Abstract:

The choice behaviors of Oligonychus ununguis to host plants and Amblyseius finlandicus were determined with a Y-tube olfactometer. Result showed that the spruce spider mites were attracted by the odors from the leaves of Quercus acutissima Carr.,Quercus variabilis Bl.,Castanea mollissima BL. and Quercus dentata Thunb. uninfested by Oligonychus ununguis. But the odors from the leaves of Q.dentata were less attactive to the spider mites than those from Q.acutissima,Q.variabilis and C.mollissima. The needle leaves odors of Pinus tabulaeformis Caff. and Picea koraiensis Nakai were repulsive to the spider mites. When the uninfested leaves and infested leaves with O. ununguis of the same host plant were compared in the olfactometer, the spider mites showed an obvious preference to odors released from the infestd leaves. The spider mites showed a greater preference to the infested leaves with spider mites and their products than to the infested leaves from which all the spider mites and their products had been removed. The host plants infested or not, the infested host plants with spider mites or without had significant influence on the taxis of A.finlandicus. A. finlandicus could be attracted by the odors from uninjured leaves and injured leaves by O.ununguis. But it showed a greater preference to the latter than to the former. There was a significant difference between the response of A.finlandicus to the infested leaves with spider mites and their products and to the infested leaves without spider mites or their products.

Key words: Oligonychus ununguis, Host plants, Ambliscius finlandicus, Olfactory response