Biology of the Fall Armyworm (Spodoptera frugiperda) on Maize, Sorghum and Millet in Burkina Faso

Native to the Americas, Spodoptera frugiperda is an invasive pest that was first identified in Africa in 2016, where it is responsible for considerable damage to various cereal crops. This study aims at understanding its biology on the principal food cereal crops in Burkina Faso. These include maize, sorghum and millet. The research was conducted under laboratory conditions at a temperature of 25±1°C, a photoperiod of 12 h light and 12 h dark and a relative humidity of 75±5%. Spodoptera frugiperda was reared on seven varieties of the three crops. For each variety, 160 freshly laid eggs were used in four replicates of 40 eggs each in a completely randomised block design. These eggs were incubated in Petri dishes. Upon hatching, the larvae were placed individually in small 59-ml pots fed exclusively with fresh leaves harvested from 5–7-day-old seedlings of each tested variety. The adults were fed with a 5% diluted honey solution. Egg incubation differed significantly among crops and varieties, ranging from 3.00±0.00 days to 3.16±0.53 days. The average duration of the insect’s larval phase was shorter on maize (14.23±1.93 days) than on sorghum (17.46±1.08 days) and millet (17.68±1.29 days). Adults had an average lifespan of 7.49±2.55 days for males and 8.26±2.36 days for females. The total developmental duration (egg to adult) of the insect pest was 38.18±1.34 days on maize, 42.72±1.15 days on millet and 43.57±1.06 days on sorghum. These results suggest that the host plant strongly influences the development of S. frugiperda. These fundamental findings on the pest’s biology may inform integrated pest management strategies for this pest in Burkina Faso: developing biological control methods, optimising the timing of insecticide applications in the field, and selecting resistant or tolerant varieties.