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The Cambrian radiation of euarthropods can be attributed to an adaptable body plan. Sophisticated brains and specialized feeding appendages, which are elaborations of serially repeated organ systems and jointed appendages, underpin the dominance of Euarthropoda in a broad suite of ecological settings. The origin of the euarthropod body plan from a grade of vermiform taxa with hydrostatic lobopodous appendages ('lobopodian worms') 1,2 is founded on data from Burgess Shale-type fossils. However, the compaction associated with such preservation obscures internal anatomy 3-6 . Phosphatized microfossils provide a complementary three-dimensional perspective on early crown group euarthropods 7 , but few lobopodians 8,9 . Here we describe the internal and external anatomy of a three-dimensionally preserved euarthropod larva with lobopods, midgut glands and a sophisticated head. The architecture of the nervous system informs the early configuration of the euarthropod brain and its associated appendages and sensory organs, clarifying homologies across Panarthropoda. The deep evolutionary position of Youti yuanshi gen. et sp. nov. informs the sequence of character acquisition during arthropod evolution, demonstrating a deep origin of sophisticated haemolymph circulatory systems, and illuminating the internal anatomical changes that propelled the rise and diversification of this enduringly successful group., (© 2024. The Author(s).)

Diplopods are terrestrial arthropods important for the dynamics of terrestrial ecosystems. One of the reasons for that can be their low predation rate due to their defensive secretion. Thus, Orthoporus fuscipes, a species belonging to this group and endemic to northeastern Brazil, was investigated as to its population structure and chemical constituents of defensive secretion. The population structure showed that females are larger and have greater mass than do males, along with negative allometric growth between males and females. The defensive secretion hexane extract was submitted to fractionation using SiO2 open-column chromatography and the gas chromatographic coupled to mass spectrometric analysis was applied in the fraction possibilities to identify major fatty acid methyl esthers, along with minor alkanes, alkenes and fatty acids derivatives and the known quinoids 2-methoxy-3-methylhydroquinone, 2-methoxy-3-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone and 2,3-dimethoxyhydroquinone. In addition, the cytochrome oxidase I sequence for the species was deposited for the first time.

The dynamics of soil arthropod communities in annual monoculture grasslands is still unclear, which restricts the understanding of the degradation mechanism of cultivated grasslands. We cultivated two annual gramineae species, Lolium multiflorum and Avena sativa , separately in Hongyuan County, located on the eastern edge of the Qinghai-Tibet Plateau, in April 2019. We investigated soil arthropods, plant communities and soil properties in the cultivated grasslands and natural grassland in the late September every year from 2019 to 2022. The results showed that: 1) The taxonomic composition of soil arthropod communities differed significantly among three grasslands and sampling years. 2) There was no significant difference in the density, taxonomic richness, Shannon index and evenness index of soil arthropod communities among three grasslands. 3) The density of soil arthropod communities significantly fluctuated across years in three grasslands, and the taxonomic richness and Shannon index decreased significantly in the L. multiflorum and A. sativa grasslands, with the evenness index declining significantly only in the fourth year. The Shannon index fluctuated significantly and the evenness index varied little in natural grassland. 4) The above- and below-ground biomass, the contents of soil total P, total K and available N were the main factors influencing the taxonomic composition, density and diversity indices of soil arthropod communities. The results suggested that the cultivation of annual gramineae grasslands have significant effects on taxonomic composition, but not on density and diversity of soil arthropod communities, and those variables change significantly across different years.

Lobopodians represent a key step in the early history of ecdysozoans since they were the first animals to evolve legs within this clade. Their Cambrian representatives share a similar body plan with a typically cylindrical annulated trunk and a series of non-jointed legs. However, they do not form a monophyletic group and likely include ancestors of the three extant panarthropod lineages (Tardigrada, Onychophora, Euarthropoda). Some species display astonishing protective devices such as cuticular plates and spines. We describe here the armor and molting process of Microdictyon from the early Cambrian of China. Microdictyon secreted ovoid paired cuticular sclerites that were duplicated in a non-synchronous way along the animal's body. The reticulated pattern and cuticular architecture of these sclerites have similarities to extant armored tardigrades that recently served in hypothesizing that tardigrades are possibly miniaturized lobopodians. Ecdysis and hard cuticular protection are now well documented in the whole spectrum of early Cambrian ecdysozoans such as soft-bodied scalidophorans, lobopodians and fully articulated euarthropods. We hypothesize that the secretion of sclerotized cuticular elements periodically renewed via ecdysis was a key innovation that opened large-scale evolutionary opportunities to invertebrate animal life, specifically ecdysozoans, both in terms of anatomical functionalities and ecological success., (© 2024. The Author(s).)

Springtails (Collembola) stand as one of the most abundant, widespread, and ancient terrestrial arthropods on earth. However, their evolutionary history and deep phylogenetic relationships remain elusive. In this study, we employed phylogenomic approaches to elucidate the basal relationships among Collembola. We sampled whole-genome data representing all major collembolan lineages in proportion to their known diversity. To account for potential phylogenomic biases, we implemented various data extraction, locus sampling, and signal filtering strategies to generate matrices. Subsequently, we applied a diverse array of tree-searching and rate-modelling methods to reconstruct the phylogeny. Our analyses, utilizing different matrices and methods, converged on the same unrooted relationships among collembolan ingroups, supporting the current ordinal classification and challenging the monophyly of Arthropleona and Symphypleona s.l. However, discrepancies across analyses existed in the root of Collembola. Among various root positions, those based on more informative matrices and biologically realistic models, favoring a basal topology of Entomobryomorpha + (Symphypleona s.s. + (Neelipleona + Poduromorpha)), were supported by subsequent methodological assessment, topology tests, and rooting analyses. This optimal topology suggests multiple independent reduction of the pronotum in non-poduromorph orders and aligns with the plesiomorphic status of neuroendocrine organs and epicuticular structure of Entomobryomorpha. Fossil-calibrated dating analyses based on the optimal topology indicated late-Paleozoic to mid-Mesozoic origins of the crown Collembola and four orders. In addition, our results questioned the monophyly of Isotomidae and Neanuridae, underscoring the need for further attention to the systematics of these families. Overall, this study provides novel insights into the phylogenetic backbone of Collembola, which will inform future studies on the systematics, ecology, and evolution of this significant arthropod lineage., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Knowledge of Cambrian animal anatomy is limited by preservational processes that result in compaction, size bias, and incompleteness. We documented pristine three-dimensional (3D) anatomy of trilobites fossilized through rapid ash burial from a pyroclastic flow entering a shallow marine environment. Cambrian ellipsocephaloid trilobites from Morocco are articulated and undistorted, revealing exquisite details of the appendages and digestive system. Previously unknown anatomy includes a soft-tissue labrum attached to the hypostome, a slit-like mouth, and distinctive cephalic feeding appendages. Our findings resolve controversy over whether the trilobite hypostome is the labrum or incorporates it and establish crown-group euarthropod homologies in trilobites. This occurrence of moldic fossils with 3D soft parts highlights volcanic ash deposits in marine settings as an underexplored source for exceptionally preserved organisms.

