Collaborative Research: Detection, Perception and Utilization of Floral CO2 by Manduca sexta

合作研究：蜜桔取食蜜柑时对二氧化碳的检测、感知和利用。Hildebrand和Robert A.许多昆虫对环境中的二氧化碳（CO2）很敏感，众所周知，它对吸血物种对宿主的吸引力很重要，但CO2对以花蜜为食的昆虫的行为意义在很大程度上尚不清楚。初步研究结果表明，天蛾Manduca sexta（鳞翅目：天蛾科）可能会利用新开放的花朵排放的二氧化碳来帮助它在觅食期间找到未开发的花蜜来源。建议的研究的主要目标是确认和建立的作用，花卉CO2蛾的觅食行为，因此授粉的花，通过调查生态，行为和神经生理方面的感觉检测CO2在天蛾。特别是，该项目旨在发现：（1）在飞蛾访问之前和之后，花的花蜜含量与花前的CO2浓度之间的关系;（2）Manduca在觅食期间是否以及如何使用花卉CO2;以及（3）关于CO2的感官信息如何处理并与飞蛾大脑中的花香信息相结合。目标（2）中的觅食行为研究在单独的实验中解决了蛾是否评估有益的个体花朵或植物斑块，以及觅食蛾是否使用有关花卉CO2的感官信息来增加花蜜摄入量。我们还将测试飞蛾是否单独使用花卉CO2或与花卉气味一起使用。 为了实现这些目标，我们将使用实验方法的组合。我们将测量个体蛾的行为反应，无论是在实验室（在隧道和气候控制的飞行竞技场中的飞行蛾的实验）和在现场（在室外飞行外壳），以人工和天然的花朵，在花蜜，二氧化碳和花香，他们发出的量不同。我们将使用感觉神经生理学的技术来记录蛾的大脑的嗅觉中心的神经细胞的反应，当蛾被刺激与CO2和花香化合物，无论是单独的和一起。这种方法应该产生的见解觅食蛾花刺激的适应性反应及其潜在的神经生物学机制。 在其更广泛的影响中，这项研究预计将对农业界有用，因为许多飞蛾和其他与植物有关的昆虫是有益的传粉者和/或经济上重要的害虫。通过CO2线索操纵昆虫的表现已经用于控制吸血昆虫，如蚊子，并在这项研究的基础上，可以类似地开发，以帮助控制农业环境中的蛾。这项工作还可能有助于评估如果环境中的二氧化碳水平继续增加，如全球气候变化所预测的那样，对生态相互作用（食物网、互惠）的影响。此外，重要的是，该项目的参与者将受益于其多学科方法，并获得一系列方法和技术挑战的经验。计划有两名本科生参与。这两个合作实验室都有支持和培训少数民族学生的记录，并将继续这样做。在南卡罗来纳州实验室的本科生将从全州范围内的少数民族参与研究（SCAMP）SC联盟中选出，并将每年访问图森，与项目参与者会面并参加外联活动。研究结果将在科学会议上以书面和口头形式传播，并通过面向公众的机构，如亚利桑那-索诺拉沙漠博物馆传播。

COLLABORATIVE RESEARCH: DETECTION, PERCEPTION AND USE OF FLORAL CO2 IN NECTAR FEEDING BY MANDUCA SEXTAJohn G. Hildebrand and Robert A. RagusoUniversity of Arizona and University of South CarolinaMany insects are sensitive to environmental carbon dioxide (CO2), and it is known to be important for attraction of blood-feeding species to their hosts, but the behavioral significance of CO2 for insects that feed on floral nectar is largely unclear. Preliminary studies yielded findings suggesting that the hawkmoth Manduca sexta (Lepidoptera: Sphingidae) may use elevated CO2, emitted by newly opened flowers, to help it find unexploited nectar sources during foraging. The principal goal of the proposed research is to confirm and establish the roles of floral CO2 in moths' foraging behavior, and hence pollination of flowers, by investigating ecological, behavioral, and neurophysiological aspects of the sensory detection of CO2 in Manduca. In particular, the project aims to discover: (1) the relationship between a flower's nectar content and CO2 concentration in front of the flower, both before and after a moth's visit; (2) whether and how Manduca uses floral CO2 during foraging; and (3) how sensory information about CO2 is processed and integrated with information about floral scent in the moth's brain. The investigation of foraging behavior in aim (2) addresses, in separate experiments, whether moths evaluate profitable individual flowers or plant patches, and whether foraging moths use sensory information about floral CO2 to increase their nectar intake. We also will test whether moths use floral CO2 alone or in conjunction with floral odor. To achieve these aims, we will use a combination of experimental approaches. We will measure behavioral responses of individual moths, both in the laboratory (for experiments on flying moths in a tunnel and in a climate-controlled flight arena) and in the field (in outdoor flight enclosures), to artificial and natural flowers that vary in the amounts of nectar, CO2, and floral scent that they emit. We will use the techniques of sensory neurophysiology to record responses of nerve cells in the olfactory center of the moth's brain, when the moths are stimulated with CO2 and floral-scent compounds, both separately and together. This approach should yield insights about the adaptive responses of foraging moths to floral stimuli and their underlying neurobiological mechanisms. Among its broader impacts, this research is expected to be useful to the agricultural community, as many moths and other plant-associated insects are beneficial pollinators and/or economically important pests. Manipulation of insect performance via CO2 cues is already used to control blood-feeding insects such as mosquitoes and, on the basis of this research, may be developed similarly to help control moths in an agricultural context. This work may also help to assess the consequences for ecological interactions (food webs, mutualisms) if ambient levels of CO2 continue to increase, as is predicted for global climate change. Importantly, moreover, participants in the project will profit from its multidisciplinary approach and gain experience with a range of methods and technical challenges. Involvement of two undergraduate students is planned. Both collaborating laboratories have records of supporting and training minority students and will continue to do so. The undergraduate student in the South Carolina laboratory will be chosen from the state-wide SC Alliance for Minority Participation in Research (SCAMP) and will visit Tucson each year to meet with project participants and participate in outreach activities. Research findings will be disseminated in written and oral form at scientific conferences and through institutions targeting the public, e.g. the Arizona-Sonora Desert Museum.