Functionally graded structures in the involucre of Job's tears.

Nature is filled with materials that are both strong and light, such as bones, teeth, bamboo, seashells, arthropod exoskeletons, and nut shells. The insights gained from analyzing the changing chemical compositions and structural characteristics, as well as the mechanical properties of these materials, have been applied in developing innovative, durable, and lightweight materials like those used for impact absorption. This research concentrates on the involucres of Job's tears (Coix lacryma-jobivar.lacryma-jobi), which are rich in silica, hard, and serve to encase the seeds. The chemical composition and structural characteristics of involucres were observed using scanning electron microscopy and energy-dispersive x-ray spectroscopy and optical microscopy with safranin staining. The hardness of the outer and inner surfaces of the involucre was measured using the micro-Vickers hardness test, and the Young's modulus of the involucre's cross-section was measured using nanoindentation. Additionally, the breaking behavior of involucres was measured through compression test and three-point bending tests. The results revealed a smooth transition in chemical composition, as well as in the orientation and dimensions of the tissues from the outer to the inner layers of involucres. Furthermore, it was estimated that the spatial gradient of the Young's modulus is due to the gradient of silica deposition. By distributing the hard, brittle silica in the outer layer and elastoplastic organic components in the middle and inner layers, the involucres effectively respond to compressive and tensile stresses that occur when loads are applied to the outside of the involucre. Furthermore, the involucres are reinforced in both meridional and equatorial directions by robust fibrovascular bundles, fibrous bundles, and the inner layer's sclerenchyma fibers. From these factors, it was found that involucres exhibit high toughness against loads from outside, making it less prone to cracking.

Locomotor Assays in Drosophila Larvae and Adult Flies.

Brain defects often lead to motor dysfunctions in humans. Drosophila melanogaster has been one of the most useful organisms in the study of neuronal biology due to its similarities with humans and has contributed to a more detailed understanding of the effects of genetic dysfunctions in the brain on behavior. We herein present modified protocols for the crawling assay with larvae and the climbing assay with adult flies that are simple to perform as well as a series of commands for ImageJ to automatically analyze data for the crawling assay.

High-resolution vision in pelagic polychaetes.

High-resolution object vision - the ability to separate, classify, and interact with specific objects in the environment against the visual background - has only been conclusively shown to have evolved in three of the thirty-five animal phyla: chordates, arthropods, and mollusks (cephalopods)1. However, alciopid polychaetes (Phyllodocidae, Alciopini), which possess a pair of bulbous camera-type eyes, have also been hypothesized to achieve high acuity. In this study, we examined three species of night-active pelagic alciopids from the Mediterranean Sea. Our optical, morphological, and electrophysiological investigations show that their eyes have high spatial acuity and temporal resolution, supporting the notion that they are capable of active, high-resolution object vision. These results encourage interesting hypotheses about the visual ecology of these enigmatic polychaetes.

Community Structure and Water Quality Assessment of Benthic Macroinvertebrates in Hongze Lake.

This study investigated the species, density, biomass and physicochemical factors of benthic macroinvertebrates in Hongze Lake from 2016 to 2020. Redundancy analysis (RDA) was used to analyze the relationship between physicochemical parameters and the community structure of macroinvertebrates. Macroinvertebrate-based indices were used to evaluate the water quality conditions in Hongze Lake. The results showed that a total of 50 benthic species (10 annelids, 21 arthropods and 19 mollusks) were collected. The community structure of benthic macroinvertebrates varied in time and space. The dominant species were Limnodrilus hoffmeisteri (L.hoffmeisteri), Corbicula fluminea (C.fluminea), Nephtys oligobranchia (N.oligobranchia). In 2016, arthropods such as Grandidierella sp. were the dominant species of benthos in Hongze Lake while annelids and mollusks dominated from 2017 to 2020, such as L.hoffmeisteri, N.oligobranchia, C.fluminea. The benthic fauna of Chengzi Lake and Lihewa District were relatively abundant and showed slight variation, while the benthic macroinvertebrates of the Crossing the water area were few and varied greatly. RDA showed that changes in benthic macroinvertebrate structure were significantly correlated with dissolved oxygen (DO), Pondus Hydrogenii (pH) and transparency (SD). The Shannon Wiener, Pielou, and Margalef indices indicate that Hongze Lake is currently in a moderately polluted state. Future studies should focus on the combined effects of various physicochemical indicators and other environmental factors on benthic communities.

