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Simple Summary: Ctenolepisma calvum, commonly known as the ghost silverfish, is an insect that lives in buildings, including museums, libraries, and archives. It is regarded as a pest of paper-based objects. Recently, C. calvum was discovered in several areas of Japan for the first time, and it may be a new threat to the conservation of collections that are of cultural and historical importance. Because the biological characteristics of this species in Japan are not well known, we observed their growth and reproduction. We found that eggs were laid from April to November, especially in early June, and eggs usually hatched within two months. The young insects grew through molting, and started laying eggs the next year. Females laid around 10 or more eggs at one time, and they were able to lay eggs once or more per year. Through this study, only females were found, and they were able to reproduce without male individuals. Further research on practical control methods for this species in museums and other facilities is required. Ctenolepisma calvum (Ritter, 1910) (Zygentoma: Lepismatidae) is a primitive wingless insect that causes damage to paper, and it is regarded as a pest of collections in museums, archives, and libraries. This species was recently discovered in Japan for the first time and may have already spread over large areas of Japan, but, currently, no information is available on the biological characteristics of C. calvum in Japan. In this study, we observed the processes of development and reproduction of C. calvum found in Japan at room temperature. Oviposition was observed from April to November, with a peak in early June. The average egg period was 56.9 days at average temperatures above 24.0 °C, and was 72.4 days at average temperatures below 24.0 °C. The 1st, 2nd, and 3rd instars lasted 4.7 days, 13.2 days, and 26.1 days on average, respectively, at average temperatures above 22.0 °C. Average instar periods were 23–28 days in 4th–7th instars and tended to increase in later instars. Instar periods also increased when the average temperature was 22.0 °C or lower. In individual rearing, the longest-living individual lived for approximately two years, up to the 15th instar. The head width grew at an approximate ratio of 1.1 per molt. First oviposition occurred at the 10th or 11th instar. Individually observed females oviposited once or twice a year, laying 6–16 eggs at one time, but females at least two years old laid 78.2 eggs per year on average in a mass-culture cage. Through this study, only females were found, and the mature females produced their progenies parthenogenetically. [ABSTRACT FROM AUTHOR]

At the moment, the six species regularly recorded in Central Europe are the common silverfish I L. saccharinum i , the firebrat I Thermobia domestica i Packard, 1873, I Atelura formicaria i Heyden, 1805 (a species living in ant nests), and three recently introduced species: the invasive gray or long-tailed silverfish I Ctenolepisma longicaudatum i Escherich, 1905, the four-lined silverfish I C. lineatum i (Fabricius, 1775), and I C. calvum i (Ritter, 1910). Museum collections used the insect blunder trap I Catchmaster i and pheromone trap I Finicon i for webbing clothes moths ( I Tineola bisselliella i ) in museums in Austria, Switzerland, and Liechtenstein (provided by PPS www.pps-vertrieb.de, accessed on 1 July 2022). Insect traps from Austrian museums provide a clear picture of an increasing catch of I C. calvum i (Figure 4a), as well as a sharp rise in the number of museums where the insect is present (Figure 4b). Keywords: introduced pest; invasive species; DNA barcoding; identification key; monitoring; insect traps; Lepismatidae EN introduced pest invasive species DNA barcoding identification key monitoring insect traps Lepismatidae N.PAG N.PAG 20 09/27/22 20220901 NES 220901 1. I C. calvum i and other species of Zygentoma, e.g., I L. saccharinum i and the invasive I C. longicaudatum i , are regularly found in museums on insect traps. [Extracted from the article]

Simple Summary: Ctenolepisma longicaudatum, an invasive silverfish species, has high tolerance to low humidity and temperatures and has been passively introduced to the majority of European territory. Its presence may cause stress and discomfort to people inhabiting or working the infested areas. In addition, it may cause damage to organic materials, contaminate food and carry microbes. This paper summarizes the available data on its spreading and current distribution of species in Europe and displayed the species is present throughout the continent including Scandinavia. This northward shift of C. longicaudatum might be explained by use of the insulation and central heating to provide optimal climate for the species to establish. The paper also contains updates on the current status of C. longicaudatum in Czechia, United Kingdom, and Ireland, where its first populations were recently detected. Based on the collected data, the spread in the monitored countries continues rapidly, when the domestic settings were the main habitat. Furthermore, the species is often present in accommodation facilities, warehouses, factories, public institutions, shopping malls, archives, museums, and art galleries. Therefore, the study indicates the species may occur everywhere indoors. The paper also highlights an urgent need for establishment of effective pest management strategy and preventive measures. Synanthropic invasive silverfish, Ctenolepisma longicaudatum, has been recently reported to cause nuisance in the indoor environment in many European countries. To get more details on the species distribution, the species occurrence was monitored by the authors in the countries where establishment of C. longicaudatum has been revealed in the last years. In Czechia, 20 findings from 14 municipalities in eight regions were recorded within the last three years. In the United Kingdom, 49 cases, including the first occurrence in Scotland, were recorded. Five cases were recorded for the Republic of Ireland. Domestic settings were the main habitat in the study countries (50.0% for the Czechia and Ireland and 36.8% for the United Kingdom). Regarding C. longicaudatum control, the standard silverfish strategy fails, and the use of insecticidal baits complemented by dust insecticides was suggested as the most promising approach. To reveal presence of C. longicaudatum in Europe, the search of literature, social platforms and databases on invasive species was conducted. According to these sources, the species is known from majority of European countries, when the high increase of records in recent decade was detected. [ABSTRACT FROM AUTHOR]