Abstract Electric organ discharge (EOD) waveform diversity in African elephantfish is often attributed to sexual selection, yet EODs also mediate active electrolocation during prey detection, raising the possibility that natural selection on foraging ecology contributes to waveform divergence. Paramormyrops kingsleyae exhibits an intraspecific polymorphism where certain populations emit biphasic EODs whereas other populations emit triphasic waveforms. The genes underlying this polymorphism show signatures of selection; the polymorphism persists despite gene flow and is behaviorally discriminable by the fish themselves. If waveform differences influence prey detection during active electrolocation, biphasic and triphasic fish should consume systematically different prey. We tested this prediction using DNA metabarcoding of gut contents from 186 mormyrids representing 16 species across eight sites in Gabon, employing two independent COI primer sets for cross-validation and pairing dietary data with environmental invertebrate sampling to distinguish active prey preference from passive availability. At the community level in the diverse Balé Creek mormyrid assemblage, species identity was the dominant predictor of diet composition (R² ≈ 24%), consistent with phylogenetic signal in foraging ecology. Within P. kingsleyae , waveform type was the strongest independent predictor of dietary composition (R² = 5–6%), explaining variance independently of geographic region, sex, body size, and parasitism status — a result concordant across both primer sets. Dietary differences were driven by prey species turnover rather than differential abundance of shared prey, and prey selectivity analyses confirmed that waveform types differ in which prey they actively prefer, not merely in what is locally available. These findings are consistent with natural selection on foraging ecology contributing to the maintenance of EOD waveform polymorphism, though the sensory mechanisms linking subtle waveform differences to prey detection remain an open question.

Sapronotic pathogens are constituents of complex trophic networks, such as those that structure aquatic and soil ecosystems. In such habitats, sapronotic pathogens live and reproduce among microbial consortia; they also may occasionally infect hosts and cause sapronotic disease (sapronosis). Sapronotic pathogens regroup almost all fungal microparasites and about a third of the bacterial pathogens infecting humans, including for instance nontuberculous mycobacteria. Even though sapronotic agents are naturally present in the environment, their population dynamics are unknown. Despite growing rates of sapronotic disease incidence among humans, wild, and domestic animals, very few studies have examined sapronotic transmission and dynamics in the context of spatially implicit trophic networks. Patterns of sapronotic pathogen transmission arise from complex interactions, including pathogen natural history, nonhost and host environments, and spatial and temporal scales of the system. In order to infer and ultimately predict how environmental disturbances affect trophic interactions and influence sapronotic ecology, we analysed host and nonhost species interacting as prey and as micro- and macropredators within a metacommunity context. Using a set of differential equation models, we assessed responses of environmental load dynamics of a sapronotic disease agent, i.e. a mycobacterial pathogen, within a general framework of environmental disturbance. We show that variation in top-down and horizontal interactions mediated sapronotic pathogen abundance and dynamics in the environment. Our findings indicate that habitat change and trophic interactions within these host-pathogen relationships may strongly affect sapronotic pathogen ecology through both synergistic and opposing mechanisms. This work provides for the first time an understanding of environmental disturbance consequences on trophic webs that include major sapronotic pathogens. In addition, the results provide a basis for interpreting the development of sapronotic epidemics and epizootics in the context of ecosystem modifications, particularly that of agriculture and land-use transformation. Further research of this type will provide a better understanding of the complex dynamics of sapronotic pathogens in animals and humans responding to global change.

