ABSTRACT Many hypotheses have been proposed to explain the megadiversity of angiosperms and insects. Flowers and their pollinators represent the most common terrestrial mutualistic interaction today and this is thought to have driven the evolution of angiosperms and their visitors. Within the framework of that interaction, this paper develops and tests two new hypotheses: 1) megadiversity of canopy beetles in tropical rainforests is largely based on flower resources, and 2) the majority of adult canopy beetles are adapted to visit flowers. To test hypothesis 1, the beetle fauna associated with 23 canopy tree species (13 families, 45 individuals) in a 1.4 ha canopy plot of pristine lowland tropical rainforest in southern Venezuela was studied over one year. In total, 6698 adult beetles were collected and identified to 859 species in 44 families. Of these 859 species, 647 species (75.3%) were found with at least one individual on flowering trees, and 527 species (61.4%) were associated exclusively with flowering trees. The proportion of beetle species visiting exclusively small white flowers of the morphological generalist syndrome amounts to 36.6% of the entire canopy beetle community. Based on these findings, the second hypothesis was formulated that canopy beetles are specially adapted flower visitors. To test hypothesis 2, a sub-set study was conducted of the beetles visiting flowers of one tree species in the canopy plot, Hymenopus heteromorphus (Benth.) Sothers and Prance (Chrysobalanaceae). This is a mass-flowering tree with white flowers of a generalised morphology. A total of 440 adult beetles were collected in 20 days and identified to 138 species in 54 genera in 23 families. This assemblage was restricted to the flowering season of this tree. Data collected for H. heteromorphus and other mass-flowering tree species in the same plot indicates that a particular combination of flowering characteristics – massively flowering, white colour, and generalised morphology – attracts the highest diversity of beetles. These findings together suggest that the enormous diversity of canopy beetles in Amazonian tropical rainforests is due mainly to flowers and that mass-flowering trees with small white flowers of the generalist syndrome play a particularly crucial role in assembly and nourishment of this megadiverse beetle community.

中文翻译：

---

花对于在新热带雨林树冠中保持高甲虫多样性（鞘翅目）至关重要

摘要 已经提出了许多假设来解释被子植物和昆虫的巨大多样性。花朵及其传粉者代表了当今最常见的陆地互惠互动，这被认为推动了被子植物及其访客的进化。在这种相互作用的框架内，本文提出并检验了两个新假设：1) 热带雨林中冠甲虫的巨大多样性主要基于花卉资源，2) 大多数成年冠甲虫都适应了访花。为了检验假设 1，对委内瑞拉南部原始低地热带雨林 1.4 公顷林冠地块中与 23 种树冠树种（13 个科，45 个个体）相关的甲虫动物群进行了一年多的研究。共采集成虫6698只，鉴定为44科859种。在这 859 个物种中，647 个物种（75.3%）在开花树木上至少有一个个体，527 个物种（61.4%）与开花树木完全相关。仅访问形态学通才综合征的小白花的甲虫物种的比例占整个树冠甲虫群落的 36.6%。基于这些发现，提出了第二个假设，即冠甲虫是特别适应的花客。为了检验假设 2，对树冠区的甲虫访问一种树种的花朵进行了子集研究，Hymenopus heteromorphus (Benth.) Sothers 和 Prance (Chrysobalanaceae)。这是一棵大量开花的树，具有普遍形态的白花。20天共采集成虫440只，鉴定为23科54属138种。这种组合仅限于这棵树的开花季节。为同一地块中的异形异形蜂和其他大量开花树种收集的数据表明，开花特征的特定组合——大量开花、白色和普遍形态——吸引了最高多样性的甲虫。这些发现共同表明，亚马逊热带雨林中冠层甲虫的巨大多样性主要是由于花朵，并且具有通才综合症的小白花的大量开花的树木在这个庞大的甲虫群落的组装和营养中发挥着特别重要的作用。同一地块中的异形和其他大量开花的树种表明开花特征的特定组合——大量开花、白色和普遍形态——吸引了最高多样性的甲虫。这些发现共同表明，亚马逊热带雨林中冠层甲虫的巨大多样性主要是由于花朵，并且具有通才综合症的小白花的大量开花的树木在这个庞大的甲虫群落的组装和营养中发挥着特别重要的作用。同一地块中的异形和其他大量开花的树种表明开花特征的特定组合——大量开花、白色和普遍形态——吸引了最高多样性的甲虫。这些发现共同表明，亚马逊热带雨林中冠层甲虫的巨大多样性主要是由于花朵，并且具有通才综合症的小白花的大量开花的树木在这个庞大的甲虫群落的组装和营养中发挥着特别重要的作用。