DISSERTATION RESEARCH: Inducible egg stacking defends against parasitism in a seed beetle

许多生物体似乎能够预测未来环境的严酷程度，并相应地改变其后代的质量。这个项目的重点是一种普通的甲虫，它会下两个蛋，以保护下层的蛋不受卵寄生虫的侵袭，并提高其存活率。顶卵比底层卵质量小，即使在没有寄生的情况下也不能完全发育。虽然堆放鸡蛋提高了最底层鸡蛋的质量，但它需要更多的资源，因此减少了可以生产的后代数量。雌性甲虫通过在下蛋前减少分配给牺牲蛋(顶部)的营养物质来预测这种权衡，但目前尚不清楚引发营养重新分配和堆积行为的线索。研究人员将启动一系列实验，以确定导致堆积行为的特定环境线索，以及雌性甲虫对这些线索的敏感性。他们预测，来自寄生蜂的化学和挥发性线索都会引起堆积反应；甲虫会根据寄生蜂的密度调整它们产生的堆积物的数量。甲虫-黄蜂相互作用系统为向年轻人传达科学发现的兴奋提供了特殊的机会。这项研究已被用于K-12班级和公共环境，以说明昆虫的多样性，并教授诸如草食和寄生等生态相互作用。在该项目的整个过程中，将通过亚利桑那大学昆虫发现小学和中学的推广计划，继续利用这种种间互动进行推广。此外，从生物学专业的弱势群体中招募的本科生将参与该项目。

A broad range of organisms appears able to predict the harshness of future environments and to change the quality of their offspring accordingly. This project focuses on a common beetle that lays stacks of two eggs in order to protect the lower egg from an egg parasitoid and to increase its survival.. Top eggs have reduced mass relative to bottom eggs, and do not complete development, even in the absnce of parasitism. While stacking eggs improves the quality of the bottom-most eggs, it requires more resources and therefore decreases the number of offspring that can be produced. Female beetles anticipate this tradeoff by reducing the nutrients allocated to the sacrificial (top) eggs before they are laid, but the cues eliciting nutrient reallocation and stacking behavior are currently unknown. The researchers will initiate a series of experiments to determine the specific environmental cues responsible for stacking behavior and the sensitivity of female beetles to these cues. They predict that both chemical and volatile cues from the parasitoid cause the stacking response; and that beetles adjust the number of stacks they produce in response to parasitoid density.The beetle-wasp interaction system offers special opportunities for communicating the excitement of scientific discovery to young people. The research has been used in K-12 classes and public settings to illustrate insect diversity and to teach ecological interactions such as herbivory and parasitism. Over the course of the project, outreach using this interspecific interaction will be continued through an elementary and middle school outreach program at the University of Arizona, Insect Discovery. In addition, undergraduate students recruited from under-served groups in biology will participate in the project.