Biologically provided nitrogen (from diet or symbionts) is overwhelmingly vital to animal life on Earth. Biological nitrogen provisioning (BNP), mainly via nitrogen fixation and recycling, is a well-established function of the gut microbiomes of various terrestrial insects but remains less well-studied in freshwater insects. One possible route for BNP in freshwater insects is microbial nitrate reduction to ammonium (NRA), which produces the same intermediate metabolite, ammonium, as microbial nitrogen fixation in terrestrial insects. In this study, we characterized gut microbiome composition using 16S amplicon sequencing, followed by compound-specific stable isotope analyses (CSIA), to examine gut microbial NRA as a possible function in nymphs of the herbivorous, filter-feeding mayfly (Hexagenia bilineata) and the predatory dragonfly (Tetragoneuria spinigera). We first uncovered significant differences in microbiome community composition and elevated NRA potential in mayflies compared with dragonflies. We subsequently determined significantly greater 15N-signatures across essential amino acids (δ15NEAA) and non-essential amino acids (δ15NNEAAs) in the herbivorous mayfly than the predatory dragonfly, after incubation in K15NO3 for 5 days. This is interpreted as insect host uptake and incorporation of microbe-derived 15NH4 into amino acids following NRA. Taken together, the results presented here suggest that gut microbial NRA may be a potential mechanism for supplying biological nitrogen to freshwater insects, potentially helping alleviate nitrogen limitations. This work advances our understanding of freshwater insect host-gut microbe associations (nature and function) and the potential impacts of these associations on host and ecosystem processes.

The diversity of resources, such as plants or dung of different mammal species, is an essential basis for the diversity of consumers at higher trophic levels. Here, animal carcasses provide an ephemeral and unpredictable resource of high nutrient content used by microbes, insects and vertebrates. While succession stage or season have already been identified as important for the composition and diversity of scavengers, the role of the carrion species is, compared to other necromass resources such as deadwood, not well understood. In this study, we investigated the role of ten mammal carrion species for the diversity of fungi, bacteria, Dipterans, Coleoptera and vertebrates. To do so, we exposed 100 carcasses of ten vertebrate species with varying body sizes in a low-mountain range area (Bavarian Forest National Park, Bavaria, Germany). To quantify the role of carrion species identity on the carcass necrobiome groups, we used sample coverage standardized diversity estimates of α-, β- and γ-diversity and uniqueness in composition. Despite a range in carcass size from 0.04 kg (single stoat carcass) to >100 kg (single red deer carcass), we found no significant differences in α- and β-diversity, except for bacteria. Thus, the highest γ-diversity was found in small-sized carrion species for vertebrate scavengers (stoat) and fungi (marten), and in medium-sized species for Coleoptera (beaver), bacteria (red fox) and Diptera (red fox). However, carcass size alone did not explain diversity. The uniqueness of Coleoptera was highest for beaver carcasses, while all other groups showed the highest uniqueness for stoat. Our findings suggest that particular small and medium-sized carcasses can make an important contribution to necrobiome diversity at the landscape scale, although the mechanisms underlying these patterns and their management implications require further studies.

Background Microbial clocks have shown high accuracy in estimating time since death, or post-mortem interval (PMI), across diverse contexts, including controlled laboratory settings, outdoor environments, and both human cadavers and animal models. However, the limited number of studies performed under different environmental and climatic conditions, particularly in Europe, restricts the broader applicability of these models, as data from distinct climates may not reliably translate across geographic regions. This study investigates the nasal thanatomicrobiome of pig carcasses exposed to outdoor summer conditions in the United Kingdom to assess the potential of microbial succession as a PMI estimator in a temperate climate. Model generalisation was further evaluated through an independent external validation on a published human thanatomicrobiome dataset spanning three geographically distinct states of the USA and all four seasons. Results Three pig carcasses were exposed for 10 days in June 2023, with duplicate swabs collected from both internal and external nares across 26 time points, yielding 312 samples in total. Microbial communities were profiled by 16S rRNA gene amplicon sequencing on an Illumina MiSeq platform; reads were processed in QIIME2 and taxonomy was assigned against the SILVA v138 database. A Random Forest regression model trained on combined internal and external nasal data achieved the highest predictive accuracy for PMI estimation (R² = 0.96, MAE = 8.83 h), outperforming models built on external or internal swabs alone. Ambient temperature, which remained overall stable throughout the study period, was not a significant predictor under these conditions. Dominant taxa associated with decomposition succession included Moraxella, Myroides, Ignatzschineria, Acinetobacter, Vagococcus, Pasteurella, Clostridium, and Savagea; the prominence of Ignatzschineria and Myroides in particular is consistent with insect-associated microbial transfer, suggesting that carrion fly activity significantly shaped the microbial community succession at this site. External validation on a published human facial skin thanatomicrobiome dataset, sampled across all four seasons, confirmed robust model performance with an R² = 0.594 and MAE = 30.3 ADD. Conclusions This study demonstrates that thanatomicrobiome-based PMI estimation can achieve high accuracy under temperate European conditions, and that results can be extended beyond the original experimental conditions, with model performance remaining robust across host species, geographic locations, anatomical location and inter-laboratory variation. However, predictive accuracy was optimised when models were trained on locally derived data, underscoring the importance of generating climate-specific models to improve the robustness and forensic applicability of microbial clocks in casework. By expanding reference datasets across diverse climatic environments and performing external validations, thanatomicrobiome-based microbial clocks have the potential to become a reliable and court-admissible tool for PMI estimation in forensic investigations.

