Toward Advanced Superomniphobicity: Hierarchical Insights from Serif-T Nanostructures to Microscale Wrinkles

Developing a superomniphobic surface that exceeds the static and dynamic repellency observed in nature's springtails for various liquids presents a significant challenge in the realm of surface and interface science. However, progress in this field has been particularly limited when dealing with low-surface-tension liquids. This is because dynamic repellency values are typically at least 2 orders of magnitude lower than those observed with water droplets. Our study introduces an innovative hierarchical topography demonstrating exceptional dynamic repellency to low-surface-tension liquids. Inspired by the structural advantages found in springtails, we achieve a static contact angle of >160° and the complete rebound of droplet impact with a Weber number (We) of ∼104 using ethanol. These results surpass all existing benchmarks that have been reported thus far, including those of natural surfaces. The key insight from our research is the vital role of the microscale air pocket size, governed by wrinkle wavelength, in both static and dynamic repellency. Additionally, nanoscale air pockets within serif-T nanostructures prove to be essential for achieving omniphobicity. Our investigations into the wetting dynamics of ethanol droplets further reveal aspects such as the reduction in contact time and the occurrence of a fragmentation phenomenon beyond We ∼ 350, which has not been previously observed.

The genome sequence of the springtail Allacma fusca (Linnaeus, 1758)

We present a genome assembly from an individual male Allacma fusca (the springtail; Arthropoda; Collembola; Symphypleona; Sminthuridae). The genome sequence is 392.8 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules, including the X 1 and X 2 sex chromosomes. The mitochondrial genome has also been assembled and is 14.94 kilobases in length.

Effects of Species Invasion and Inundation on the Collembola Community in Coastal Mudflat Wetland from the Perspective of Functional Traits

The group of soil arthropods known as Collembola is characterized by its abundance and sensitivity to environmental changes. They are ideal an species for soil indicators. In order to clarify the effects of species invasion and inundation on the Collembola community in coastal mudflat wetlands, the correlation between the collembolan functional traits and environmental factors was studied in Shanghai Jiuduansha Wetland National Nature Reserve for the first time. Five sample plots, including three vegetations-Spartina alterniflora (an invasive species), Phragmites australis, and Zizania latifolia-were set up following the differences in vegetation types and between high and low tidal flats. Data on the diversity of the Collembolan species and their functional traits were collected and combined with the soil physicochemical properties and vegetation environment factors in different tidal flats. The key findings and conclusions of the study are as follows: a total of 18 species, four families, and three orders make up the obtained Collembola, two species of Proisotoma are dominant species that account for 49.59% and 24.91% of the total, respectively. The maintenance of the species diversity of Collembola is disturbed by the higher conversion efficiency of Spartina alterniflora rather than Phragmites australis with lower organic carbon (C) content and higher total nitrogen (N) content. The primary environmental variables influencing species distribution were the C/N ratio, total N, and bulk soil density. The bulk density of the soil impacts the movement and dispersal of the functional traits. The depth of the soil layer is related to the functional traits of the sensory ability. The analysis of the functional traits and environment is fairly helpful in exploring how species respond to their environment and offers a better explanation for the habitat selection of Collembola.

Food origin influences microbiota and stable isotope enrichment profiles of cold-adapted Collembola (Desoria ruseki)

Collembola are a group of globally distributed microarthropods that can tolerate low temperature and are active in extremely cold environments. While it is well known that animal diets can shape their microbiota, the microbiota of soil animals is not well described, particularly for animals with limited food resources, such as Collembola active in winter at low temperatures. In this study, we explored the effects of three different food sources; corn litter (agriculture grain residuals), Mongolian oak litter (natural plant residuals), and yeast (common food for Collembola culture), on the microbiota of a winter-active Collembola species, Desoria ruseki. We found that microbial diversity and community composition of the Collembola were strongly altered after feeding with different food sources for 30 days. Collembola individuals fed on corn litter harbored the highest bacterial richness and were dominated by a representative of Microbacteriaceae. In contrast, those fed on yeast exhibited the lowest bacterial richness and were primarily colonized by Pseudomonas. The microbial communities associated with the winter-active Collembola differed significantly from those observed in the food. Collembola nutrient turnover also differed when cultured with different food sources, as indicated by the C and N stable isotopic signatures. Our study highlights microbial associations with stable isotopic enrichments of the host. Specifically, the Arthrobacter was positively correlated with δ¹³C enrichment in the host. Representatives of Microbacteriaceae, Micrococcaceae, TM7a, Devosia, and Rathayibacter were positively correlated with δ¹⁵N enrichment of the host. Our study indicates that food sources are major determinants for Collembola microbiota that simultaneously alter consumers' isotopic niches, thereby improving our understanding of the roles played by host-microbiota interactions in sustaining soil biodiversity during the winter.