Arthropods contribute importantly to ecosystem functioning but remain understudied. This undermines the validity of conservation decisions. Modern methods are now making arthropods easier to study, since arthropods can be mass-trapped, mass-identified, and semi-mass-quantified into 'many-row (observation), many-column (species)' datasets, with homogeneous error, high resolution, and copious environmental-covariate information. These 'novel community datasets' let us efficiently generate information on arthropod species distributions, conservation values, uncertainty, and the magnitude and direction of human impacts. We use a DNA-based method (barcode mapping) to produce an arthropod-community dataset from 121 Malaise-trap samples, and combine it with 29 remote-imagery layers using a deep neural net in a joint species distribution model. With this approach, we generate distribution maps for 76 arthropod species across a 225 km 2 temperate-zone forested landscape. We combine the maps to visualize the fine-scale spatial distributions of species richness, community composition, and site irreplaceability. Old-growth forests show distinct community composition and higher species richness, and stream courses have the highest site-irreplaceability values. With this 'sideways biodiversity modelling' method, we demonstrate the feasibility of biodiversity mapping at sufficient spatial resolution to inform local management choices, while also being efficient enough to scale up to thousands of square kilometres. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.

Bromeliads play a vital role in preserving biodiversity in the Neotropical region. To understand their impact on arthropod diversity in Brazil's semi-arid region, we studied the rupicolous bromeliad Encholirium spectabile. From 2011 to 2018, we observed the arthropod fauna in E. spectabile clumps, documenting the associated taxa, their abundance, and interactions. We also investigated how seasonality affects arthropod richness and composition during the dry and rainy seasons. Over the observation period, 15 orders and 57 arthropod families were recorded in association with E. spectabile. Insecta dominated, followed by predatory chelicerates. Eight usage categories were identified, with Shelter being the most prevalent, followed by Predators, Nesters, and Nectarivores. Significant differences in taxonomic richness were noted between rainy and dry seasons, with the rainy season exhibiting higher diversity. Seasonal variation was also observed in species composition. Clumps of E. spectabile emerged as crucial habitats for surrounding arthropod fauna. This research underscores the importance of non-phylotelm bromeliads, particularly in high abiotic stress environments like semi-arid regions. The taxonomic diversity observed aligns with findings from diverse environments, shedding light on the relevance of E. spectabile for associated arthropod fauna. These results prompt further exploration of non-phylotelm bromeliads in semi-arid settings, providing a fresh perspective on their significance in shaping arthropod communities., (© 2024. Sociedade Entomológica do Brasil.)

Previous difficulties in arthropod taxonomy (such as limitations in conventional morphological approaches, the possibility of cryptic species and a shortage of knowledgeable taxonomists) has been overcome by the powerful tool of DNA barcoding. This study presents a thorough analysis of DNA barcoding in regards to Pakistani arthropods, which were collected from Lahore's Jinnah Garden. The 88 % (9,451) of the 10,792 specimens that were examined were able to generate DNA barcodes and 83% (8,974) of specimens were assigned 1,361 barcode index numbers (BINs). However, the success rate differed significantly between the orders of arthropods, from 77% for Thysanoptera to an astounding 93% for Diptera. Through morphological exams, DNA barcoding, and cross-referencing with the Barcode of Life Data system (BOLD), the Barcode Index Numbers (BINs) were assigned with a high degree of accuracy, both at the order (100%) and family (98%) levels. Though, identifications at the genus (37%) and species (15%) levels showed room for improvement. This underscores the ongoing need for enhancing and expanding the DNA barcode reference library. This study identified 324 genera and 191 species, underscoring the advantages of DNA barcoding over traditional morphological identification methods. Among the 17 arthropod orders identified, Coleoptera, Diptera, Hemiptera, Hymenoptera, and Lepidoptera from the class Insecta dominated, collectively constituting 94% of BINs. Expected malaise trap Arthropod fauna in Jinnah Garden could contain approximately 2,785 BINs according to Preston log-normal species distribution, yet the Chao-1 Index predicts 2,389.74 BINs. The Simpson Index of Diversity (1-D) is 0.989, signaling high species diversity, while the Shannon Index is 5.77, indicating significant species richness and evenness. These results demonstrated that in Pakistani arthropods, DNA barcoding and BOLD are an invaluable tool for improving taxonomic understanding and biodiversity assessment, opening the door for further eDNA and metabarcoding research., Competing Interests: The authors declare that they have no competing interests., (© 2024 Samreen and Manzoor.)

Terminalia argentea tree, native to Brazil, is widely used in landscaping, recovering degraded areas, its wood, coal production, and the bark or leaf extracts has medicinal use. Despite of its importance, the arthropod fauna associated to this plant and its interspecific relationships still needs further studies. The objectives of this study were to evaluate the arthropods, their ecological indices and the distribution in the leaf faces on T. argentea saplings. The numbers of phytophagous insects (e.g., Cephalocoema sp.), pollinators (e.g., Tetragonisca angustula), and natural enemies (e.g., Oxyopidae), and their ecological indices (e.g., species richness), were higher on the adaxial leaf faces on T. argentea saplings. Aggregated distribution of phytophagous insects (e.g., Aphis spiraecola), pollinators (e.g., Trigona spinipes), and natural enemies (e.g., Camponotus sp.) on T. argentea saplings was observed. Abundance, diversity, and species richness of natural enemies correlated, positively, with those of phytophagous and pollinators insects. Predators and tending ants followed their prey and sucking insects, respectively. Tending ants protected sucking insects against predators, and reduced chewing insects. The high number of Cephalocoema sp. on T. argentea saplings is a problem, because this insect can feed on leaves of this plant, but its preference for the adaxial leaf face favors its control. The aggregation behavior of arthropods on T. argentea saplings favors the control of potential pests of this plant. There seems to be competition between tending ants for space and food resources on T. argentea saplings.

