Methodology and results: The current study was performed in three villages of the cotton growing areas of central Benin (Glazoue municipality). Four treatments consisting of 1) unsprayed control, 2) TopbioMaviMNPV mixture, 3) B. bassiana and 4) Decis were arranged in a randomized complete block design with three replicates. Seventy five grams per ha of B. bassiana (isolate Bb 115) conidia were formulated with peanut oil and applied at a volume of 2 litres/ha-1. Virus MaviMNPV suspension was applied at 2.10 9 OB/ha in a formulation containing neem (TopBio).The Decis and TopBio, 1L /ha. The effects of the different pesticides used on cowpea pests populations' densities (M. vitrata, Megalurothrips sjostedti, Clavigralla tomentosicollis) were evaluated as well as their damage of reproductive organs (flowers buds, flowers and pods). Fruiting bodies organs were collected weekly to monitor alive and dead of M. vitrata larvae, and other key cowpea insect pests and their damage on flower budsl, flowers and pods as well. Cowpea grain yield was evaluated. Although, the great variation in their effects, the biopesticides tested have significantly reduced the population density of M. vitrata and of the other insect species as well as damage level. The overall grain yield was improved in treated cowpea compared to the untreated control. In farmers' cowpea fields, pest control by the various pesticides used, was similar with yields of 933.03 ± 8.7Kg / ha obtained in plots treated with B. bassiana. Conclusion and results' applications: These results showed that the biopesticides used in our study can significantly reduce the densities of different target pests. This study suggested the possibilities of the use of biopesticides as alternatives to chemical insecticides in the control of cowpea pests.