An updated checklist of Collembola in Taiwan, with DNA barcoding of Papirioidesjacobsoni Folsom, 1924 (Symphypleona, Dicyrtomidae)

From urban green space to pristine forest, Collembola is one of the most numerous and species-rich members of the soil fauna around the world. However, due to lack of taxonomic expertise and research, its diversity is poorly understood, especially in tropical and subtropical regions. Collembola biodiversity studies in Taiwan have not seen much progress since 1981, when Hsin Chi reviewed 26 species belonging to 20 genera and eight families. Additionally, reports of new records in Taiwan in the last 40 years are scattered amongst several publications and not easily accessible to most end-users. Thus, a concise summary of related research is urgently needed. In this study, we updated the checklist of Collembola in Taiwan, based on published papers as well as images recorded in 2020-2022. We concluded that 58 species of Collembola belonging to 31 genera and 12 families have been reported in Taiwan, including 13 newly-recorded species. This species richness marks a 123% increase from the 1981 review. The results have been made publicly available in the Catalog of Life in Taiwan database and the images recorded have been used to update species information in collembola.org. We also characterised morphological and genetic variations in the globular springtail species Papirioidesjacobsoni Folsom, 1924 using DNA barcodes and highlighted potential research directions.

One-Step Fabrication of Flexible Bioinspired Superomniphobic Surfaces

Flexible superomniphobic doubly re-entrant (Dual-T) microstructures inspired by springtails have attracted growing attention due to their excellent liquid-repellent properties. However, the simple and practical manufacturing processes of the flexible Dual-T microstructures are urgently needed. Here, we proposed a one-step molding process coupled with the lithography technique to fabricate the elastomeric polydimethylsiloxane (PDMS) Dual-T microstructure surfaces with high uniformity. The angle between the downward overhang and the horizontal direction could reach 90° (vertical overhang). The flexible superomniphobic Dual-T microstructure surfaces, without fluorination treatment and physical treatments, could repel liquids with a surface tension lower than 20 mN m^-1 in the Cassie-Baxter state. Owing to the excellent robustness of the one-step molding downward overhanging, the max breakthrough pressure of this surface could reach up to 164.3 Pa for ethanol droplets. Furthermore, the flexible superomniphobic Dual-T surface allowed impinging ethanol droplets to completely rebound at the Weber number up to 7.1 with an impact velocity of ∼0.32 m s^-1. The Dual-T microstructure surface maintained excellent superomniphobicity even after surface oxygen plasma treatment and exhibited excellent structural robustness and recoverability to various large mechanical deformations.

Conversion of rainforest into oil palm and rubber plantations affects the functional composition of litter and soil Collembola

Rainforest conversion and expansion of plantations in tropical regions are associated with changes in animal communities and biodiversity decline. In soil, Collembola are one of the most numerous invertebrate groups that affect the functioning of microbial communities and support arthropod predators. Despite that, information on the impact of changes in land use in the tropics on species and trait composition of Collembola communities is very limited. We investigated the response of Collembola to the conversion of rainforest into rubber agroforestry ("jungle rubber"), rubber, and oil palm plantations in Jambi Province (Sumatra, Indonesia), a region which experienced one of the strongest recent deforestation globally. Collembola were sampled in 2013 and 2016 from the litter and soil layer using heat extraction, and environmental factors were measured (litter C/N ratio, pH, water content, composition of microbial community and predator abundance). In the litter layer, density and species richness in plantation systems were 25%-38% and 30%-40% lower, respectively, than in rainforest. However, in the soil layer, density, species richness, and trait diversity of Collembola were only slightly affected by land-use change, contrasting the response of many other animal groups. Species and trait composition of Collembola communities in litter and soil differed between each of the land-use systems. Water content and pH were identified as main factors related to the differences in species and trait composition in both litter and soil, followed by the density of micro- and macropredators. Dominant species of Collembola in rainforest and jungle rubber were characterized by small body size, absence of furca, and absence of intense pigmentation, while in plantations, larger species with long furca and diffuse or patterned pigmentation were more abundant. Overall, land-use change negatively affected Collembola communities in the litter layer, but its impact was lower in the soil layer. Several pantropical genera of Collembola (i.e., Isotomiella, Pseudosinella, and Folsomides) dominated across land-use systems, reflecting their high environmental adaptability and/or efficient dispersal, calling for studies on their ecology and genetic diversity. The decline in species richness and density of litter-dwelling Collembola with the conversion of rainforest into plantation systems calls for management practices mitigating negative effects of the deterioration of the litter layer in rubber plantations, but even more in oil palm plantations.

