Search Results (157)

Urbanization is widely recognized as a major driver of biodiversity loss; however, cities can also provide important refuges for pollinators when diverse and continuous floral resources are available. This study assessed the diversity of spontaneous insect-pollinated flora and its associated pollinator communities across five major urban habitat types (grasslands, road verges, artificial surfaces, wooded areas, and wetlands) in the Mediterranean cities of Pisa, Livorno, and Lucca (central Italy). During a three-year field survey, spontaneous flowering plant species were systematically recorded, and pollinator visitation rates were quantified using standardized sampling protocols. Approximately 150 spontaneous insect-pollinated plant species were identified, providing a continuous supply of nectar and pollen throughout the flowering season. Pollinator assemblages included honey bees (Apis mellifera), solitary bees, bumblebees, Diptera, and Lepidoptera, with bees representing the dominant group across all habitats. Pollinator visitation rates differed significantly among habitat types, reaching their highest values in grasslands, road verges, and wetlands, whereas wooded habitats and artificial surfaces supported significantly lower pollinator activity. Numerous plant species belonging to diverse botanical families attracted a broad range of pollinator taxa, revealing complex plant–pollinator interactions and demonstrating the ecological value of spontaneous urban vegetation for sustaining pollinator diversity. In summary, the present study shows that spontaneous flora constitutes a fundamental component of urban green infrastructure, supporting pollination services and enhancing ecological connectivity within cities. Biodiversity-friendly management strategies that conserve and promote spontaneous flowering vegetation should therefore be considered a key element of sustainable urban planning and the ecological resilience of Mediterranean urban landscapes. Full article

Within the framework of animal learning theory, information transfer refers to the generalization or transmission of acquired knowledge to novel situations, individuals, or environments. In pollinators, this process is critical for adaptive foraging and ecological success. Although olfactory information transfer has been demonstrated in bumblebees through classical conditioning or colony exposure, the influence of reward type (nectar vs. pollen) remains poorly understood. Here, we evaluated olfactory information transfer and decision-making in the South American bumblebee Bombus pauloensis using complementary laboratory and colony-based experiments. Under laboratory conditions, bees were either classically conditioned through the proboscis extension reflex (PER) paradigm using scented sucrose solution or exposed overnight to scented pollen and subsequently tested in a four-arm arena. In a more natural context, colonies were exposed to scented sucrose solution or scented pollen through in-nest feeders, after which foraging choices were assessed in a flight cage. Sucrose-conditioned bees exhibited an odor-contingent preference in the four-arm arena, consistent with associative learning under our conditions. In contrast, pollen exposure produced odor-associated trends. Linalool exhibited a bias, although airborne volatile concentrations were not directly quantified, representing a methodological limitation. Moreover, linalool-scented pollen induced intense feeder manipulation and increased mortality during overnight exposure, highlighting substantial physiological costs. Under colony conditions, 24-h exposure to scented pollen promoted significant odor-guided search preferences, particularly with linalool, whereas no significant effect of scented sucrose was detected under our 24 h in-nest exposure; individual feeder contact was not verified. Overall, behavioral responses varied jointly with odor identity and the combined operational framework; the salience of pollen-associated odors observed here is consistent with reward-specific effects but cannot be fully disentangled from differences in protocol structure between the sucrose and pollen experiments. Full article

Transformer architectures, originally developed for language modeling, have been increasingly applied to time-series forecasting, but deploying them on sensitive data such as patient vital signs, financial records, or energy use raises privacy risks at two points: inference (the server sees raw inputs and outputs) and training (the model can memorize individual records). This survey organizes privacy-preserving methods for Transformer forecasting along a two-axis taxonomy: protection stage (inference, training, and data-level) and protection locus/mechanism (cryptographic wrapper, gradient, input, feature, output, or data path). For inference, we review secure multi-party computation (CrypTen through MPCFormer, SecFormer, Iron, BOLT, PUMA, BumbleBee, and CipherPrune) and homomorphic encryption (CKKS, THE-X, hybrid HE-MPC, and automated FHE compilation via Orion), focusing on how each handles the Transformer non-linearities (softmax, GELU, and LayerNorm). For training, we organize differential-privacy mechanisms by where noise enters the gradient path (DP-SGD, DP-FedAvg, DP-FTRL, PATE, and adaptive clipping), the input path, and the more recent feature path and analyze the privacy, utility, and dimensionality trade-offs. We further survey privacy in large language and foundation models, federated Transformers, time-series privacy attacks (membership inference, gradient inversion, and attribute inference), differentially private synthetic data, and applications in energy, health care, and finance, closing with open problems and future directions. Throughout, we show that the surveyed mechanisms provide non-comparable privacy guarantees and should be chosen by threat model instead of headline utility. Full article

