The mandibular glands and the tergal glands have been suggested to play a crucial role in queen pheromone production. However, very few studies have linked changes in mandibular and tergal gland morphology to variations in their pheromone secretions. In this study, we aimed to reveal the age-related morphological development of these glands based on the morphological images and traits. We provided detailed information about how the mandibles, the mandibular glands, and the tergal glands changed in Apis cerana virgin queens aged 0 to 10 days. We detected only slight variations in mandible size (length and width of bilateral mandibles) across different age groups. However, the age of virgin queens had a significant effect on the morphological development of their mandibular and tergal glands, as reflected by the mandibular gland area and the morphology of tergal gland cell nuclei. The mandibular gland area of the 7-day-old virgin queens was significantly larger than that of the other age groups. Concurrently, the development of tergal glands reached a stable plateau in queens aged 5 to 7 days. In addition, significant differences were also detected in the surface area of tergal gland cells and the cell nucleus, and the cell nucleus diameter among tergites III, IV, and V. Compared to tergites IV and V, the cell nucleus surface area and the nucleus/cytoplasm index in tergite III exhibited greater variations across different age groups. These results are valuable for expanding our understanding of exocrine gland development in A. cerana queens.

Pollen is one of the main food sources for honeybees. The honeybee gut microbiota plays a crucial role in maintaining digestive function and host health during long-term coevolution. While the consumption and utilization of pollen have been extensively studied, there is limited information about the effects of pollen on the gut microbiota of Apis cerana. In this study, we used 16S rRNA amplicon sequencing to evaluate the effects of four natural pollens (oilseed rape pollen, camellia pollen, lotus pollen and buckwheat pollen) and two pollen substitutes (Diet 1 and Diet 2) on the hindgut microbiota of newly emerged A. cerana worker bees, following feeding periods of 5, 10 and 15 days. The results showed that Firmicutes and Proteobacteria are dominant in the gut microbiota of A. cerana. A. cerana workers fed with pollen diets had a higher diversity of gut microbiota than those fed with pollen substitutes. There have been significant differences in the gut microbiota structure and relative abundance of the core microbial community among A. cerana workers supplied with different diets. Our results confirm that gut bacterial communities of A. cerana can be influenced by pollen diets and may play an important role in host adaptation.

After the introduction of various Apis mellifera subspecies into China, prolonged breeding and selection have substantially altered the genetic structure and diversity of commercial populations. Currently, A. mellifera has become the most widely managed and numerically dominant honey bee species in China, providing important agricultural pollination services and substantial economic benefits. Nevertheless, the genetic diversity and progenitor of commercially managed A. mellifera populations within different regions in China remain poorly understood. To assess the maternal lineage diversity of A. mellifera populations and to support regional breeding strategies, we examined DNA sequence diversity in the cytochrome C oxidase I (COI) and tRNAleu-COII gene segment of the mitochondrial genome in 178 samples of A. mellifera drones from 12 sites in the urban districts of Beijing. Three haplotypes were found for the COI gene segment, and eight haplotypes were discovered for the tRNAleu-COII gene segment. Mitochondrial sequencing revealed that the frequency of C evolutionary lineage dominates in A. mellifera populations in Beijing. In addition, one unexpected haplotype from the Z lineage was detected. The subspecies Apis mellifera ligustica, representing the C1 haplotype, demonstrates the widest distribution and highest frequency. Our results also showed that significant genetic differentiation exists among commercial populations of A. mellifera in the urban districts of Beijing.

In recent years, honey bees have been stressed by multiple factors, with malnutrition posing a significant threat to the healthy development of honey bee colonies. To keep a colony healthy and productive, beekeepers supply their colonies with supplementary pollen or commercial pollen substitutes during periods of pollen dearth or insufficient pollen quantity or quality. In this study, we evaluated the effects of four natural pollen types (oilseed rape pollen, camellia pollen, lotus pollen and buckwheat pollen) and two commercial pollen substitutes (Diet 1 and Diet 2) against a control group (sucrose solution) on Apis cerana through cage experiments. The food consumption, live body weight, longevity, hypopharyngeal gland development and midgut proteolytic enzyme activity of caged workers were measured. The food consumption rates of oilseed rape pollen and buckwheat pollen were greater than the other diets. Oilseed rape pollen and camellia pollen were recognized as excellent-quality diets for hypopharyngeal gland development and midgut proteolytic enzyme activity. Over the entire experimental period, the caged workers fed with lotus pollen had a similar diet consumption and body weight to those fed with pollen substitutes, and these bees had a significantly higher survival rate than those fed with other diets. The results indicated that the commercial pollen substitutes appeared to be less beneficial to caged A. cerana workers than the natural pollen resources.

Background/Objectives: Apis cerana development is described as comprising four stages: embryo, larva, pupa, and adult. There are significant differences between workers and drones in terms of physiological functions and social roles, and the formation of the organ primordia occurs during the embryonic stage. Therefore, the objective of this study is to investigate the differential expression of and alternative splicing of genes in worker and drone embryos and to explain their unique developmental patterns. Methods: Long-read sequencing (PacBio Iso-Seq) and short-read sequencing (Illumina RNA-Seq) were used to investigate worker and drone embryo gene expression differences in A. cerana across five developmental points (12, 24, 36, 48, and 60 h). Results: The study identified 59,254 common isoforms, with 5744 and 5106 isoforms specific to worker and drone embryos, respectively. Additionally, a new transcript of the csd gene was identified. The number of differentially expressed genes (3391) and differential splicing events (470 genes) peaked at the 24-h embryonic stage. Differential splicing events of csd, dsx, and Y-y were observed in the worker and drone embryos. Conclusions: The gene expression results indicated that the 24-h embryonic point is a critical period for the expression of genes related to developmental and behavioral differences between workers and drones. The findings provide a theoretical basis for future research on the developmental differences between workers and drones.

