Following heightened colony losses, we screened 132 colonies from 23 commercial beekeeping operations in the states of Florida and California. We assessed chemical residues, finding beekeeper-applied miticides, followed by fungicides, were in the highest prevalence and concentration in all colony matrices. Insecticides comprised a minority of detections and concentration. Due to their heightened toxicity, insecticides contributed substantially to hazard quotients with one residue, the neonicotinoid imidacloprid, contributing 99.9% to overall HQ. We found both high prevalence and high levels of imidacloprid in adult bee bodies. Additionally, we preserved a small subsample of dying bees. Our findings highlight a survivorship bias, where dying bees had active ingredients known to have acute toxicity to bees. This result mirrors recent evidence for viral drivers of bee declines that were missed in whole-colony surveys. While bees die from multiple, often interacting, stressors, here we show single contributors at levels capable of causing acute harm.

Commercial beekeepers in the US reported severe colony losses early in 2025, as colonies were being staged for their critical role in the almond pollination season in California. Average reported losses since the preceding spring exceeded 60%, with substantial variation among operations. Many colonies were still actively collapsing in January 2025, at which time pooled and individual samples were collected and then screened for levels of 13 known honey bee pathogens and parasites. Acute bee paralysis virus and other known viral pathogens were found at high levels in pooled bee samples from all collapsing apiaries. Nevertheless, viral loads did not differ between healthy colonies and colonies in active collapse. However, individual bees exhibiting shaking behaviors and morbidity showed distinctly higher loads of two strains of deformed wing virus. Differences between these two analyses suggest that direct collections of morbid bees provide a complementary diagnostic for causal viruses, a suggestion supported by inoculation experiments that successfully replicated observed pathologies. Since these viruses are known to be vectored by the parasitic mite Varroa destructor, mites from collapsed colonies were in turn screened for resistance to amitraz, a critical miticide used widely by beekeepers, including all beekeepers surveyed in this study. A genetic trait linked with miticide resistance was found in all collected mites, underscoring the urgent need for new control strategies for this parasite. While viruses are a likely end-stage cause of colony death, other stressors such as nutritional stress and agrochemicals may have also played significant roles.

Efforts to improve honey bee colony health continue due to persistent high loss rates. A major focus in this area is Deformed wing virus (DWV), a key driver of colony loss. The application of modern molecular techniques has characterized the DWV genome and its high mutational rate that enables the formation of diverse quasi-species populations capable of evading host immune responses, while other work has led to the development of DWV clones suitable for sequence-specific tracking of viral dynamics. In this work we combine knowledge of these efforts to track the mutational progression in a DWV clone surrounding an area of low nucleotide diversity and compare it to its wild-type source. We achieve this through amplicon sequencing of the structural viral protein, VP2, after incubation across three generations and multiple host genetic sources. Inocula were injected into pupae, allowed to replicate, then extracted for a further two generations of injections. For the final injection generation, recipient pupae were injected with preparations from either the same genetic source or cross-fostered from other colonies. Overall, we compared the mean number and type of mutations, their proportional abundance in the read pool, and specific locations across strains. Sequencing results indicate a limited number of mutational hotspots, which were driven by silent mutations in the final injection generation of the wild-type strains. No significant differences were found among other mutation types, cross-fostering status, or interactions with host genetics. This work is an initial attempt at examining viral dynamics in a cloned system across multiple generations and treatment groups. The results provide valuable insights, which may further enhance our understanding of viral dynamics and potentially improve future honey bee therapeutics.

The widespread use of neonicotinoid pesticides has severely impacted honey bees, driving population declines. Gut microbiota are increasingly recognized for their role in mitigating pesticide toxicity. This study evaluated the ability of Gilliamella sp. G0441, a core microbiome member of the Asian honey bee (Apis cerana), to confer resistance to the toxicity of a neonicotinoid nitenpyram. Newly emerged Asian honey bees were first colonized with gut microbiota in the source colony, then divided into four treatments: SS (fed sucrose solution throughout), SN (fed sucrose solution, then exposed to nitenpyram), GS (fed Gilliamella, then sucrose solution), and GN (fed Gilliamella, then exposed to nitenpyram), and their responses-mortality, food consumption, body weight, and sucrose sensitivity-were assessed. The protective effects of Gilliamella administration on the host were further validated using a microbiota-free bee model. Gilliamella supplementation significantly mitigated nitenpyram-induced appetite suppression, weight loss, impaired learning, and gut microbiota disruption. Mechanistic analyses revealed that nitenpyram disrupted brain metabolism via the intestinal MAPK pathway, reducing ascorbate and aldarate metabolism. Prophylactic Gilliamella treatment reversed these effects, restored metabolic balance, and modulated esterase E4 expression, enhancing pesticide resistance. This study underscores Gilliamella's vital role in honey bee resilience to neonicotinoids, offering insights into the microbiota-gut-brain axis (MGBA) as a pathway for enhancing pesticide tolerance and ecological health.

