Studies On The Selectivity Of Tetranychus Viennensis To Different Host Plants

This paper determined the olfactory respones of Tetranychus viennensis to different plants odors with "Y" olfactometer and petri-dish, volatiles from leaves of different plants were absorbed with SPME(solid phase microextraction) and analyzed with GC-MS (gas chromatograph-mass spectrometer). At the same time, the effects of different host plants on the development of Tetranychus viennensis were determined by means of the leaf-dish rearing method , in addition, the contents of some chemicals in the leaves of different plants were also determined. The main results are as follows:l.The olfactory response of Tetranychus viennensis to different plants odors: Olfaction takes part in the response during the hawthorn spider mite looking for host plants, that means Tetranychus viennensis were attracted by odors from host plants. Different host plants have different attraction to the Tetranychus viennensis, some attract strongly, some were less than the others. The non-host plants were tested have neither attraction nor repulsion to the mite.2.GC-MS analysis of the volatiles from the different plant: After analysis the volatiles from leaves of different plants such as Mains pumila ? Pyrus bretschneideri ^ Amygdalus persica > Armeniaca vulgaris ^ Mains spectabili-, Crataegus pinnatifida > Primus yedoensis^ Quercus acutissima^ Euonymus japonicus etc. Preliminarily regarded that 3-hexen-1-ol.acetate and alpha farensene were strongly attractive to Tetranychus viennensis. butanolc acid,3-hexenyl ester and nerolido and perhaps have attraction. l,4-hexadiene,3,3,5-trimethyl and heptane,2,3,5-trimethyl have no attraction.3. The contents of chemical in leaves of different plants : The contents of total nitrogen, total soluble sugar, crude fat and tannin in these plants were tested .The contents of tannin in two non-host plants were more than in the host plants, so regard that tannin was the important factor of repressing the feeding of Tetranychus viennensis. Higher nitrogen will in favor of the development of Tetranychus viennensis.4.The effects of different host plants on the development and reproduction of Tetranychus viennensis: Under the same breeding conditions the Tetranychus viennensis feeding on apple leaves had the shortest developmental period, the longest life-span of adult female and oviposition period ,the highest ovipositional quantity. And the secondary is those feeding on peach leaves. There were no significantly difference between those mites feeding on other plant leaves.