Abstract Pulp of fleshy fruits may serve as a reward on seed dispersal by animals, but the effect of pulp nutritional value on seed removal speed has not been investigated. To quantify the effects of pulp nutritional value on seed removal speed, we conducted four experiments in the National Park of Hainan Tropical Rainforest, using depulped seeds, seeds with pulp, and artificial-pulp seeds with variable nutritional levels (carbohydrate-rich corn-based pulp and protein/fat-rich peanut-based pulp) across three tree species: Gnetum luofuense (Luofushan Joint-fir), Daemonorops jenkinsiana (Jenkins’ rattan palm), and Dimocarpus longan (longan). We found intact D. longan seeds with pulp exhibited significantly higher seed removal speed (i.e. reversal value of seed survival time at the seed stations) than depulped seeds; and high pulp nutritional value (i.e. proportion of peanut mass to total artificial seed mass) significantly increased seed removal speed at seed stations, supporting the Optimal Foraging Hypothesis. However, contrasting to the hypothesis, we found pulp nutrition value showed a saturation effect on seed removal speed by small rodents, supporting our Pulp Reward Saturation Hypothesis, probably because animals would balance their nutrient demands (e.g. protein, fat and carbohydrate) by avoiding a single diet. Our study highlights the critical role of pulp in shaping seed-rodent interactions in tropical rainforest ecosystems.

Mitogenomes provide important molecular information for resolving evolutionary relationships in mayflies. However, both the evolutionary patterns of mitogenomes and the phylogenetic structure of Ephemerellidae remain insufficiently understood. In this study, we sequenced six complete mitogenomes representing five ephemerellid genera and performed comprehensive comparative analyses that included all currently available ephemerellid mitogenomes. Our results reveal that trnI-associated inversion and translocation are characteristic features of Ephemerellidae mitogenomes, likely generated through tandem duplication followed by random loss during mitochondrial evolution. All species exhibited strong A + T bias and distinct compositional asymmetry, with codon usage heavily skewed toward A/T at third codon positions. Nucleotide diversity and evolutionary rate analyses indicated that ND6 and ND2 were the most variable protein-coding genes, whereas COX1 was the most conserved among the 13 protein-coding genes. Phylogenetic analyses based on 13 PCGs and two rRNAs using Bayesian inference (BI) and Maximum likelihood (ML) consistently supported the monophyly of Torleya, Cincticostella, and Serratella, and recovered stable relationships among the major lineages within Ephemerellidae. Overall, the six newly sequenced mitogenomes enrich the mitochondrial genomic resources for Ephemerellidae and provide valuable insights into mitogenome evolution and phylogenetic relationships in this family.

Coccotorus beijingensis is a typical gall-inducing insect whose larvae complete their development within enclosed galls, providing a unique model for investigating host-microbe symbiosis. This study aimed to characterize the dynamic succession of the symbiotic microbiota in C. beijingensis across the larval stage (April-August) and pupal stage (September). Using high-throughput 16S rRNA gene sequencing, we performed a systematic analysis of monthly collected samples spanning the larval and pupal stages. The results revealed significant temporal variation in the structure of the larval microbial community. Bacillota and Bacteroidota were the dominant bacterial phyla throughout development. Although non-core bacterial groups, such as Pseudomonadota, showed pronounced seasonal fluctuations, no clear microbial reset was observed during metamorphosis. Exploratory PICRUSt2-based functional prediction suggested that the predicted metabolic potential of the microbiota may vary across development, with pathways related to carbohydrate metabolism, amino acid metabolism, and energy metabolism showing higher predicted representation during the middle larval stages. Overall, this study demonstrates that, within the confined gall microhabitat, larval development and seasonal dynamics jointly drive the temporal restructuring and functional adaptation of the microbial community. These findings provide new insights into the symbiotic mechanisms of holometabolous insects and their associated microbiota.