Bumblebees are dominant pollinators threatened by environmental antibiotic residues. This study investigated sublethal chloramphenicol (12 and 120 μg/L) effects on Bombus terrestris after 15 days’ exposure. The results showed that chloramphenicol exposure had no significant effect on the survival rate and cumulative food intake of bumblebees, confirming the sublethal property of the tested concentrations. However, chloramphenicol significantly dysregulated the expression of genes related to learning–memory (DopR2, Oamb, NMDA), immunity (abaecin, defensin) and detoxification (cyp9Q6) in bumblebees. High-dose chloramphenicol significantly increased carboxylesterase activity and reduced malondialdehyde content, while superoxide dismutase activity remained unchanged. In addition, chloramphenicol exposure significantly reshaped the gut microbiota structure of bumblebees, reduced the abundance of core beneficial symbiotic bacteria, and increased the proportion of drug-resistant bacteria. Our findings indicate that sublethal concentrations of chloramphenicol can impair bumblebee health through multiple pathways, including regulating gene expression, altering antioxidant enzyme activity and disrupting gut microbiota homeostasis. This study provides multi-dimensional toxicological data and a scientific basis for the ecological risk assessment of agricultural antibiotic residues to pollinator insects. Full article

We developed a laboratory-based setup to perform behavioral tests of the effect of the neonicotinoid insecticide Thiacloprid in the CALYPSO^® formulation on bumblebees. This setup simulates essential components of navigation and pollination under natural conditions. The behavioral components are exploration, exploratory learning, learning of a rewarded local cue in the context of a specific panorama, and retrieving the memory for this association. The walking bumblebees navigated under their own motivation between a fully functional colony and a training/test arena. They explored the arena and learned the association of a rewarded local cue in the context of a panorama. The rule of association was that the local cue was bound to a particular part of the panorama irrespective of where it appeared in its spatial relation to the entrance gate through which the animal came from the colony. Extinction tests were performed for two conditions, match and mismatch. The match condition resembled the training condition. In the mismatch condition the local cue appeared in a different part of the panorama. Solving this task requires the learning and remembering of a rule under variable conditions, mimicking the cognitive requirements faced by bumblebees under natural conditions. The control animals solved this task, whereas animals treated with Thiacloprid 400 ng CALYPSO^® diluted in 4 µL per animal were significantly compromised, as shown by several parameters of the walking trajectories under the match and mismatch conditions. No dose–response functions were established, but a volume of 800 ng CALYPSO^® diluted in 8 µL per animal did not show any significant differences from a volume of 4 µL CALYPSO^®. The setup and the experimental paradigm are suitable for routine quantitative tests on the effects of insecticides on the cognitive faculties of insects during navigation and pollination. Full article

