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.

我的目标是建立一个基于过程的概念框架，毛毛虫早期生态学，通过确定如何物候，植物物理和化学防御，集团生活和天敌相互作用，以产生幼虫生存的紧急模式。 一般来说，对幼幼虫的研究很少，但由于物种特异性压力源的相互作用，幼幼虫的死亡率往往差异很大。 这种在空间和时间上的高度变异性意味着早期幼虫的存活在种群动态中起着重要作用。 我的比较方法使用三个系统选择他们的生活史，群居性和人口动态的差异：两个重要的加拿大爆发森林害虫-云杉芽虫（Choristoneura fumiferana，孤独，针叶树饲养），森林帐篷毛虫（天幕毛虫disstria，群居，落叶饲养）和不同的热带透翅蝶（Ithominae，一些物种群居，其他人孤独）。 1.什么样的行为机制驱动的波动，在早期的生存加拿大东部最重要的森林害虫？早期存活率的极端变化构成了预测夜蛾暴发的一个重要知识空白。我将填补这一空白，通过测试行为机制连接宿主植物物候，叶化学和以前的落叶分散，竞争和建立一个喂养网站。 2.群体生活如何调节森林帐篷毛虫的三养相互作用？我将检验这样一个假设，即群体生活意味着随着群体变小，生存率会下降，而且这种反馈会加速由于捕食和植物防御而引起的损耗。 3.群体生活如何调节透翅毛虫的三养相互作用？我将应用的概念和工具开发的温带群居毛虫在热带地区发现的更大的多样性;具体来说，我将测试如何分组允许建立机械防御植物和殖民化的干扰栖息地。 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的机制的假设。他们一起形成了一个雄心勃勃的，创新的，广泛的研究计划，综合相互作用的压力的影响，以解释复杂的紧急模式，在早期的生存。我独特的基于个人的方法为热带森林的保护提供了坚实的科学基础，并对寒带森林的爆发动态进行了机械解释，包括对气候变暖的反应。对爆发性害虫的研究特别及时，因为这两种害虫目前在加拿大大部分地区都在激增。