Abstract
The learning systems of the parasitoid Ascogaster reticulata were investigated using 5 authentic chemicals from tea leaf. The learning efficiency for geraniol and linalool was higher than for the other 3 components, (Z)-3-hexenol, methyl salicylate and benzyl alcohol. Discrimination between geraniol and linalool became clear when the number of conditionings increased. Furthermore, A. reticulata females preferred the chemical information after successive oviposition experience and the newly learned information. A 2-choice bioassay using a mixture of these tea leaf components suggested that geraniol and linalool play a key role in the discrimination of mixtures. However, A. reticulata females could also discriminate minor components in the mixture. They use several key components in the discrimination of plant species as well as other hymenopteran species. Increased preference for a certain plant species after successive oviposition experience of the same plant is adaptive for female's host-searching behavior in the field.
