Department of Biology, Queen's University, Kingston, Ontario, Canada.
Science. 2013 Aug 16;341(6147):796-9. doi: 10.1126/science.1238477. Epub 2013 Aug 1.
Insects often undergo regular outbreaks in population density but identifying the causal mechanism for such outbreaks in any particular species has proven difficult. Here, we show that outbreak cycles in the tea tortrix Adoxophyes honmai can be explained by temperature-driven changes in system stability. Wavelet analysis of a 51-year time series spanning more than 200 outbreaks reveals a threshold in outbreak amplitude each spring when temperature exceeds 15°C and a secession of outbreaks each fall as temperature decreases. This is in close agreement with our independently parameterized mathematical model that predicts the system crosses a Hopf bifurcation from stability to sustained cycles as temperature increases. These results suggest that temperature can alter system stability and provide an explanation for generation cycles in multivoltine insects.
昆虫的种群密度经常会出现有规律的爆发,但要确定任何特定物种爆发的因果机制都非常困难。在这里,我们表明,茶尺蠖 Adoxophyes honmai 的爆发周期可以用温度驱动的系统稳定性变化来解释。对跨越 200 多次爆发的 51 年时间序列进行小波分析显示,每年春季当温度超过 15°C 时,爆发幅度会出现一个阈值,而秋季随着温度下降,爆发会逐渐分离。这与我们独立参数化的数学模型非常吻合,该模型预测随着温度的升高,系统会从稳定性跨越到Hopf 分岔,从而产生持续的周期。这些结果表明,温度可以改变系统的稳定性,并为多化性昆虫的世代周期提供解释。