From 1984 to 2015, the Bee Disease Diagnostic Lab at the USDA-ARS Beltsville Bee Research Laboratory (MD, USA) analyzed 66,056 samples submitted for disease diagnosis, comprising 35,883 adult bees and 30,173 brood samples collected from symptomatic colonies nationwide. This dataset provided valuable insights into honey bee disease dynamics over three decades. Adult bee samples were screened for Nosema spp. and tracheal mite (Acarapis woodi). Brood samples were microscopically analyzed for the presence of both Paenibacillus larvae and Melissococcus plutonius, the causative agents of American foulbrood (AFB) and European foulbrood (EFB) diseases, respectively. Antibiotic resistance was tested in AFB-positive samples (n = 6,785) for tetracycline and tylosin. Longitudinal analysis revealed significant (p < 0.001) inter-state and seasonal differences in disease prevalence. AFB was significantly more prevalent nationwide (44.71%) compared to EFB (10.01%), with a negative correlation between the two diseases (R = -0.4, p < 0.01). P. larvae resistance to tetracycline and tylosin declined significantly (p < 0.001) in later years, with national resistance averages of 42.52% and 27.78%, respectively. Additionally, positive correlations were recorded between AFB prevalence and P. larvae resistance to both antibiotics. Nosema spp. prevalence ranged from 0% to 77.9% across states, with a national average of 24.09% and significant seasonal variations (p < 0.001). From 2008 to 2015, Nosema infection rates increased significantly, contrasting with a marked decline in tracheal mite prevalence since 2007 (national average of 12.48%), which was negatively correlated with Nosema infection (R = -0.3, p < 0.05). This study provides unprecedented longitudinal insights into honey bee disease dynamics in the United States, highlighting the significant emergence of EFB and Nosema as threats from 2008 to 2015 and a drastic reduction in tracheal mite prevalence. These findings underscore the need for continued monitoring and adaptive management strategies to protect honey bee health and ensure sustainable pollination services.

This study examined the physicochemical, microbiological, antioxidant, and antibacterial properties of honey derived from stingless bees (Tetragonula pagdeni Schwarz). The honey samples were from different botanical zones in Sa Kaeo province, recognized as a "herb hub" in eastern Thailand. The analysis of 17 stingless bee honey (SBH) samples revelaed an average moisture content of 25.67 + 2.43 %, protein content of 1.99 + 0.11 g/100 g, ash content of 0.77 + 0.42 g/100 g, total soluble solids (TSS) of 77.19 + 1.31 degrees Brix, hydroxymethylfurfural (HMF) level of 0.036 + 0.026 mg/g, pH of 3.9 + 0.19, and free acidity of 127.28 + 52.63. The sugar composition was analyzed, revealing an average glucose content of 19.56 + 7.02 g/100 g, fructose content of 29.52 + 7.19 g/ 100 g, estimated reducing sugars (sum of fructose and glucose; F + G of 49.08 + 13.85), estimated fructose/ glucose ratio (F/G) of 1.60 + 0.37, and estimated glucose/water ratio (G/W) of 0.77 + 0.27. The antioxidant activity was assessed using ABTS and DPPH with average IC50 values of 4.42 + 0.87 and 46.99 + 10.68, respectively. The SBH exhibited an inhibitory effect against Salmonella enterica (10.39 + 3.02 mm), Escherichia coli O157:H7 (9.38 + 1.95 mm), Staphylococcus aureus (11.81 + 5.01 mm), Bacillus cereus DSM4384 (6.90 + 3.55 mm), and Bacillus cereus F4810/72 (10.78 + 2.71 mm) with the agar well diffusion method. Furthermore, the principal components analysis demonstrated that vegetation type influenced the physicochemical and antibacterial properties. Microbiological assessments were conducted to evaluate the quality and food safety of SBH. We analyzed the total bacteria, total yeast and mold, coliforms, E. coli, S. aureus, and presumptive Salmonella spp.. We additionally investigated the culturable bacteria and their enzymatic activities. Bacillus constituted the predominant bacterial isolates from SBH, and numerous isolates exhibited the ability to produce hydrolytic enzymes advantageous for industrial applications.

