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The Peruvian genera of Edrotini (Pimeliinae) are revised. A new genus Pachacamacius Flores & Giraldo gen. nov. with two new species, Pachacamacius aguilari Giraldo & Flores sp. nov. (type species) and Pachacamacius koepckeae Flores & Giraldo sp. nov., is described. Two species originally described in the genus ProhylithusKaszab, 1964 are reassigned to two new monotypic genera: Sechuranus Flores and Giraldo gen. nov. (type species Prohylithus barbatusKaszab, 1964) and Koneus Giraldo and Flores, gen. nov. (type species Prohylithus peruanusKaszab, 1981). This article includes diagnoses for five genera and redescriptions or descriptions, distributional data, habitat records and habitus photographs for six species. A dichotomous key for all 11 Peruvian species of Edrotini, drawings of new species' male genitalic features, and distribution maps are also provided. A discussion of the external morphological characters and male genitalia of the new taxa compared to the genera and species previously described and on endemicity and zoogeography of Peruvian Edrotini is presented.
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This content will become publicly available on August 1, 2025
Linear Morphometry of Male Genitalia Distinguishes the Ant Genera Monomorium and Syllophopsis (Hymenoptera: Formicidae) in Madagascar
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 Monomorium and Syllophopsis 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.
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- Award ID(s):
- 1932467
- PAR ID:
- 10540177
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Insects
- Volume:
- 15
- Issue:
- 8
- ISSN:
- 2075-4450
- Page Range / eLocation ID:
- 605
- Subject(s) / Keyword(s):
- species delimitation male genitalia linear morphometry multivariate analysis Formicidae Madagascar
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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