School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
J Insect Physiol. 2010 Feb;56(2):123-31. doi: 10.1016/j.jinsphys.2009.08.022. Epub 2009 Sep 12.
Although the impact of warming on winter limitation of aphid populations is reasonably well understood, the impacts of hot summers and heat wave events are less clear. In this study, we address this question through a detailed analysis of the thermal ecology of three closely related aphid species: Myzus persicae, a widespread, polyphagous temperate zone pest, Myzus polaris, an arctic aphid potentially threatened by climate warming, and, Myzus ornatus, a glasshouse pest that may benefit from warming. The upper lethal limits (ULT(50)) and heat coma temperatures of the aphid species reared at both 15 and 20 degrees C did not differ significantly, suggesting that heat coma is a reliable indicator of fatal heat stress. Heat coma and CT(max) were also measured after aphids were reared at 10 and 25 degrees C for one and three generations. The extent of the acclimation response was not influenced by the number of generations. Acclimation increased CT(max) with rearing temperature for all species. The acclimation temperature also influenced heat coma; this relationship was linear for M. ornatus and M. polaris but non-linear for M. persicae (increased tolerance at 10 and 25 degrees C). Bacteria known generically as secondary symbionts can promote thermal tolerance of aphids, but they were not detected in the aphids studied here. Assays of optimum development temperature were also performed for each species. All data indicate that M. persicae has the greatest tolerance of high temperatures.
虽然变暖对蚜虫种群冬季限制的影响已经得到了很好的理解，但对炎热的夏季和热浪事件的影响还不太清楚。在这项研究中，我们通过对三种密切相关的蚜虫物种的热生态学的详细分析来解决这个问题：桃蚜，一种分布广泛、多食性的温带害虫；极地蚜虫，一种可能受到气候变暖威胁的北极蚜虫；粉虱，一种可能受益于变暖的温室害虫。在 15 和 20°C 下饲养的蚜虫的上限致死温度 (ULT(50)) 和热昏迷温度没有显著差异，这表明热昏迷是致命热应激的可靠指标。在 10 和 25°C 下分别饲养一代和三代后，还测量了蚜虫的热昏迷和 CT(max)。适应反应的程度不受世代数的影响。适应使所有物种的 CT(max)随饲养温度的升高而升高。适应温度也影响热昏迷；对于 M. ornatus 和 M. polaris，这种关系是线性的，但对于 M. persicae 是非线性的（在 10 和 25°C 下耐受性增加）。通常被称为次生共生菌的细菌可以促进蚜虫的耐热性，但在我们研究的蚜虫中没有检测到。还对每个物种的最佳发育温度进行了测定。所有数据表明，桃蚜对高温的耐受性最强。