Global biodiversity gradients are generally expected to reflect greater species replacement closer to the equator. However, empirical validation of global biodiversity gradients largely relies on vertebrates, plants, and other less diverse taxa. Here we assess the temporal and spatial dynamics of global arthropod biodiversity dynamics using a beta-diversity framework. Sampling includes 129 sampling sites whereby malaise traps are deployed to monitor temporal changes in arthropod communities. Overall, we encountered more than 150,000 unique barcode index numbers (BINs) (i.e. species proxies). We assess between site differences in community diversity using beta-diversity and the partitioned components of species replacement and richness difference. Global total beta-diversity (dissimilarity) increases with decreasing latitude, greater spatial distance and greater temporal distance. Species replacement and richness difference patterns vary across biogeographic regions. Our findings support long-standing, general expectations of global biodiversity patterns. However, we also show that the underlying processes driving patterns may be regionally linked., (© 2024. The Author(s).)

Euchelicerata is a clade of arthropods comprising horseshoe crabs, scorpions, spiders, mites and ticks, as well as the extinct eurypterids (sea scorpions) and chasmataspidids. The understanding of the ground plans and relationships between these crown-group euchelicerates has benefited from the discovery of numerous fossils. However, little is known regarding the origin and early evolution of the euchelicerate body plan because the relationships between their Cambrian sister taxa and synziphosurines, a group of Silurian to Carboniferous stem euchelicerates with chelicerae and an unfused opisthosoma, remain poorly understood owing to the scarce fossil record of appendages. Here we describe a synziphosurine from the Lower Ordovician (ca. 478 Ma) Fezouata Shale of Morocco. This species possesses five biramous appendages with stenopodous exopods bearing setae in the prosoma and a fully expressed first tergite in the opisthosoma illuminating the ancestral anatomy of the group. Phylogenetic analyses recover this fossil as a member of the stem euchelicerate family Offacolidae, which is characterized by biramous prosomal appendages. Moreover, it also shares anatomical features with the Cambrian euarthropod Habelia optata, filling the anatomical gap between euchelicerates and Cambrian stem taxa, while also contributing to our understanding of the evolution of euchelicerate uniramous prosomal appendages and tagmosis., (© 2024. The Author(s).)

Amber preserves an exceptional record of tiny, soft-bodied organisms and chemical environmental signatures, elucidating the evolution of arthropod lineages and the diversity, ecology, and biogeochemistry of ancient ecosystems. However, globally, fossiliferous amber deposits are rare in the latest Cretaceous and surrounding the Cretaceous-Paleogene (K-Pg) mass extinction. 1 , 2 , 3 , 4 , 5 This faunal gap limits our understanding of arthropod diversity and survival across the extinction boundary. 2 , 6 Contrasting hypotheses propose that arthropods were either relatively unaffected by the K-Pg extinction or experienced a steady decline in diversity before the extinction event followed by rapid diversification in the Cenozoic. 2 , 6 These hypotheses are primarily based on arthropod feeding traces on fossil leaves and time-calibrated molecular phylogenies, not direct observation of the fossil record. 2 , 7 Here, we report a diverse amber assemblage from the Late Cretaceous (67.04 ± 0.16 Ma) of the Big Muddy Badlands, Canada. The new deposit fills a critical 16-million-year gap in the arthropod fossil record spanning the K-Pg mass extinction. Seven arthropod orders and at least 11 insect families have been recovered, making the Big Muddy amber deposit the most diverse arthropod assemblage near the K-Pg extinction. Amber chemistry and stable isotopes suggest the amber was produced by coniferous (Cupressaceae) trees in a subtropical swamp near remnants of the Western Interior Seaway. The unexpected abundance of ants from extant families and the virtual absence of arthropods from common, exclusively Cretaceous families suggests that Big Muddy amber may represent a yet unsampled Late Cretaceous environment and provides evidence of a faunal transition before the end of the Cretaceous., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

We collected one new species and one new record in the genus Mesogastrura Bonet, 1930 (family Hypogastruridae) from three caves with different origins in the Korean Peninsula; Mesogastrura seotalensis sp. nov. and Mesogastrura ojcoviensis (Stach, 1919). The genus Mesogastrura Bonet, 1930 is newly recorded from the Korean Peninsula. Mesogastrura seotalensis sp. nov. shows various body color (light brown or much less and light purple), 3 + 3 eyes and unguis with three inner teeth. On the other hand, Mesogastrura ojcoviensis (Stach, 1919) is characterized by white body color, 2 + 2 eyes and unguis without inner tooth (rarely with 1). These species were found in piles of bat's guano inside of caves, so they are considered as troglophilous and guanophilous species. Partial DNA sequences of mitochondrial cytochrome c oxidase subunit I (COI) gene were used as DNA barcodes to clarify the species delimitation.

Bats are reservoirs of important zoonotic viruses like Nipah and SARS viruses. However, whether the blood-sucking arthropods on the body surface of bats also carry these viruses and the relationship between viruses carried by the blood-sucking arthropods and viruses carried by bats have not been reported. This study collected 686 blood-sucking arthropods on the body surface of bats from Yunnan Province, China, between 2012 and 2015, and they included wingless bat flies, bat flies, ticks, mites, and fleas. The viruses carried by these arthropods were analyzed using a meta-transcriptomic approach, and 144 highly diverse positive-sense single-stranded RNA, negative-sense single-stranded RNA, and double-stranded RNA viruses were found, of which 138 were potentially new viruses. These viruses were classified into 14 different virus families or orders, including Bunyavirales , Mononegavirales , Reoviridae , and Picornavirales . Further analyses found that Bunyavirales were the most abundant virus group (84% of total virus RNA) in ticks, whereas narnaviruses were the most abundant (52 to 92%) in the bat flies and wingless bat flies libraries, followed by solemoviruses (1 to 29%) and reoviruses (0 to 43%). These viruses were highly structured based on the arthropod types. It is worth noting that no bat-borne zoonotic viruses were found in the virome of bat-infesting arthropod, seemingly not supporting that bat surface arthropods are vectors of zoonotic viruses carried by bats. IMPORTANCE Bats are reservoirs of many important viral pathogens. To evaluate whether bat-parasitic blood-sucking arthropods participate in the circulation of these important viruses, it is necessary to conduct unbiased virome studies on these arthropods. We evaluated five types of blood-sucking parasitic arthropods on the surface of bats in Yunnan, China, and identified a variety of viruses, some of which had high prevalence and abundance levels, although there is limited overlap in virome between distant arthropods. While most of the virome discovered here is potentially arthropod-specific viruses, we identified three possible arboviruses, including one orthobunyavirus and two vesiculoviruses (family Rhabdoviridae ), suggesting bat-parasitic arthropods carry viruses with risk of spillage, which warrants further study.

