Chemical and behavioural strategies along the spectrum of host specificity in ant-associated silverfish

BACKGROUND: Host range is a fundamental trait to understand the ecological and evolutionary dynamics of symbionts. Increasing host specificity is expected to be accompanied with specialization in different symbiont traits. We tested this specificity-specialization association in a large group of 16 ant-associated silverfish species by linking their level of host specificity to their degree of behavioural integration into the colony and to their accuracy of chemically imitating the host's recognition system, i.e. the cuticular hydrocarbon (CHC) profile. RESULTS: As expected, facultative associates and host generalists (targeting multiple unrelated ants) tend to avoid the host, whereas host-specialists (typically restricted to Messor ants) were bolder, approached the host and allowed inspection. Generalists and host specialists regularly followed a host worker, unlike the other silverfish. Host aggression was extremely high toward non-ant-associated silverfish and modest to low in ant-associated groups. Surprisingly, the degree of chemical deception was not linked to host specificity as most silverfish, including facultative ant associates, imitated the host's CHC profile. Messor specialists retained the same CHC profile as the host after moulting, in contrast to a host generalist, suggesting an active production of the cues (chemical mimicry). Host generalist and facultative associates flexibly copied the highly different CHC profiles of alternative host species, pointing at passive acquisition (chemical camouflage) of the host's odour. CONCLUSIONS: Overall, we found that behaviour that seems to facilitate the integration in the host colony was more pronounced in host specialist silverfish. Chemical deception, however, was employed by all ant-associated species, irrespective of their degree of host specificity.status: publishe

On the genera Allomachilis Silvestri, 1906, and Kuschelochilis Wygodzinsky, 1951 (Insecta: Microcoryphia)

A revisao das espécies nominais (e únicas conhecidas) do género Allomachilis Silvestri, 1906 da Austrália e Kuschelochilis Wygodzinsky, 1951 do Chile (Microcoryphia: Meinertellidae) permitiram considerer o género Neotropical como sinónomo júnior do AustralianoO objetivo deste estudo foi revisar as espécies nominais, e somente descritas, do gênero Allomachilis Silvestri, 1906, da Austrália, e Kuschelochilis Wygodzinsky, 1951, do Chile (Microcoryphia: Meinertellidae). Os espécimens estudados vieram das coleções depositadas no: American Museun of Natural History (EUA); Instituto di Entomologia Agraria dell'Università di Portici (Itália); South Australian Museum (Austrália); Coleção Carmen Bach da Universidad Autónoma de Barcelona (Espanha); e a coleção entomológica do Instituto de Investigação Científica Tropical (Portugal). A revisão das espécies nominais do gênero Allomachilis e Kuschelochilis permite considerar o gênero Neotropical como sinônimo júnior do gênero Australiano.The objective of this study was to revise the nominal, and only described, species of the genera Allomachilis Silvestri, 1906, from Australia, and Kuschelochilis Wygodzinsky, 1951, from Chile (Microcoryphia: Meinertellidae). The studied specimens came from the collections deposited in the: American Museum of Natural History (USA); Instituto di Entomologia Agraria dell'Università di Portici (Italy); South Australian Museum (Australia); Carmen Bach collection of the Universidad Autónoma de Barcelona (Spain); and the entomology collection of the Instituto de Investigação Científica Tropical (Portugal). The revision of the nominal species of the genera Allomachilis and Kuschelochilis allows to consider the Neotropical genus a junior synonym of the Australian one

Sobre os gêneros Allomachilis Silvestri, 1906 e Kuschelochilis Wygodzinsky, 1951 (Insecta: Microcoryphia)

The objective of this study was to revise the nominal, and only described, species of the genera Allomachilis Silvestri, 1906, from Australia, and Kuschelochilis Wygodzinsky, 1951, from Chile (Microcoryphia: Meinertellidae). The studied specimens came from the collections deposited in the: American Museum of Natural History (USA); Instituto di Entomologia Agraria dell'Università di Portici (Italy); South Australian Museum (Australia); Carmen Bach collection of the Universidad Autónoma de Barcelona (Spain); and the entomology collection of the Instituto de Investigação Científica Tropical (Portugal). The revision of the nominal species of the genera Allomachilis and Kuschelochilis allows to consider the Neotropical genus a junior synonym of the Australian one.A revisao das espécies nominais (e únicas conhecidas) do género Allomachilis Silvestri, 1906 da Austrália e Kuschelochilis Wygodzinsky, 1951 do Chile (Microcoryphia: Meinertellidae) permitiram considerer o género Neotropical como sinónomo júnior do AustralianoO objetivo deste estudo foi revisar as espécies nominais, e somente descritas, do gênero Allomachilis Silvestri, 1906, da Austrália, e Kuschelochilis Wygodzinsky, 1951, do Chile (Microcoryphia: Meinertellidae). Os espécimens estudados vieram das coleções depositadas no: American Museun of Natural History (EUA); Instituto di Entomologia Agraria dell'Università di Portici (Itália); South Australian Museum (Austrália); Coleção Carmen Bach da Universidad Autónoma de Barcelona (Espanha); e a coleção entomológica do Instituto de Investigação Científica Tropical (Portugal). A revisão das espécies nominais do gênero Allomachilis e Kuschelochilis permite considerar o gênero Neotropical como sinônimo júnior do gênero Australiano

Assessing the Diversity of Ant-Associated Silverfish (Insecta: Zygentoma) in Mediterranean Countries: The Most Important Hotspot for Lepismatidae in Western Palaearctic

