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Spodoptera frugiperda is an exotic Lepidoptera that causes enormous damage to cereal crops worldwide. The study was conducted at a research station in western Burkina Faso during two consecutive rainy seasons in 2020 and 2021. The objective of this work was to estimate crop damage and yield losses by S. frugiperda. Each scenario was tested according to a split-plot design with four randomized replicates. The main plots were the varieties and the secondary plots the levels of insecticide treatments. Three varieties of each cereal crop were tested and the insecticide Lambda-cyhalothrin (15 g/l) + Acetamiprid (10 g) was used in three levels of protection: no insecticide application, 4 insecticide applications and 6 insecticide applications. The results showed that the highest average infestation rate was recorded on maize (50.27% of the plants attacked), followed by sorghum (38.61%) and millet (33.19%) in 2020. In 2021, these rates were 41.38%, 26.80% and 26.38% for maize, sorghum and millet, respectively. The average damage score on the Davis scale associated with maize cobs was 2.13 in 2020 in control plots, 1.74 in plots receiving 4 times the insecticide and 1.54 in those receiving 6 times the insecticide. In 2021, the same trend was observed. S. frugiperda infestation on grain of the three crops studied were only recorded on maize, leading to yield losses of around 22.19% in 2020 and 22.18% in 2021. These results may help technical and political decision-makers in the management policy of S. frugiperda, in Burkina Faso. • Maize is the main host plant of Spodoptera frugiperda in Burkina Faso. • As a result, losses due to the insect pest are 2–3 times higher on maize than on other cereals. • These results may help decision-makers in the management policy of Spodoptera frugiperda in Burina Faso. [ABSTRACT FROM AUTHOR]

In West Africa, the use of organophospates and pyrethroid insecticides to control cotton pests has led to the evolution of resistance in field populations of Bemisia tabaci Gennadius. Three pest management programs have been commonly recommended: the Conventional Program (CP) where 6 treatments are applied, the use of Bt cotton plants for which only 2 applications of neonicotinoids are required and that has been adopted in many countries, and a biological program (BP) without any chemical treatment. The present study aimed to determine the influence of these practices on the frequency of mutations that confer resistance to pyrethroids (mutation L925I in the para -type voltage-gated sodium channel gene) and organophosphates (mutation F331W in the acetylcholinesterase enzyme ace1 : allele Ace 1 R ) in B. tabaci populations using Bt cotton and CP areas in Pô and Saria (Burkina Faso), CP and BP areas in Kandi (Benin) and only CP areas in Tové and Infa (Togo). All individuals sampled belonged to the MED (biotypes MED-Q1) and Africa Silver Leafing (ASL) species. MED-Q1 was found in sympatry with ASL in Burkina Faso both on CP and Bt cotton areas at variable frequencies. In Togo and Benin, only ASL was found, except in Tové where MED-Q1 was also detected, but at low frequency. Frequencies of mutations that confer resistance varied between localities and species but we did not find any strong evidence of a relationship between the pest management program and these frequencies except for the allele Ace 1 R in Burkina Faso for which the frequencies decrease when chemical applications are reduced. This study provides valuable information for the development of efficient integrated pest management programs. [ABSTRACT FROM AUTHOR]