Blow flies are early colonizers of human remains, allowing their developmental rates to be used to estimate postmortem interval (PMI). Accurate species identification is essential for PMI estimation, yet traditional methods can be subjective. Recently, the use of cuticular hydrocarbons (CHCs) for more objective species identification has been demonstrated. These studies generally use multivariate statistical approaches to evaluate differences in CHC profiles among different species. Principal component analysis (PCA) is among the more common procedures used to evaluate these differences. However, PCA often requires data pretreatment steps to address inherent biological differences among specimens, which can result in the loss of meaningful biological trends. Further, few studies have developed the predictive classification models necessary for downstream PMI estimation. In this work, CHCs were extracted from adult females of seven blow fly species and analyzed by gas chromatography-mass spectrometry (GC-MS). Profiles were initially evaluated with PCA and non-metric multidimensional scaling (NMDS). From PCA, six of the seven species were distinguished, but distinction was influenced heavily by abundance differences due to inherent variability among specimens. From NMDS, tighter species clusters were observed without the need for data pretreatment. Classification models were then developed using partial least squares-discriminant analysis (PLS-DA) and random forest modeling. Both models demonstrated high classification success for cross validation (98.67% and 98.67%) and external validation (66.67% and 61.11%), although the random forest classifier had the advantage of requiring no data pretreatment. This work demonstrates successful species classification and highlights considerations for the statistical evaluation of CHC profiles.

Carrion is a ubiquitous resource in both terrestrial and aquatic ecosystems, yet it has long been overlooked in ecological research. Over the past two decades, studies on carrion and the many organisms that exploit it have flourished, revealing not only wide-ranging ecological functions but also significance far beyond ecology. This growing body of knowledge underscores the need for the formal recognition and consolidation of carrion ecology as a distinct ecological discipline. In this review, we begin by outlining the ecological features that make carrion a unique resource, provide practical definitions of scavenger and scavenging to reduce persistent ambiguities, describe carcass decomposition by linking stages with insect succession, and position carrion within a broader scientific context. Building on this foundation, we then pursue three main goals. First, we show how incorporating carrion ecology enriches ecological concepts and paradigms across levels of biological organisation, from individuals to ecosystems. Second, we emphasise how expanding knowledge of carrion ecology informs many disciplines beyond ecology. Third, we present a conceptual framework that integrates the diverse ecological functions of carrion across eco-evolutionary timescales and addresses the structured and dynamic connections among the multiple disciplines concerned with carrion. By underscoring the ecological and interdisciplinary relevance of this resource, our framework not only clarifies the components and flows of the carrion system but also highlights opportunities for novel cross-disciplinary collaborations. As carrion ecology continues to mature as a scientific field, we expect that this review and synthesis will consolidate current knowledge, stimulate innovative research across disciplines, and firmly position carrion ecology within the broader ecological and scientific landscape.

