Seasonal Dynamics of the Alien Invasive Insect Pest Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) in Manica Province, Central Mozambique

Abstract

The alien invasive insect pest Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), commonly referred to as fall armyworm (FAW), is causing significant losses to maize production in Africa since its detection in 2016. Despite being the primary insect pest of the main food crop in the country, researchers have concentrated their efforts on methods of control, and there are no published studies on its seasonality which could assist farmers in delivering effective methods of control in periods of heavy infestations. The primary goal of this study was to assess the seasonal dynamics of FAW in maize fields. We conducted a field survey from May to August 2019 (dry season of the 2018/2019 cropping season) and in December 2019 and January 2020 (rainy season of the 2019/2020 cropping season) in 622 maize fields. In each field, 20 plants were selected in a “W” pattern and checked for the presence of FAW egg masses and/or larvae. Plants were also assessed for damage. Preliminary results show increased infestation, damages, and population density of FAW in the dry season. Our results suggest that early planting of maize in the primary cropping season may significantly reduce the infestation and damage by FAW when compared to the dry season.

Farmers’ knowledge, perception and management practices of fall armyworm (Spodoptera frugiperda Smith) in Manica province, Mozambique

“…This can be explained by the fact that in this interval, maize planted from October to December is still in the vegetative stage which is the most preferred by FAW. But a field survey conducted from May to August 2019 and between December 2019 and January 2020 in the same area, found that FAW infestation was higher during the dry season (Caniço et al 2020).…”

Managing a Transboundary Pest: The Fall Armyworm on Maize in Africa

“…In a study conducted by Midega et al [49] in Kenya, Uganda, and Tanzania, the team reported 82.7% and 86.7% reduction in larvae per plant and plant damage, respectively in climate-adapted push-pull compared to maize monocrop plots, and a resultant 2.7-fold higher grain yield in the climate-adapted push-pull plots (Figure 6). There was a similar finding in Uganda, where maize yield from climateadapted PPT was significantly greater compared with maize intercropped with edible legumes or mono-cropped maize [48].…”

“…Successful agroecological management is based on the understanding of key principles such as complex interactions within the ecosystem and contextualized solutions to local problems [47]. Agroecological management practices to reduce FAW populations in Africa include cultural and mechanical control, intercropping, crop rotation with non-host crop, weed management and intercropping maize with the moth repellant Greenleaf desmodium ("Push") with Brachiaria cv Mulato planted around the intercrop ("Pull") [47][48][49].…”

“…Figure 6.Mean (± S.E.) grain yields of maize (t/ha) planted in sole stands (maize monocrop) or in climate-adapted push-pull stands[49].…”

Integrative taxonomy and phylogeography of Telenomus remus (Scelionidae), with the first record of natural parasitism of Spodoptera spp. in Brazil

“…S. frugiperda is particularly serious because of frequent population outbreaks in corn (maize), soybean, and cotton crops 1 , 2 , 5 , 6 . Spodoptera frugiperda was first reported in Africa in 2016 and subsequently in Asia and Oceania, and has become a serious cosmopolitan pest of corn, rice and other cereal crops 7 , 8 .…”