Seasonal fluctuations of litter and soil Collembola and their drivers in rainforest and plantation systems.

Rainforest conversion and expansion of plantations in tropical regions change local microclimate and are associated with biodiversity decline. Tropical soils are a hotspot of animal biodiversity and may sensitively respond to microclimate changes, but these responses remain unexplored. To address this knowledge gap, here we investigated seasonal fluctuations in density and community composition of Collembola, a dominant group of soil invertebrates, in rainforest, and in rubber and oil palm plantations in Jambi province (Sumatra, Indonesia). Across land-use systems, the density of Collembola in the litter was at a maximum at the beginning of the wet season, whereas in soil it generally varied little. The community composition of Collembola changed with season and the differences between land-use systems were most pronounced at the beginning of the dry season. Water content, pH, fungal and bacterial biomarkers, C/N ratio and root biomass were identified as factors related to seasonal variations in species composition of Collembola across different land-use systems. We conclude that (1) conversion of rainforest into plantation systems aggravates detrimental effects of low moisture during the dry season on soil invertebrate communities; (2) Collembola communities are driven by common environmental factors across land-use systems, with water content, pH and food availability being most important; (3) Collembola in litter are more sensitive to climatic variations than those in soil. Overall, the results document the sensitivity of tropical soil invertebrate communities to seasonal climatic variations, which intensifies the effects of the conversion of rainforest into plantation systems on soil biodiversity.

Microscopic Menaces: The Impact of Mites on Human Health.

Mites are highly prevalent arthropods that infest diverse ecological niches globally. Approximately 55,000 species of mites have been identified but many more are yet to be discovered. Of the ones we do know about, most go unnoticed by humans and animals. However, there are several species from the Acariformes superorder that exert a significant impact on global human health. House dust mites are a major source of inhaled allergens, affecting 10-20% of the world's population; storage mites also cause a significant allergy in susceptible individuals; chiggers are the sole vectors for the bacterium that causes scrub typhus; Demodex mites are part of the normal microfauna of humans and their pets, but under certain conditions populations grow out of control and affect the integrity of the integumentary system; and scabies mites cause one of the most common dermatological diseases worldwide. On the other hand, recent genome sequences of mites provide novel tools for mite control and the development of new biomaterial with applications in biomedicine. Despite the palpable disease burden, mites remain understudied in parasitological research. By better understanding mite biology and disease processes, researchers can identify new ways to diagnose, manage, and prevent common mite-induced afflictions. This knowledge can lead to improved clinical outcomes and reduced disease burden from these remarkably widespread yet understudied creatures.

The BALA project: A pioneering monitoring of Azorean forest invertebrates over two decades (1999-2022).

Globally, there is a concerning decline in many insect populations, and this trend likely extends to all arthropods, potentially impacting unique island biota. Native non-endemic and endemic species on islands are under threat due to habitat destruction, with the introduction of exotic, and potentially invasive, species, further contributing to this decline. While long-term studies of plants and vertebrate fauna are available, long-term arthropod datasets are limited, hindering comparisons with better-studied taxa. The Biodiversity of Arthropods of the Laurisilva of the Azores (BALA) project has allowed gathering comprehensive data since 1997 in the Azorean Islands (Portugal), using standardised sampling methods across islands. The dataset includes arthropod counts from epigean (pitfall traps) and canopy-dwelling (beating samples) communities, enriched with species information, biogeographic origins, and IUCN categories. Metadata associated with the sample protocol and events, like sample identifier, archive number, sampled tree species, and trap type are also recorded. The database is available in multiple formats, including Darwin Core, which facilitates the ecological analysis of pressing environmental concerns, such as arthropod population declines and biological invasions.

