Degradation and fragmentation of mulching films represents an increasing source of microplastics (MPs, plastic particles 1 μm to 5 mm in size) to agricultural soils. MPs have been shown to affect many soil invertebrates, including springtails. However, these studies typically use test materials representing less environmentally relevant particle types, such as pristine uniform MPs, which do not represent the large range of particle sizes and morphologies found in the field. This study aimed at providing insight into the adverse effects of MPs originating from agricultural mulching films, by using artificially aged MPs derived from both biodegradable (starch-polybutadiene adipate terephthalate (PBAT)) blend, as well as conventional (linear low-density polyethylene (LLDPE)) plastic polymers. The soil dwelling springtail Folsomia candida was exposed to these MPs for five generations in order to elucidate population effects due to possible reproduction toxicity, endocrine disruption, mutagenesis or developmental toxicity. F. candida were exposed to 0, 0.0016, 0.008, 0.04, 0.2, 1, 2, 3, 4 and 5 % (w/w dry soil) MPs in Lufa 2.2 soil, which includes concentrations within the range of environmental relevance. Juveniles produced at each concentration were transferred to the next generation, with the parental, F2 and F4 generations being exposed for four weeks and F1 and F3 generations for five weeks. No concentration-dependent effects on F. candida survival or reproduction were observed in exposures to either of the MPs, in any of the generations. These results suggest that the particular MPs used in this study, derived from mulching films used on agricultural soils, may not be potent toxicants to F. candida, even after long-term exposure and at elevated concentrations.

The neonicotinoid acetamiprid is used as a foliar insecticide spray, which results in direct exposure of a wide variety of soil organisms. Laboratory testing indicated that acetamiprid is toxic to the Collembola (springtails) species Folsomia candida, while Acari (mites) seem relatively insensitive to neonicotinoids. Since such opposing effects on different soil arthropods might imbalance natural arthropod communities, this study determined: (i) if field-realistic doses of acetamiprid affect the abundance and diversity in soil arthropod communities, and (ii) whether these potential effects are short-term or persist after degradation of acetamiprid. Intact soil cores collected from an untreated grassland field were placed in the mesocosm set up \'CLIMECS\', and the naturally sourced communities were exposed to a control and increasing field-realistic doses of acetamiprid (i.e. 0, 0.05, 0.2, 0.8 mg a.s./kg dry soil). Before and 7 and 54 days after spraying the insecticide, the abundance of mites and springtails and springtail diversity were assessed. Springtail and mite abundances were similar at the start of the experiment, but springtail abundance was significantly lowered while mite abundance increased shortly after exposure to increasing doses of acetamiprid. At the highest dose, springtail numbers decreased by 53% on average while the number of mites increased by 26%. This effect was no longer visible after 54 days, suggesting recovery of the community as a whole reflected by observed changes in community dissimilarity: shortly after application springtail communities clearly diverged from the control in terms of species composition, while communities converged again in the long-term. With our results, we are the first to show that field-realistic applications of N-nitroguanidine neonicotinoids can significantly impact natural soil fauna communities, which might have implications for soil ecosystem functioning.

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.

Springtails use unique compounds for their outermost epicuticular wax layer, often of terpenoid origin. We report here the structure and synthesis of socialane, the major cuticular constituent of the Collembola Hypogastrura socialis. Socialane is also the first regular nonaprenyl terpene with a cyclic head group. The saturated side chain has seven stereogenic centers, making the determination of the configuration difficult. We describe here the identification of socialane and a synthetic approach using the building blocks farnesol and phytol, enantioselective hydrogenation, and α-alkylation of sulfones for the synthesis of various stereoisomers. NMR experiments showed the presence of an anti-configuration of the methyl groups closest to the benzene ring and that the other methyl groups of the polyprenyl side-chain are not uniformly configured. Furthermore, socialane is structurally different from [6+2]-terpene viaticene of the closely related H. viatica, showing species specificity of the epicuticular lipids of this genus and hinting at a possible role of surface lipids in the communication of these gregarious arthropods.

Volatile organic compounds (VOCs) emitted by fungi play a key role in locating and selecting hosts for fungivorous arthropods. However, the ecological functions of many common VOC classes, such as sesquiterpenes, remain unknown. Mutants of Trichoderma virens, defective in the emission of most sesquiterpenes owing to the deletion of the terpene cyclase vir4, were used to evaluate the role of this compound class in the food preference and fitness of the soil Collembola Folsomia candida. Choice experiments with and without direct contact with fungal mycelium revealed that Collembola were preferentially attracted to Δvir4 mutants impaired in sesquiterpene synthesis compared to wild-type T. virens. Grazing by F. candida on the sesquiterpene deficient T. virens strain had no effect on Collembola survival, reproduction and growth compared to wild-type T. virens. The results suggest that sesquiterpenes play an important role in fungal defence as repellents, but not as deterrents or toxins, against fungivorous Collembola. Our research contributes to the understanding of ecological interactions between fungi and fungivorous arthropods, providing insights into the specific ecological functions of sesquiterpenes. The study has implications for chemical ecology and the dynamics of multitrophic interactions in soil ecosystems.