To associate specimens identified by molecular characters to other biological knowledge, we need reference sequences annotated by Linnaean taxonomy. In this study, we (1) report the creation of a comprehensive reference library of DNA barcodes for the arthropods of an entire country (Finland), (2) publish this library, and (3) deliver a new identification tool for insects and spiders, as based on this resource. The reference library contains mtDNA COI barcodes for 11,275 (43%) of 26,437 arthropod species known from Finland, including 10,811 (45%) of 23,956 insect species. To quantify the improvement in identification accuracy enabled by the current reference library, we ran 1000 Finnish insect and spider species through the Barcode of Life Data system (BOLD) identification engine. Of these, 91% were correctly assigned to a unique species when compared to the new reference library alone, 85% were correctly identified when compared to BOLD with the new material included, and 75% with the new material excluded. To capitalize on this resource, we used the new reference material to train a probabilistic taxonomic assignment tool, FinPROTAX, scoring high success. For the full-length barcode region, the accuracy of taxonomic assignments at the level of classes, orders, families, subfamilies, tribes, genera, and species reached 99.9%, 99.9%, 99.8%, 99.7%, 99.4%, 96.8%, and 88.5%, respectively. The FinBOL arthropod reference library and FinPROTAX are available through the Finnish Biodiversity Information Facility (www.laji.fi) at https://laji.fi/en/theme/protax. Overall, the FinBOL investment represents a massive capacity-transfer from the taxonomic community of Finland to all sectors of society., (© 2021 The Authors. Molecular Ecology Resources published by John Wiley & Sons Ltd.)

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) has proved effective for the identification of many arthropods. A total of 432 termite specimens were collected in Mali, Cote d'Ivoire, Togo, Senegal, Switzerland and France. Morphologically, 22 species were identified, including Ancistrotermes cavithorax, Amitermes evuncifer, Cryptotermes brevis, Cubitermes orthognathus, Kalotermes flavicollis, Macrotermes bellicosus, Macrotermes herus, Macrotermes ivorensis, Macrotermes subhyalinus, Microcerotermes parvus, Microtermes sp., Odontotermes latericius, Procubitermes sjostedti, Promirotermes holmgreni, Reticulitermes grassei, Reticulitermes lucifugus, Reticulitermes santonensis, Trinervitermes geminatus, Trinervitermes occidentalis, Trinervitermes togoensis, Trinervitermes sp., Trinervitermes trinervoides and Trinervitermes trinervius. Analysis of MALDI-TOF MS spectra profiles from termites revealed that all were of high quality, with intra-species reproducibility and inter-species specificity. Blind testing of the spectra of 389 termites against our updated database with the spectra of 43 specimens of different termite species revealed that all were correctly identified with log score values (LSVs) ranging from 1.65 to 2.851, mean 2.290 ± 0.225, median 2.299, and 98.4% (383) had LSVs > 1.8. This study is the first on the use of MALDI-TOF for termite identification and shows its importance as a tool for arthropod taxonomy and reinforces the idea that MALDI-TOF MS is a promising tool in the field of entomology., (© 2022. The Author(s).)

The name "millipede" translates to a thousand feet (from mille "thousand" and pes "foot"). However, no millipede has ever been described with more than 750 legs. We discovered a new record-setting species of millipede with 1,306 legs, Eumillipes persephone, from Western Australia. This diminutive animal (0.95 mm wide, 95.7 mm long) has 330 segments, a cone-shaped head with enormous antennae, and a beak for feeding. A distant relative of the previous record holder, Illacme plenipes from California, it belongs to a different order, the Polyzoniida. Discovered 60 m below ground in a drill hole created for mineral exploration, E. persephone possesses troglomorphic features; it lacks eyes and pigmentation, and it has a greatly elongated body-features that stand in stark contrast to its closest surface-dwelling relatives in Australia and all other members of its order. Using phylogenomics, we found that super-elongation (> 180 segments) evolved repeatedly in the millipede class Diplopoda. The striking morphological similarity between E. persephone and I. plenipes is a result of convergent evolution, probably for locomotion in similar soil habitats. Discovered in the resource-rich Goldfields-Esperance region and threatened by encroaching surface mining, documentation of this species and conservation of its habitat are of critical importance., (© 2021. The Author(s).)

We analyzed 769 242 occurrence records for 115 424 species of terrestrial arthropods, from three biodiversity repositories (Global Biodiversity Information Facility (GBIF), Natural History Museum, London, and "Sistema de Informação Distribuído para Coleções Biológicas" (SpeciesLink)), to test the use of global-scale data points for quantitative assessments of areas of endemism. The data include Insecta (105,941 species), Arachnida (7984 species), Myriapoda (1229) and terrestrial crustaceans (270 Branchiopoda). The species were assigned to 14 543 higher taxonomic groups because such groups often characterize larger areas of endemism. Putative areas of endemism were visualized as sets of cells displaying unique groups of species without the assumption of hierarchical relationships. Yet, the use of 10° grid cells recovered many large areas broadly corresponding to biogeographic Regions (Nearctic, Neotropical, Panamanian, Palaearctic, Afrotropical, Australian, Oceanian and Oriental) albeit with the limits poorly defined. An analysis of 5° grids resulted in 306 sets included in the different biogeographic Realms: Afrotropical, Australian, Madagascan, Nearctic, Neotropical, Oceanian, Oriental, Palaearctic, Saharo-Arabian and Sino-Japanese. The Panamanian Realm comprises 89 partly overlapping sets, crossing the Nearctic and Neotropical boundaries. A total of 7338 species of Insecta were endemic to some areas (Sino-Japanese, Afrotropical, Panamanian, Palaearctic, among others), followed by Arachnida (412 spp) and 105 species in other clades ranked as "classes". Six sets were supported only by genera, except for Panamanian sets that were supported by genera and families. Many of the species in the dataset are included in IUCN red lists, but probably most of those have distributions more restricted than global areas of endemism; only 102 appear as endemic to some area (Neartic, Madagascan, Panamanian, Afrotropical, among others). The results show that data from global databases can be used to identify areas of endemism on a worldwide basis but-owing to their incompleteness-only at a relatively coarse level. At the level of resolution currently allowed by such databases, such global studies are only complementary to studies where areas are determined subjectively by systematists (instead of actual point records), or studies using point records in datasets for specific taxonomic groups curated and compiled by specialists., (© 2020 The Willi Hennig Society.)

