Sarracenia Purpurea Prey Capture at Harvard Forest 2008

We experimentally demonstrate that nectar, not color, is the primary attractant of prey to carnivorous pitcher plants in their native habitats. Prey capture (either all taxa summed or individual common taxa considered separately) was not associated with total red area or patterning on pitchers of living pitcher plants. We separated effects of nectar availability and coloration using painted "pseudopitchers", half of which were coated with sugar solution. Unsugared pseudopitchers captured virtually no prey, whereas pseudopitchers with sugar solution captured the same amount of prey as living pitchers. In contrast to a recent study that associated red coloration with prey capture but that lacked appropriate controls for nectar availability, we conclude that nectar, not color, is the primary means by which pitcher plants attract prey.本研究通过实验证实，在原生栖息地中，食虫猪笼草（carnivorous pitcher plants）吸引猎物的核心诱因为花蜜而非体色。无论是将所有猎物类群合并统计，还是单独分析常见的单一类群，活体猪笼草捕虫笼的总红色区域面积及其斑纹模式，均与猎物捕获量无显著关联。本研究采用涂装的“模拟捕虫笼（pseudopitchers）”区分花蜜供给与体色的影响，其中半数模拟笼表面涂抹了糖溶液。未涂抹糖溶液的模拟捕虫笼几乎未捕获任何猎物，而涂抹糖溶液的模拟捕虫笼的猎物捕获量与活体猪笼草持平。与近期一项将红色体色与猎物捕获量相关联，但未针对花蜜供给设置恰当对照的研究不同，本研究最终得出结论：食虫猪笼草吸引猎物的主要途径为花蜜而非体色。