We assessed the intraspecific morphological variation in Erythrodiplax media Borror 1942 (Odonata, Libellulidae) among grassland physiognomies (“Coastal,” “Highland,” and “Steppic”) in the South Brazilian Campos. We measured six morphological traits (total body length, thorax height, length, and width of the fore- and hindwings) from 90 specimens (60 males and 45 females). We tested the effect of the grassland type on the set of traits using one-way MANOVA and principal component analysis (PCA) (separately for each sex). Grassland physiognomy affected the morphology of males and females. In both sexes, the PCA mostly opposed the specimens of the Coastal from the Highland and Steppic grasslands. The first PCA axis separated specimens according to body lengths, thorax heights, and wing width, while the second PCA axis opposed specimens according to wing length and thorax height from specimens with broader wings and longer body lengths. Males from the Coastal had longer body lengths and shorter thorax heights than Highland and Steppic grasslands, while males from the Steppic had longer fore- and hindwings than specimens from the Coastal and Highland grasslands. Females from the Coastal had significantly shorter forewings than specimens from the Steppic grasslands and shorter hindwings than Highland grasslands. Our results are likely explained by the differences in climate and habitat complexity among grassland types and indicate that the processes driving odonate performance vary among grassland biotopes. This study potentially indicates that dragonflies are sensitive to changes in the vegetation structure in South American subtropical grasslands.

我们评估了Erythrodiplax 培养基中的种内形态变异Borror 1942 (Odonata, Libellulidae) 在巴西南部坎波斯的草原地貌（“沿海”、“高地”和“草原”）中。我们测量了 90 个标本（60 只雄性和 45 只雌性）的六种形态特征（体长、胸高、前后翅的长度和宽度）。我们使用单向多元方差分析和主成分分析 (PCA)（分别针对每个性别）测试了草地类型对一组性状的影响。草原地貌影响了雄性和雌性的形态。在两性中，PCA 主要反对来自高地和草原草原的沿海标本。第一个 PCA 轴根据体长、胸高和翼宽分离标本，而第二个 PCA 轴根据翼长和胸高与翼长和体长较长的标本相对立。沿海地区的雄性比高地和草原草原的雄性体长更长，胸高更短，而草原的雄性的前翅和后翅比沿海和高地草原的标本长。沿海地区的雌性前翅明显短于草原草原的标本，后翅短于高地草原。我们的结果可能是由草原类型之间气候和栖息地复杂性的差异来解释的，并表明驱动齿状体性能的过程因草原生物群落而异。