Forensic entomology, and potentially microbiology in the future, can be used during death investigations to corroborate an estimated time since death. Instances where products are introduced to a cadaver, either in attempt to conceal or by accident, can affect decomposition and succession of associated decomposer taxa (i.e., insects and bacteria). In this study, we tested the effect of two bleach (sodium hypochlorite) submersions on the outdoor decomposition and succession of carcass, soil, and beetle postmortem microbiomes using replicate (n = 5 per treatment) stillborn swine carcasses. Microbiomes from beetles, the carcasses, and the soil beneath them were sequenced from samples collected every two days. Beetle communities collected from pitfall traps were not significantly different between bleached and control carcasses through decomposition; however, there were fewer beetles collected from bleached carcasses until the last experimental day. Results from 16S rRNA amplicon sequencing revealed that microbiomes of carcasses and the soil beneath them did not significantly change when carcasses were bleached, and beetle internal microbiomes were not affected by the addition of bleach. Random forest modeling using soil microbiomes from underneath carcasses from both treatments was used to predict time since placement in the field with a 74.4% successful prediction rate, and modeling using beetle internal microbiomes predicted beetle family with 74.0% success. The introduction of bleach to the carcasses did not affect microbial or beetle communities, total decomposition time, or decrease accuracy of time of placement models.

BACKGROUND:Understanding the spatial distribution of skin neglected tropical diseases (NTDs) is paramount for surveillance and control strategies, although little is known regarding their natural origin, ecology, and distribution. This study aims to determine how natural and anthropogenic factors affect local to global spatial distribution patterns of a major skin NTD, Buruli ulcer (BU), and its pathogen, Mycobacterium ulcerans (MU). METHODS:Generalized linear modelling of 110 variables grouped into five categories (i.e., physical, edaphic/climatic, animal diversity, plant diversity, and socio-demographic/geographic) were used to estimate continental-scale patterns of both MU and BU cases in Africa. Spatial models allowed the production of BU and MU maps for tropical and subtropical zones worldwide. RESULTS:Natural factors and their interactions consistently influence MU and BU distributions in Africa, with these distributions also responding to anthropogenic factors such as invasive plant species, agriculture and other activities. BU case distribution was driven by sunlight radiation, especially UV-B seasonality. Our extrapolation maps provide a quantitative understanding of the potential distribution of this pathogen and associated BU disease burden. DISCUSSION:Our findings highlight the utility of a disease ecology perspective using large-scale spatial data for understanding drivers of skin NTDs. Complex interactions between natural and anthropogenic factors indicate that developing preventive and control measures is challenging. Particular attention is needed on the role of invasive plant species in the spread of these pathogens, and the complex influence of sun exposure on skin NTDs.

Despite recent interest in land-use and land-cover (LULC) change effects on emerging infectious diseases (EIDs), the debate on global potential health threats remains polarizing. These depend on diverse LULC changes, different types of infectious disease systems, and spatio-temporal scales of studies. Here, using both a bibliometric and scoping review method, we summarize the reliability and availability of published relevant studies on LULC effects on mycobacteria, an important group of infectious bacteria that affect humans and both wild and domestic animals. We make connections of LULC with environmental changes (e.g. soils) that likely lead to an increased risk of mycobacteria spillover to human and other animal populations. An important feature of our review is a focus on research from the richest countries of the world, though some studies have been done in Africa, Asia and South America. Geographically, regions experiencing important LULC transformations, such as many tropical regions of Meso- and South America and Southeast Asia, have been given little or no attention in this important topic. Research on Mycobacterium bovis, and to a larger extent on M. ulcerans, constitutes convincing illustrations of the importance of acknowledging shifts in spatio-temporal scales, from local to global and inter-annual to decadal ones, when evaluating responses of mycobacteria to LULC changes. However, studies on other pathogenic mycobacteria remain very much confined to local and dispersed scales. To date, the role of LULC change effects has not been adequately studied for many human and animal pathogens, and more research and attention to this issue is clearly needed. This review provides a comprehensive set of data on the updates of LULC change and their impact on animal and human mycobacterial infections. It also proposes several research recommendations, in particular to better understand the emergence of mycobacteria in context, by multiplying study sites in different regions of the world and in adopting an ecosystem-based perspective, in order to encourage interdisciplinary research better linking environmental microbiology, veterinary science and medical research.

