Large-scale patterns in morphological diversity, and species assembly in Neotropical Triatominae (Heteroptera: Reduviidae)

We analysed the spatial variation in morphological diversity (MDiv) and species richness (SR) in 91 species of Neotropical Triatominae to test the hypothesis that ecological relationships between SR, MDiv and environmental factors underlie the structuring of species assemblages. On each 110 km x 110 km-cell in a grid map of America., we counted determined the number of species (SR), and estimated the mean Gower index (MDiv) based on 12 morphological attributes, We bootstrapped species assemblages to detect species assemblages more similar or dissimilar in their morphology than expected by chance. We applied a multi-model selection procedure and spatial explicit analyses to account for the association of diversity-environment relationships. MDiv and SR showed a latitudinal gradient, although peaked at different locations. SR decreased with temperature variability, and MDiv increased with mean temperature suggesting a predominant role of the ambient energy hypothesis. MDiv and SR are components of diversity that cannot strictly be considered surrogates from each other. Species more similar than expected by chance co-occurred near the limits of the Triatominae distribution in association with changes in environmental variables. This suggests environmental that filtering may underlie the Triatominae structuring of species assemblages towards their Triatominae distributional limits.<br>Keywords (6): kissing bugs, morphology, species richness, environmental filtering, assembly rules, functional diversity

本研究针对91种新热带区锥蝽亚科（Triatominae）昆虫，分析其形态多样性（morphological diversity, MDiv）与物种丰富度（species richness, SR）的空间分布格局，旨在验证“物种丰富度、形态多样性与环境因子间的生态关联是物种群落构建的基础”这一假说。在美洲区域的网格地图中，每个110 km×110 km的网格单元内，我们统计并确定了物种数量（SR），并基于12项形态学性状估算了平均高沃指数（Gower index，即形态多样性MDiv）。我们通过自举法（bootstrapping）对物种群落进行分析，以识别形态相似度相较于随机预期显著更高或更低的物种群落。我们采用多模型遴选方法与空间显式分析，以厘清多样性与环境因子间的关联机制。形态多样性与物种丰富度均呈现纬度梯度分布，但二者的峰值出现位置存在差异。物种丰富度随温度变异性升高而降低，形态多样性则随平均温度升高而增加，这一结果支持环境能量假说（ambient energy hypothesis）占据主导地位的推论。形态多样性与物种丰富度作为多样性的不同组成维度，无法严格互为替代指标。在锥蝽亚科分布边界附近，形态相似度高于随机预期的物种会共同出现，且该现象与环境变量的变化存在关联。这表明环境过滤（environmental filtering）可能是锥蝽亚科物种群落在其分布边界处完成群落构建的核心机制。
关键词（共6个）：接吻虫（kissing bugs）、形态学、物种丰富度、环境过滤、群落构建规则、功能多样性