The four-spotted bean weevil, Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae), is a significant pest feeds on the stored legumes, particularly beans, causing damage and reducing quantity and quality of the products. In this study, the effectiveness of diatomaceous earth (DE) formulations, both alone and in combination with in insecicides imidacloprid and deltamethrin, was evaluated on the mortality and progeny production of C. maculatus. The research further assessed the impact of these formulations on oviposition inhibition, egg hatching percentage, and prevention of adult emergence in cowpeas. Diatomaceous earth formulations were tested at the concentrations of 500 and 1000 mg/kg, with six replications for each treatment. The experiments were conducted in the Toxicology Laboratory of Shahid Chamran University of Ahvaz, Faculty of Agriculture, Department of Plant Protection at a temperature of 28±1°C, 65±5% r.h., and dark conditions. The lowest lethal time (LT50) was recorded for the Dryasil DE formulation combined with imidacloprid at 4.695 days. Mortality rates of C. maculatus adults increased with prolonged exposure and higher concentrations. The control and talcum powder treatments recorded the highest egg-laying numbers, with 21 and 19.16 eggs respectively. In contrast, at 1000 ppm, the lowest egg counts were observed in the Dryasil + imidacloprid (7.33), Dryasil + deltamethrin (8.66), and imidacloprid (9) treatments. The highest oviposition inhibition rates at this concentration were noted for Dryasil + imidacloprid (65.08%), Dryasil + deltamethrin (58.73%), and imidacloprid (57.14%). Additionally, the lowest adult emergence percentage (21.67%) and the longest developmental period from egg to adult (21.92 days) occurred in the Dryasil + imidacloprid treatment. Cowpeas seed weight loss due to C. maculatus damage was also evaluated in these treatments, with the lowest percentage of weight loss (5.37%) in seeds treated with 1000 ppm of Dryasil + Imidac