The physiological and microbiome-modulating benefits of dietary forage in monogastrics are impeded by recalcitrant fiber and anti-nutritional factors. However, fermentation and appropriate inclusion levels may overcome these limitations. This study evaluated the effects of two fermented cultivars of elephant grass (Cenchrus purpureus cv. Guiminyin and cv. Purple) incorporated into broiler diets at different inclusion levels, with emphasis on cultivar-specific responses, growth performance, physiological status, and gut microbial composition. A total of 240 male (30-days old) Jinling earth-neck chickens were housed in four replicate pens of 12 birds each, and randomly assigned to five dietary treatments (48 birds per treatment): a control diet with no inclusion (0%), CpGui5 (5% Guiminyin inclusion), CpGui10 (10% Guiminyin inclusion), CpPur5 (5% Purple inclusion), and CpPur10 (10% Purple inclusion). CpGui5 and Control diets had statistically similar and higher final weight, total weight gain, average daily gain and feed efficiency which were higher than the other treatments (P < 0.05). On the other hand, Control, CpGui5 and CpPur5 had higher daily feed intake compared to CpGui10 and CpPur10 which had the lower daily feed intake (P < 0.05). Slaughter performance revealed significant differences (P < 0.05), with the control, CpGui5, CpPur5 and CpPur10 groups maintaining higher live weight, dressed weight, half-bore, and breast muscle rate while CpGui10 recorded the lowest values. Blood biochemical indices, including total protein, albumin, liver enzymes, and renal function markers, were unaffected by dietary treatments (P > 0.05), indicating no adverse physiological effects. Gut microbiome analysis showed stable richness (Chao1, ACE) across treatments, while diversity (Shannon, Simpson) was reduced in CpPur5 relative to other groups (P < 0.05). A shared core microbiome of 202 OTUs was detected across all treatments, alongside treatment-specific enrichment of taxa. LEfSe (Linear Discriminant Analysis Effect Size) analysis identified treatment-specific enrichment of functionally relevant bacterial genera, including Megamonas in CpGui5 and Ruminococcaceae_UCG-014 and unclassified Lachnospiraceae at higher inclusion levels (CpGui10). Overall, moderate inclusion of fermented elephant grass, especially CpGui5 supports broiler performance while maintaining physiological health and gut microbial stability, highlighting its potential as a sustainable functional feed resource for poultry production.

Chemosensory systems play an essential role in insect survival and reproduction, mediating behaviours such as host location, mating and oviposition. The rice grasshopper Oxya intricata is an important rice pest in Asia, yet the molecular basis of its olfaction remains poorly understood. In this study, we sequenced antennal transcriptomes from adult males and females and systematically identified chemosensory-related genes. A total of 104 candidates were identified, including 14 odorant-binding proteins (OBPs), 12 chemosensory proteins (CSPs), 67 odorant receptors (ORs), nine ionotropic receptors (IRs) and two sensory neuron membrane proteins (SNMPs). Expression profiling by quantitative real-time PCR revealed broad antennal enrichment across families, with subsets showing antenna-specific or sex-biased patterns, suggesting differential chemosensory deployment between tissues and sexes. Several OBPs, CSPs and ORs were also elevated in maxillary palps or tarsi, raising the possibility that these genes may be associated with contact or near-field chemosensation. Collectively, these results provide the first comprehensive survey of chemosensory genes in O. intricata and establish a molecular resource for future functional analyses of odour coding. The identified gene set offers tractable targets for ligand screening and behavioural assays, and may inform future efforts to develop semiochemical-based monitoring and management strategies for this economically important pest.

