Fitness consequences of host plant choice: a field experiment
Fitness consequences of host plant choice: a field experiment
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DOI：
10.1111/j.1600-0706.2009.17242.x
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发表时间：
2010-03-01
期刊：
影响因子：
3.4
通讯作者：
Kingsolver, Joel G.
中科院分区：
文献类型：
--
作者：
Diamond, Sarah E.;Kingsolver, Joel G.
确定不同生态因素对食草动物适应性的相对贡献是了解食草动物选择寄主植物的生态和进化的关键之一。天敌越来越被认为是一个重要因素：质量较差的寄主植物如果提供无敌空间（EFS），仍然可能被食草动物利用。在这里，我们使用烟草天蛾（Manduca sexta）通过实验将天敌的影响与寄主植物质量、竞争和微生境等潜在混杂因素分开。我们在存在寄生天敌 Cotesia congregata 的实验田间环境中，探讨了以典型的高质量寄主植物烟草 (Nicotiana tabacum) 和新型低质量寄主植物魔鬼爪 Proboscidea louisianica 为食的 M. sexta 的个体适应度和总体适应度的影响。尽管以魔爪为食的 M. sexta 的早期幼虫存活率、发育和生长率、最终体型和繁殖力均有所下降，但对烟草的高寄生率和对魔爪的不寄生导致两种寄主植物物种的总适应度相似（净繁殖率，R(0)）。我们的结果表明，M. sexta 在其典型寄主范围之外采用了一种新的寄主植物（魔鬼爪），因为这种寄主植物提供了敌人的自由空间。此外，成年雌性 M. sexta 的产卵行为似乎非常适合利用魔鬼爪上无敌的空间。 M. sexta 在魔鬼爪上的产卵似乎与寄生蜂丰度的季节性变化相对应。
Determining the relative contributions of different ecological factors for herbivore fitness is one key to understanding the ecology and evolution of host plant choice by herbivores. Natural enemies are increasingly being recognized as an important factor: host plants of inferior quality for development may still be used by herbivores if they provide enemy-free space (EFS). Here we used the tobacco hornworm, Manduca sexta, to experimentally disentangle the effects of natural enemies from the potentially confounding factors of host plant quality, competition and microhabitat. We explored the consequences for both individual components of fitness and total fitness of M. sexta feeding on a typical high quality host plant, tobacco Nicotiana tabacum and a novel, low quality host plant, devil's claw Proboscidea louisianica in an experimental field environment in the presence of a parasitoid natural enemy, Cotesia congregata. Although early larval survival, development and growth rates, final body size and fecundity were all reduced for M. sexta feeding on devil's claw, a high rate of parasitism on tobacco and an absence of parasitism on devil's claw contributed to similar total fitness (net reproductive rate, R(0)) across the two host plant species. Our results Suggest M. sexta has adopted a novel host plant (devil's claw) outside its typical host range because this host plant provides enemy free space. In addition, oviposition behavior of adult female M. sexta appears to be well suited to exploiting the enemy-free space on devil's claw; oviposition by M. sexta on devil's claw appears to correspond with seasonal variation in parasitoid abundance.