First records of two new silverfish species (Ctenolepisma longicaudatum and Ctenolepisma calvum) in Slovakia, with checklist and identification key of Slovak Zygentoma

Abstract

In recent years, introduced synanthropic species of the order Zygentoma (especially Ctenolepisma longicaudatum and C. calvum) have begun to spread in Central Europe. The two above-mentioned non-native species of silverfish have also recently been confirmed in Slovakia. This paper aims to comment on the occurrence of the two non-native species in Slovakia, to compile an identification key for all (i.e. also native) Slovak silverfish species and establish local species names.

Worldwide revision of synanthropic silverfish (Insecta: Zygentoma: Lepismatidae) combining morphological and molecular data

“…There are several available descriptions of this species (e.g., Aak et al 2019 , Thomsen et al 2019 ), but most of them are incomplete or not clearly diagnostic. The photographs shown by Thomsen et al (2019) and Bednár et al (2023) illustrate good-quality specimens collected in the Faeroe islands and in Slovakia, respectively, and are useful for distinguishing this species from Lepisma saccharinum. However, some diagnostic characters required for comparison with other Ctenolepisma species are not mentioned.…”

“…Records of this species in Europe and Asian countries different from Sri Lanka are recent, all of them in the last 2 decades, but unfortunately, the reliability of most of them should be considered with caution because most ‘experts’ that identified them did not provide accurate morphological support for their identifications, so at this moment most of them should be considered as doubtful (see Supplementary Material 4 ). Nevertheless, it is clear that the species is widespread in Central Europe ( Kulma et al 2022 , Querner et al 2022 , Bednár et al 2023 ), the Caribbean area ( Wygodzinsky 1972 ), and southern and eastern Asia: Ceylon ( Ritter 1910 , Wygodzinsky, 1957 ) and Japan ( Shimada et al 2022 ). It is likely that the species has been introduced in other geographic areas (i.e., Singapore, Venezuela), but an accurate morphological or genetic assessment of the specimens of most countries should be carried out to validate the most inaccurate records.…”

“…In recent years, several species have been reported for the first time in some countries, suggesting an increasing tendency in the expansion of these silverfish. These are the cases of Ctenolepisma longicaudatum Escherich (1905) ( Goddard et al 2016 , Kulma et al 2018 , Thomsen et al 2019 , Aak et al 2021 ), Ctenolepisma lineatum (Fabricius, 1775) ( Hage et al 2020 ), and the lesser-known Ctenolepisma calvum ( Ritter, 1910 ) ( Kulma et al 2022 , Querner et al 2022 , Shimada et al 2022 , Bednár et al 2023 ). The list of synanthropic silverfish also includes species already well known and widely distributed, such as Lepisma saccharinum Linnaeus, 1758 , Acrotelsa collaris (Fabricius, 1793), Thermobia domestica (Packard, 1873), Thermobia aegyptiaca (Lucas, 1840), Ctenolepisma rothschildi Silvestri, 1907, Ctenolepisma targionii (Grassi and Rovelli, 1889), and Ctenolepisma villosum (Fabricius, 1775).…”