The mesovoid shallow substratum (MSS) can act as a climatic refuge for invertebrates, as a biogeographic corridor to deeper substrates or as a permanent habitat for some species. This study characterizes the seasonal invertebrate diversity and abundance of MSS ecosystems in central Portugal focusing on Diplopoda, Diplura, Orthoptera and Coleoptera during one year. Sampling was performed with standard MSS pitfalls in scree slopes (colluvial MSS) of karst areas and environmental parameters (temperature, pH, conductivity, water content, organic carbon, nitrate, phosphate and ammonium) were quantified. Our results show that winter was the season with the highest arthropod abundance and that the MSS acts as a permanent habitat for chordeumatidan millipedes and as a climatic refuge for orthopterans and most beetles. All Diplura collected belong to a single species known previously from surface habitats in the Iberian Peninsula, which does not seem to use the Portuguese MSS as a refuge. MSS habitats in central Portugal, classified as western Mediterranean and thermophile deposits protected by the Natura 2000 network based on plant communities and geology, revealed an abundant and diverse invertebrate community that urges characterization and protection., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Two new species of Cyphoderus are described; full body chaetotaxy is given. Cyphoderus pataxo sp. nov. and Cyphoderus palaciosi sp. nov. were originally found in metalogenic areas covered with transitional vegetation of savanna and subtropical forest from Minas Gerais, Southeastern Brazil. Both new species are part of the "bidenticulati-group," with mucronal formula 'Aa' and show remarkable plurichaetosis on posterior manubrium and dens., (© 2021. Sociedade Entomológica do Brasil.)

The last common ancestor of all living arthropods had biramous postantennal appendages, with an endopodite and exopodite branching off the limb base. Morphological evidence for homology of these rami between crustaceans and chelicerates has, however, been challenged by data from clonal composition and from knockout of leg patterning genes. Cambrian arthropod fossils have been cited as providing support for competing hypotheses about biramy but have shed little light on additional lateral outgrowths, known as exites. Here we draw on microtomographic imaging of the Cambrian great-appendage arthropod Leanchoilia to reveal a previously undetected exite at the base of most appendages, composed of overlapping lamellae. A morphologically similar, and we infer homologous, exite is documented in the same position in members of the trilobite-allied Artiopoda. This early Cambrian exite morphology supplements an emerging picture from gene expression that exites may have a deeper origin in arthropod phylogeny than has been appreciated., (© 2021. The Author(s).)

Two new species of Homidia are described from Eastern China: H. hangzhouensis sp. nov. and H. wanensis sp. nov. The former is characterised by smooth chaetae e and l1 on labial base, two irregular transverse stripes on Abd. IV, absence of blue pigment on Ant. I-II and Abd. I-II and presence on Ant. III-IV, 7-9 macrochaetae on Abd. IV posteriorly and 24-34 smooth inner spines on dens. The latter can be identified by reduced blue body pigment, smooth chaeta e on labial base and having some posterior labial chaetae modified, appearing leaflike, 8-9 macrochaetae on Abd. IV posteriorly and 83 smooth inner spines on dens.

We studied Entomobryidae and Orchesellidae springtails collected throughout Chechnya, Ingushetia, and Dagestan, Russia. Three new species of the genus Entomobrya (E. multisetis sp. nov., E. hirsutothorax sp. nov., and E. kremenitsai sp. nov.), and one of Entomobryoides (E. dagestanicus sp. nov.) are described. Taxonomic information for Entomobrya nicoleti (Lubbock, 1868), Willowsia potapovi Zhang et al., 2011, and Heteromurus nitidus (Templeton, 1836) in Templeton Westwood 1836 from the Caucasus are given.

The Japanese members of the proturan genus Gracilentulus comprise five species: G. aokii Imadaté, G. chichibuensis Nakamura, G. macrotarsus sp. nov., G. microtrichus sp. nov., and G. europaeus Szeptycki. In the present study, the new Gracilentulus species are described while G. europaeus is described based on Japanese specimens. Gracilentulus europaeus belongs to the "gracilis" group, which was recorded in Japan for the first time herein. Supplementary notes are provided on G. aokii and G. chichibuensis. A key to the species that lack sensillum b' on the foretarsus is also provided.

The genus Songius Sun Guo in Guo et al., 2010 (Pauropoda: Pauropodidae) was established for two new species from China: Songius rugosus Sun Guo in Guo et al., 2010 and Songius bicruris Guo Sun in Guo et al., 2010. The manuscript was received by the journal Zoological Science on 7th April 2010 and the article is displayed on the BioOne platform with the publication date of 1st November 2010. In the same year, Yin et al. (2010) established the genus Songius Yin Li in Yin et al., 2010 (Coleoptera: Staphylinidae: Pselaphinae).

A new species, Anurophorus hallaensis sp. nov. was collected from the withered leaves of Korean fir (Abies koreana Wilson), which is distributed at higher than 1,300 m in altitude on Mt. Hallasan (Jeju Island, South Korea). The morphology and two partial gene regions of this species are described herein. Anurophorus hallaensis sp. nov. showed the same formulas of macrochaetae and sensilla on thoracic segment II to abdominal segment IV as those exhibited by A. laricis Nicolet and A. palearcticus Potapov; however, this new species can be distinguished from them by the number of knobbed hairs on ventral side of legs. Partial DNA sequences of the mitochondrial Cytochrome c Oxidase subunit I (COI) gene and ribosomal DNA (28S rDNA) were used as DNA barcodes to distinguish between A. hallaensis sp. nov. and closely related congeners. The results of the present study indicate that the COI and rDNA are useful for species discrimination within the genus Anurophorus. An identification key to the Korean species of Anurophorus is provided.

