Hayes Jane Leslie
Department of Zoology, University of California, Davis, 95616, Davis, California, USA.
The Rocky Mountain Biological Laboratory, 81224, Crested Butte, Colorado, USA.
Oecologia. 1982 Jun;53(3):317-322. doi: 10.1007/BF00389007.
The mechanisms and adaptations involved in the "obligate" third instar larval diapause of Colias alexandra, a native Rocky Mountain and intermountain region butterfly, are examined. Generally univoltine throughout its distribution, scattered, isolated bivoltine populations occur. Factors influencing continuous development were investigated under laboratory conditions on a single generation of offspring from a univoltine population each year from 1976-1979. If exposed to mean temperatures >24°C during the second instar, a significant number of larvae fail to diapause. These results are interpreted in the context of the actual environmental conditions experienced by the univoltine source population and a bivoltine population. A high degree of individual variability in response to continuous development conditions is shown. Variation in certainty of diapause, within an originally univoltine population, could be the evolutionary starting point for evolving a genuine multivoltine cueing system and provide the mechanism for ecological range expansion.
对产于落基山脉和山间地区的本土蝴蝶——亚历山大云粉蝶“专性”三龄幼虫滞育所涉及的机制和适应性进行了研究。在其整个分布范围内通常一年一代，但也存在分散、孤立的一年两代种群。1976年至1979年期间，每年在实验室条件下对来自一年一代种群的单代后代进行研究，以探究影响持续发育的因素。如果二龄幼虫期间暴露于平均温度>24°C的环境中，大量幼虫不会进入滞育状态。结合一年一代的源种群和一年两代的种群所经历的实际环境条件对这些结果进行了解释。结果显示，在对持续发育条件的反应方面存在高度的个体变异性。在原本一年一代的种群中，滞育确定性的变化可能是进化出真正的多代提示系统的进化起点，并为生态范围扩展提供机制。
