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Ant nests accommodate a diverse group of strictly associated arthropods. Most of these arthropods are seldom observed outside their host nest, emphasizing significant gaps in our knowledge regarding their biology. We recorded a series of field observations of lepismatid silverfish (Zygentoma: Lepismatidae) moving outside their usual Messor nest habitat in southern Spain and France. We illustrate how they move between different nests and locate nests by closely tracking the foraging trails of their hosts. Additionally, we confirm a prior observation that they can follow their host ants when they migrate to a new nest site. Our observations offer new insights into the hidden biology and the intricate interactions of specialized arthropod symbionts with their hosts within a spatial context. [ABSTRACT FROM AUTHOR]

A new species of the genus Thermobia (Zygentoma: Lepismatidae), Thermobia smithi sp. nov., found in a library and store rooms from Kerala, India, is described and diagnosed. This is the second species in the genus Thermobia reported from India. The report presents morphological, meristic and molecular details of the species and discusses its differences with related species of the genus. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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]

A survey of wingless insects belonging to the orders Microcoryphia (=Archaeognatha) and Zygentoma (=Thysanura s. str.) has been performed in subterranean habitats of central Iran. As a result, several new species have been discovered. In this work, three new species are described: a new species of bristletail of the family Machilidae, Haslundiella iranica sp. n., a new silverfish of the family Lepismatidae, Ctenolepisma subterraneum sp. n., and a new Nicoletiidae, Lepidospora (Brinckina) momtaziana sp. n. These new taxa are compared with related species in their respective genera and keys for their identification are provided: one for all known species of Haslundiella and one for all basal insects of subterranean environments of Iran which includes those previously reported. Moreover, the previously published keys of Iranian Ctenolepisma and the subgenus Brinckina are modified to include the new species. Three additional species of Lepismatidae are reported in this work: Neoasterolepìsma palmonii and Ctenolepisma targionii are newly recorded from Iran and both species, together with Acrotelsa collaris, are cited for the first time in the subterranean habitats. This survey progresses the knowledge on the biodiversity of these insects in Iran. [ABSTRACT FROM AUTHOR]

A basic method for rearing Heterolepisma sclerophyllum is provided. It appears that this species might only take water by mouth in contrast to the Ctenolepismatinae which are capable of absorbing moisture from the atmosphere via their anus. [ABSTRACT FROM AUTHOR]

The morphology of the enigmatic silverfish genus Anisolepisma Paclt is clarified with a redescription of the type species and the description of three new species. The genus is placed within the subfamily Acrotelsatinae and its relevance to the phylogeny and zoogeography of the Lepismatidae discussed. Paracrotelsa Paclt is also placed within the Acrotelsatinae. [ABSTRACT FROM AUTHOR]

The silverfish fauna of Tasmania is reviewed. Seven species are now recorded, including the introduced anthropophilic Ctenolepisma longicaudata Escherich. Within the Ctenolepismatinae Hemitelsella clarksonorum n.gen., n.sp. and Acrotelsella parlevar n.sp. are described. The Heterolepismatinae are represented by an unconfirmed record of Heterolepisma kraepelini Silvestri and Heterolepisma buntonorum n.sp. is described. The inquiline Atelurinae are represented by Australiatelura tasmanica Silvestri, which is redescribed, and a further sympatric species, Australiatelura eugenanae n.sp., is described. [ABSTRACT FROM AUTHOR]

Nutrient self-selection represents an important behaviour that has been measured across many taxa. Despite the amount of research on this phenomenon, few studies report the evaluation of the effects of environmental variables such as temperature on nutrient selection by animals. In the present study, the nutrient selections of the silverfish Lepisma saccharina L. are measured across a range of temperatures (10, 15, 20, 25, 30 and 35 °C) using feeding arenas with three nutrient choices: carbohydrate (sucrose), protein (casein) and fat (lard). An overall preference for carbohydrates is shown across the range of temperatures, followed by protein, and then fat. However, the proportional consumption of each dietary component changes with temperature; the proportional carbohydrate consumption decreases dramatically with increasing temperature (>94% of the diet at 15 °C but <58% at 30 °C), whereas the proportional protein and lipid consumption increases with increasing temperature up to 30 °C. Changes in nutrient selection with temperature may be related to the dietary requirements of the insect at different temperatures. [ABSTRACT FROM AUTHOR]