A new genus, Martenseya, is described for Martenseya minutocaeca n. sp., a tiny, blind species in the family Caseyidae from Marin County, California, USA. A key to the chordeumatidan families of northwestern North America is provided, as well as a key to caseyid genera.

Hedinomorpha martensorum spec. nov., H. jaegeri spec. nov. and H. sympatrica spec. nov. are described, the former species from Qinghai Province, and both latter ones occurring syntopically in Shaanxi Province, China. A brief description and a new diagnosis of Hedinomorpha, a key to its 24 species presently known, and a map showing their distributions are provided. The affinities of Hedinomorpha within the tribe Sulciferini are discussed.

The genus Lepidocyrtus Bourlet is currently considered to consist of eight subgenera of which Setogaster Salmon is one. Here we describe three new species in this subgenus, L. agricolus sp. nov., L. coorongensis sp. nov., and L. nashi sp. nov. It appears to be the most widespread and numerically dominant subgenus of Lepidocyrtus in Australia. The three new species live in different habitats and in different parts of the continent. It is assumed they are endemic species, one is likely to be a short range endemic. The characters and a list of species of the Lepidocyrtus praecisus-group, and an identification key for the Australian species of genus Lepidocyrtus are provided.

Klimakodesmus Carl, 1932 is briefly redescribed, rediagnosed, and shown to be an oligotypic genus endemic to southern India and distinct from the particularly similar genus Pyrgodesmus Pocock, 1892, monobasic and endemic to Sri Lanka, by several important features of peripheral and, especially, gonopodal structure. A new species, Klimakodesmus bilobocaudatus sp. nov., is described from Kerala state, India, differing from the sole accepted, and type species K. gravelyi Carl, 1932, from Tamil Nadu state, primarily by the laterally trilobate paraterga, the caudally more deeply bilobate mid-dorsal keel on ring 19, and certain minor details of the gonopodal structure.

A survey of Sminthurides Börner, 1900 with specimens from the Americas was performed and two new species from Mexico are described and illustrated (drawings and SEM photographs), including a detailed study of body chaetotaxy. Sminthurides cihuatlensis sp. nov. is part of the Aquaticus group by the presence of ciliate seta B1 on Ant. II; it has a narrow mucro and lives in soil from the slopes of Iztaccíhuatl volcano. Sminthurides fridakahloae sp. nov. belongs to the Penicillifer group by the presence of Tra-2 on the Ant. II; it has a broad, trilamellate mucro, dens with plurichaetosis, and lives on surface freshwater from Colima and Morelos states. In addition, a key for the species is provided.

We summarise here publications on Collembola in the journal Zootaxa over the years 2001 to 2020 and include numbers and nationalities of authors and referees. We also list numbers of new species and genera described. For a relatively small pool of taxonomists, we conclude their output has been considerable and Zootaxa has provided a useful vehicle in which to publish their research findings. Of interest, is the shift away from a Eurocentric origin of authors to a Chinese and Brazilian one. Reasons for this change are suggested.

Three new genera, Retrorsioides, Rowlandesmus and Benedictesmus, are described and the polydesmid millipede fauna of North America is briefly reviewed with an emphasis on the genera Bidentogon Buckett Gardner, 1968 and Retrorsia Shelley, 2003. Eighteen new species are described: Bidentogon buttensis, Bidentogon norcal, Retrorsia leonardi, Retrorsia benedictae, Retrorsia richarti, Retrorsia gracilis, Retrorsia simplicissima, Retrorsioides castellum, Retrorsioides linnensis, Retrorsioides kittitas, Retrorsioides bammerti, Retrorsioides arboramagna, Rowlandesmus millicoma, Rowlandesmus dentogonopus, Benedictesmus aureua, Benedictesmus ellenae, Benedictesmus yaquina and Benedictesmus timber. Natural history notes and illustrations are provided of putative commensal fungi, nematodes and a mite found on the millipede specimens.

Forest habitats host enormous diversity, but little is known about the seasonal turnover of arthropod species between the above- and below ground forest layers. In this study, we used metabarcoding approaches to uncover arthropod diversity in different forest types and seasons. Our study shows that metabarcoding soil eDNA and Malaise trap bulk samples can provide valuable insights into the phenology and life cycles of arthropods. We found major differences in arthropod species diversity between soil samples and Malaise traps, with only 11.8% species overlap. Higher diversity levels were found in Malaise traps in summer whereas soil samples showed a diversity peak in winter, highlighting the seasonal habitat preferences and life strategies of arthropods. We conclude that collecting time series of bulk arthropod samples and eDNA in the same locations provides a more complete picture of local arthropod diversity and turnover rates and may provide valuable information on climate induced phenological shifts for long-term monitoring.

Chelodesmidae is one of the most diverse families belonging to the Polydesmida, comprising almost 800 described species distributed in 172 genera, 20 tribes and two subfamilies. Among the tribes within the Neotropical subfamily Chelodesminae, Arthrosolaenomeridini represents a very interesting group occurring in the Central-West region of Brazil. Currently the tribe contains three genera: Arthrosolaenomeris Schubart, 1943, Gangugia Schubart, 1947, and Angelodesmus Schubart, 1962. In this study, we conducted a cladistic analysis including 18 species of Arthrosolaenomeridini and 7 species of other associated Chelodesminae tribes as an outgroup. The matrix is composed of 64 morphological characters from which 39 are herein proposed for the first time. The data were analyzed under the parsimony criterion using TNT 1.5. Based on the results, Arthrosolaenomeridini was recovered as monophyletic with Macrocoxodesmini + Telonychopodini as sister group. Arthrosolaenomeris Schubart, 1943 and Gangugia Schubart, 1947 were recovered as monophyletics. The genus Angelodesmus Schubart, 1962 was recovered as paraphyletic and redefined as monotypic. The tribe is now composed of the genera Arthrosolaenomeris (6 spp.), Gangugia (6 spp.), Angelodesmus (monotypic), Abiliodesmus n. gen. (4 spp.) and Folcloredesmus n. gen. (monotypic). In addition, we conduct a taxonomic revision of the tribe Arthrosolaenomeridini providing detailed redescriptions, drawings, and distribution maps for all species and genera, including the two new genera and the ten new species proposed: Arthrosolaenomeris saci n. sp.; A. curupira n. sp.; A. caipora n. sp.; A. iara n. sp.; Gangugia boitata n. sp.; G. cuca n. sp.; G. boto n. sp.; G. mula n. sp.; Abiliodesmus mapinguari n. sp. and Folcloredesmus thomasi n. sp. Furthermore, we include an identification key to all the genera and species.

