Taxonomy of the Iberian species of Pseudochelidura (Dermaptera: Forficulidae)

Abstract

Male cerci variability was used as the main source of information to separate taxonomic units in the genus Pseudochelidura. Based on these data it was considered that three species of Pseudochelidura coexisted in the Pyrenees: P. sinuata, P. minor and P. montuosa. However, our phylogeographic and phylogenetic analyses based on molecular data (mitochondrial cytb and nuclear ITS2) do not support those conclusions. Combining these analyses with morphological studies we concluded that: 1) the Pyrenees are inhabited by a single evolutionary unit: P. sinuata (Germar, 1825) (= P. minor Steinmann, 1979 syn. nov., = P. montuosa Steinmann, 1981 syn. nov.). 2) Cantabrian and Pyrenean populations are reciprocally monophyletic and morphologically diagnosable representing two independent evolutionary units: Pseudochelidura cantabrica Cuesta-Segura, Jurado-Angulo & García-París sp. nov. and P. sinuata. And, 3) their conservation status needs to be evaluated in the light of current taxonomic changes. We have shown that the use of male cerci for species identification is problematic. Patterns of variation possibly affected by sexual selection (e.g., intrapopulational variability) appear to be very difficult to separate from variation driven by natural selection or genetic drift (i.e., character divergence in geographical isolation). The large sequence divergence observed between Pyrenean and Cantabrian populations of Pseudochelidura suggest a lasting genetic and geographic isolation between them, rendering difficult to ascertain their phylogenetic relationships.

Systematics of the Sierra Nevada endemic earwig: Eulithinus analis (Forficulidae, Dermaptera)

“…Pygidium and male forceps morphology are traits widely used as diagnostic taxonomic characters, however these are characters with high intraspecific variability in earwigs (Dohrn 1867;Diajonov 1925;Ollason 1970;Simpson & Mayer 1990;Tomkins & Simmons 1996;García-París 2017;Kirstová et al 2020;Fontana et al 2021;García-París et al 2021;Jurado-Angulo et al 2021;Cuesta-Segura et al 2023). It has been recently demonstrated by morphological and molecular analyses (Fontana et al 2021;Jurado-Angulo et al 2021;Cuesta-Segura et al 2023), that the misinterpretation of the morphological variability of male cerci in Chelidura and Pseudochelidura led to errors in the determination of the geographic distribution of the species and in the delimitation of independent evolutionary units (e.g., species).…”

“…To evaluate the phylogenetic placement of the Sierra Nevada earwigs we combined our cytb dataset with the data set from Pseudochelidura generated in Cuesta-Segura et al (2023). We used the cytb data set instead of cox1 because, as reported by Cuesta-Segura et al (2023), amplifications of cox1 from Pyrenean Pseudochelidura consistently yielded Wolbachia (Rickettsiales) (Werren et al 2008) sequences.…”

“…To evaluate the phylogenetic placement of the Sierra Nevada earwigs we combined our cytb dataset with the data set from Pseudochelidura generated in Cuesta-Segura et al (2023). We used the cytb data set instead of cox1 because, as reported by Cuesta-Segura et al (2023), amplifications of cox1 from Pyrenean Pseudochelidura consistently yielded Wolbachia (Rickettsiales) (Werren et al 2008) sequences. Phylogenetic analyses were carried out under Bayesian inference (BI) methods using a dataset that included 19 specimens of Pseudochelidura sinuata (Germar, 1825), 13 specimens of Pseudochelidura cantabrica (Cuesta-Segura et al, 2023), four specimens of Eulithinus analis (sensu Hincks 1935), and one specimen of Mesochelidura bolivari (Dubrony, 1878) used as distant outgroup.…”

“…We used the cytb data set instead of cox1 because, as reported by Cuesta-Segura et al (2023), amplifications of cox1 from Pyrenean Pseudochelidura consistently yielded Wolbachia (Rickettsiales) (Werren et al 2008) sequences. Phylogenetic analyses were carried out under Bayesian inference (BI) methods using a dataset that included 19 specimens of Pseudochelidura sinuata (Germar, 1825), 13 specimens of Pseudochelidura cantabrica (Cuesta-Segura et al, 2023), four specimens of Eulithinus analis (sensu Hincks 1935), and one specimen of Mesochelidura bolivari (Dubrony, 1878) used as distant outgroup. We also include as outgroups the Eudohrnia metallica (Dohrn, 1865) and Paratimomenus flavocapitatus (Shiraki, 1905) cytb fragment obtained from their partial mitochondrial genome available in GenBank (Table 1).…”

“…This concept considers a species as "a single lineage of ancestral descendant populations of organisms which maintains its identity from other such lineages and which has its own evolutionary tendencies and historical fate" (Wiley 1978: 18). Testing for cohesion was performed identifying levels of concordance between morphology and nuclear and mitochondrial markers (Sainz-Escudero et al 2021;Cuesta-Segura et al 2023).…”