The stingless bee Geniotrigona thoracica is an ecologically and economically important pollinator in Southeast Asia, yet comprehensive genomic resources for this species remain limited. In this study, we sequenced, assembled, and annotated the complete mitochondrial genome (mitogenome) of G. thoracica to investigate its genomic architecture and phylogenetic position. The circular mitogenome is 16,061 bp in length and comprises the typical set of 37 genes, including 13 protein-coding genes (PCGs), 22 transfer RNA genes, and two ribosomal RNA genes. The genome exhibits a strong A + T bias, consistent with other hymenopteran mitogenomes, and codon usage patterns reflect this nucleotide composition. Most tRNAs display the canonical cloverleaf secondary structure, although minor structural variations were observed. Comparative analyses revealed several gene rearrangements, including transposition and inversion events, suggesting lineage-specific rearrangements, including transposition of the cox1–trnL–cox2–trnD–atp8–atp6–cox3 block and transposition with inversion of the trnF–nad5–nad4–nad4l–trnP block, relative to the ancestral hymenopteran gene order. Phylogenomic analyses based on concatenated mitochondrial genes strongly supported the monophyly of Meliponini and placed G. thoracica within a well-supported Indo-Malayan clade, closely related to Tetragonula, Heterotrigona, and Lepidotrigona. Furthermore, stingless bees were recovered as more closely related to bumblebees than to honeybees, consistent with previous studies. Overall, this study provides a complete, annotated mitogenomic resource for G. thoracica and contributes to a better understanding of mitochondrial genome evolution, phylogenetic relationships, and biogeographic patterns in stingless bees. Full article

Heavy metals in soil can be translocated to floral rewards via specific physiological pathways, potentially altering pollinator behavior and reducing plant reproductive fitness. However, the comparative effects of different heavy metals on floral rewards and pollination remain poorly understood. Here, blueberries were used as a model system to examine the accumulation of four heavy metals (Zn, Pb, Cu, and Ni) in floral rewards and assess their impacts on plant reproductive performance and bumblebee visitation behavior under controlled conditions. Heavy metals accumulated in floral rewards in a concentration-dependent manner, with strong positive relation to soil metal levels; pollen generally contained higher concentrations than nectar. Increasing soil heavy metal concentrations significantly shortened bumblebee visit duration to individual flowers, with the greatest reduction under high Pb treatment (26.32%), followed by Zn (21.49%), Ni (17.70%), and Cu (15.40%). Visit frequency also declined under medium to high concentrations. All heavy metal treatments reduced pollen viability (1.62–24.48%), pollen deposition on stigmas (9.91–40.59%), and single-fruit weight (16.25–32.51%), with effect magnitudes varying by metal (generally Pb > Cu > Zn > Ni). Overall, heavy metal accumulation in floral rewards negatively affects pollinator behavior and compromises plant reproductive fitness, with metal-specific effect strengths. Full article

Evolutionary trees are of central importance in biology to develop explanatory frameworks for many kinds of studies, including studies of behaviour, ecology, and conservation. Since the last major estimate of evolutionary relationships among many bumblebee species two decades ago, there have been revisions to their taxonomy, descriptions of new species, and sequencing of many rarer species. By combining: (1) earlier data mostly from slow-evolving nuclear genes as a backbone tree; with (2) new data from fast-evolving mitochondrial COI barcodes to resolve more of the twigs on the tree, including sequences obtained from rare old specimens with ancient DNA techniques; as well as (3) the results from broader genomic data for resolving deep relationships, we make a Bayesian estimate of evolutionary relationships with BEAST 2 among all 289 published and accepted extant bumblebee species, an increase of more than 29% of the species on the previous largest tree. The new tree will serve as a framework for future comparative studies that should enable broader insights into the evolution and ecology of all bumblebees. We illustrate this with an analysis of the evolution of some male morphological characters related to male mate-searching behaviour. We also present a novel map of spatial variation in net diversification rates among bumblebee species world-wide, which indicates an especially rapid net diversification within the more recent Mesoamerican and South American faunas. Full article

Odor source localization in turbulent environments remains a major challenge for autonomous robots, as odor plumes are highly intermittent, spatially fragmented, and often lack stable concentration gradients. Here, we propose a bio-inspired navigation framework that translates key principles of bumblebee olfactory cognition into robotic decision-making. First, classical conditioning and olfactorily triggered spatial memory experiments demonstrated that bumblebees could form robust odor memories and that training frequency is positively correlated with both proboscis extension response retention and spatial directional preference. Based on these biological findings, a bio-inspired navigation framework, termed Bio-Nav, is constructed by integrating a Partially Observable Markov Decision Process, a Hidden Markov Model, short-term memory, long-term directional reference memory, fuzzy inference, and value iteration. High-fidelity two-dimensional turbulent simulations show that the proposed algorithm substantially outperforms moth-inspired search, Infotaxis, and standard POMDP-based navigation. In 100 Monte Carlo trials, Bio-Nav achieved a success rate of 96.0%, an average of 20.3 search steps, an average path length of 155.1 cm, and a path-to-straight-line distance ratio of 1.6. Even under strong turbulence, the success rate remained above 91%. These results indicate that memory–perception coupling, inspired by bumblebee navigation, provides an effective and robust strategy for odor source localization in complex turbulent environments, offering a generalizable principle for bio-inspired robotic search under uncertainty. Full article