ABSTRACT The butterfly genus Acytolepis (Lepidoptera: Lycaenidae: Polyommatinae) is widely distributed in the Indomalayan and Australasian realms. However, no complete mitochondrial genome has been reported for this genus, leaving its mitogenomic characteristics and evolutionary patterns unclear. In this study, we sequenced and characterized the first complete mitogenome of Acytolepis puspa, the type species of the genus. The circular double‐stranded mitogenome is 15,511 bp in length and comprises 13 protein‐coding genes (PCGs), two ribosomal RNA genes (rRNAs), 22 transfer RNA genes (tRNAs), and one A + T‐rich control region, exhibiting a typical gene content and organization conserved in Lepidoptera. Comparative analyses of Polyommatinae mitogenomes revealed pronounced heterogeneity in evolutionary rates among PCGs, with ND6 and ND3 showing relatively high nucleotide diversity, whereas COX1 was the most conserved gene. Selection pressure analyses indicated that all PCGs are evolving under purifying selection, with ATP8 and ND6 exhibiting relatively relaxed selective constraints compared to other genes. Phylogenetic analyses based on concatenated mitochondrial PCGs using both Maximum likelihood (ML) and Bayesian inference (BI) methods produced identical and well‐supported topologies, recovering A. puspa as the sister taxon to Celastrina species within Polyommatinae. Overall, this study provides the first mitogenomic resource for Acytolepis, enriches mitochondrial molecular markers for lycaenid butterflies, and contributes new insights into mitogenome evolution and phylogenetic relationships within Polyommatinae.

Numerous hibernating species within the family Sciuridae display distinct hibernation bout patterns and initiate reproductive activities shortly after arousal from torpor. However, the influence of different hibernation phases on testicular function has not yet been fully elucidated. To address this knowledge gap, we investigated alterations in testicular morphology and glycogen as well as lipid metabolism in Siberian chipmunks (Tamias sibiricus) across key physiological stages associated with the hibernation cycle. We found that serum lipid levels were high during torpor, while glucose peaked during interbout arousal. Although body weight decreased, testicular mass increased during hibernation, accompanied by stable levels of testosterone, follicle-stimulating hormone, and luteinizing hormone. Spermatogonia density dropped, but spermatocytes increased, along with larger seminiferous tubules and a thicker spermatogenic epithelium. Glycogen content and glycogenosome density were significantly reduced compared to pre-hibernation levels, accompanied by decreased glycogen synthase activity and elevated phosphorylase activity. Fatty acid levels remained high throughout hibernation, though triglycerides were lower during interbout arousal than in torpor. Fatty acid synthase and acetyl-CoA carboxylase activities increased during interbout arousal, whereas lipoprotein lipase and glycerol kinase activities were elevated during torpor. Together, these results are consistent with a coordinated shift between glucose- and lipid-related pathways across torpor-arousal cycles, which may be associated with maintaining testicular energy homeostasis during hibernation.

Food habits are closely associated with the gut microbiota of herbivorous animals; however, limited knowledge exists regarding the arid-adapted rodents. This study investigates the relationship between gut microbiota and dietary composition to offer a scientific basis for comprehending the ecological adaptation strategies of grassland rodents. Cecal contents of Spermophilus alashanicus, S. dauricus, and Meriones unguiculatus were collected and analyzed by using 16S rRNA amplicon sequencing and DNA metabarcoding techniques to determine the structure of gut microbial communities and dietary composition. The results showed that S. alashanicus presented significantly higher gut microbial richness and diversity than S. dauricus and M. unguiculatus. The dominant gut bacterial genera in S. alashanicus and S. dauricus were similar, suggesting that their common genetic backgrounds might influence the colonization and symbiosis of gut microbiota. The three species consumed both plant-based and animal-based foods but differed in their dietary preferences. S. dauricus displayed a significantly higher diversity of animal-based food consumption compared with the other two species. Correlation analysis between diet and gut microbiota indicated that plant-based foods significantly enhanced the diversity and composition of gut microbiota. In contrast, the consumption of animal-based foods significantly decreased microbial diversity. This finding suggests a potential link between the host’s genetic background, dietary composition, and the gut microbiota.

