Efficacy of Some Plant Extracts Against Stored-Product Pest Red Flour Beetle, Tribolium Confusum (Jacquelin Du Val) (Coleoptera: Tenebrionidae) Adults

Abstract

The efficacy of five plant extracts, Lantana camara, Ruta chalepensis, Rhazya stricta, Heliotropium bacciferum and Marrubium vulgare against Tribolium confusum ware investigated by admixing plant extract with wheat grains. Mortality (%) increased with increasing concentrations, exposure periods and varying from plant to plant. L.camara and R. chalepensis induced the highest percent of mortalities (95.4 and 93.8%) at 500 ppm after 6 days of exposure respectively, for T. confusum, followed by Rh. Stricta, M. vulgare and H. baccifirum. (91.4, 84.5 and 83,3%) respectively. The lowest LC50s were for L. camara and R. chalepensis (114.61 and 117.78 ppm), after 6 days from exposure respectively, followed by Rh. Stricta, M. vulgare and H. bacciferum (175.48, 251.99 and 309.67 ppm respectively. The rate of repellency increased with increase of dose level. L. camara had the lead in repellent action where repellent percentage was 100 % at 500 ppm followed by R. chalepensiswith, 91%. The repellency rates of other plant extracts were between 50.22 -66.54 at the same concentration which had a moderate repellent action. Statistical analysis showed that all plant extracts revealed significant deference except between H. bacciferum and M. vulgare. Among all the plant extracts L.camara and R. chalepensi were generally more toxic than other plant extracts against T. confusum.