Arthropod appendages are among the most diverse animal organs and have been adapted to a variety of functions. Due to this diversity, it can be difficult to recognize homologous parts in different appendage types and different species. Gene expression patterns of appendage development genes have been used to overcome this problem and to identify homologous limb portions across different species and their appendages. However, regarding the largest arthropod group, the hexapods, most of these studies focused on members of the winged insects (Pterygota), but primitively wingless groups like the springtails (Collembola) or silverfish and allies (Zygentoma) are underrepresented. We have studied the expression of a set of appendage patterning genes in the firebrat Thermobia domestica and the white springtail Folsomia candida. The expressions of Distal- less ( Dll) and dachshund ( dac) are generally similar to the patterns reported for pterygote insects. Modifications of gene regulation, for example, the lack of Dll expression in the palp of F. candida mouthparts, however, point to changes in gene function that can make the use of single genes and specific expression domains problematic for homology inference. Such hypotheses should therefore not rely on a small number of genes and should ideally also include information about gene function. The expression patterns of homothorax ( hth) and extradenticle ( exd) in both species are similar to the patterns of crustaceans and pterygote insects, but differ from those in chelicerates and myriapods. The proximal specificity of hth thus appears to trace from a common hexapod ancestor and also provides a link to the regulation of this gene in crustaceans. [ABSTRACT FROM AUTHOR]

The firebrat, Thermobia domestica (Packard) (Thysanura: Lepismatidae), aggregates in response to the faeces of conspecifics as well as shelters previously inhabited by conspecifics. Our objective was to determine the source of the aggregation signal. Filter paper previously exposed to firebrats induced strong arrestment of firebrats. Polar solvents (water, methanol, acetonitrile) and less polar solvents (hexane, dichloromethane, ethyl ether), alone or in combination, failed to extract the aggregation signal from firebrat-exposed paper. Moreover, solvent-extracted paper continued to induce firebrat arrestment. In contrast, the aggregation signal could be obtained by physical extraction (freeze/thawing or ultrasonication) of firebrat-exposed paper submerged in water. Five fungal species and four bacterial species were isolated from ultrasonicant solutions on potato dextrose-, nutrient-, and Glc NAc-agar. Of the nine isolated microbes tested, only the fungus Mycotypha microspora Fenner (Mucorales) and the bacterium Enterobacter cloacae (Jordan) Hormaeche & Edwards (Enterobacteriaceae) induced arrestment of firebrats in bioassays. Our data support the conclusion that firebrats do not form aggregations in response to pheromones; instead, they aggregate in the presence of specific microbes or their metabolites. [ABSTRACT FROM AUTHOR]

The firebrat, Thermobia domestica (Packard) (Thysanura: Lepismatidae), aggregates in response to the faeces of conspecifics. This aggregation response is mediated by two microbial symbionts, the bacterium Enterobacter cloacae (Jordan) Hormaeche & Edwards (Enterobacteriaceae) and the fungus Mycotypha microspora Fenner (Mucorales). Our objective was to determine how these microbes are transmitted between firebrats. We produced fluorescently labelled E. cloacae and M. microspora and presented them to firebrats. Firebrats consumed large quantities of these labelled microbes and deposited them with their faeces where they proliferated rapidly. Firebrats did not harbour E. cloacae or M. microspora within their ovarioles or eggs, and thus cannot transmit them transovarially. Instead, firebrats acquired them horizontally whenever they fed on microbe-contaminated material, such as faeces, faeces-contaminated paper, or egg surfaces. Firebrats moult throughout their life, and with each moult they shed the cuticular lining of their digestive tract and likely any microbes residing therein. Because firebrats remain in close contact and live in groups of mixed age and gender, newly moulted individuals can readily re-acquire E. cloacae or M. microspora from group members. This ensures the perpetuation of their microbial aggregation and arrestment signal. [ABSTRACT FROM AUTHOR]

Abstract: Two fossil silverfish preserved in Burmese amber (dated from the Cretaceous: Upper Albian, 100–110 MY) are described in the new genus and species Burmalepisma cretacicum (Lepismatidae: Lepismatinae). The fossil species is characterized mainly by its chaetotaxy. [Copyright &y& Elsevier]