The genus Vairimorpha was proposed for several species of Nosema in 1976 (Pilley, 1976), almost 70 years after Nosema apis Zander (Zander, 1909). Tokarev and colleagues proposed the redefinition of 17 microsporidian species in four genera, Nosema, Vairimorpha, Rugispora, and Oligosporidium, based on phylogenetic trees of two genetic markers (SSU rRNA and RPB1) (Tokarev et al., 2020). Several issues should invalidate this new classification, leading to the synonymization of Vairimorpha within Nosema.

Honey bees provide vital pollination services to agricultural crops and wild plants worldwide. Unfortunately, the misuse and overuse of pesticides in agricultural production have led to an increase in incidents harming honey bees in recent years. Among the commonly utilized bee species in beekeeping are Apis cerana and Apis mellifera, with wild A. cerana populations widely dispersed in forests, contributing substantially to ecosystem balance. Yet, the impact of paraquat, a toxic herbicide, on A. cerana remains largely unexplored. This study aims to address this gap by examining acute exposure endpoints based on mortality represented by median lethal doses (LD50 values) of paraquat, survival rates, and gene expression patterns between the A. cerana and A. mellifera. The findings revealed that A. cerana exhibits greater sensitivity to paraquat compared to A. mellifera. The acute oral LD50 values for A. cerana were 5.85, 1.74, and 1.21 mu g/bee at 24, 48, and 72 h, respectively, whereas the corresponding values for A. mellifera were 104.00, 11.00, and 6.41 mu g/bee. Further, the study demonstrated significant upregulation of the detoxification (antioxidative) enzymes SOD1, CAT, and LLDH-X2 in both A. mellifera and A. cerana following exposure to the lethal dose of paraquat. However, SOD2 expression was notably downregulated in both species, indicating potential mitochondrial damage. These findings suggest that while honey bees initiate activate defense mechanisms against oxidative damage, paraquat exposure may still impair mitochondrial function. Paraquat was found to be moderately toxic to A. mellifera but highly toxic to A. cerana, indicating the importance of screening multiple bee species when assessing the risks of chemical exposure. This research provides a rare comparative analysis of chemical stress effects on morbidity and gene expression in two different honey bee species, establishing a foundational framework for risk assessment and the regulation of herbicide risks to pollinating insects.

BACKGROUND: The parasitic mite, Varroa destructor has posed a threat to the health and survival of European honey bees, Apis mellifera worldwide. There is a prevailing belief that small comb cells could provide a management tool against Varroa mites. However, the hypothesis that smaller cells can impede Varroa reproduction has not been fully tested. Here, we tested this hypothesis under laboratory conditions by using two distinct Varroa in vitro rearing systems: one involved gelatin capsules of different sizes, specifically size 00 (0.95 mL) versus size 1 (0.48 mL), and the second consisted of brood comb cells drawn on 3D printed foundations with varying cell sizes, ranging from 5.0 mm to 7.0 mm at 0.5 mm intervals. RESULTS: The results showed that mother mites in size 00 cells had significantly lower fecundity and fertility compared to those in size 1 cells. Interestingly, the reproductive suppression in larger cells could be reversed by adding an extra worker larva. Similarly, gonopore size of mother mites was smaller in size 00 cells, but restored with another host larva. Furthermore, both the fecundity and fertility of mother mites decreased linearly with the size of brood comb cells. CONCLUSIONS: Our results suggest that the reproduction of V. destructor is hindered by larger cells, possibly because larger brood cells disperse or weaken host volatile chemical cues that are crucial for Varroa reproduction. The insights derived from this study are expected to hold significant implications for the implementation of Varroa management programs. (c) 2024 Society of Chemical Industry.