Understanding the dispersal ability of insects is critical for conservation efforts, as well as for preventing economic and health risks, such as the spread of bluetongue disease or African swine fever (ASF). However, knowledge of the dispersal ability of a wide range of insect species is limited. One highly unpredictable resource in space and time is carcasses, which provide an ephemeral habitat for the necrophilous insect community. In 2021 and 2022, we marked more than 5000 specimens of the carrion beetle Necrodes littoralis (L. 1758, Coleoptera: Staphylinidae: Silphinae) and released them within a forested landscape with experimentally placed cadavers to test two hypotheses. Our first question was how far N. littoralis could disperse; we hypothesised that the beetles are highly mobile and disperse over more than 3 km, which is the distance currently used for buffer strips around wild boar carcasses infected by ASF. Our second question was if wind affected the colonisation of cadavers by N. littoralis. As beetles locate carrion using olfactory cues, we hypothesised that the probability of cadaver colonisation by insects increases when positioned up-wind. Based on recapture rates of 4%-7% per year, we estimated a mean distance between release and carrion of 6 km using a dispersal kernel. Some individuals were recaptured at distances exceeding 30 km. The probability of colonising an experimental cadaver increased when the resource was placed up-wind, but colonisation probability did not increase consistently over both years with the body mass of the carcasses. Our findings support previous work suggesting high dispersal ability of the carrion beetle N. littoralis, as an adaption to colonising highly ephemeral necromass resources. From a conservation perspective, these results suggest that there are limited dispersal barriers for carrion insects within a management region. From the perspective of disease control, however, these results also indicate that buffer strips of 3 km, as used in ASF mitigation, may not be sufficient to prevent the spread of pathogens by insects.

SUMMARYDespite the clinical relevance of major tuberculous pathogens to domestic animals and humans, the understanding of mycobacterial transmission modes, pathways, and interactions in their natural habitats remains very limited. The reason for this is primarily because ecological and evolutionary concepts have not yet been widely applied to the understanding of these bacteria. Most existing research on mycobacterial transmission is not founded on hypothesis testing but rather tends to accept the most recent explanation and turn it into a canonical fact. In this comparative review, we discuss plausible alternative hypotheses against a null hypothesis of environmental origin to intensify research on mycobacterial pathogens and their capacity to spread in the context of global change. We highlight a major bias in perceptions of mycobacterial infection transmission, with most work concentrating only on the contagious stage of tuberculous clones. We suggest broadening the field to include research on environmental non-tuberculous mycobacteria and their life histories. A deeper understanding of mycobacterial ecology and evolution is more important now than ever, considering the vast diversity of known and unknown mycobacterial species in natural ecosystems. Infectious disease medicine, veterinary science, and public health surveillance should take a more integrative disease ecology approach to enhance the development of new approaches for control of these animal and human pathogens.

Blow flies (Lucilia sericata and Phormia regina) are necrophagous insects that interact with dense microbial reservoirs and are opportunistic vectors of human and animal pathogens. Despite constant exposure to diverse environmental microbes, it is unclear whether their bacterial communities are primarily acquired stochastically or shaped by host factors that could influence pathogen carriage. We conducted a systematic comparison of wild L. sericata and P. regina collected from seven cities across an urban-rural gradient to determine whether microbiome composition is structured by host species identity or environmental variables. Using 16S rRNA gene sequencing of individual flies, we profiled bacterial communities and applied alpha- and beta-diversity analyses, PERMANOVA, and Random Forest classification to quantify species-level microbiome differentiation. Species identity was the strongest predictor of microbiome composition (PERMANOVA, p = 0.001), while location, land cover type, sampling month, and sex had no significant effects. Random Forest modeling identified multiple bacterial taxa that consistently distinguished the two species, including Ignatzschineria and Dysgonomonas, which were enriched in P. regina, and Vagococcus and Escherichia-Shigella, which were enriched in L. sericata. These taxa are of clinical relevance, with Ignatzschineria in particular increasingly reported from human myiasis and soft-tissue infections, sometimes exhibiting antimicrobial resistance. Our findings demonstrate that wild blow flies maintain species-specific microbiomes despite shared environments, suggesting that host identity strongly filters microbial communities. The presence of opportunistic pathogens within these structured microbiomes underscores the need to understand how blow fly–microbe associations contribute to pathogen persistence and dissemination. By revealing predictable, species-dependent microbiome patterns, this study highlights potential targets for microbiome-based strategies aimed at mitigating blow fly–associated disease risks.