Female, male, and juvenile firebrats, Thermobia domestica (Packard) (Thysanura: Lepismatidae), employ a pheromone that arrests conspecifics on contact. Paper shelters placed in a T. domestica colony accumulate fecal excreta (= frass) and other insect-derived debris. Such shelters elicit arrestment by conspecifics. However, the definitive source of the arrestment pheromone was not known. We tested the hypothesis that one or more debris components from a T. domestica shelter constitute the source of the arrestment pheromone. In dual-choice, still-air olfactometer experiments, scales, exuviae, antennae, caudal filaments, gregarine parasite cysts, and silk (each intact or macerated) retrieved from shelters and separated for experiments, as well as saliva, hemolymph, and fat body extracted from insects all failed to arrest female T. domestica. Similarly, paper that had been fed upon by insects did not elicit an arrestment response, eliminating insect-altered cellulose as the arrestant pheromone. In contrast, insect-exposed glass significantly arrested females. Moreover, females were significantly arrested by (i) loose, insect-derived debris brushed from shelters, (ii) a frass mixture manually separated from loose debris, and (iii) specific amber-type frass manually separated from the frass mixture. These results lead us to conclude that amber-type frass constitutes the source of at least part of the T. domestica arrestment pheromone. [ABSTRACT FROM AUTHOR]

Abstract  Aggregations of the common silverfish, Lepisma saccharina, and giant silverfish, Ctenolepisma longicaudata (both Thysanura: Lepismatidae), are mediated by species-specific pheromones. In dual-choice, still-air olfactometer experiments, filter paper previously exposed to 12 male, female, or juvenile L. saccharina or C. longicaudata arrested conspecifics regardless of developmental stage or sex. Arrestment responses required physical contact with the pheromone. Insect-derived frass, scales, antennae, and setae, as well as salivary gland content, are not the source of the contact pheromone in L. saccharina. Lepisma saccharina did not respond to the pheromone of C. longicaudata, nor to that of another thysanuran, the firebrat Thermobia domestica. However, C. longicaudata responded to pheromones of both L. saccharina and T. domestica, whereas T. domestica responded to the C. longicaudata but not L. saccharina pheromone. These results support the hypothesis that a closer phylogenetic relationship exists between C. longicaudata and T. domestica than between C. longicaudata and L. saccharina, but a definitive conclusion must await molecular genetic analyses of all three species. [ABSTRACT FROM AUTHOR]

Pleuropodia of the invaginated type were observed on the first abdominal segment in 8-d-old embryos of Thermobia domestica (Packard). The pleuropodium is formed by a cytoplasmatic internal part and a mushroom-like cavity. The latter is filled with fluid and is composed of a stem protruding through the epidermis and a vesicle-like copula. The arrangement of membrane folds, mitochondria, and lipid drops was observed on electron micrographs (TEM) of pleuropodium cells. The position and structure of these organelles indicates that the cells of this organ perform transport and secretory functions. [ABSTRACT FROM AUTHOR]

The lockdowns that came with policies to reduce the spread of COVID-19 in 2020 required some 90% of museums and historic properties across the globe to be closed. Lowered visitor numbers and reduced staffing levels allowed a range of fauna to make their way indoors, bringing an increase in birds, rodents and insect pests. Silverfish are shy, so benefit from low occupancy in museums and present a potential vector for damage to books and paper. This study is the first to report changes in insect populations in museums and examines six years (2015–2020) trapping data for silverfish and similar insects (Lepismatidae): Lepisma saccharinum , Ctenolepisma calvum , Ctenolepisma longicaudatum and Ctenolepisma lineatum from: (i) the Technisches Museum Wien, (ii) Schönbrunn Palace, (iii) Hofburg Museum and a shorter record from (iv) Weltmuseum Wien. Analysis of the trap contents gives an impression that the number of insects caught had increased over time, but 2020 was distinctive and gave typically higher insect numbers during the COVID-19 lockdown compared to other years, especially for Lepisma saccharinum. Individual traps caught up to 100 silverfish in only a few weeks. Because silverfish usually need between four months to one year to become mature, we assume that it was increased activity during museum closure and not higher reproduction which led to higher numbers. The parts of the museums showing increased populations under lockdown were similar to the areas where they were more frequent in earlier years. This means that such areas deserve continued monitoring even when the museum is closed. No damage to paper objects were reported in the museums investigated. • Silverfish trapped have generally increased over the years 2015–2020. • During museum closures silverfish increased in places typically seen as habitats. • Increased trapping arose because silverfish could range widely in unoccupied museums. [ABSTRACT FROM AUTHOR]

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]

In this study, we investigated the fauna of Zygentoma in different regions of Kermanshah Province (Kermanshah, Iran) during 2013. Among the different specimens collected, the species Neoasterolepisma priesneri (Stach, 1946) was found, being new for Iran and for Asia. Moreover, the capture of a representative of the genus Trinemophora (Schaeffer, 1897) represents the first citation of the family Protrinemuridae in Iran. [ABSTRACT FROM AUTHOR]