Dicistroviridae is a family of arthropod-infecting viruses within the Order Picornavirales and Realm Riboviria. This family represents a large group of small, nonenveloped isometric viruses with a monopartite, single-stranded, positive-sense RNA genome. The name Dicistroviridae is derived from the characteristic dicistronic arrangement of the genome, which contains two non-overlapping open reading frames (ORFs), or cistrons, separated by an intergenic region (IGR), and flanked by untranslated regions (UTRs). The 5′-proximal and 3′-proximal ORFs encode non-structural and structural protein precursors, respectively. Each ORF is preceded by a specific RNA structure identified as an internal ribosome entry site (IRES), which allows for the initiation of translation in a cap-independent manner. Based on their phylogenetic distance, viral capsid structure, and distinctive features exhibited in IRESs, dicistroviruses are divided into three genera: Aparavirus, Cripavirus, and Triatovirus. The Dicistroviridae family comprises members that are serious disease agents of medical and agricultural importance against arthropods, such as fruit flies (Drosophila melanogaster), honey bees (Apis mellifera), and species of shrimp, prawn, and crab. Some dicistroviruses infect pest insects and thus have the potential for being used as biopesticides to control agricultural and urban pests. Transmission of dicistroviruses can occur through both horizontal and vertical pathways. Dicistroviruses generally have a broad host range and have been identified in multiple host species. Infection with dicistroviruses can lead to a spectrum of illnesses ranging from reduced growth and fecundity to severe disease and host death.

Polycipiviridae is a family of picorna-like viruses with non-segmented, linear, positive-sense RNA genomes of approximately 10–12 kb. Unusually for viruses within the order Picornavirales , their genomes are polycistronic, with four (or more) consecutive 5′-proximal open reading frames (ORFs) encoding structural (and possibly other) proteins and a long 3′ ORF encoding the replication polyprotein. Members of species within the family have all been detected in ants or via arthropod transcriptomic datasets. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the Polycipiviridae , which is available at www.ictv.global/report/polycipiviridae .

Nosema ceranae is a microsporidian parasite that infects the honeybee midgut epithelium. The protein‐coding gene Dicer is lost in most microsporidian genomes but is present in N. ceranae. By feeding infected honeybees with small interfering RNA targeting the N. ceranae gene coding Dicer (siRNA‐Dicer), we found that N. ceranae spore loads were significantly reduced. In addition, over 10% of total parasite protein‐coding genes showed significantly divergent expression profiles after siRNA‐Dicer treatment. Parasite genes for cell proliferation, ABC transporters and hexokinase were downregulated at 3 days postinfection, a key point in the middle of parasite replication cycles. In addition, genes involved in metabolic pathways of honeybees and N. ceranae showed significant co‐expression. Furthermore, the siRNA‐Dicer treatment partly reversed the expression patterns of honeybee genes. The honeybee gene mucin‐2‐like showed significantly upregulation in the siRNA‐Dicer group compared with the infection group continually at 4, 5 and 6 days postinfection, suggesting that the siRNA‐Dicer feeding promoted the strength of the mucus barrier resulted from interrupted parasite proliferation. As the gene Dicer broadly regulates N. ceranae proliferation and honeybee metabolism, our data suggest the RNA interference pathway is an important infection strategy for N. ceranae.

