Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Illinois, United States of America.
PLoS One. 2013 Aug 5;8(8):e71812. doi: 10.1371/journal.pone.0071812. Print 2013.
Lentic freshwater systems including those inhabited by aquatic stages of mosquitoes derive most of their carbon inputs from terrestrial organic matter mainly leaf litter. The leaf litter is colonized by microbial communities that provide the resource base for mosquito larvae. While the microbial biomass associated with different leaf species in container aquatic habitats is well documented, the taxonomic composition of these microbes and their response to common environmental stressors is poorly understood. We used indoor aquatic microcosms to determine the abundances of major taxonomic groups of bacteria in leaf litters from seven plant species and their responses to low concentrations of four pesticides with different modes of action on the target organisms; permethrin, malathion, atrazine and glyphosate. We tested the hypotheses that leaf species support different quantities of major taxonomic groups of bacteria and that exposure to pesticides at environmentally relevant concentrations alters bacterial abundance and community structure in mosquito larval habitats. We found support for both hypotheses suggesting that leaf litter identity and chemical contamination may alter the quality and quantity of mosquito food base (microbial communities) in larval habitats. The effect of pesticides on microbial communities varied significantly among leaf types, suggesting that the impact of pesticides on natural microbial communities may be highly complex and difficult to predict. Collectively, these findings demonstrate the potential for detritus composition within mosquito larval habitats and exposure to pesticides to influence the quality of mosquito larval habitats.
包括水生蚊子阶段在内的内陆淡水系统从陆地有机物质（主要是落叶）中获得大部分碳输入。落叶被微生物群落占据，为蚊子幼虫提供资源基础。虽然容器水生栖息地中不同叶物种相关的微生物生物量已有详细记录，但这些微生物的分类组成及其对常见环境胁迫的反应仍知之甚少。我们使用室内水生微宇宙来确定来自 7 种植物的叶凋落物中主要细菌分类群的丰度及其对具有不同作用模式的 4 种农药（拟除虫菊酯、马拉硫磷、莠去津和草甘膦）在低浓度下的反应。我们检验了以下假设：叶物种支持不同数量的主要细菌分类群，并且在环境相关浓度下接触农药会改变蚊子幼虫栖息地中细菌的丰度和群落结构。我们同时支持这两个假设，这表明落叶身份和化学污染可能会改变幼虫栖息地中蚊子食物基础（微生物群落）的质量和数量。农药对微生物群落的影响在不同叶类型之间差异显著，这表明农药对自然微生物群落的影响可能非常复杂且难以预测。总的来说，这些发现表明，蚊子幼虫栖息地内的碎屑组成和接触农药可能会影响蚊子幼虫栖息地的质量。