Evidence for cryptic molting behavior in the trilobite Toxochasmops vormsiensis from the Upper Ordovician Katian Kõrgessaare Formation, Estonia.

Documentation of cryptic trilobite behavior has presented important insights into the paleoecology of this fully extinct arthropod group. One such example is the preservation of trilobites inside the remains of larger animals. To date, evidence for trilobites within cephalopods, gastropods, hyoliths, and other trilobites has been presented. Importantly, most of these interactions show trilobite molts, suggesting that trilobites used larger animals for protection during molting. To expand the record of molted trilobites within cephalopods, we present a unique case of a Toxochasmops vormsiensis trilobite within the body chamber of a Gorbyoceras textumaraneum nautiloid from the Upper Ordovician Kõrgessaare Formation of Estonia. By examining this material, we present new insights into the ecology of pterygometopid trilobites, highlighting how these forms used large cephalopods as areas to successfully molt.

INFLUENCE OF GROOMING ON PERMANENT ARTHROPOD ASSOCIATES OF BIRDS: CATTLE EGRETS, LICE, AND MITES.

Birds have a diverse community of "permanent" arthropods that complete their entire life cycle on the body of the host. Because some of these arthropods are parasites that reduce host fitness, birds control them by grooming, which consists of preening with the beak and scratching with the feet. Although preening is the primary component of grooming, scratching is essential for controlling arthropods on the head and neck, which cannot be preened. Several unrelated groups of birds have evolved comb-like pectinate claws on the middle toenail of each foot. We tested the role of these claws in the control of arthropods by experimentally removing teeth from the claws of captive western cattle egrets (Bubulcus ibis) infested with chewing lice (Insecta: Phthiraptera), feather mites (Acari: Sarcoptiformes), and nasal mites (Acari: Mesostigmata). After a period of 4 mo, we compared the abundance of arthropods on experimental birds to that of control birds with intact teeth. We used video to quantify the grooming rates of the captive birds, which groomed twice as much as wild birds. Experimental and control birds did not differ significantly in grooming time. Both groups virtually eradicated the chewing lice, but not feather mites or nasal mites. We found no support for the hypothesis that pectinate claws increase the efficiency of arthropod control by grooming. Experiments with wild birds are needed to test the hypothesis further under conditions in which birds devote less time to grooming.

Diversity and complexity of arthropod references in haiku.

Haiku are short poems, each composed of about 10 words, that typically describe moments in nature. People have written haiku since at least the 17th century, and the medium continues to be popular with poets, amateurs, educators, and students. Collectively, these poems represent an opportunity to understand which aspects of nature-e.g., which taxa and biological traits-resonate with humans and whether there are temporal trends in their representation or the emotions associated with these moments. We tested this potential using a mix of linguistic and biological methods, in analyses of nearly 4,000 haiku that reference arthropods. We documented the taxa and the life history traits represented in these poems and how they changed over time. We also analyzed the poems for emotion and tone. Our results reveal a mix of predictable trends and compelling surprises, each of which stand to potentially inform engagement strategies. At least 99 families of arthropods, in 28 orders, are represented in these haiku. The eight most commonly referenced taxa, from highest to lowest number of references, include: Lepidoptera, Hymenoptera, Diptera, Coleoptera, Araneae, Orthoptera, Hemiptera, and Odonata. Several common, conspicuous orders were never referenced, including Trichoptera, Plecoptera, and Megaloptera. The most commonly referenced traits relate to ecology (especially habitat, phenology, time of day), behavior (especially sound production), phenotype (especially color), and locomotion (especially flight). The least common traits in haiku relate to arthropod reproduction and physiology. Our analyses revealed few obvious temporal trends in the representations of taxa, biological traits, or emotion and tone. The broader implications of these results and possible future directions are discussed.