The Agricultural Research Service (ARS) is the intramural research agency of the United States Department of Agriculture (USDA) which addresses basic scientific questions and develops applied solutions to a range of agricultural problems, and in doing so protects national food security and supports international trade. The damage to agricultural commodities inflicted by insects and other arthropod pest species causes a reduction in producer output and profitability, thereby affecting product quality, such that the development of novel and effective arthropod control tactics remains a research challenge at USDA ARS. Additionally, USDA ARS conducts research into arthropod control within urban settings, where damage to dwellings, and ornamental and shade plants are of concern to homeowners and businesses alike. These goals of controlling pests must be balanced with environmental concerns, including the protection of pollinators and other beneficial species. The recent development of RNA interference (RNAi) and gene-editing technologies, such as Clustered Regularly Interspaced Short Palindromic Repeats and associated protein (CRISPR/Cas), opened new avenues for the development of novel arthropod control measures. Future RNAi applications United States Department of Agriculture, Agricultural Research Service: Invasive Insect Biocontrol and Behavior Laboratory, Beltsville, MD, 20705; Center for Grain and Animal Health Research, Manhattan, KS 66502; Biocontrol of Pests Research Unit, Stoneville, MS 38776; Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL 32608; Bee Research Laboratory, Beltsville, MD 20705; Horticultural Crops Research Unit, Corvallis, OR 97330; Temperate Tree Fruit and Vegetable Research Unit, Wapato, WA 98951; Tropical Crop and Commodity Protection Research Unit, Hilo, HI 96720; U.S. Vegetable Laboratory, Charleston, SC 29414; Pest Management and Biocontrol Research Unit, Maricopa, AZ 85138; U.S. Horticultural Research Laboratory, Fort Pierce, FL 34945; U.S. Agricultural Research Station, Salinas, CA 93905; Arthropod-Borne Animal Diseases Research Unit, Manhattan, KS 66502; Southern Insect Management Research Unit, Stoneville, MS 38776; Knipling-Bushland U.S. Livestock Insects Research Laboratory, Kerrville, Texas 78028; Office of National Programs, Crop Production and Protection, Beltsville, MD 20705; Corn Insects and Crop Genetics Research Unit, Ames, IA 50011, USA. Dawn E. Gundersen-Rindal, Sherry L. Adrianos, Margaret L. Allen, James J. Becnel, Yan Ping Chen, Man-Yeon Choi, Alden Estep, Jay D. Evans, Stephen F. Garczynski, Scott M. Geib, Saikat Kumar B. Ghosh, Alfred M. Handler, Daniel K. Hasegawa, Matthew C. Heerman, J. Joe Hull, Wayne B. Hunter, Navneet Kaur, Jianghong Li, Wengfeng Li, Kai-Shu Ling, Dana Nayduch, Brenda S. Oppert, Omaththage P. Perera, Lindsey C. Perkin, Neil D. Sanscrainte, Sheina B. Sim, Michael E. Sparks, Kevin B. Temeyer, Robert K. Vander Meer, William M. Wintermantel, Rosalind R. James, Kevin J. Hackett and Brad S. Coates T r e n d s i n

Nosema ceranae is an intracellular parasite that infects honey bee mid-gut epithelial cells. Previously, we identified microRNA-like small RNAs and found evidence for expression of the N. ceranae gene coding Dicer. The Dicer protein is critical for small regulatory RNA synthesis and RNA interference. In order to test the effects of Dicer on N. ceranae reproduction, we designed small interfering RNAs (siRNAs) to suppress Dicer gene expression. After inoculating honey bees with N. ceranae spores, siRNAs targeting the gene for Dicer were fed to individual honey bees for three days post infection at 24 h intervals (siRNA-Dicer group). Additional honey bees were fed with non-specific siRNAs (siRNA-scramble group). The third group of honey bees was inoculated with N. ceranae spores without any siRNA treatment (infection group). Overall, siRNA-Dicer significantly inhibited the spore production (ANOVA, P<0.05). The honey bees fed with siRNA-Dicer showed 60% less spores than the honey bees from infection and siRNA-scramble groups (adjusted P<0.05). The expression of Dicer was not detected at one day post infection (dpi) in the siRNA-Dicer group and the expression level of Dicer remained significantly suppressed at two dpi. The results suggest the gene Dicer is critical for N. ceranae reproduction and provide a new insight for this parasite control.

作为超级大国,美国在经济、文化、军事等各方面独树一帜,至今仍遥遥领先于世界其他国家,美国至今常盛不衰或许源于其自身在各领域强烈的忧患、危机意识,这也是发展中的我们值得借鉴、学习的地方.自2006～2007冬天突发的那场大规模的、无法解释的蜜蜂大量消失事件——蜂群崩溃失调症(colony collapse disorder,CCD)以来,对高度重视蜜蜂对农业发展具有重要性的美国来说,该事件的重要性及受关注的程度不亚于一起针对美国的暴力恐怖事件.

Summary Honey bee virus research is an enormously broad area, ranging from subcellular molecular biology through physiology and behaviour, to individual and colony-level symptoms, transmission and epidemiology. The research methods used in virology are therefore equally diverse. This article covers those methods that are very particular to virological research in bees, with numerous cross-referrals to other BEEBOOK papers on more general methods, used in virology as well as other research. At the root of these methods is the realization that viruses at their most primary level inhabit a molecular, subcellular world, which they manipulate and interact with, to produce all higher order phenomena associated with virus infection and disease. Secondly, that viruses operate in an exponential world, while the host operates in a linear world and that much of the understanding and management of viruses hinges on reconciling these fundamental mathematical differences between virus and host. The article concentrates heavily on virus propagation and methods for detection, with minor excursions into surveying, sampling management and background information on the many viruses found in bees.