The studied area (Far East of Russia) is very little investigated for the Entomobryidae family. A specific sampling in the area has made it possible to detect the presence of four and one new species of the genera Entomobrya and Willowsia respectively, which are herein described (E. amurica sp. nov., E. mediostriata sp. nov., E. umbroviolacea sp. nov., E. bicincta sp. nov. and W. babykinae sp. nov.) from the western part of the Far East of Russia. Homidia hjesanica is also recorded.

Two new species of the genus Psyllaphorura Bagnall, 1948, namely P. silvestris sp. nov. and P. pseudopodis sp. nov., are described from the European Russia. The former species can be compared to the Nearctic P. obesa (Mills, 1934) which has almost the same number of dorsal pseudocelli, but differs in having compound vesicles in PAO. Psyllaphorura pseudopodis sp. nov. is similar to P. altaica Weiner, Stebaeva Kaprus', 2019 recently described from the Altai Mountains, southern Siberia. Both these species have the same number and arrangement of the cephalic pseudocelli. Nonetheless, P. pseudopodis sp. nov. can be distinguished by the absence of pseudocelli on Abd. IV, only 2+2 dental setae and a shorter unguiculus. Besides this, P. pseudopodis sp. nov. is unique in the presence of a pair of ventral swellings on the fourth abdominal segment. Based on a revision of the types, P. sensillifera (Martynova, 1981) is considered a senior synonym of P. raoheensis Sun Wu, 2013. Taxonomic notes on the most important diagnostic characters of the genus are given, as well as a key and a table summarizing these characters in all Psyllaphorura species known in the World so far.

Coronavirus-like organisms have been previously identified in Arthropod ectoparasites (such as ticks and unfed cat flea). Yet, the question regarding the possible role of these arthropods as SARS-CoV-2 passive/biological transmission vectors is still poorly explored. In this study, we performed in silico structural and binding energy calculations to assess the risks associated with possible ectoparasite transmission. We found sufficient similarity between ectoparasite ACE and human ACE2 protein sequences to build good quality 3D-models of the SARS-CoV-2 Spike:ACE complex to assess the impacts of ectoparasite mutations on complex stability. For several species (e.g., water flea, deer tick, body louse), our analyses showed no significant destabilisation of the SARS-CoV-2 Spike:ACE complex, suggesting these species would bind the viral Spike protein. Our structural analyses also provide structural rationale for interactions between the viral Spike and the ectoparasite ACE proteins. Although we do not have experimental evidence of infection in these ectoparasites, the predicted stability of the complex suggests this is possible, raising concerns of a possible role in passive transmission of the virus to their human hosts.

A new genus of Callipallenidae, Agnathia, is established to accommodate two new species of pycnogonid from southern Australia; A. aria and A. chuki. Both new species are represented by adult and sub-adult forms. Gravid females and ovigerous and larvigerous males are represented. Postembryonic growth stages are recorded and briefly discussed. The presence of six-segmented ovigers in males of one species, as opposed to the usual ten segments in both sexes, is recorded. Genera that share morphological relationships are discussed and a key to these genera is provided. The genera Bradypallene, Pycnopallene and Safropallene are reassessed and reassigned to family incertae sedis.

A new large species of the millipede genus Prionopetalum Attems, 1909, P. nessiae sp. nov. from Mt. Kilimanjaro, Tanzania, is described, with SEM imaging and illustrations of relevant taxonomic characters, and mapped. Comments on the significance of sternum 9 in descriptions of Odontopygidae, and on the intrageneric differences in Prionopetalum, are included.

Arthropod vectors have historically been identified morphologically, and more recently using molecular biology methods. However, both of these methods are time-consuming and require specific expertise and equipment. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry, which has revolutionized the routine identification of microorganisms in clinical microbiology laboratories, was recently successfully applied to the identification of arthropod vectors. Since then, the robustness of this identification technique has been confirmed, extended to a large panel of arthropod vectors, and assessed for detecting blood feeding behavior and identifying the infection status in regard to certain pathogenic agents. In this study, we summarize the state-of-the-art of matrix-assisted laser desorption ionization time-of-flight mass spectrometry applied to the identification of arthropod vectors (ticks, mosquitoes, phlebotomine sand-flies, fleas, triatomines, lice and Culicoides ), their trophic preferences and their ability to discriminate between infection statuses.

The subterranean islands hypothesis for calcretes of the Yilgarn region in Western Australia applies to many stygobitic (subterranean-aquatic) species that are "trapped" evolutionarily within isolated aquifers due to their aquatic lifestyles. In contrast, little is known about the distribution of terrestrial-subterranean invertebrates associated with the calcretes. We used subterranean Collembola from the Yilgarn calcretes to test the hypothesis that troglobitic species, those inhabiting the subterranean unsaturated (non-aquatic) zone of calcretes, are also restricted in their distribution and represent reciprocally monophyletic and endemic lineages. We used the barcoding fragment of the mtDNA cytochrome c oxidase subunit 1 ( COI ) gene from 183 individuals to reconstruct the phylogenetic history of the genus Pseudosinella Schäffer (Collembola, Lepidocyrtidae) from 10 calcretes in the Yilgarn. These calcretes represent less than 5% of the total possible calcretes in this region, yet we show that their diversity for subterranean Collembola comprises a minimum of 25 new species. Regionally, multiple levels of diversity exist in Pseudosinella , indicative of a complex evolutionary history for this genus in the Yilgarn. These species have probably been impacted by climatic oscillations, facilitating their dispersal across the landscape. The results represent a small proportion of the undiscovered diversity in Australia's arid zone.

