New records of Ctenolepisma calvum (Ritter,1910) (Zygentoma, Lepismatidae) from Japan

Abstract

Silverfish are known as one of the major pests which feed on paper and starch-based materials and can cause serious problems in museums, libraries and archives. Ctenolepisma calvum (Ritter, 1910) was first recorded from Ceylon (now Sri Lanka) and has also been known from Central American countries including Guyana and Cuba. Recently, its rapid spread to European countries, including Austria, Czech, Germany and Norway, has been reported. In addition, there are unverified records of C. calvum from 17 more countries in the on-line citizen-science platforms iNaturalist. We report C. calvum in Japan for the first time, from Hokkaido, Miyagi, Tokyo, Fukuoka and Nagasaki Prefectures. The specimens in Japan were observed in detail by stereomicroscope, optical microscope and scanning electron microscope. The occurrence of this species is a serious problem from the viewpoint of protection of cultural properties. We also registered their mitochondrial cytochrome oxidase I (COI) gene in EMBL/GenBank/DDBJ.

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

“…13B and 19B ; see also Fig. 3A and B in Shimada et al 2022 ). Ventral scales have more numerous and dense ribs ( Fig.…”

“…The distance between these combs ranges from 8 to 18 times the width of a comb. Dorsal and ventral views of the abdomen were shown by Shimada et al (2022) in Fig. 3D and E of that paper.…”

“…The thorax is slightly wider than the abdomen, which tapers slightly posteriorly from the fifth abdominal segment. Live specimens are very light colored, dorsally grayish white or yellowish-white, ventrally whitish or light yellowish; (photographs in Kulma et al 2022 , Querner et al 2022 , Shimada et al 2022 ), but some specimens are slightly more grayish. Antennae and terminal filaments are almost hyaline, with a very faint yellowish-white tonality.…”

“…Body size. Spanish specimens can grow up to 10 mm, but specimens from Japan maintained in the laboratory can reach 12 mm in length ( Shimada et al 2022 ); head width of up to 1.2 mm; thorax length of up to 3 mm; thorax width up to 2.1 mm (at mesothorax level). Antennae shorter than body length, when intact up to 7.5 mm.…”

“…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).…”