The Influence of Herb Species on Population Processes of Sitophilus oryzae L (Coleoptera: Curculionidae)

The objective of this study was to investigate the effect of powdered herbs: sage Salvia officinalis L, wormwood Artemisia absinthium L. lavender Lavandula officinalis L, and peppermint Mentha piperita L on the population of the rice weevil Sitophilus oryzae (Linnaeus 1763). The population number, mortality and the sex structure of rice weevil populations were studied. The powdered herb preparations were applied at two concentrations: 1.2% and 0.5%. The experiments were conducted in the laboratory at 28 [degree]C and 60 [plus or minus] 5% RH. The effect of the plant preparations depended on their concentrations. The complete inhibition of the development of S oryzae occurred at the concentration of 1.2% of the powdered material. An inhibition effect on the rice weevil populations was also demonstrated for wormwood, sage, and the lavender at a 0.5% concentration. The chemical compounds contained in these herbs result in a higher mortality among females. The wormwood, sage, and the lavender may possibly be applied to protect stored products against infestation by S oryzae.