Rasoarimalala Nomena F, Ramiadantsoa Tanjona, Rakotonirina Jean Claude, Fisher Brian L
Madagascar Biodiversity Center, Parc Botanique et Zoologique de Tsimbazaza, Antananarivo 101, Madagascar.
Mention Entomologie Cultures Élevage et Santé, Faculté des Sciences, Université d'Antananarivo, Antananarivo 101, Madagascar.
Insects. 2024 Aug 11;15(8):605. doi: 10.3390/insects15080605.
Morphometric analyses of male genitalia are routinely used to distinguish genera and species in beetles, butterflies, and flies, but are rarely used in ants, where most morphometric analyses focus on the external morphology of the worker caste. In this work, we performed linear morphometric analysis of the male genitalia to distinguish and in Madagascar. For 80 specimens, we measured 10 morphometric characters, especially on the paramere, volsella, and penisvalvae. Three datasets were made from linear measurements: mean (raw data), the ratios of characters (ratio data), and the Removal of Allometric Variance (RAV data). The following quantitative methods were applied to these datasets: hierarchical clustering (Ward's method), unconstrained ordination methods including Principal Component Analysis (PCA), Non-Metric Multidimensional Scaling analyses (NMDS), Linear Discriminant Analysis (LDA), and Conditional Inference Trees (CITs). The results from statistical analysis show that the ratios proved to be the most effective approach for genus-level differentiation. However, the RAV method exhibited overlap between the genera. Meanwhile, the raw data facilitated more nuanced distinctions at the species level compared with the ratios and RAV approaches. The CITs revealed that the ratios of denticle length of the valviceps (SeL) to the paramere height (PaH) effectively distinguished between genera and identified key variables for species-level differentiation. Overall, this study shows that linear morphometric analysis of male genitalia is a useful data source for taxonomic delimitation.
雄性生殖器的形态计量分析通常用于区分甲虫、蝴蝶和苍蝇的属和种，但在蚂蚁中很少使用，在蚂蚁中，大多数形态计量分析集中在工蚁等级的外部形态上。在这项研究中，我们对马达加斯加的[具体物种1]和[具体物种2]进行了雄性生殖器的线性形态计量分析。对于80个标本，我们测量了10个形态计量特征，特别是在阳茎侧叶、抱器和阳茎瓣上。从线性测量中得出了三个数据集：均值（原始数据）、特征比率（比率数据）和消除异速生长方差（RAV数据）。以下定量方法应用于这些数据集：层次聚类（沃德法）、无约束排序方法，包括主成分分析（PCA）、非度量多维尺度分析（NMDS）、线性判别分析（LDA）和条件推断树（CITs）。统计分析结果表明，比率被证明是属级区分最有效的方法。然而，RAV方法在属之间表现出重叠。同时，与比率和RAV方法相比，原始数据有助于在物种水平上进行更细微的区分。CITs显示，阳茎瓣齿长度（SeL）与阳茎侧叶高度（PaH）的比率有效地区分了属，并确定了物种水平区分的关键变量。总体而言，这项研究表明，雄性生殖器的线性形态计量分析是分类界定的有用数据源。