Seasonal patterns of mycobacterial infections affecting humans and animals remain a complex and understudied aspect of infectious disease dynamics. These intra-annual patterns are increasingly relevant in the context of global climate change, which may influence the timing and geographic spread of these diseases. A better understanding of such patterns could improve surveillance, prevention, and control strategies. We conducted a mixed-methods bibliometric review combining bibliographic searches and scoping analysis to synthesize decades of research on the seasonality of mycobacterial infections in humans and animals. We systematically searched three major scientific databases—Scopus, PubMed-MEDLINE, and Web of Science—for articles published between 1971 and April 2023. From an initial dataset of 1830 unique articles, we identified and analysed 122 studies that met predefined inclusion criteria. We extracted information on pathogen type, statistical methods, geographic location, and host species. In addition, we conducted a co-citation network analysis to identify key methodological influences and research clusters. The retained studies encompassed tuberculosis, Buruli ulcer, bovine tuberculosis, and other mycobacterial diseases such as leprosy and Johne’s disease. Most articles focused on tuberculosis in humans, followed by Buruli ulcer caused by Mycobacterium ulcerans. There was a marked increase in studies on seasonal trends in tuberculosis and Buruli ulcer over time, with notable variation in geographic and methodological coverage. Research was heavily concentrated in the northern hemisphere, especially in China, while southern regions remained underrepresented. Advanced statistical tools, including generalized linear models and time-series analyses, were instrumental in detecting seasonality, particularly for tuberculosis and Buruli ulcer. Seasonality appears to be a common yet understudied feature of many mycobacterial infections. Greater interdisciplinary collaboration and the use of appropriate analytical tools are essential to better understand these patterns, especially in underrepresented regions. Addressing methodological and geographic gaps will be crucial to improve responses to these diseases in a changing global environment.

Ecosystem processes affect the transfer and cycling of energy and nutrients within a given ecosystem. A critical link in these processes is nutrient recycling via carrion decomposition. The spatial and temporal distribution of species, nutrients, and energy dene the mosaic structure of ecosystems; the extent and rate of cycling within dened geographic boundaries is an important aspect of landscape ecology (Urban et al. 1987; Forman 1995a,b) within which carrion metacommunity processes operate.

Mycobacterium ulcerans pseudoshottsii is a mycolactone-producing bacterium previously isolated from Striped Bass (Morone saxatilis (Walbaum)) from Chesapeake Bay and adjacent waters of the Atlantic Coast of North America. We report the first molecular detection of this pathogen in the native Gulf strain of Morone saxatilis collected from the Pearl River, Mississippi (USA). Molecular identification was conducted using a novel PCR assay targeting the parA-625 intergenic spacer of the virulence-associated pMUM plasmid. The isolate was unambiguously assigned to M. u. pseudoshottsii based on diagnostic single nucleotide polymorphisms (SNPs) and phylogenetic analysis. This report expands the known range of M. u. pseudoshottsii to include Gulf Coast watersheds and highlights the need for enhanced surveillance in wild and aquacultured fish populations of the southern United States.

