The influence of the herbs sage and wormwood on the migration of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) populations

The repellent or attractant effects of adding powdered sage, Salvia officinalis, or wormwood, Artemisia absinthium, to wheat on the migratory behaviour of the lesser grain borer Rhyzopertha dominica was investigated. Under conditions permitting the migration of adult R. dominica, the addition of powdered sage to wheat grain resulted in a lower colonisation of this substrate. It was also found that emigration from grain containing sage was very high, especially in the initial period of grain infestation. This leads to the conclusion that sage is a strong repellent. On the other hand, the addition of pulverised wormwood to wheat did not seem to cause significant mortality or migration activity. Females demonstrated a higher sensitivity to the action of herbal chemicals than males, as confirmed by their higher mortality. This resulted in a change in the sex ratio of the population.