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.
Keywords (6): kissing bugs, morphology, species richness, environmental filtering, assembly rules, functional diversity