Strategies of chemical anti-predator defences in leaf beetles: is sequestration of plant toxins less costly than de novo synthesis?

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• 作者：Elena L. Zvereva ; Vitali Zverev ; Oksana Y. Kruglova ; Mikhail V. Kozlov
• 关键词：Energetic costs ; Fitness ; Insects ; Meta ; analysis ; Plant ; herbivore interactions
• 刊名：Oecologia
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：183
• 期：1
• 页码：93-106
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Ecology; Plant Sciences; Hydrology/Water Resources;
• 出版者：Springer Berlin Heidelberg
• ISSN：1432-1939
• 卷排序：183

文摘

The evolution of defensive traits is driven both by benefits gained from protection against enemies and by costs of defence production. We tested the hypothesis that specialisation of herbivores on toxic host plants, accompanied by the ability to acquire plant defensive compounds for herbivore defence, is favoured by the lower costs of sequestration compared to de novo synthesis of defensive compounds. We measured physiological costs of chemical defence as a reduction in larval performance in response to repeated removal of secretions (simulating predator attack) and compared these costs between five species synthesising defences de novo and three species sequestering salicylic glucosides (SGs) from their host plants. Experiments simulating low predator pressure revealed no physiological costs in terms of survival, weight and duration of development in any of study species. However, simulation of high predation caused reduction in relative growth rate in Chrysomela lapponica larvae producing autogenous defences more frequently, than in larvae sequestering SGs. Still meta-analysis of combined data showed no overall difference in costs of autogenous and sequestered defences. However, larvae synthesising their defences de novo demonstrated secretion-conserving behaviour, produced smaller amounts of secretions, replenished them at considerably lower rates and employed other types of defences (regurgitation, evasion) more frequently when compared to sequestering larvae. These latter results provide indirect evidence for biosynthetic constraints for amounts of defensive secretions produced de novo, resulting in low defence effectiveness. Lifting these constraints by sequestration may have driven some leaf beetle lineages toward sequestration of plant allelochemicals as the main defensive strategy.