Vol. 10, Issue 9, Part A (2024)

An experiment was carried out during two successive summer seasons in 2022 and 2023 to determine the potency of two microbial insecticides combined with a chemical insecticide against fall armyworms (Spodoptera frugiperda Smith) on maize plants in field conditions in El-Sabein village, Sidi Salem District, Kafr El-Sheikh governorate, Egypt. Results indicated that the highest monthly average of S. frugiperda was recorded in August with an average of 19.25±0.88 and 17.90 ±1.19 larvae in the first and second seasons, respectively. The greatest average population decrease percentage was Spinetoram, which showed reductions of 89.33 and 91.30% during the first and second seasons, respectively, and represented by all average 90.31%. Followed by Emamectin Benzoate (SG 5%) with average values of 85.38 and 87.33% reduction during the both seasons, respectively with overall average 86.35%. Protecto (Bacillus thuringiensis) with average values of 44.09 and 43.65%, in the first and second seasons, respectively and represented by overall average of 43.87%. On the other hand, Biossiana 2,5%WP (Beauveria bassiana) had the lowest compounds, with average values of 39.42 and 41.68% at the first and second seasons, respectively, and an overall average of 40.55%. Furthermore, the overall average of the mean population reduction of all compounds against S. frugiperda was 65.27%, with reported values of 64.55 and 65.99 in the both seasons, respectively.