How tri-trophic interactions and social behaviour drive early instar survival rates of caterpillars

三营养相互作用和社会行为如何提高毛毛虫的早期存活率

• 批准号: RGPIN-2017-06815
• 负责人: Despland, Emma
• 金额: $ 2.04万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=682423
• 关键词: How; tri; trophic; interactions; social

My goal is to build a process-based conceptual framework for caterpillar early-instar ecology, by determining how phenology, plant physical and chemical defenses, group-living and natural enemies interact to produce emergent patterns of larval survivorship. In general, young larvae are poorly studied, but often suffer very variable high mortality rates caused by interacting species-specific stressors. This high variability in space and time implies that early-larval survival plays an important role in population dynamics. ******My comparative approach uses three systems chosen for their differences in life history, gregariousness and population dynamics: two important Canadian outbreaking forest pests - spruce budworm (Choristoneura fumiferana, solitary, conifer-feeders), forest tent caterpillars (Malacosoma disstria, gregarious, deciduous-feeders) and the diverse tropical clearwing butterflies (Ithominae, some species gregarious, others solitary). ***1. What behavioural mechanisms drive fluctuations in early-instar survival of Eastern Canada's most important forest pest? Extreme variations in early-instar survival constitute an important knowledge gap in predicting budworm outbreaks. I will fill this gap by testing behavioural mechanisms linking host plant phenology, leaf chemistry and previous defoliation to dispersal, competition and establishment of a feeding site. ***2. How does group-living modulate tri-trophic interactions in the forest tent caterpillar? I will test the hypothesis that group living implies a decrease in survival rate as groups get smaller, and that this feedback accelerates the attrition due to predation and plant defenses. ***3. How does group-living modulate tri-trophic interactions in clearwing caterpillars? I will apply the concepts and tools developed using temperate-zone gregarious caterpillars to the far greater diversity found in the tropics; specifically, I will test how grouping permits establishment on mechanically defended plants and colonization of disturbed habitats. ******These sub-objectives draw on the particular natural history of each study organism to formulate hypotheses about mechanisms driving early-instar ecology. Together they form an ambitious, innovative, wide-ranging research programme that synthesizes the effects of interacting stressors to explain complex emergent patterns in early-instar survivorship. My unique individual-based approach provides solid scientific grounding for conservation in tropical forests and mechanistic explanations of outbreak dynamics in the boreal forest, including responses to climate warming. The research on outbreaking pests is particularly timely since both are currently on the upsurge across much of Canada.**

我的目标是通过确定物候、植物物理和化学防御、群体生活和天敌如何相互作用以产生幼虫生存的新兴模式，为毛毛虫早期生态学建立一个基于过程的概念框架。 一般来说，幼虫的研究很少，但由于物种特异性应激源的相互作用，它们常常遭受变化很大的高死亡率。 这种空间和时间的高度变化意味着早期幼虫的存活在种群动态中起着重要作用。 ******我的比较方法使用了三个系统，这些系统因其生活史、群居性和种群动态方面的差异而被选择：两种重要的加拿大爆发性森林害虫 - 云杉芽虫（Choristoneura fumiferana，独居，针叶树饲养者），森林帐篷毛毛虫（Malacosoma） disstria，群居，落叶饲养者）和各种热带明翼蝴蝶（Ithominae，一些物种群居，其他物种独居）。 ***1.哪些行为机制导致加拿大东部最重要的森林害虫早期存活率的波动？早期存活率的极端变化构成了预测芽虫爆发的重要知识差距。我将通过测试将寄主植物物候、叶子化学和先前落叶与传播、竞争和取食地点建立联系起来的行为机制来填补这一空白。 ***2.群体生活如何调节森林帐篷毛毛虫的三营养相互作用？我将检验这样一个假设：群体生活意味着随着群体变小，存活率会下降，并且这种反馈会加速由于捕食和植物防御而导致的消耗。 ***3.群体生活如何调节明翅毛毛虫的三营养相互作用？我将把利用温带群居毛毛虫开发的概念和工具应用到热带地区发现的更丰富的多样性；具体来说，我将测试分组如何允许在机械防御植物上建立和在受干扰的栖息地中定居。 ******这些子目标利用每个研究生物体的特定自然历史来制定有关驱动早期生态学机制的假设。他们共同形成了一个雄心勃勃、创新且范围广泛的研究计划，综合了相互作用的压力源的影响，以解释早期生存中复杂的新兴模式。我独特的基于个人的方法为热带森林的保护和北方森林爆发动态（包括对气候变暖的反应）的机械解释提供了坚实的科学基础。对爆发性害虫的研究尤其及时，因为目前这两种害虫在加拿大大部分地区都呈上升趋势。 **