Crop Diversification and Pest Management: An Analysis of Faw (Spodoptera frugiperda Smith) in Quelimane, Mozambique

For a better understanding of how crop diversification affects the dynamics of the new invasive pest in Africa, the FAW Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) and the extent to which it causes damage to maize in such situations, a field survey was carried out in 215 farms in the district of Quelimane, Mozambique. Around 96% of the farms were found to be under intercrop with up to seven different crops. Sweet potato, cassava, tomato, cowpea, pumpkin and okra were found to be the most common crops intercropped with maize. While the number of damaged plants increased with the age of maize, the contrary was observed in relation to the number of FAW larvae. No differences were observed in the number of FAW larvae in different sampling locations, but differences were observed in the number of damaged plants. We found an inverse relationship between the number of damaged plants and the number of FAW larvae with the number of crops per farm. Independent of the sampling location, development stage and number of crops in the farm, maize plants were found to have between 10 and 25% of their leaf surface area damaged by FAW. Control measures should be stepped up when maize is in its vegetative and flowering stages, and farmers should avoid planting maize as a sole crop.