RESUMO: Dichotomius nisus (Olivier, 1789) is a large tunneler dung beetle with potential relevance for ecological restoration and livestock management in Brazilian pastures through its capacity to reduce cattle dung accumulation. This study examined its reproductive biology in the laboratory under ambient temperature and light conditions to assess the feasibility of ex situ breeding for future population reinforcement programs. The study commenced in October 2023 and concluded in January 2025 and was conducted using four males and five females collected from pastures in southern Brazil. Ex situ reproduction was simple and consistent, with the production of five brood balls, which had an average diameter of 37.9 ± 3.59 mm and an average weight of 25.9 ± 3.28 g. The duration of the different developmental stages was four days from egg to larva, 56 days from larva to pupa, and 21 days from pupa to adult. Thus, the total developmental time from egg to adult was 82 ± 0.6 days, with reproductive activity occurring from spring to summer (November to March). Maximum adult longevity reached 207 days in the parental generation and 284 days in the F1 individuals. These findings highlight the reproductive capacity of D. nisus, underscoring its suitability for population reinforcement in livestock landscapes in Brazil. Such an approach offers a sustainable strategy for manure recycling, improving soil function, and increasing environmental quality without relying on chemical inputs