Re-Evaluating the Internal Phylogenetic Relationships of Collembola by Means of Mitogenome Data

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.

Reliable and Robust Fabrication Rules for Springtail-Inspired Superomniphobic Surfaces

We report a reliable and robust method for the fabrication of bioinspired superomniphobic surfaces with precise concave-cap-shaped micropillar arrays. This method includes silicon-based conventional microelectromechanical systems (MEMS) and polymer replication processes. We have elucidated two critical cases of fabrication rules for precise micromachining of a negative-shaped bioinspired silicon master. The fabricated polymeric structure replicated from the semipermanent silicon master based on the design rules exhibited high structural fidelity and robustness. Finally, we validated the superomniphobic properties, structural durability, and long-term stability of the fabricated bioinspired surfaces.

Springtail phylogeography highlights biosecurity risks of repeated invasions and intraregional transfers among remote islands

Human-mediated transport of species outside their natural range is a rapidly growing threat to biodiversity, particularly for island ecosystems that have evolved in isolation. The genetic structure underpinning island populations will largely determine their response to increased transport and thus help to inform biosecurity management. However, this information is severely lacking for some groups, such as the soil fauna. We therefore analysed the phylogeographic structure of an indigenous and an invasive springtail species (Collembola: Poduromorpha), each distributed across multiple remote sub-Antarctic islands, where human activity is currently intensifying. For both species, we generated a genome-wide SNP data set and additionally analysed all available COI barcodes. Genetic differentiation in the indigenous springtail Tullbergia bisetosa is substantial among (and, to a lesser degree, within) islands, reflecting low dispersal and historic population fragmentation, while COI patterns reveal ancestral signatures of postglacial recolonization. This pronounced geographic structure demonstrates the key role of allopatric divergence in shaping the region's diversity and highlights the vulnerability of indigenous populations to genetic homogenization via human transport. For the invasive species Hypogastrura viatica, nuclear genetic structure is much less apparent, particularly for islands linked by regular shipping, while diverged COI haplotypes indicate multiple independent introductions to each island. Thus, human transport has likely facilitated this species' persistence since its initial colonization, through the ongoing introduction and inter-island spread of genetic variation. These findings highlight the different evolutionary consequences of human transport for indigenous and invasive soil species. Crucially, both outcomes demonstrate the need for improved intraregional biosecurity among remote island systems, where the policy focus to date has been on external introductions.

The complete mitochondrial genome of Orthonychiurus folsomi (Collembola: Onychiuridae)

The complete mitochondrial genome of Orthonychiurus folsomi (Schäffer 1900) was sequenced, assembled, and annotated. The mitochondrial genome of O. folsomi has a length of 15,283bp and comprises 13 protein-coding genes, 22 tRNA genes, and two rRNA genes. Two tRNA genes trnS(uga) and trnQ have changed position. A phylogenetic tree of Onychiuridae species showed the polyphyly of this family.

Nitrogen Inputs by Marine Vertebrates Drive Abundance and Richness in Antarctic Terrestrial Ecosystems

Biodiversity is threatened by climate change and other human activities [1], but to assess impacts, we also need to identify the current distribution of species on Earth. Predicting abundance and richness patterns is difficult in many regions and especially so on the remote Antarctic continent, due to periods of snow cover, which limit remote sensing, and the small size of the biota present. As the Earth's coldest continent, temperature and water availability have received particular attention in understanding patterns of Antarctic biodiversity [2], whereas nitrogen availability has received less attention [3]. Nitrogen input by birds is a major nutrient source in many regions on Earth [4-7], and input from penguins and seals is associated with increased plant growth [8-10] and soil respiration [11-13] at some Antarctic locations. However, the consequences of increased nitrogen concentrations in Antarctic mosses and lichens for their associated food web has hardly been addressed [14, 15], despite the fact that nutrient status of primary producers affects the abundance and diversity of higher trophic levels [16, 17]. We show that nitrogen input and δ¹⁵N signatures from marine vertebrates are associated with terrestrial biodiversity hotspots well beyond (>1,000 m) their immediate colony borders along the Antarctic Peninsula. Invertebrate abundance and richness was two to eight times higher under penguin and elephant seal influence. The nitrogen footprint area was correlated with the vertebrate population size. These findings improve our ability to predict biogeographical patterns of Antarctic terrestrial biodiversity through knowledge of the location and size of penguin and elephant seal concentrations.

