Aphaenogaster ichnusa Santschi, 1925, bona species, and Redescription of Aphaenogaster subterranea (Latreille, 1798) (Hymenoptera, Formicidae)

Abstract

IntroductionAphaenogaster subterranea (Latreille, 1798) is considered a common species in Europe. The type specimens were collected around Brive-la-Gaillarde, Corrèze, France. The identification of specimens from France was not considered problematic. However, specimens from Corsica and the Mediterranean coast show morphological characters that differ noticeably from those of specimens from the rest of France (including Brive-la-Gaillarde). These characters are (i) shorter and more triangular propodeal spines, (ii) a smoother cuticle, and (iii) a body color globally lighter. This combination of characters led to identification errors: specimens with propodeal spines particularly reduced are labeled as Aphaenogaster pallida (Nylander, 1849) in the André collection at the Muséum National d'Histoire Naturelle of Paris (MNHN). These specimens, used as reference, led numerous authors to mention A. pallida from Southern France and Corsica in a range of publications (Abstract Morphological and molecular investigation conducted in France and the Tyrrhenian islands reveal that Aphaenogaster subterranea is composed of two distinct species. We propose to raise A. subterranea var. ichnusa Santschi, 1925, described from Sardinia, to the species status, A. ichnusa Santschi, 1925 stat. nov. This species differs from A. subterranea by having shorter propodeal spines and a less sculptured cuticle. Phylogenetic reconstruction using the mitochondrial marker COI shows that the two species form well separated clades, with a genetic distance (K2p) of 9.8 %. In the studied area, the two species are parapatric, A. ichnusa occurring in Sardinia, Corsica and the Mediterranean area of continental France, and A. subterranea occurring north of this area. We propose a redescription of both species and designation of a neotype for A. subterranea.

Taxonomic revision of the Malagasy Aphaenogaster swammerdami group (Hymenoptera: Formicidae)

“…A. friederichsi is indistinguishable from A. subterranea Latreille based on the redescription and neotype designation by Galkowski, Aubert & Blatrix (2019) . A. friederichsi was described based on two syntype works collected in Diego Surarez, a port city in the North of Madagascar.…”

“…Aphaenogaster swammerdami group species One species described from Madagascar, Aphaenogaster friederichsi Forel, is excluded from the swammerdami group and placed in the A. subterranea group and synonymized with A. subterranea Latreille . friederichsi is indistinguishable from A. subterranea Latreille based on the redescription and neotype designation byGalkowski, Aubert & Blatrix (2019). A. friederichsi was described based on two syntype works collected in Diego Surarez, a port city in the North of Madagascar.…”

Unrecognized for centuries: distribution and sexual caste descriptions of the West European Aphaenogaster species of the subterranea group (Hymenoptera, Formicidae)

“…We re-identified worker specimens belonging to the subterranea species group found in the authors’ personal collections and the Natural History Museum of Milan. Specimen identification was performed using the morphological characters illustrated by Galkowski et al (2019) : A. ichnusa differs from A.…”

“… subterranea . Their separation as two distinct species was only recently demonstrated based on worker morphology and mitochondrial DNA ( Galkowski et al 2019 ). The recent recognition implies that reliable data over the distribution of the two species is scarce in the sympatric range, where they were historically confused.…”

“…The recent recognition implies that reliable data over the distribution of the two species is scarce in the sympatric range, where they were historically confused. Apart from Sardinia, Galkowski et al (2019) reported the presence of A. ichnusa in Corsica and southern mainland France.…”