CAREER: Testing the adaptive significance of thermally-mediated behavioral responses of tropical and temperate dung beetles in a changing world

气温影响昆虫的发育和生存，气温升高预计会导致昆虫数量下降。昆虫可能会通过改变它们的行为来利用它们环境中较凉爽的小气候来弥补气温上升的影响。然而，与在温带等温度多变的环境中进化的物种相比，在热带地区等相对恒定的热环境中进化的物种改变其行为以应对气温变化的能力可能有限。为了了解行为变化缓冲生物变暖的可能性，该项目将通过实验室实验和野外操作，让热带和温带屎甲虫这一有益的昆虫群体暴露在气温上升的环境中。具体地说，研究人员将研究屎甲虫在更温暖和更多变的温度下的繁殖行为，并调查行为反应如何影响后代的生存和发育。然后，研究人员将建立一个模型来预测气温变化对昆虫种群的影响。美国原住民高中生和本科生实习生将进行这项研究的关键部分。该项目将同时支持STEM扫盲和对STEM领域的兴趣，同时促进我们对不同纬度物种对环境胁迫的敏感性的理解。其他更广泛的影响包括在美国和国际现场对研究生进行生理学和生态学方面的培训，从而加强学生的全球网络。该项目将加强基础设施，将昆虫标本添加到美国和厄瓜多尔的收藏品中，用于教学和未来的研究。热带外温带生物代表着地球上绝大多数的生物多样性，预计将特别容易受到气温平均值和方差上升的影响。然而，这些预测存在很大的不确定性，因为模型往往没有考虑到行为可塑性，这可能会缓冲生物免受温度变化的影响。理论表明，行为可塑性的能力应该随着生物的进化史而变化；来自温带的物种进化出更多的昼夜和季节温度变化，可能比来自更恒定的热带的物种具有更大的行为可塑性。该项目将纳入实际的温度变化(即均值和方差的增加)，并侧重于热带和温带屎甲虫生殖行为的可塑性。金龟子是一类具有生态和经济价值的昆虫，对其后代的发育环境有相当大的控制作用，进而影响后代的表型、适合度和种群动态。通过一系列综合的实验室和野外实验，该项目将1)比较热带和温带物种对温度变化的生殖行为的可塑性，2)研究这些反应如何影响后代的表型和适应能力。然后，生命表数据将被用于3)开发一个模型来评估热带和温带物种的种群生存能力。研究将与美国原住民高中教育计划和本科生实习相结合，以同时支持STEM扫盲和对STEM领域的兴趣，同时促进我们对行为可塑性潜力的理解，以缓冲物种免受温度变化的影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Temperature impacts the development and survival of insects, and warmer temperatures are expected to result in insect population declines. Insects could potentially compensate for temperature increases by shifting their behavior to take advantage of cooler microclimates in their environment. However, species that have evolved in relatively constant thermal environments, like tropical regions, may have limited ability to shift their behavior in response to temperature changes compared to species that have evolved in thermally variable environments, like temperate regions. To understand the potential for behavioral shifts to buffer organisms from warming, this project will expose tropical and temperate dung beetles, a beneficial insect group, to temperature increases using laboratory experiments and field manipulations. Specifically, researchers will examine reproductive behaviors of dung beetles in response to warmer and more variable temperatures and investigate how behavioral responses impact offspring survival and development. The researchers will then build a model to predict impacts of temperature change on insect populations. Native American high school students and undergraduate interns will carry out key pieces of the research. The project will simultaneously support STEM literacy and interest in STEM fields while advancing our understanding of the sensitivity of species from different latitudes to environmental stress. Additional broader impacts include training of graduate students in physiology and ecology in the USA and at international field sites, thus strengthening students’ global networks. This project will enhance infrastructure by adding insect specimens to collections in the USA and Ecuador for teaching and future research.Tropical ectotherms, which represent the vast majority of biological diversity on Earth, are predicted to be particularly at risk from increases in temperature mean and variance. However, there is a great deal of uncertainty in these predictions because models often fail to consider behavioral plasticity, which could buffer organisms from temperature change. Theory suggests the capacity for behavioral plasticity should vary with the evolutionary history of organisms; species from temperate zones that evolved with more diurnal and seasonal temperature variation may have greater behavioral plasticity than species from the more invariant tropical zones. This project will incorporate realistic temperature changes (i.e. increases in both mean and variance) and focus on plasticity of reproductive behaviors of tropical and temperate dung beetles. Dung beetles—an ecologically and economically valuable insect group—have considerable control over the developmental environment of their offspring, which in turn impacts offspring phenotype, fitness, and population dynamics. Using an integrated series of lab and field experiments, the project will 1) compare plasticity of reproductive behaviors among tropical and temperate species in response to temperature change, and 2) examine how these responses shape offspring phenotype and fitness. Life table data will then be used to 3) develop a model to assess population viability of tropical and temperate species. Research will be integrated with a Native American high school education program and undergraduate internships to simultaneously support STEM literacy and interest in STEM fields while advancing our understanding of the potential for behavioral plasticity to buffer species from temperature changes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.