Bumblebees are key pollinators in agricultural and natural ecosystems; however, climate change is driving shifts in population size, body size, and diversity. Accelerating global warming affects bumblebee body size, thereby influencing the strength of sexual selection and overall population fitness. Thus, this study aimed to investigate the effects of body mass and temperature on sexual selection in Bombus terrestris reared under warm conditions, with mating conducted between equal sex ratios at both optimal (23 °C) and elevated (32 °C) temperatures. Mating success was lower at 32 °C than at 23 °C, regardless of body mass; however, larger queens and males consistently exhibited higher mating success at both temperatures than their smaller counterparts. Mate-choice patterns were similar across temperatures: large queens predominantly mated large males, whereas small ones mainly mated small males. However, small queens tended to mate large males at 32 °C than at 23 °C. Meanwhile, matings between small queens and small males occurred relatively later at both temperatures. Although small males exhibited longer mating durations than large ones, the amount of sperm transferred to the spermathecae of the queens was positively associated with the body size of both males and queens. Our findings indicate that, at equal sex ratios, mate choice in bumblebees is primarily determined by body mass at all temperatures. Thus, smaller bumblebees associated with higher temperatures had the lowest mating success. Full article

The effects of fungicides on pollinators remain relatively understudied despite their widespread use and high likelihood of environmental exposure. We assessed the effects of a single exposure to the commercial formulation Tebucur^® 250 EW (containing tebuconazole as the active ingredient) on learning and memory in Bombus terrestris workers. Using the Free-Moving Proboscis Extension Response (FMPER) paradigm, bees were exposed to two concentrations: 9.4 µg of tebuconazole per mL (group T 1/100) and 94 ng of tebuconazole per mL (group T/10,000) of tebuconazole through either pure sucrose (Method 1) or Tebucur^® 250 EW-supplemented sucrose (Method 2) during conditioning. No significant differences between groups were detected during the learning phase (all p > 0.05). In contrast, significant differences emerged during the memory test at the earliest time point (5 min). In Method 1, bees exposed to the higher concentration (treatment group T 1/100) showed significantly lower performance compared to the control group (p < 0.05). In Method 2, the lowest performance was observed in the group exposed to the lower concentration (treatment group T 1/10,000; p < 0.01). No significant differences were detected at later time points (10 and 30 min). These results indicate that a single exposure to Tebucur^® 250 EW (active ingredient: tebuconazole, 250 g/L) can affect short-term memory in bumblebees without impairing initial learning performance. Although the observed effects were subtle and time-limited, they may have important implications for foraging efficiency and pollination under natural conditions. Full article

While the gut microbiota of pollen-carrying bees (e.g., honeybees and bumblebees) has been well studied, the gut microbiota of vespine wasps remains poorly understood. Unlike pollen-carrying bees, which primarily consume pollen and nectar, vespine wasp larvae mainly feed on insects, suggesting that their gut bacterial communities may be different. Therefore, this study aimed to reveal the differences in larval gut bacterial communities between pollen-carrying bees and vespine wasps. Using datasets obtained from our own samplings and public resources released by other researchers, we compared the diversity and composition of larval gut bacterial communities between vespine wasps and pollen-carrying bees. Alpha diversity and beta diversity of bacterial communities were measured. Results showed that vespine wasp larvae harbored distinct gut bacterial communities from those of pollen-carrying bees, dominated by Leuconostoc, Hafnia-Obesumbacterium and Lactobacillus. Significant differences in bacterial composition were observed at both the community level and the dominant taxa level between pollen-carrying bee larvae and vespine wasp larvae. Moreover, significant differences were also found among larval gut bacteria of vespine wasps. These findings provide insights into the bacterial composition of aculeate wasps with different dietary habits. Full article

