 7-16 days, respectively. The optimal temperature range for immature stage survival and female fecundity was identified as 21-25°C, with the intrinsic rate of increase (rm) and gross reproductive rate (GRR) peaking at 25-28°C. Model validation confirmed the accuracy of these findings. The research further projected the Establishment Risk Index (ERI), Activity Index (AI), and Generation Index (GI) for FAW under current and future climates (2050 and 2070) using RCP 2.6 and RCP 8.5 scenarios. Results indicate that RCP 2.6 leads to a reduction in high-risk FAW areas, particularly in central Africa. Conversely, RCP 8.5 suggests an increase in areas conducive to FAW activity. These findings highlight the impact of climate policy on pest dynamics and the importance of incorporating climatic factors into pest management strategies. The study predicts a potential decrease in FAW prevalence in West Africa by 2070 under aggressive climate mitigation, providing a basis for future FAW management approaches.