Trait matching, the phenomenon where ecological interactions are mediated by compatibility, constitutes a cornerstone of frugivore-fruit interaction network dynamics. Given that biotic interactions have long been hypothesized to be more intense or specialized in the tropics, the intensity of trait matching patterns might likewise exhibit a latitudinal gradient in frugivory networks, yet this remains unverified. Here, we established a dataset encompassing 200 avian frugivorous networks to explore the relationships between the body mass and gape size of frugivore birds and fruit traits (size and color) on a global scale. Our results indicated that frugivore traits were closely associated with fruit traits regardless of the climate, demonstrating a biotic match between the two counterparts. We detected a significant decrease in frugivore-fruit trait matching toward the tropics, which challenges prevailing concepts considering the high biodiversity therein. Our structural equation modeling clarified that latitude and temperature exert an indirect influence on trait matching by affecting gape size and fruit traits. These discoveries emphasize the impact of the latitudinal gradient of temperature in driving the observed patterns of trait matching. The weaker trait matching in tropical regions may suggest more complex interactions therein and also highlights the potential for altered network structures amid global climate change.

Introduction:Olfactory dysfunction and cognition decline are frequently observed; however, very little is known about whether olfactory disorders trigger cognitive impairment. Methods:Here, we induced olfactory loss in mice and investigated whether and how olfactory loss induces cognitive impairment and anxiety behavior. Results:Olfactory loss not only causes a significant decrease in food intake and body weight and an increase in O2 consumption but also induces cognitive impairment and anxiety behavior. Olfactory loss-induced alteration of the gut microbiota is associated with subsequent changes in cecal short-chain fatty acids and serum neurotransmitter levels. Hippocampus proteome and fecal microbial transplantation provide further support for the mechanisms by which olfactory loss triggers cognitive impairment and anxiety behavior via the microbiota-gut-brain axis. Discussion:Our study is expected to provide some evidence for olfactory dysfunction in triggering cognitive impairment through the microbiota-gut-brain axis.

IntroductionGall formation caused by plant-organism interactions affects plant development and is essential for the life cycle of gall-inducing insects. Plant hormones like auxins and cytokinins, regulate gall development and defense responses. Despite the extensive morphological characterization of galls, the molecular mechanisms underlying gall induction remain largely unresolved.MethodsIn this study, we quantified hormone concentrations and performed transcriptome analyses to investigate the mechanisms by which leaf galls are induced by the cynipid wasp Trichagalma acutissimae on two oak host species, Quercus variabilis and Q. acutissima.ResultsOur preliminary results indicate that wasp larvae may synthesize auxins and cytokinins—a conclusion supported by the gall transcriptome data. Downregulation of IAA biosynthesis genes in gall tissues coincides with significantly higher IAA levels in the larvae compared to the leaves and galls. Likewise, the detection of active cytokinins in the larvae indicates their ability to synthesize cytokinins autonomously. Furthermore, we observed significant suppression of jasmonic acid (JA) biosynthesis in the gall tissues, which strongly supports the nutritional hypothesis. We also identified the upregulation of biosynthetic genes involved in carbohydrate metabolism, amino acid metabolism, and lipid metabolism, providing evidence for the ‘nutritional hypothesis’ of gall formation.DiscussionThis integrative exploration of hormonal dynamics and transcriptomic changes offers insights into the mechanisms of gall induction.

The gut microbiota plays a crucial role in shaping animal life history, particularly by mediating interactions between herbivorous insects and their host plants. Phytophagous insects that feed on oak leaves must overcome the challenge of detoxifying tannins. While gut microbes contribute significantly to this detoxification process, the mechanisms by which insects acquire tannin-degrading bacteria remain poorly understood. In this study, we investigated tannin-degrading bacterial communities in Nothomyllocerus illitus, a phytophagous weevil that primarily consumes oak leaves. Through 16S rRNA sequencing, bacterial isolation, enzymatic activity assays, and fluorescence tracing experiments, we identified Bacillus, Acinetobacter, and Enterobacter as key tannin-degrading genera associated with N. illitus. These bacteria are predominantly acquired from the oak phyllosphere rather than from soil sources. Fluorescently labelled Bacillus and Acinetobacter strains were shown to successfully colonise the weevil gut, underscoring their functional relevance in tannin degradation. Furthermore, supplementation of oak leaves with these bacterial strains enhanced feeding behaviour, larval growth, and reproductive performance, whereas antibiotic treatment diminished these effects, thereby confirming the critical contribution of phyllosphere-derived bacteria to the overall fitness of foliar-feeding weevils N. illitus.

