The current study was conducted in Laboratory of Department of Crop Protection, Modibbo Adama University of Technology, Yola to evaluate the biocidal effects of different concentrations of extracts of Azadirachta indica, Hyptis souveolens and Moringa oleifera against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) at different time interval. Three applications of 5, 10 and 15% were used to assess the mortality of T. castaneum at five different periods of 24, 48, 72, 96 and 120 hours. The results revealed that the mortality of T. castaneum increased with increase in concentration of plant extracts. Tribolium castaneum gave highest mortality (36.0 %) at 15%, while least mortality (7.32 %) was obtained in M. oleifera at lower concentration (5%). Comparing the relative efficacy of these plant extracts in relation to time, highest percent mortality (38.9 %) was also observed in A. indica after 24 hours compared to the extracts of H. souveolens and M. oleifera which gave high mortality of 33.33 and 10.0 %, respectively. Regarding interaction between concentration and time, mortality increases with respect to increase in concentration, but reduces with passage of time. This shows that toxicity effects of these plant extracts is directly affected by concentration and time. Therefore, this study confirmed that these plant extracts are effective in the management of T. castaneum and most effectively at higher concentration with longer duration of time

Keywords : Tribolium Castaneum, Plant Extracts, Mortality, Biocidal.