BACKGROUND: Septoria tritici blotch (STB), caused by the fungus Zymoseptoria tritici, is a foliar disease affecting wheat crops against which conventional control methods are not totally effective. During inter-epidemic periods the fungus survives in wheat residues left on the ground. In this study, we tested the potential of the collembolan Heteromurus nitidus - a springtail species present in field soils and known to interact with different fungal species - as a potential bioregulation agent of Z. tritici on wheat residues through a choice and consumption experiment.
RESULTS: Springtails preferred inoculated fresh residues but did not have a preference between inoculated and uninoculated old residues. Springtails grazed on Z. tritici fruiting bodies and reduced pycnidiospore numbers by ten-fold compared to control inoculated fresh residues. Attraction toward fresh inoculated residues and pycnidiospore reduction support the hypothesis that Z. tritici is a food source for springtails. Heteromurus nitidus showed no preference between inoculated and uninoculated 18-month-old residues, probably because they no longer produced ascospores.
CONCLUSIONS: Attraction towards fresh residues and spore reduction support our hypothesis that H. nitidus may contribute to the bioregulation of Z. tritici. Perspectives for field application would be determined by the ability of H. nitidus and Z. tritici to interact at key epidemiological stages. The impact of H. nitidus on the quantity of pathogen primary inoculum over time should be estimated using residues of intermediate age. This would help to identify the optimal period for enhancing the effectiveness of springtails as consumers of Z. tritici. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The present paper reports the first occurrence of Seiraferrarii Parona, 1888 from Hungary. On this occasion, molecular analyses were performed on both S.ferrarii and another historical species of the genus, S.pallidipes Reuter, 1895, originally described from Hungary. Using low-coverage whole-genome sequencing, the complete mitogenomes were assembled and annotated using MitoZ. To test the phylogenetic placement of both species, we performed maximum likelihood and Bayesian analyses using a matrix containing 14 Seirinae species and two outgroups. Both resultant trees showed that the European populations of the sampled Seira spp. likely derive from ancestral branches of Seirinae, compared to the Asian and American populations. Our results put in question the monophyly of the genus Seira, as already observed in previous studies.

This study investigated the influence of soil water status on the toxicokinetics of phenanthrene in the springtail Folsomia candida allowing estimation of uptake and elimination rates at two contrasting soil water potentials. Fitting a three-phase model to the observations showed that uptake rate (ku) was almost two times higher in moist soil (-2 kPa) than in dry soil (-360 kPa). During the first days of the exposure, elimination rate (ke) was not significantly different in moist and dry soil, but after eight days ke had increased significantly more in moist soil than in dry soil. Our results confirm the general notion that the exposure route via soil pore water is important. Understanding the significance of soil moisture in exposure and effects of contaminants on soil invertebrates is crucial for assessing the ecological risks associated with soil pollution in a changing climate.

UNASSIGNED: Soils have been studied and classified in terms of their physical and chemical characteristics, while the knowledge about biodiversity and the ecosystem processes that they support is lagging behind. Furthermore, the advance in scientific knowledge contributed by different researchers is dispersed and it is necessary to collect it to bring the big picture into focus. Today, it is possible to have the findings and data collected by different researchers, compile them and, based on technological advances, have tools that allow the information to be analysed in its entirety. The main objective of this work is to compile and systematise all the bibliographic information available on the main organisms that make up biodiversity in the soil: Acari, Collembola and Crassiclitellata in Argentina. This information will then allow us to link the composition and structure of the soil community with processes and flows in the ecosystem, and to estimate them at different scales and in soils with different anthropic impact. The database presented here gathers presence information on the mentioned taxa, their geographical location for the entire country, while preserving the identity and authorship of each scientific work retrieved. The taxonomic range of the organisms of the edaphic biota collected in this database ranges from class to subspecies and are registered, based on the taxonomic level reported by the original author in their research. The publications were obtained from Google Scholar, Scopus and JSTOR. In addition, records were added from INEDES theses, library searches, information requested from authors cited in other articles and unpublished works. In total, information was collected from 224 scientific publications, as well as personal information requested directly from some authors. The total number of registered individuals so far is 4838 of which 3049 specimens correspond to Acari, 944 to Classiclitellata and 845 belong to Collembola.
UNASSIGNED: This work is the first to gather, in a single publication, the entire dataset for all the Acari, Collembola and Clitellata recorded for Argentina.

Neonicotinoid insecticides are harmful to non-target soil invertebrates, which are crucial for sustainable agriculture. Gene expression biomarkers could provide economic and high-throughput metrics of neonicotinoid exposure and toxicity to non-target invertebrates. Thereby, biomarkers can help guide remediation efforts or policy enforcement. Gene expression of Glutathione S-Transferase 3 (GST3) has previously been proposed as a biomarker for the neonicotinoid imidacloprid in the soil ecotoxicological model species Folsomia candida (Collembola). However, it remains unclear how reliably gene expression of neonicotinoid biomarkers, such as GST3, can indicate the exposure to the broader neonicotinoid family under putative GST enzymatic inhibition. In this work, we exposed springtails to two neonicotinoids, thiacloprid and imidacloprid, alongside diethyl maleate (DEM), a known GST metabolic inhibitor that imposes oxidative stress. First, we determined the influence of DEM on neonicotinoid toxicity to springtail fecundity. Second, we surveyed the gene expression of four biomarkers, including GST3, under mutual exposure to neonicotinoids and DEM. We observed no effect of DEM on springtail fecundity. Moreover, the expression of GST3 was only influenced by DEM under mutual exposure with thiacloprid but not with imidacloprid. The results indicate that GST3 is not a robust indicator of neonicotinoid exposure and that probable GST enzymatic inhibition mediates the toxicity of imidacloprid and thiacloprid differentially. Future research should investigate biomarker reliability under shifting metabolic conditions such as provided by DEM exposure.