Neonicotinoids are widely used pesticides that have caused a catastrophic decrease in bee and bumblebee populations worldwide. In addition to insects, neonicotinoids induce toxic effects in other species, including lizards, birds, and mammals. Previous studies have shown that gestational exposure to thiacloprid promotes transgenerational effects in the testes and thyroid. In this project, we described the epigenetic effects of thiacloprid on prostate tissue in directly exposed F1 and non-directly exposed F3 outbred Swiss male mice. We used paraffin sections for morphological analysis and frozen tissue for immunofluorescence analysis, RT–qPCR, and protein analysis. We purified histones and analyzed them through Western blot. We used ChIP–qPCR for histone H3K4me3 occupancy analysis. A tendency to increase in epithelial hyperplasia in F1 but not in F3 prostate was detected. Elevated levels of phosphorylated histone H3 at serine 10, a marker of mitosis, in both the F1 and F3 prostates were noted. A significant increase in the level of the Ki-67 marker of proliferation was detected in the F1 but not in the F3 anterior prostate. Hox gene expression was upregulated in the F1 and downregulated in the F3 prostate. The changes in gene expression were positively associated with histone H3K4me3 alterations at the promoters of the Hoxa and Hoxb13 genes. We determined that regions of Hox genes that play important roles in prostate development had altered DNA methylation in the sperm of F1 and F3. These alterations in DNA methylation were negatively related to gene expression. This is an observational study, as it was part of our previous research on the effects of thiacloprid on the testis and thyroid. Our analysis revealed that gestational exposure to thiacloprid induced an increase in cell proliferation in the prostates of directly exposed F1. Some persistent epigenetic alterations in the prostate of F3 males were not associated with phenotypic changes. Full article

This study examined nectar and pollen production as well as pollinator visitation in Nigella damascena (Ranunculaceae), an annual ornamental and seed crop, over two flowering seasons. Flower anthesis lasted 6–7 days, with protandry: the male phase began on the first day, and pollen presentation continued until corolla senescence. Peak stigma receptivity occurred in 5-day-old flowers, resulting in a partial overlap of male and female functions between days 5 and 7. Nectar was secreted by petal-derived structures, with secretion beginning in 1-day-old flowers and steadily increasing, peaking on the day of maximum stigma receptivity. The nectar sugar composition differed between floral phases; it was sucrose-dominant in the male phase and sucrose-rich in the female phase. Significant year effects were observed for flowering abundance, nectar traits (volume, sugar production, concentration), and pollen output. Flowers were visited predominantly by honey bees, but bumblebees, solitary bees, and dipterans were also recorded. These results demonstrate that floral reward traits vary between years and contribute to differences in the temporal availability of nectar and pollen resources. Full article

Florivory is the consumption or damage of flowers by herbivorous animals. It can directly affect plant fitness by damaging reproductive organs or indirectly by negatively influencing flower attractiveness to pollinators. We investigated florivory in field bindweed Convolvulus arvensis L. (Convolvulaceae) by combining data from natural surveys, experimental damage, and laboratory experiments on flower preferences of florivores. Surveys showed that flowers suffer damage from predators, including Leptophyes albovittata Kollar (Orthoptera: Tettigoniidae), which causes partial corolla damage, and from unknown predators that cause holes in the corolla. Experimentally damaged flowers had significantly lower reproductive success (number of seeds and proportion of total reproductive failure) than intact flowers. However, laboratory experiments with naïve bumblebees Bombus terrestris L. (Hymenoptera: Apidae) failed to detect a preference for undamaged flowers. This may be because B. terrestris is not a frequent pollinator of C. arvensis at our field sites, and naïve foragers, lacking prior experience, had not learned to associate corolla damage with reduced floral rewards. Our research shows that florivory negatively impacts C. arvensis reproductive success by altering pollinator behavior through reduced flower attractiveness. Full article