Phylogenetic assessments of functional traits are important for mechanistically understanding the interactions between organisms and environments, but such practices are strongly limited by the availability of phylogenetic frameworks. The tomocerin springtails are an ancient, widespread and ecologically important group of terrestrial arthropods, whereas their phylogeny and trait evolution remained unaddressed. In the present study, we conducted the first comprehensive phylogenetic reconstruction of Tomocerinae, based on a multi-loci molecular dataset covering all major lineages within the subfamily, using Bayesian inference (BI), maximum-likelihood (ML) and maximum-parsimony (MP) approaches. Divergence time was estimated and ancestral character state reconstruction (ACSR) was performed to trace the evolutionary history of five ecomorphological traits correlated with sensory and locomotory functions. Our results support the monophyly of Tomocerinae, and indicate that current classification of Tomocerinae only partially reflects evolutionary relationships, notably the commonest and speciose genus Tomocerus is polyphyletic. The subfamily probably originated in Early Cretaceous and diversified in two Cretaceous and one Eocene radiation events. As indicated by the evolutionary patterns of functional traits, multiple ecological divergences took place during the diversification of Tomocerinae. The study suggests a potential underestimation of ecological divergence and functional diversity in terrestrial arthropods, calls for an update of present trait databases, and demonstrates the value of macroevolutionary knowledge for improving the trait-based ecology. In addition, Tomocerus, Tomocerina and Tritomurus are redefined, a new genus Yoshiicerusgen. n. and new subgenera Coloratomurussubgen. n., Ciliatomurussubgen. n., Striatomurussubgen. n. and Ocreatomurussubgen. n. are described in the appendix., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background and Objective: Predatory arthropods may play a crucial role in decreasing the pest population that causes a significant loss in oil palm production. In this study, we investigated the diversity of predatory arthropods and their abundance on immature and mature oil palm plantation grown in Aceh Tamiang, Sumatra, Indonesia., Materials and Methods: Arthropod predators were collected by using light trap, yellow-pan trap and pitfall trap that were placed on an immature and mature oil palm plantation. Specimens were sorted and identified in the Laboratory., Results: The results showed that there were 674 individuals arthropod predators (insects and spiders) consisted of 7 orders, 22 families and 37 morphospecies collected in the immature plantation. While in mature plantation, arthropod predators found were 740 individuals consisted of 6 orders 23 families and 42 morphospecies. Ants (Hymenoptera: Formicidae) dominated other families regarding morphospecies and individual numbers. There was no significant difference in term of species richness and abundance of predators between both phases of the plantation which implied that the two plantations hosted a similar composition and abundance of predators. The diversity indices of predators calculated in both plantations showed that the predators were categorized as middle level of diversity and middle level of individual distribution, However, the community is unstable., Conclusion: Our results suggested that predatory predators were present in similar structure in both phases of oil palm plantations. Efforts to conserve them are needed to enhance their performance as part of a sustainable and environmentally friendly method for controlling pests in oil palm plantation.

The discovery of enzyme-derived d-amino acid-containing peptides (DAACPs) that have physiological importance in the metazoan challenges previous assumptions about the homochirality of animal proteins while simultaneously revealing new analytical challenges in the structural and functional characterization of peptides. Most known DAACPs have been identified though laborious activity-guided purification studies or by homology to previously identified DAACPs. Peptide characterization experiments are increasingly dominated by high throughput mass spectrometry-based peptidomics, with stereochemistry rarely considered due to the technical challenges of identifying l/d isomerization. This review discusses the prevalence of enzyme-derived DAACPs among animals and the physiological consequences of peptide isomerization. Also highlighted are the analytical methods that have been applied for structural characterization/discovery of DAACPs, including results of several recent studies using non-targeted discovery methods for revealing novel DAACPs, strongly suggesting that more DAACPs remain to be uncovered., (Copyright © 2020. Published by Elsevier B.V.)

Collembola are an ancient and early diverging lineage of basal hexapods that occur in virtually all terrestrial habitats on Earth. Phylogenetic relationships between the different orders of Collembola are fiercely debated. Despite a range of studies and the application of both morphological and genetic approaches (singly or in combination) to assess the evolutionary relationships of major lineages in the group, no consensus has been reached. Several mitogenome sequences have been published for key taxa of the class (and their number is increasing rapidly). Here, we describe two new Antarctic Collembola mitogenomes and compare all complete or semi-complete springtail mitogenome sequences available on GenBank in terms of both gene order and DNA sequence analyses in a genome evolution and molecular phylogenetic framework. With minor exceptions, we confirm the monophyly of Poduromorpha and Symphypleona sensu stricto (the latter placed at the most basal position in the springtail phylogenetic tree), whereas monophyly of Neelipleona and Entomobryomorpha is only supported when a handful of critical taxa in these two lineages are excluded. Finally, we review gene order models observed in the class, as well as the overall mitochondrial nucleotide composition.

Herein Lepidocyrtinus Börner is reviewed based on African species and a new diagnosis to the genus is provided, including the description of intermediary stages of two species and a proposal for the interpretation of the dorsal chaetotaxy based in juveniles. In total, 17 species previously assigned as Seira Lubbock are transferred to Lepidocyrtinus, and three of them are redescribed: L. barnardi Womersley and L. dayi Yosii from South Africa, and L. voeltzkowi (Börner) from Madagascar. Neotypes are designated for these last two species. In addition, nine new species are described from Africa: one from Botswana, two from Republic of the Congo, two from South Africa, and four from Madagascar. Finally, identification keys for the current genera of Seirinae and for the African species of Lepidocyrtinus are provided. After our revision, Lepidocyrtinus has now its generic status revalidated with 36 species, 29 of them from African continent, two from Oceania and five from Brazil.

The expansion of agriculture and intensive mechanized production have resulted in the loss of habitats and biodiversity, which has led to the loss of ecological services such as the biological control of pests and diseases, and insect-borne pollination. Current studies mainly focus on the impact of small-scale crop diversity (such as intercropping) on ecological service but lack research on the effects of crop diversity at the landscape scale. In this study, vegetation-dwelling arthropods in naked oat ( Avena chinensis ) fields under different planting patterns were collected at different growth stages by standardized sweep netting sampling, and the differences in arthropod communities and temporal dynamics were analyzed. Taking this information as an example, the effects of crop diversity at the landscape scale caused by different planting patterns on arthropod communities were studied. It was found that herbivores were the most abundant functional group in the arthropod community in naked oat fields, accounting for 70.13% of the total abundance, followed by natural enemies, accounting for 23.45%, and, finally, other insects. The abundance and species richness of natural enemies in naked oat fields under diversified planting pattern were significantly higher than those under intensive planting pattern, while the abundance and species richness of herbivorous pests showed no significant difference between the two planting patterns. Planting patterns significantly affected the composition and structure of arthropod communities in naked oat fields. Significantly higher ratio of natural enemy to pest and more diverse natural enemies under the diversified planting pattern have shown better biological control potential and the significance of biodiversity protection.