The Mediterranean Basin is considered one of the most important hotspots of biodiversity in the European region. Many taxa exhibit high levels of speciation and endemicity in this area. This is the case of the myrmecophilous insects of the families Lepismatidae and Nicoletiidae (Insecta: Zygentoma) that are further assessed in this study using unpublished and bibliographic data. A complete checklist of all ant-associated silverfish occurring in the Mediterranean Basin is presented, together with an updated identification key and interesting new records for several countries. Considering all described Zygentoma species, the myrmecophilous silverfish of the Mediterranean area represent 28% of all ant-associated species of the world and about 35% of the studied area. Even with the scarce knowledge of Zygentoma in other biogeographic areas and with insufficient sampling in other continents, we conclude that the Mediterranean region, and neighbouring areas of the Western Palaearctic, represent the most important biodiversity hotspot of ant-associated Lepismatidae (about 30% of the myrmecophilous species of this family described in the world so far), while the highest diversity of myrmecophilous Atelurinae is linked to tropical regions.This work was partially covered by the Project «Relaciones entre Formicidae y sus huéspedes en ecosistemas mediterráneos: diversidad y el grado de especialización de los artrópodos mirmecófilos» (Ref. XXIII PP. Mod. 4.1) by the University of Córdoba in the ‘Programa propio de fomento de la investigación’ (1-VII-2018 to 31-X-2020).Peer reviewe

A survey of basal insects (Microcoryphia and Zygentoma) from subterranean environments of Iran, with description of three new species

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) momtazianasp. 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

Non-audible acoustic emission characterization of Reticulitermes termites in pine wood

This research evaluates and characterizes the acoustic emission activity generated by Reticulitermes termites as recorded by piezoelectric sensors with sensitivity in the ultrasound range (greater than 20 kHz). To this end, the acoustic emission activity was recorded under controlled conditions of temperature and moisture content in three pine wood samples in which termites were artificially inoculated: only soldiers, only workers, or a colony of workers and soldiers. Different traditional parameters of the acoustic emission signals were analyzed, in both the time and frequency domains. This study proved feasible to use acoustic emission to detect the activity of this kind of termites, although it was not possible to distinguish between workers and soldiers. It is also demonstrated that, by using several sensors, one can locate the activity of the insects, a finding of great practical interest for the accurate detection of colonies in real buildings.General Secretariat of Housing of the Office of Development, Infrastructure and Territory Planning of the Junta de Andalucía regional government (ACUSMADERA Project, UGR.20-06)Program of Precompetitive Research Projects of Young Researchers of the University of Granada (PP-JIA2021.31). Funding for open access charge: Universidad de Granada / CBUA

On the genera Allomachilis Silvestri, 1906, and Kuschelochilis Wygodzinsky, 1951 (Insecta: Microcoryphia) Sobre os gêneros Allomachilis Silvestri, 1906 e Kuschelochilis Wygodzinsky, 1951 (Insecta: Microcoryphia)

The objective of this study was to revise the nominal, and only described, species of the genera Allomachilis Silvestri, 1906, from Australia, and Kuschelochilis Wygodzinsky, 1951, from Chile (Microcoryphia: Meinertellidae). The studied specimens came from the collections deposited in the: American Museum of Natural History (USA); Instituto di Entomologia Agraria dell'Università di Portici (Italy); South Australian Museum (Australia); Carmen Bach collection of the Universidad Autónoma de Barcelona (Spain); and the entomology collection of the Instituto de Investigação Científica Tropical (Portugal). The revision of the nominal species of the genera Allomachilis and Kuschelochilis allows to consider the Neotropical genus a junior synonym of the Australian one.O objetivo deste estudo foi revisar as espécies nominais, e somente descritas, do gênero Allomachilis Silvestri, 1906, da Austrália, e Kuschelochilis Wygodzinsky, 1951, do Chile (Microcoryphia: Meinertellidae). Os espécimens estudados vieram das coleções depositadas no: American Museun of Natural History (EUA); Instituto di Entomologia Agraria dell'Università di Portici (Itália); South Australian Museum (Austrália); Coleção Carmen Bach da Universidad Autónoma de Barcelona (Espanha); e a coleção entomológica do Instituto de Investigação Científica Tropical (Portugal). A revisão das espécies nominais do gênero Allomachilis e Kuschelochilis permite considerar o gênero Neotropical como sinônimo júnior do gênero Australiano

Erstnachweis von Nicoletia phytophila Gervais, 1844 (Zygentoma, Nicoletiidae) in Gewächshäusern in der Schweiz

Females and juveniles of the silverfish Nicoletia phytophila were captured in the tropical greenhouses of the botanical gardens in Basel and Zürich. The species was not found in any of seven other tropical greenhouses in Switzerland

Characterization of the complete mitochondrial genome of Neoasterolepisma foreli (Insecta: Zygentoma: Lepismatidae) and the phylogeny of basal Ectognatha

The silverfish Neoasterolepisma foreli belongs to the family Lepismatidae within Zygentoma and is well known for the peculiar habit of living in strict association with ant nests (myrmecophily). In this study, we describe its mitochondrial genome, a circular molecule of 15,398 bp including the canonical 13 PCGs, 22 tRNAs, 2 rRNAs, as well as a 403 bp AT-rich region. A phylomitogenomic analysis of the new sequence, alongside basal hexapod mtDNAs, confirmed the monophyly of all orders, with some uncertainty over the position of the enigmatic Tricholepidion gertschi that would make Zygentoma paraphyletic. Neoasterolepisma foreli is recovered in a basal position within family Lepismatidae, at odd with our current understanding of the group that would, in turn, suggest a closer relationship with the genus Lepisma (Mendes, )