Submitted to: International Journal of Pest Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2024
Publication Date: 7/7/2024
Citation: Koffi, D., Agboka, K., Adom, M., Adjevi, M.A., Tounu, A.K., Meagher Jr, R.L. 2024. Eco-friendly management of fall armyworm: can host-plant intercropping drive to a sustainable IPM?. International Journal of Pest Management. https://doi.org/10.1080/09670874.2024.2372301.
DOI: https://doi.org/10.1080/09670874.2024.2372301

Interpretive Summary: Fall armyworm is a worldwide pest of several agricultural crops. In sub-Saharan Africa, it has been infesting crops since 2016 and is mostly affecting corn yields. Initial control measures were predominately the use of insecticides, however, the use of intercrops has not been tested in west Africa. Researchers with the Université de Lomé, Lomé, Togo, and the University of Ghana, in collaboration with a scientist with the USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida, conducted laboratory and field studies to evaluate host utilization of intercrops. In the laboratory, caterpillar feeding of 10 different crops showed that only grass crops allowed the fall armyworm to become adults. Caterpillar development was higher when fed corn than the other crops. In field studies, intercropping corn with sorghum, rice, millet, tomato, sweet pepper, cowpeas, and soybeans showed that corn that was intercropped was less damaged than corn that was in a monoculture. It appears that intercropping in west Africa can be considered an eco-friendly integrated pest management strategy.

Technical Abstract: Although over 350 plants have been documented to host the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), its invasion in West Africa has been mainly on maize. This study investigated the factors that limit the host utilization, and tested the effects of intercropping of Poaceae (maize, sorghum, rice and Proso millet), Solanaceae (tomato and sweet pepper), and Fabaceae (cowpea and soya bean) plants on FAW severity. The laboratory feeding of larvae with these crops showed higher pupation rates for maize (33.6%) than sorghum (20%), rice (24.17%), Proso millet (17.6%), tomato (fruit = 5.33% and leaf = 6 .4%), sweet pepper (fruit = 1.33% and leaf = 1.6%). Only larvae fed with Poaceae plants reached the adult stage. Female ovipositional potentiality was higher with maize compared to other Poaceae plants. In the semi-field and field experiments, FAW severities were recorded only on Poaceae plants. However, the severity of FAW was significantly reduced in intercropped maize with other crops compared to monocultures of maize. Therefore, intercropping can be considered as an eco-friend FAW-IPM program in West Africa.