Nonfluorinated Superomniphobic Surfaces through Shape-Tunable Mushroom-like Polymeric Micropillar Arrays

Superomniphobic surfaces showing extremely liquid-repellent properties have received a great amount of attention as they can be used in various industrial and biomedical applications. However, so far, the fabrication processes of these materials mostly have involved the coating of perfluorocarbons onto micro- and nanohierarchical structures of these surfaces, which inevitably causes environmental pollution, leading to health concerns. Herein, we developed a facile method to obtain flexible superomniphobic surfaces without perfluorocarbon coatings that have shape-tunable mushroom-like micropillars (MPs). Inspired by the unique structures on the skin of springtails, we fabricated mushroom-like structures with downward facing edges (i.e., a doubly re-entrant structure) on a surface. The flexible MP structures were fabricated using a conventional micromolding technique, and the shapes of the mushroom caps were made highly tunable via the deposition of a thin aluminum (Al) layer. Due to the compressive residual stress of the Al, the mushroom caps were observed to bend toward the polymer upon forming doubly re-entrant-MP structures. The obtained surface was found to repel most low-surface-tension liquids such as oils, alcohols, and even fluorinated solvents. The developed flexible superomniphobic surface showed liquid repellency even upon mechanical stretching and after surface energy modification. We envision that the developed superomniphobic surface with high flexibility and wetting resistance after surface energy modification will be used in a wide range of applications such as self-cleaning clothes and gloves.

Impact of the springtail's cuticle nanotopography on bioadhesion and biofilm formation in vitro and in the oral cavity

Springtails (Collembola) have a nanostructured cuticle. To evaluate and to understand anti-biofouling properties of springtail cuticles' morphology under different conditions, springtails, shed cuticles and cuticle replicates were studied after incubation with protein solutions and bacterial cultures using common in vitro models. In a second step, they were exposed to human oral environment in situ in order to explore potential application in dentistry. In vitro, the cuticular structures were found to resist wetting by albumin solutions for up to 3 h and colonization by Staphylococcus epidermidis was inhibited. When exposed in the oral cavity, initial pellicle formation was of high heterogeneity: parts of the surface were coated by adsorbed proteins, others remained uncoated but exhibited locally attached, 'bridging', proteinaceous membranes spanning across cavities of the cuticle surface; this unique phenomenon was observed for the first time. Also the degree of bacterial colonization varied considerably. In conclusion, the springtail cuticle partially modulates bioadhesion in the oral cavity in a unique and specific manner, but it has no universal effect. Especially after longer exposure, the nanotextured surface of springtails is masked by the pellicle, resulting in subsequent bacterial colonization, and, thus, cannot effectively avoid bioadhesion in the oral cavity comprehensively. Nevertheless, the observed phenomena offer valuable information and new perspectives for the development of antifouling surfaces applicable in the oral cavity.

Two new species of Sinella from Guangdong Province, China (Collembola: Entomobryidae)

Two new blind species of Sinella are described from Guangdong Province, China. Sinella colubra sp. n. possesses minute smooth postlabial chaetae, long mucronal spine, and 4+4(5) lateral mac on Abd. IV, and can be distinguished from two closely related species by the postlabial chaetae and the dorsal macrochaetotaxy. Sinella zhangi sp. n. is also described and can be diagnosed by having minute labial chaeta r and postlabial chaetae X and X4, 5+5 mac on Abd. I, 4+4 central mac on Abd. II, and 4+4 central and 5+5 lateral mac on Abd. IV.

