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: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712463
• 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，植物的物理和化学防御，群体生活和自然敌人的相互作用，以产生幼体生存的新模式，以确定物候，植物物理和化学防御，群体生命和自然敌人如何建立一个基于过程的概念框架。 通常，对年轻幼虫的研究很少，但经常遭受相互作用特异性压力源引起的高死亡率的差异很大。 空间和时间上的这种高差异意味着早期的生存在人群动态中起着重要作用。 我的比较方法使用了三种用于其生活史差异，人群和人口动态差异的系统：两个重要的加拿大爆发森林害虫 - 云杉芽虫（Choristoneura fumiferana，sytary，单独的，针叶树饲养者），森林帐篷caterpillars（森林帐篷caterpillars）物种群体，其他人孤立）。 1。哪些行为机制在加拿大东部最重要的森林害虫的早期生存中驱动了波动？早期式生存的极端变化构成了预测芽虫爆发的重要知识差距。我将通过测试将宿主植物物候，叶子化学和以前的脱叶与饲料分散，竞争和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中的三型相互作用？我将检验以下假设：群体的生活意味着随着群体的较小，生存率降低，并且由于捕食和植物防御能力，这种反馈加速了损耗。 3。小组生活如何调节Clearwing毛毛虫中的三四光相互作用？我将使用温带地区的群居毛毛虫开发的概念和工具，以在热带地区发现的多样性中。具体而言，我将测试分组如何允许建立机械捍卫的植物和受干扰栖息地的定植。 这些亚物体借鉴了每个研究生物的特定自然历史，以提出有关驱动早期生态学的机制的假设。它们共同构成了一个雄心勃勃，创新，广泛的研究计划，该计划综合了相互作用的压力源以解释早期式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中的保护和北方森林中暴发动态的机理解释提供了扎实的科学基础，包括对气候变暖的反应。关于爆发的害虫的研究尤其及时，因为两者目前都在加拿大大部分地区的高潮。