火炬树抗螨性生物测定

本文分别测定了二斑叶螨Tetranychus urticae Koch和山楂叶螨Tetranychus viennensis Zacher对火炬树的选择性，以及限制性条件下火炬树对叶螨的生存及产卵的影响。结果表明：在火炬树叶和苹果叶之间，二斑叶螨和山楂叶螨在2 h， 6 h， 10 h， 12 h对火炬树的选择率分别为9.5%， 6.5%，5%，5%和2%，5%，1%和0，显著低于对苹果的选择率。被限制于火炬树叶上生存的山楂叶螨144 h后死亡率100%，产卵力随生存时间增加而下降，至96 h后产卵终止； 被限制于火炬树叶上生存的二斑叶螨240 h后全部死亡，整个观察期内（24～216 h）始终没有产卵。据此认为： 叶螨强烈拒食火炬树，火炬树对叶螨具有生存、产卵抑制作用，但这种抑制作用呈现种间差异。

Bioassay of the resistance of Rhus typhina L. against spider mites

The selectivity of Tetranychus urticae Koch and Tetranychus viennensis Zacher to the Buck's horn(Rhus typhina L.)and effects of R.typhina on the survival and fecundity of spider mites confined in the Buck's horn leaves were bioassayed in the laboratory.The results indicated that the selecting rates of T.urticae and T.viennensis for Rhus typhina L.were 9.5%,6.5%,5%,5% and 2%,5%,1%,0 at 2 h,6 h,10 h,12 h,respectively.The survival of T.uiennensis confined on R.typhina leaves was fully inhibited after 144 h,and the fecundity was going down with increase of the survival time,and terminated at 96 h.The survival rate of T.urticae confined on R.typhina leaves was 0 after 240 h,and no oviposition was observed during the whole observation period from 24 h to 216 h.It was so concluded that R.typhina has the high antifeedant activity against spider mites and may distinctly inhibit the survival and fecundity of spider mites,but the inhibition is inter-specifically different for spider mites.