Herbivore seasonality responds to conflicting cues: Untangling the effects of host, temperature, and photoperiod
Herbivore seasonality responds to conflicting cues: Untangling the effects of host, temperature, and photoperiod
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DOI：
10.1371/journal.pone.0222227
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发表时间：
2019-09-05
期刊：
影响因子：
3.7
通讯作者：
Abarca, Mariana
中科院分区：
文献类型：
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作者：
Abarca, Mariana
温带生态系统中的生物经历了有利季节的循环交替，当它们可以生长和发育时，不利时期的特征是低温和资源可用性减少。对这些变化条件的一种常见适应是在不利时期经历由环境线索（例如滞育）触发的代谢停滞状态。全球变化导致的环境条件改变可能使生物体暴露于相互矛盾的线索，可能引发适应不良的反应。在这里，我比较了一个寡食蝴蝶的表现时，经历一致与矛盾的环境线索，通过操纵温度，日照长度，和宿主植物在实验室。我实施了一个完全析因设计与现实的温度和光周期制度，以类似的环境条件在仲夏和夏秋过渡的焦点物种的范围内。为了评估宿主植物在介导非生物因素的影响中的作用，幼虫被喂食高质量或低质量宿主物种的叶子。减少日照是诱导滞育的主要线索，然而，在低温下饲养低质量的主机也诱导滞育的幼虫在恒定的夏季日照下生长。相反，暴露在高温下，同时喂养一个高品质的主机偶尔否决了滞育诱导的影响，减少日照。在高质量的主机上饲养减轻了寒冷的致命影响，但不是炎热的温度。此外，暴露于低温导致蛹质量显着减少，只有在减少日照。这些结果表明，在这个多化性蝴蝶不同的生长季节，根据个人的生态生理状态（无论是直接发展或滞育）的环境压力的反应。与寡食有关的特征，如对滞育诱导的多种线索的敏感性，以及其某些后果，如世代重叠的发生，可能会减轻全球变化的某些不利影响。
Organisms from temperate ecosystems experience a cyclic alternation of favorable seasons, when they can grow and develop, and unfavorable periods, characterized by low temperatures and reduced resource availability. A common adaptation to these changing conditions is to undergo a state of metabolic arrest triggered by environmental cues (e.g. diapause) during the unfavorable periods. Altered environmental conditions resulting from global change can expose organisms to contradictory cues, potentially triggering maladaptive responses. Here, I compared the performance of an oligophagous butterfly when experiencing consistent vs contradictory environmental cues by manipulating temperature, daylength, and host plant in the laboratory. I implemented a fully factorial design with realistic temperature and photoperiodic regimes to resemble environmental conditions during mid-summer and the summer-autumn transition within the focal species' range. To assess the role of host plant at mediating the effects of abiotic factors, larvae were fed foliage of either a high or a low-quality host species. Decreasing daylength was the primary cue inducing diapause; however, feeding on a low-quality host at low temperatures also induced diapause in larvae growing under constant summer daylength. Conversely, exposure to high temperatures while feeding on a high-quality host occasionally overruled the diapause-inducing effect of decreasing daylength. Feeding on a high-quality host mitigated the lethal effects of cold, but not of hot temperatures. In addition, exposure to cold temperatures resulted in a significant reduction of pupal mass only under decreasing daylength. These results indicate that responses to environmental stressors in this multivoltine butterfly differ across the growing season according to the eco-physiological state of individuals (whether they undergo direct development or diapause). Traits related to oligophagy, such as sensitivity to multiple cues for diapause induction, as well as some of its consequences, such as the occurrence of overlapping generations, are likely to mitigate some of the detrimental effects of global change.