International Research Fellowship Program: Impacts of Invasive Ants on Plant Conservation in Mauritius

0401703 Lach国际研究奖学金计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。 该计划的奖项提供了联合研究的机会，并使用独特或互补的设施，专业知识和国外的实验条件。该奖项将支持22个月的研究奖学金博士洛里拉赫与博士约翰R。Mauremootoo在毛里求斯LaPreneuse的毛里求斯野生动物基金会工作了19个月，并在伊利诺伊大学香槟分校与May Berenbaum和Andrew苏亚雷斯博士一起工作了3个月。 该项目的部分支持来自环境中的生物复杂性（BE）计划。几种蚂蚁被认为是世界上最具破坏性的入侵物种。入侵蚂蚁对本地蚂蚁和其他节肢动物的影响相对有据可查，但对它们对植物的影响知之甚少。入侵蚂蚁可能依赖花或花外花蜜，或同翅目分泌物来为它们的大型殖民地提供燃料。寄主植物的适合度可能会下降，如果同翅目往往蚂蚁达到高密度，但蚂蚁访问蜜腺或同翅目可能会阻止植食动物的植物的利益。几种最严重的入侵蚂蚁广泛分布在热带岛国毛里求斯，但它们的生态从未在这些岛屿上进行过研究。几个恢复种群的稀有地方性植物是宿主同翅目爆发，最广泛的杂草之一有花外蜜腺，这表明有多种途径，入侵蚂蚁可能会影响岛上的植物community.This研究正在测试四个假设：1）入侵蚂蚁在毛里求斯广泛分布，并取代了本地蚂蚁。2)蚂蚁正在促进同翅目在本地植物上的爆发，这些爆发导致植物活力下降。3)入侵蚂蚁在以食物换保护的互惠共生中阻止食草动物从花外花蜜承载入侵植物。4)蜜露、花和花外花蜜的蛋白质、氨基酸和糖组成存在差异，在蚂蚁繁殖的季节性背景下，影响蚂蚁获得碳水化合物的位置。目前正在通过以下方式对假设进行检验：（1）每季度对8个自然保护区进行蚂蚁调查;（2）对同翅目寄主本地植物进行蚂蚁排斥实验;（3）对入侵植物银合欢进行蚂蚁排斥实验;（4）对项目期间蚂蚁吸收和忽视的花蜜和分泌物进行实验室分析。拟议项目的结果将与毛里求斯和其他热带岛屿的保护生物学家以及不断增长的入侵生态学领域有关。 除了是毛里求斯蚂蚁的第一项生态研究，以及为数不多的评估入侵蚂蚁对非农业热带生态系统中植物影响的研究之一之外，这是第一项比较蚂蚁吸引力和不同季节社区分泌物和花蜜资源组成的研究。

0401703LachThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-two-month research fellowship by Dr. Lori Lach to work with Dr. John R. Mauremootoo at the Mauritius Wildlife Foundation in LaPreneuse, Mauritius, for nineteen months and at the University of Illinois, Champaign-Urbana with Drs. May Berenbaum and Andrew Suarez for three months. Partial support for this project comes from the Biocomplexity in the Environment (BE) Program.Several species of ants are considered to be among the world's most destructive invasive species. Impacts of invasive ants on native ants and other arthropods are relatively well-documented; less is known about their impacts on plants. Invasive ants may rely on floral or extrafloral nectar, or homopteran exudates to fuel their large colonies. Host plant fitness may decline if Homoptera tended by ants reach high densities, however ants visiting nectaries or Homoptera may deter herbivores to the benefit of the plant. Several of the worst invasive ants are widespread in the tropical island nation of Mauritius, but their ecology has never been researched on these islands. Several restored populations of rare endemic plants are hosting Homoptera outbreaks, and one of the most widespread weeds has extrafloral nectaries, suggesting that there are multiple avenues through which invasive ants may be affecting the islands' plant communities.This study is testing four hypotheses: 1) Invasive ants are widespread in Mauritius and have displaced native ants. 2) Ants are facilitating Homoptera outbreaks on native plants, and these outbreaks are resulting in decreased plant vigor. 3) Invasive ants are deterring herbivores from extrafloral nectar-bearing invasive plants in a food-for-protection mutualism. 4) There are differences in protein, amino acid, and sugar composition of honeydew and floral and extrafloral nectar that, in the context of the seasonality of ant reproduction, affect where ants obtain carbohydrates. Hypotheses are being tested through 1) quarterly ant surveys of eight nature reserves 2) an ant exclusion experiment on native plants hosting Homoptera, 3) an ant exclusion experiment on the invasive plant Leucaena leucocephala and 4) laboratory analyses of nectars and exudates imbibed and ignored by ants over the course of the project. Findings from the proposed project will be relevant to conservation biologists in Mauritius and other tropical islands as well as to the growing field of invasion ecology. In addition to being the first ecological study of ants in Mauritius, and one of only a handful of studies to assess the impacts of invasive ants on plants in a non-agricultural tropical ecosystem, this is the first study to compare ant attraction to and composition of exudates and nectar resources across a community over different seasons.