Molecular level toxicity effects of As(V) on Folsomia candida: Integrated transcriptomics and metabolomics analyses.

Arsenic (As) is a widespread metalloid with well-known toxicity. To date, numerous studies have focused on individual level toxicity (e.g., growth and reproduction) of As to typical invertebrate springtails in soils, however, the molecular level toxicity and mechanism was poorly understood. Here, an integrated transcriptomics and metabolomics approach was used to reveal responses of Folsomia candida exposed to As(V) of 10 and 60 mg kg-1 at which the individual level endpoints were influenced. Transcriptomics identified 5349 and 4020 differentially expressed genes (DEGs) in low and high concentration groups, respectively, and the most DEGs were down-regulated. Enrichment analysis showed that low and high concentrations of As(V) significantly inhibited chromatin/chromosome-related biological processes (chromatin/chromosome organization, nucleosome assembly and organization, etc.) in springtails. At high concentration treatment, structural constituent of cuticle, chitin metabolic process and peptidase activity (serine-type peptidase activity, endopeptidase activity, etc.) were inhibited or disturbed. Moreover, the apoptosis pathway was significantly induced. Metabolomics analysis identified 271 differential changed metabolites (DCMs) in springtails exposed to high concentration of As. Steroid hormone biosynthesis was the most significantly affected pathway. Several DCMs that related to chitin metabolism could further support above transcriptomic results. These findings further extended the knowledge of As toxic mechanisms to soil fauna and offer important information for the environmental risk assessment.

Tick hemocytes have a pleiotropic role in microbial infection and arthropod fitness.

Uncovering the complexity of systems in non-model organisms is critical for understanding arthropod immunology. Prior efforts have mostly focused on Dipteran insects, which only account for a subset of existing arthropod species in nature. Here we use and develop advanced techniques to describe immune cells (hemocytes) from the clinically relevant tick Ixodes scapularis at a single-cell resolution. We observe molecular alterations in hemocytes upon feeding and infection with either the Lyme disease spirochete Borrelia burgdorferi or the rickettsial agent Anaplasma phagocytophilum. We reveal hemocyte clusters exhibiting defined signatures related to immunity, metabolism, and proliferation. Depletion of phagocytic hemocytes affects hemocytin and astakine levels, two I. scapularis hemocyte markers, impacting blood-feeding, molting behavior, and bacterial acquisition. Mechanistically, astakine alters hemocyte proliferation, whereas hemocytin affects the c-Jun N-terminal kinase (JNK) signaling pathway in I. scapularis. Altogether, we discover a role for tick hemocytes in immunophysiology and provide a valuable resource for comparative biology in arthropods.

Genetic underpinnings of arthropod community distributions in Populus trichocarpa.

Community genetics seeks to understand the mechanisms by which natural genetic variation in heritable host phenotypes can encompass assemblages of organisms such as bacteria, fungi, and many animals including arthropods. Prior studies that focused on plant genotypes have been unable to identify genes controlling community composition, a necessary step to predict ecosystem structure and function as underlying genes shift within plant populations. We surveyed arthropods within an association population of Populus trichocarpa in three common gardens to discover plant genes that contributed to arthropod community composition. We analyzed our surveys with traditional single-trait genome-wide association analysis (GWAS), multitrait GWAS, and functional networks built from a diverse set of plant phenotypes. Plant genotype was influential in structuring arthropod community composition among several garden sites. Candidate genes important for higher level organization of arthropod communities had broadly applicable functions, such as terpenoid biosynthesis and production of dsRNA binding proteins and protein kinases, which may be capable of targeting multiple arthropod species. We have demonstrated the ability to detect, in an uncontrolled environment, individual genes that are associated with the community assemblage of arthropods on a host plant, further enhancing our understanding of genetic mechanisms that impact ecosystem structure.