Symbiotic bacteria play a pivotal role in the biology and ecology of herbivorous insects, affecting host growth and adaptation. However, the effects of host identity on the symbiotic microbiota of gall-inducing insects remain less explored. In this study, we utilized high-throughput sequencing to investigate the effects of different oak hosts on the structure and diversity of the symbiotic microbial community in the asexual larvae of the gall-inducing wasp Trichagalma acutissimae. Host plant species significantly altered the alpha and beta diversity of symbiotic microbiota of T. acutissimae. At the phylum level, Proteobacteria was the predominant microflora in both groups, with significantly higher abundance in larvae parasitizing Quercus acutissima than in those parasitizing Q. variabilis. Pseudomonas, which has been identified as responsible for tannin decomposition, was the most dominant genus in T. acutissimae larvae infesting both hosts. LEfSe analysis revealed substantial differences in the symbiotic microbial communities between the two hosts while also highlighting some commonalities. Functional prediction analysis indicated no significant difference in the functional roles of symbiotic bacteria between larvae infesting the two hosts. These findings suggest that the symbiotic microbiome of T. acutissimae larvae is influenced by host plant species, yet different microbial compositions may perform similar functions, implying the potential role of symbiotic microbiota in the adaptation to high-tannin oak leaves. This research enhances our understanding of the symbiotic relationship between forest pests and their associated microbes.

Hibernation involves complex physiological adaptations enabling animals to survive extreme conditions. During hibernation, body temperature, metabolic rate, and heart rate change significantly but are quickly restored upon arousal. Despite extensive research, the underlying mechanisms remain unclear. This study used proteomics to examine cardiac and hepatic protein levels in food-hoarding hibernator Siberian chipmunk (Tamias sibiricus) during torpor and arousal. Results show that, unlike the fat-storing hibernators, the liver of chipmunks maintains glucose, lipid, and bile acid synthesis throughout hibernation due to changes in proteins like GALE, SLC2A3, GSK-3α, HMGCS2, ACAT2, and AMACR. In contrast, reduced mitochondrial autophagy (PINK1 and PARKIN) and enhanced anti-apoptotic mechanisms (TFRC, WFS1, and NDRG1) help maintain energy balance in the heart. These findings provide new insights into cardio-protection in food-hoarding hibernators and improve our understanding of adaptive mechanisms in mammalian hibernators.

Cache pilfering is a pervasive phenomenon among seed-hoarding rodent species; nonetheless, the influence of seed species and pilferer identity on cache pilfering risk at the community level remains underexplored. This study examined the cache pilfering risk of the scatter-hoarding rodent Leopoldamys edwardsi and investigated the subsequent fate of the pilfered seeds of two dominant tree species, Camellia oleifera and Castanopsis henryi. The experiments were conducted in semi-natural enclosures, which simulate natural habitat conditions while allowing for controlled observation of rodent behavior. Sympatric pilfering rodent species involved in the study also comprised Apodemus chevrieri, A. draco, Niviventer confucianus, and N. fulvescens, all commonly found in the study area. Our findings revealed that L. edwardsi showed no significant preference between the seeds of C. henryi and C. oleifera, but the pilferage rate of C. oleifera seeds was significantly higher. The cache pilfering risk posed by sympatric rodent species varied significantly, with scatter-hoarding pilferers being primarily responsible for most cache losses. Moreover, seed species exerted a substantial impact on the cache pilfering risk imposed by these pilferers. Notably, we discovered that scatter-hoarding pilferers selectively re-cached pilfered seeds on the basis of seed species, a process that is anticipated to play a pivotal role in secondary seed dispersal and, consequently, plant regeneration.

