Tribolium castaneum, the red flour beetle, is a key pest of cereal grains and products that routinely infests food processing facilities. Such facilities represent dynamic environments comprising patches of resources of variable size and quality. To understand the influence of resource availability, insect density, and initial life stage on population regulation in T. castaneum, this study assessed the carrying capacity and population growth rates of T. castaneum populations kept for 20 weeks in a closed environment on four different amounts of diet at four starting population levels, then compared T. castaneum attraction to, reproductive output on, and the volatile profiles of previously-infested (e.g., conditioned) flour. Resource availability (e.g. the amount of flour) interacted with founding population density and life stage to influence T. castaneum population dynamics. In resource-limited patches, carrying capacity estimates were similar across founding densities, but the effect of founding population density on carrying capacity increased with flour availability. The opposite was observed for population growth rate, which tended to be more variable for small patches but stabilized as resource availability increased. Interestingly, both effects were reduced for populations founded as larvae compared to those founded as adults. The volatile profile of conditioned flour was also influenced by the interaction of patch size, density, and life stage. The relative abundance of 1-pentadecene and benzoquinones tended to be reduced in the volatile profiles of large patches, whereas 4,8-dimethyldecanal comprised a higher proportion of the total volatile emissions. Conditioned flour from large patches tended to be more attractive to T. castaneum adults, although this effect decreased as founding density increased. By contrast, when populations were founded as larvae, the volatile profiles of T. castaneum attraction to, and T. castaneum fecundity on conditioned flours were similar. These findings expand our understanding of how resource limitation and density-dependent effects influence T. castaneum population regulation and behavior, with implications for long-term trap monitoring and population thresholds in stored products.