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

温度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环境中较冷的小气候来补偿温度的升高。然而，在相对恒定的热环境中进化的物种，如热带地区，与在温度变化的环境中进化的物种相比，在温度变化中改变行为的能力可能有限，如温带地区。为了了解行为变化以缓冲生物变暖的潜力，该项目将通过实验室实验和现场操作将热带和温带蜣螂（一种有益的昆虫群体）暴露在温度升高的环境中。具体来说，研究人员将研究屎壳郎的生殖行为，以应对更温暖和更多变的温度，并研究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温度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素养和对STEM领域的兴趣，同时促进我们对不同纬度物种对环境压力敏感性的理解。其他更广泛的影响包括在美国和国际实地培训生理学和生态学研究生，从而加强学生的全球网络。该项目将加强基础设施，为美国和厄瓜多尔的教学和未来研究增加昆虫标本。代表地球上绝大多数生物多样性的热带变温动物，预计将特别受到温度平均值和方差增加的威胁。然而，这些预测存在很大的不确定性，因为模型通常没有考虑行为可塑性，而行为可塑性可以缓冲生物体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体的进化史而变化；来自温带的物种在昼夜和季节温度变化中进化得更大，可能比来自不变的热带地区的物种具有更大的行为可塑性。本项目将结合实际温度变化（即平均值和方差的增加），重点研究热带和温带蜣螂生殖行为的可塑性。屎壳虫是一种具有生态和经济价值的昆虫群体，对其后代的发育环境具有相当大的控制力，从而影响后代的表型、适应性和种群动态。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合度。然后，生命表数据将用于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，同时支持STEM素养和对STEM领域的兴趣，同时推进我们对行为可塑性缓冲物种免受温度变化影响的潜力的理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.