Seed hardness has been acknowledged as one of the most significant physical traits influencing seed consumption and caching by animals. From an evolutionary perspective, a hard seed shell should potentially be regarded as a dispersal and predator escape strategy rather than a maladaptive trait of plants. However, to our knowledge, this prediction has not been adequately tested in the context of seed dispersal. Here, we offered seeds with hard shells to the main seed consumers widely distributed in two distinct forest ecosystems to test our hypothesis that a hard seed shell might act as an ecological filter to deter predators but attract obligatory seed dispersers. Our studies demonstrated that seeds with the hardest shells consistently and directly deterred small-bodied seed consumers that have been proven to be either larder-hoarders or scatter-hoarders in the two forests. Nevertheless, rodents with the largest body size and seed handling capacity seemed to be effective seed dispersers targeting hard seed shells. The deterrence to seed predators and the attraction to an effective seed disperser reflects the evolutionary significance of seed hardness in the seed dispersal syndrome. Our studies in different forest ecosystems strongly suggest that a hard seed shell is not an evolutionary dead end in plant–animal interactions. On the contrary, the outcome of a hard seed shell in the seed dispersal syndrome is of evolutionary importance for plant–animal mutualistic interactions in various forest ecosystems.

BACKGROUND/AIMS:Ledrinae comprises about 460 described species across five tribes and represents an early-branching, morphologically distinctive lineage of leafhoppers, yet its intra-subfamilial relationships remain ambiguous owing to limited mitogenomic sampling. Here, we sequence and annotate the complete mitochondrial genome of Petalocephala arcuata-only the 18th Ledrinae mitogenome-to broaden taxon coverage within the genus and furnish critical molecular data for rigorously testing Ledrinae monophyly and refining tribal and genus level phylogenetic hypotheses. METHODS:In this study, we sequenced and annotated the complete mitochondrial genome of P. arcuata via Illumina sequencing and de novo assembly, and reconstructed the phylogeny of 62 Cicadellidae species using maximum likelihood and Bayesian inference methods. RESULTS:The 14,491 bp circular mitogenome of P. arcuata contains 37 genes with 77.4% A+T. All PCGs use ATN start codons except ND5 (TTG), and codon usage is A or U biased. Of 22 tRNAs, only trnS1 lacks a DHU arm, while the others adopt the canonical cloverleaf structure. Bayesian inference and maximum likelihood analyses produced broadly congruent topologies with mostly high nodal support, recovering Ledrinae as monophyletic and clustering all Petalocephala species into a well-supported clade. CONCLUSIONS:In this study, we enriched the molecular resources for the genus Petalocephala by sequencing, annotating, and analyzing the complete mitochondrial genome of P. arcuata. Phylogenetic reconstructions based on these genomic data align closely with previous morphological diagnoses, further confirming the monophyly of the genus Petalocephala.

Seed odor plays a crucial role in affecting the scatter-hoarding behavior of small rodents that rely on spatial memory and olfaction to cache and recover. However, evidence of how seed odor modifies olfaction function and spatial memory is still lacking. Here, we coated seeds with waterproof glue to test how seed odor intensity alters the proteome of both the olfactory bulbs and hippocampus of a dominant scatter-hoarding rodent, Leopoldamys edwardsi, in Southwest China. We showed that animals repeatedly caching and recovering weak odor seeds exhibited greater olfactory ability and spatial memory, as indicated by alterations in the protein profiles of the olfactory bulbs and hippocampus. The upregulation of proteins closely related to neural connections between the olfactory bulb and hippocampus is highly responsible for improved olfactory function and spatial memory. Our study provides new insights into how scatter-hoarding rodents manage and respond to cached seeds differing in odor intensity from a neurobiological perspective, which is of significant importance for better understanding the parallel evolution of the olfactory and hippocampal systems.