A Critical Examination of the Model for Insect Body Size Determination: the Mechanisms of Body Size Variation in Bees

生长速度和生长停止的时间决定了身体的大小，这是生存和繁殖的重要特征。停止生长的线索并没有完全理解，即使在研究充分的模式物种。独居蜜蜂为它们的后代提供食物，限制幼虫生长所需的食物。实验表明，这些食物的完全消费会引起变态。研究独居蜜蜂的变态线索提供了一个独特的机会，在生理上比较相同年龄和大小的个体，无论是否已经过渡到变态。拟议的研究将调查（1）孤独蜜蜂中饥饿引发变态的激素线索是否与达到特定大小后变态的昆虫中发现的激素线索相同，（2）变态时间的变化如何预测自然种群和不同蜜蜂物种中的身体大小变化，以及（3）蜜蜂成年体大小的决定因素如何影响蜂后和工蜂之间的差异。蜜蜂的身体大小预测授粉性能，身体大小控制的生理学理解有直接的影响传粉者的健康和性能在自然和管理的蜜蜂物种，无论是孤独的还是社会的。本科生，研究生和博士后研究员将参与这项研究，并将开发K-12学习模块的传粉者生命周期。身体大小是一个重要的生物体特征，与性能和健身的大多数方面相关。在决定生长的生物体中，身体大小在成熟时变得固定;因此，调节成熟的机制也影响个体之间的大小变化。昆虫作为幼虫生长，直到达到临界体重，此时调节变态的机制不可逆转地启动。这种建立的体型控制模型可能无法推广到幼虫生态与模式昆虫物种不同的物种。初步数据表明，完全消费的幼虫规定启动变态的团结蜜蜂壁蜂lignaria。这一结果挑战了现有的概念模型，昆虫的身体大小的建议，临界重量是不是一个普遍的性状在昆虫。拟议的研究将解决三个中心目标：1）表征变态的生理调节在孤独的蜜蜂壁蜂lignaria，2）表征因素决定的种群和物种之间的个体大小的变化，共享相似的幼虫生态;和3）测试在何种程度上饮食量有助于种姓差异真社会性蜜蜂。这些机制有可能解释大部分的身体大小的变化之间观察到的Hypherterans。最后，拟议的研究将发展一个机械明确的理解蜜蜂的身体大小决定，这是自然和管理的生态系统的关键授粉。对体型变化的更深层次的机械理解可能会在个体甚至种群的规模上改善传粉者的健康。 这些研究的结果将在同行评审的期刊上传播，并通过在科学会议上的介绍传播。

Growth rate and the timing of when growth stops determine body size, an important trait for survival and reproduction. The cues that stop growth are not fully understood, even in well-studied model species. Solitary bees provision their offspring, restricting the food available for larval growth. Experiments indicate that the complete consumption of these provisions induces metamorphosis. Studying the cues to metamorphosis in solitary bees provides a unique opportunity to physiologically compare individuals of the same age and size that either have or have not transitioned to metamorphosis. The proposed research will investigate (1) whether the hormonal cues underlying starvation-triggered metamorphosis in solitary bees are the same as those found in insects that metamorphose upon reaching a particular size, (2) how variation in the timing of metamorphosis predicts body size variation in natural populations and different bee species, and (3) how the determinants of adult size in bees shape differences between queens and workers in honeybees. Bee body size predicts pollination performance, and a physiological understanding of body size control has direct implications for pollinator health and performance in both natural and managed bee species, whether solitary or social. Undergraduates, graduate students and a postdoctoral fellow will participate in this research, and K-12 learning modules on pollinator life cycles will be developed.Body size is an important organismal trait that correlates with most aspects of performance and fitness. In determinant-growing organisms, body size becomes fixed at maturation; therefore the mechanisms regulating maturation also influence size variation among individuals. Insects grow as larvae until attainment of a critical weight, at which point the mechanisms regulating metamorphosis are irreversibly initiated. This established model of body size control may not be generalizable to species with larval ecologies that differ from model insect species. Preliminary data demonstrate that completely consuming the larval provision initiates metamorphosis in the solidary bee Osmia lignaria. This result challenges the existing conceptual model for insect body size by suggesting that the critical weight is not a universal trait in insects. The proposed research will address three central aims: 1) characterizing the physiological regulation of metamorphosis in the solitary bee Osmia lignaria, 2) characterizing factors determining body size variation among populations and species of solitary bees that share similar larval ecologies; and 3) testing the degree to which diet quantity contributes to caste differences in eusocial bees. These mechanisms have the potential to explain much of the body size variation observed among Hymenopterans. Finally, the proposed research will develop a mechanistically explicit understanding of body size determination for bees, which are key pollinators for natural and managed ecosystems. A deeper, mechanistic understanding of body size variation may yield insights into improving pollinator health at the scale of individuals or even populations. Results from these studies will be disseminated in peer reviewed journals and through presentations at scientific meetings.