Trials were designed to determine median effective concentrations or doses (LC50values) to cause mortality of 50% of test insects.Ten unsexed adult insects were put into 38 ml Plexiglas bottles with screw lids. Control insects were kept under the same conditions without any essential oil. Each dose was replicated five times. Mortality was evaluated by direct observation of insects. The number of dead and live insects in each bottle was counted 24 h after initial exposure. Data were analyzed using Finney’s method (Finney,1971).