Impact of Location, Cropping History, Tillage, and Chlorpyrifos on Soil Arthropods in Peanut

Demand for agricultural production systems that are both economically viable and environmentally conscious continues to increase. In recent years, reduced tillage systems, and grass and pasture rotations have been investigated to help maintain or improve soil quality, increase crop yield, and decrease labor requirements for production. However, documentation of the effects of reduced tillage, fescue rotation systems as well as other management practices, including pesticides, on pest damage and soil arthropod activity in peanut production for the Mid-Atlantic US region is still limited. Therefore, this project was implemented to assess impacts of fescue-based rotation systems on pests and other soil organisms when compared with cash crop rotation systems over four locations in eastern North Carolina. In addition, the effects of tillage (strip vs. conventional) and soil chlorpyrifos application on pod damage and soil-dwelling organisms were also evaluated. Soil arthropod populations were assessed by deploying pitfall traps containing 50% ethanol in each of the sampled plots. Results from the present study provide evidence that location significantly impacts pest damage and soil arthropod diversity in peanut fields. Cropping history also influenced arthropod diversity, with higher diversity in fescue compared with cash crop fields. Corn rootworm damage to pods was higher at one of our locations (Rocky Mount) compared with all others. Cropping history (fescue vs. cash crop) did not have an effect on rootworm damage, but increased numbers of hymenopterans, acarina, heteropterans, and collembolans in fescue compared with cash crop fields. Interestingly, there was an overall tendency for higher number of soil arthropods in traps placed in chlorpyrifos-treated plots compared with nontreated controls.

Effects of Season and Management of Irrigated Cotton Fields on Collembola (Hexapoda) in New South Wales, Australia

The effects of production practices on the relative abundance of springtails (Collembola) in irrigated cotton fields of northern New South Wales (NSW) were studied over 2 yr to examine effects of farm management on these decomposer organisms. Pitfall trapping and soil core extraction was undertaken in both pseudoreplicated plots within whole fields on cotton farms and on experimental replicate plots of Envirofeast cotton and Lucerne. The relative abundance of surface-active springtails in cotton rows and densities of soil species from the rhizosphere were calculated. Twenty-three species of Collembola were collected from 5 fields, 19 in pitfall traps, and 11 in soil cores. Five species, Setogaster sp., Proisotoma minuta, Entomobrya unostrigata, Entomobrya multifasciata grp, and Lepidobrya sp. were numerically dominant on the ground at 86-96% of individuals and Mesaphorura sp., Folsomides parvulus, and Hemisotoma thermophila grp dominant in the soil. Native grassland samples contained 15 species of which a probable 10 were native and 8 were not found in cotton. Nineteen species of the 24 species identified from cotton were predominantly fungal feeders. Highest catches of Collembola occurred after flowering and soil Collembola increased with depth and during cotton growth on unsprayed plots but decreased on sprayed plots. Surface soil moistures affected daily catch rates with decomposing residues, crop stage, predator abundance, and season as secondary factors. Insecticide (endosulfan, pyrethroid, carbamate, and organophosphate) and predator effects were either negligible or unclear depending on the factor involved. Springtails appear to be predominately food limited during times of adequate soil moisture in cotton fields.

Evidence of Protaphorura fimata (Collembola: Poduromorpha: Onychiuridae) feeding on germinating lettuce in the Salinas Valley of California

A series of experiments were conducted to determine the impact of Protaphorura fimata Gisin (Family: Onychiuridae) feeding on seeds and germinating seedlings of lettuce, Lactuca sativa L. (Asteraceae). First, various densities of P. fimata were incubated with 25 lettuce seeds for 7 d and feeding injury was evaluated in three soilless arena experiments. As a second step, 100 P. fimata were incubated with 25 lettuce seeds in three arena experiments with soil media. Finally, in a commercial field the incidence and impact of P. fimata on recently planted lettuce was assessed following applications of pyrethroid-insecticides: 2 d before planting, at planting, and 20 d later. In experiments without soil, the number of ungerminated seeds, feeding injury sites, and plants with injury were significantly greater in arenas with P. fimata than without. Similarly, the number of germinated seedlings, shoot fresh, and dry weights, and the length and width of fully opened-leaves were greater in arenas without than with P. fimata in assays with soil. In the field, P. fimata densities were significantly lower in beds that received insecticides at 2 d before and at planting than in untreated beds. Also, the fresh and dry weights of lettuce plants were significantly greater in the beds that received insecticide than in untreated. The results clearly show that P. fimata is a pest of lettuce and can cause severe feeding injury to germinating seeds or seedlings, thereby reducing their growth rate. The potential implications of P. fimata feeding and feeding injury characteristics are discussed.