Cadmium toxicity to and accumulation in a soil collembolan (Folsomia candida): major factors and prediction using a back-propagation neural network model.

Accurate prediction of cadmium (Cd) ecotoxicity to and accumulation in soil biota is important in soil health. However, very limited information on Cd ecotoxicity on naturally contaminated soils. Herein, we investigated soil Cd ecotoxicity using Folsomia candida, a standard single-species test animal, in 28 naturally Cd-contaminated soils, and the back-propagation neural network (BPNN) model was used to predict Cd ecotoxicity to and accumulation in F. candida. Soil total Cd and pH were the primary soil properties affecting Cd toxicity. However, soil pH was the main factor when the total Cd concentration was < 3 mg kg-1. Interestingly, correlation analysis and the K-spiked test confirmed nutrient potassium (K) was essential for Cd accumulation, highlighting the significance of studying K in Cd accumulation. The BPNN model showed greater prediction accuracy of collembolan survival rate (R2 = 0.797), reproduction inhibitory rate (R2 = 0.827), body Cd concentration (R2 = 0.961), and Cd bioaccumulation factor (R2 = 0.964) than multiple linear regression models. Then the developed BPNN model was used to predict Cd ecological risks in 57 soils in southern China. Compared to multiple linear regression models, the BPNN models can better identify high-risk regions. This study highlights the potential of BPNN as a novel and rapid tool for the evaluation and monitoring of Cd ecotoxicity in naturally contaminated soils.

Interspecific insect relationships on Terminalia argentea (Myrtales: Combretaceae) trees in the Cerrado biome.

Terminalia argentea Mart. (Combretaceae), native to Brazil, is used in habitat restoration programs. Arthropods are bioindicators because their populations reflect changes in the environment. We evaluated the recovery of a degraded area by using ecological indices and analyzing arthropod interactions on T. argentea plants. The richness and diversity of sap-sucking Hemiptera and the abundance of tending ants and Sternorrhyncha predators increased with the number of T. argentea leaves. The correlation of the abundance of tending ants and Sternorrhyncha predators was positive with that of the sap-sucking Hemiptera, and the abundance of Sternorrhyncha predators was negative with that of tending ants and sap-sucking Hemiptera. The positive correlation between the abundance, richness, and diversity of insect groups and numbers of T. argentea leaves is an example of the bottom-up regulation mechanism, with the population dynamics of the lower trophic levels dictating those of higher trophic levels. The contribution of T. argentea, a host plant of many arthropods, to the recovery of ecological relationships between organisms in degraded ecosystems is important.

The plant virus transmissions database.

Plant viruses are transmitted mechanically or by vegetative propagation, and by vectors such as arthropods, fungi, nematodes, or parasitic plants. Sources to access available information regarding plant virus transmissions are scattered and require extensive literature searches. Here, a recently created plant virus transmission database is described. This was developed to provide access to the modes of transmission and vectors of over 1600 plant viruses. The database was compiled using over 3500 publication records spanning the last 100 years. The information is publicly accessible via https://library.wur.nl/WebQuery/virus and fully searchable by virus name, taxonomic position, mode of transmission or vector.

Characterization of the complete mitochondrial genome of Spirobolus grahami (Diplopoda: Spirobolidae) with phylogenetic analysis.