Resource availability and habitat heterogeneity are essential drivers of biodiversity, but their individual roles often remain unclear since both factors are often correlated. Here, we tested the more-individuals hypothesis (MIH) and the habitat-heterogeneity hypothesis (HHH) for bacteria, fungi, dipterans, coleopterans, birds, and mammals on 100 experimentally exposed carcasses ranging by three orders of magnitude in body mass. At the level of each carcass we found marginal or significant support for the MIH for bacteria, fungi, and beetles in spring and significant support for fungi, dipterans, and mammals in summer. The HHH was supported only for bacteria in spring, while it was supported for all groups except mammals in summer. Overall multidiversity always increased with body mass, with a steeper increase in summer. Abundance based rarefaction-extrapolation curves for three classes of body mass showed the highest species richness for medium-sized carcasses, particular for dipterans and microbes, supporting the HHH also among carcasses. These findings complement existing necromass studies of deadwood, showing there are more niches associated with larger resource amounts and an increasing habitat heterogeneity between carcasses most pronounced for medium-sized species. Higher resource amount led to increased diversity of carrion-consuming organisms in summer, particularly due to the increasing number of niches with increasing size. Our findings underline the importance of distributed large carrion as well as medium-sized carrion in ecosystems supporting overall biodiversity of carrion-consumers. Furthermore, the different responses in spring and summer may inform strategies of carrion enrichment management schemes throughout the year.

The report demonstrated that a member of cockroach family, Blaptica dubia (Blattodea: Blaberidae) biodegraded commercial polystyrene (PS) plastics with Mnof n of 20.3 kDa and Mw w of 284.9 kDa. The cockroaches digested up to 46.6 % of ingested PS within 24 h. The biodegradation was confirmed by the 13 C isotopic shift of the residual PS in feces versus pristine PS (Delta Delta delta 13 C of 2.28 parts per thousand), reduction of molecular weight and formation of oxidative functional groups in the residual PS. Further tests found that B.dubia cockroaches degraded all eight high purity PS microplastics with low to ultra-high molecular weights (MW) at 0.88, 1.20, 3.92, 9.55, 62.5, 90.9, 524.0, and 1040 kDa, respectively, with superior biodegradation ability. PS depolymerization/biodegradation pattern was MW-dependent. Ingestion of PS shifted gut microbial communities and elevated abundances of plastic-degrading bacterial genes. Genomic, transcriptomic and metabolite analyses indicated that both gut microbes and cockroach host contributed to digestive enzymatic degradation. PS plastic diet promoted a highly cooperative model of gut digestive system. Weighted gene co-expression network analysis revealed different PS degradation patterns with distinct MW profiles in B. dubia. . These results have provided strong evidences of plastic-degrading ability of cockroaches or Blaberidae family and new understanding of insect and their microbe mediated biodegradation of plastics.

AbstractSilphinae (Staphylinidae; carrion beetles) are important contributors to the efficient decomposition and recycling of carrion necromass. Their community composition is important for the provision of this ecosystem function and can be affected by abiotic and biotic factors. However, investigations are lacking on the effects of carrion characteristics on Silphinae diversity. Carrion body mass may affect Silphinae diversity following the more individuals hypothesis (MIH). The MIH predicts a higher number of species at larger carrion because higher numbers of individuals can be supported on the resource patch. Additionally, biotic factors like carrion species identity or decomposition stage, and the abiotic factors elevation, season and temperature could affect Silphinae diversity. To test the hypotheses, we collected Silphinae throughout the decomposition of 100 carcasses representing 10 mammal species ranging from 0.04 to 124 kg. Experimental carcasses were exposed in a mountain forest landscape in Germany during spring and summer of 2021. We analysed Silphinae diversity using recently developed transformation models that considered the difficult data distribution we obtained. We found no consistent effect of carrion body mass on Silphinae species richness and, therefore, rejected the MIH. Carrion decomposition stage, in contrast, strongly influenced Silphinae diversity. Abundance and species richness increased with the decomposition process. Silphinae abundance increased with temperature and decreased with elevation. Furthermore, Silphinae abundance was lower in summer compared to spring, likely due to increased co‐occurrence and competition with dipteran larvae in summer. Neither carrion species identity nor any abiotic factor affected Silphinae species richness following a pattern consistent throughout the seasons. Our approach combining a broad study design with an improved method for data analysis, transformation models, revealed new insights into mechanisms driving carrion beetle diversity during carrion decomposition. Overall, our study illustrates the complexity and multifactorial nature of biotic and abiotic factors affecting diversity.