Ecological and evolutionary conseguences of diapause in the interactive system between tetranychid mites and their predators

本文研究了叶螨及其植物类捕食者沃氏钝绥螨滞育特性的变化，并阐明了这些变化对二者相互作用系统的生态学和进化意义。叶螨的种间和种内差异较大，尤其是荨麻疹叶螨。荨麻疹滞育受多基因控制，其表达受温度影响较大。在滞育强度上也存在较大差异。滞育率呈纬度梯度，北方种群在<18 C9L15D时滞育率接近100%，而冲绳种群在15 C时仍未进入滞育。中纬度种群的滞育表达与温度有很大关系，滞育率随温度的升高而降低。研究了不同种群的滞育强度与产卵率之间的关系。滞育强度高的种群在较高温度下的产卵率高于较低温度下的产卵率，而滞育强度极弱的种群的产卵率不受温度的影响，即使在较低温度范围内也有较高的产卵率。本研究比较了中纬度地区同一生境中天头螨与黄粉螨滞育特性之间的关系。叶螨的滞育在种间和种内均表现出较大的差异，而粉螨的滞育差异不大，与被捕食物种的滞育特征无关。因此，没有发现明确的关系，表明被捕食物种的物候并不是决定捕食者滞耗特性的主要选择力。叶螨与植物螨的相互作用系统往往很不稳定。为了维持其种群，捕食者保持种群内滞育属性的变化比严格根据猎物的滞育特征进化滞育策略更有利。少

We studied the variations in diapause characterisitics in tetranychid mites and their phytoseiid predator, Amblyseius womersleyi, and elucidated the ecological and evolutionary significance of the variations to the interactive system between them.1. Wide inter-and intra-spesific variations were observed in tetranychid mites, especially in Tetranychus urticae. The diapause of T.urticae was under polygenic control, and its expression was affected greatly by temperature.2. A.womersleyi had also large variations in diapause intensity. The percentage of diapause showed a latitudinal cline : northern populations showed nearly 100% of diapause at <18ﾟC9L15D,whereas many individuals in populations from Okinawa did not enter diapsue even at 15ﾟC.The diapause expression in populations from intermediate latitudes depended greatly on temperature, and the percentage of diapause decreased with increasing temperature.3. We studied the relationship between the intensity of diapause and the oviposition … More rate in seveal populations of A.womersleyi. Populations with high intensity of diapause had higher reproductive rates at higher than lower temperatures, whereas the oviposition rate in populations with very weak diapause was not affected by temperature and they had high oviposition rates even at low temperature ranges.4. We compared the relationship between the diapause characteristics of teranychid mites and A.womersleyi that occurred at the same habitats in intermediate latitudes. Tetranychid mites exhibited wide variations in diapause both between and within species, whereas A.womersleyi showed little variations irrespective of the diapause characteristics of their prey species. Thus, no clear relation was detected, showing that the phenology of the prey species is not the major selective force for determining the diapuse characteristics of the predator.5. The interactive system between tetranychid and phytoseiid mites often are very unstable. In order that phytoseiid mites maintain their populations, it will be more profitable for the predators to maintain variations in diapause attribute within their populations, than to evolve their diapause strategies strictly in response to the diapause characteristics of their prey. Less