Diplopoda is one of the most diverse and important groups of soil arthropods, but little research has been done on their phylogenetic relationship and evolution. Here, we sequenced and annotated the complete mitochondrial genomes of Spirobolus grahami. The total mitogenome of S. grahami was typical circular, double-stranded molecules, with 14,875 bp in length, including 13 protein-coding genes, 22 tRNAs, two rRNAs, and one control region. Base composition analysis suggested that the mitochondrial sequences were biased toward A and T, with A + T content of 58.68%. The mitogenomes of S. grahami exhibited negative AT and positive GC skews. Most of the 13 PCGs had ATN as the start codon, except COX1 start with CGA, and most PCGs ended with the T stop codon. The dN/dS values for most PCGs were lower than 1, suggesting that purifying selection was likely the main driver of mitochondrial PCG evolution. Phylogenetic analyses based on 13 PCGs using BI and ML methods support the classification of genus Spirobolus and Tropostreptus. Glomeridesmus spelaeus is distantly related to the other Diplopoda species.

Exploring Collembola Diversity in the Green Open Spaces of Baruga Forest, Kendari City, Indonesia.

<b>Background and Objective:</b> The rapid development of Kendari City as the capital of Southeast Sulawesi Province has led to changes in land use patterns, particularly an increase in built-up areas, which threaten environmental stability. Rapid population growth contributes to rising carbon dioxide emissions, impacting air quality. Green spaces like Baruga Forest are ideal for environmental balance and bioservation. This study aims to identify the diversity of Collembola species in Baruga Forest, Kendari and understand the environmental factors influencing their presence. <b>Materials and Methods:</b> Collembola was collected in the Baruga Forest using a Berlese funnel, then identified and classified based on the family by counting the number of individuals in each taxonomic group. The diversity of Collembola was measured using the Shannon-Wiener index, while the evenness of individual distribution in each family was assessed using an evenness index. Additionally, environmental parameters such as air temperature, air humidity and soil pH were measured. The collected data were analyzed using descriptive statistical analysis. <b>Results:</b> The research results indicate that there are 75 individuals of Collembola belonging to the class Entognatha. The dominant order observed is Entomobryomorpha, consisting of three families: Oncopoduridae with 60 individuals, Isotomidae with 7 individuals and Orchesellidae with 5 individuals. Additionally, there is the order Symphypleona, represented by a single family, Bourletiellidae, with one individual. The biodiversity index (H') yielded a moderate value of 0.622, where the most significant contribution comes from the genus Isotomidae. Meanwhile, the evenness index (E) indicates a uniform distribution among the various genera of Collembola. <b>Conclusion:</b> Observed variations in temperature, humidity and soil pH changes underscore the need for ongoing management and conservation of Baruga Forest to maintain the diversity of Collembola species and the sustainability of the ecosystem in Baruga Forest.

Do bed bugs transmit human viruses, or do humans spread bed bugs and their viruses? A worldwide survey of the bed bug RNA virosphere.

BED BUGS: (Hemiptera: Cimicidae) are a globally distributed hematophagous pest that routinely feed on humans. Unlike many blood-sucking arthropods, they have never been linked to pathogen transmission in a natural setting, and despite increasing interest in their role as disease vectors, little is known about the viruses that bed bugs naturally harbor. Here, we present a global-scale survey of the bed bug RNA virosphere. We sequenced the metatranscriptomes of 22 individual bed bugs (Cimex lectularius and Cimex hemipterus) from 8 locations around the world. We detected sequences from two known bed bug viruses (Shuangao bedbug virus 1 and Shuangao bedbug virus 2) which extends their geographical range. We identified three novel bed bug virus sequences from a tenui-like virus (Bunyavirales), a toti-like virus (Ghabrivirales), and a luteo-like virus (Tolivirales). Interestingly, some of the bed bug viruses branch near to insect-transmitted plant-infecting viruses, opening questions regarding the evolution of plant virus infection. When we analyzed the viral sequences by their host's collection location, we found unexpected patterns of geographical diversity that may reflect humans' role in bed bug dispersal. Additionally, we investigated the effect that Wolbachia, the primary bed bug endosymbiont, may have on viral abundance and found that Wolbachia infection neither promotes nor inhibits viral infection. Finally, our results provide no evidence that bed bugs transmit any known human pathogenic viruses.