Li Dingxu, Tian Juan, Shen Zuorui
Department of Entomology, China Agricultural University, Beijing 100094, P.R. China.
Exp Appl Acarol. 2006;38(4):255-73. doi: 10.1007/s10493-006-0016-0.
A leaf disc bioassay was employed in the laboratory to assess the population responses of Tetranychus viennensis Zacher to clofentezine at three concentrations (LC(10), LC(25) and LC(50)) in three successive generations. Life-table parameters were calculated in each acaricide exposure regime and compared by jackknife procedures. Clofentezine treatments in the juvenile stages significantly delayed development of the mites, and this delay increased with increasing dose but decreased as the mites developed. Exposure to clofentezine reduced the net reproduction rate (R(0)) in a concentration-dependent manner. The LC(50) treatment had strong effects on the hatchability of eggs produced by surviving females. Hatch rate dropped from 0.83 in the untreated control to 0.51 in the third generation. When exposed to constant concentrations of clofentezine in three successive generations, the intrinsic rate of increase and R(0) of the mites decreased significantly, but they increased significantly when exposed to decreasing concentrations. Unexposed offspring of the exposed mother also displayed increases in R(0) and the jackknife procedures indicated no significant differences in R(0) between LC(10) and LC(25) offspring and their mothers vs. the control, while R(0) in unexposed LC(50) offspring was significantly higher than their mother's, but lower than that in the control. These changing patterns of r(m) reveal that acaricide effects at the population level strongly depend on the life-history characteristics of T. viennensis and the chemical mode of action.
在实验室中采用叶碟生物测定法，评估了山楂叶螨在连续三代中对三氯杀螨醇三种浓度（LC(10)、LC(25)和LC(50)）的种群反应。在每种杀螨剂处理条件下计算生命表参数，并通过刀切法进行比较。在幼螨阶段用三氯杀螨醇处理显著延迟了螨的发育，且这种延迟随着剂量增加而增加，但随着螨的发育而减少。接触三氯杀螨醇以浓度依赖方式降低了净繁殖率（R(0)）。LC(50)处理对存活雌螨所产的卵的孵化率有强烈影响。孵化率从未处理对照中的0.83降至第三代中的0.51。当连续三代接触恒定浓度的三氯杀螨醇时，螨的内禀增长率和R(0)显著下降，但当接触浓度降低时则显著增加。接触处理的雌螨未接触药剂的后代的R(0)也有所增加，刀切法表明LC(10)和LC(25)处理的后代及其母亲与对照相比，R(0)无显著差异，而未接触药剂的LC(50)处理的后代的R(0)显著高于其母亲，但低于对照。r(m)的这些变化模式表明，杀螨剂在种群水平上的作用强烈依赖于山楂叶螨的生活史特征和化学作用方式。