Polyandry is widespread among eusocial Hymenoptera, and the honey bee is a typical representative of this. It has been widely shown that polyandry can confer benefits to queens and their offspring, including enhanced productivity and fitness, stronger resistance to pathogens, and resilient division of labor, which promotes colony-level homeostasis. A previous study conducted in Australia demonstrated that 33.8% commercial Apis mellifera queens produced in autumn were not adequately mated. Beekeepers of Apis cerana in China also claimed that the queens reared in autumn are inferior to those reared in spring. To confirm whether the quality difference of queens produced in different periods is related to their mating frequency, we estimated the observed mating frequency (k) and the effective mating frequency (me) of A. cerana queens produced at the beginning and end of the queen production season in Liaoning Province. We found that all the queens were suitably mated and there was no significant difference in the mating frequency between early spring queens and late summer queens. In addition, our study indicated that the queens and their offspring workers owned a high level of heterozygosity and their inbreeding coefficients were universally low. Further studies on the queens’ performance and health are required to verify the statement that the queens reared in autumn are not as good as those reared in spring.

Honey bees ( Apis spp.) are important pollinators in many natural and agro-ecosystems across the world. Effective means of surveying wild populations are therefore key to their conservation and management. One available survey method infers honey bee colony density from the genotype of drones (males) sampled from sites known as Drone Congregation Areas (DCAs). While this approach has been commonly used for the Western honey bee ( A. mellifera ), its feasibility for other Apis species is unknown. Here, we investigate drone congregation behaviour in the Asian honey bee Apis cerana in north-east Australia and its suitability for inferring colony density. As this A. cerana population is invasive, surveys in this case can aid in monitoring the population’s growth and spread. Over 5 years, we identified 30 DCAs, many of which were stable across time. DCAs were sheltered areas beside tree-lines or openings in the forest canopy. A. cerana drones joined DCAs during 1–2-h afternoon intervals and could be sampled at heights of 2–24 m via adhesive lines attached to helium balloons carrying lures coated in queen pheromone. Drones were more likely to be present at a DCA as temperature increased, though abiotic factors did not predict overall drone abundance. Drones could be sampled in low numbers even where colony density was extremely low. Based on the genotyping and inferred sibship of drones sampled at DCAs between 2016 and 2021, we estimate population density in Australia’s A. cerana to be in the range 1.1–8.1 colonies/km 2 . This extrapolates to a total population size in the range 11,000–83,000 colonies, with more refined estimates requiring better knowledge of drone flight distance and the effect of habitat on colony density. We conclude that population surveys based on drones from DCAs are possible for A. cerana and propose that this approach be part of a toolkit of methods used to monitor Asian honey bee populations in both their native and invasive ranges.

The quality of the queen is crucial for the survival and growth of honey bee colonies. There have been studies related to raising queens with excellent performance since the invention of artificial queen rearing technologies. However, relatively few studies have been undertaken that evaluate the relationship between queen quality and queen morphology and the expression level of reproduction-related genes using different-aged brood in artificial queen rearing practices of Eastern honey bees (Apis cerana). Therefore, we transferred eggs, 1-day-old larvae, 2-day-old larvae, and 3-day-old larvae to queen cells to rear queens until the queen emerged. We measured 12 indicators (the acceptance rate, birth weight, length, caliber and maximum diameter of queen cells, thorax length, width and weight, head width, wing length and width, and number of ovarian tubes). Moreover, the relative expression levels of Hexamerin, Vitellogenin, and Transferrin were measured using fat bodies and ovaries dissected from the newly emerged virgin queens. The results showed that queens reared from eggs exhibited the best morphological indexes and occupied the most abundant reproductive related gene expression level. Parameter values for queen from 1-day-old larvae were significantly higher than those for queens from 2-day-old larvae and 3-day-old larvae, and there was no significant difference between values for queens from 2-day-old larvae and 3-day-old larvae in most data, except for the relative gene expression. In conclusion, as the age of the brood increased, the quality of the queen bees declined. Rearing queens from fertilized eggs are far more likely to yield a better outcome for queen performance and colony function. This study provides data support for raising high-quality queens of Apis cerana, which would be benefit for the protection and better utilization of our native honey bee species.

In Asia, the sap beetle Phenolia (Lasiodites) picta (Macleay) (Coleoptera, Nitidulidae) (hereafter P. picta) is endemic to the southeastern Palaearctic and northeastern Oriental regions. It is commonly found in orchards and plantations, where it feeds on ripe or rotten fruits. Here, P. picta was recorded for the first time to invade the hive of the Eastern honey bee (Apis cerana). Both DNA barcode and morphological data were used to identify the beetle, with the DNA barcoding comparison to the P. picta sequence in the BOLD library reaching 100% similarity. Additionally, the body sizes were measured, with the males averaging 7.87 +/- 0.21 mm in length and the females averaging 8.27 +/- 0.15 mm. The beetle's body colour is primarily brownish with yellowish to pale orange spots on the elytra. P. picta invades the honey bee hive, feeds on honey and bee pupae, and tunnels through the comb, which causes the honey bees to abandon their hive. Such invasions could have severe impacts on honey bee colonies. This report provides essential information for beekeepers to use when identifying P. picta, which could be useful for preventing and controlling parasitic beetles.

The influence of gene expression on female caste determination in social Hymenoptera is one of the best-characterized examples of developmental polyphenism. We used mRNA-seq to profile differentially expressed genes (DEGs) between workers and queens at four development stages (early larvae: 1-day-old larvae; mid larvae: 5-day-old larvae; late larvae: 9-day-old larvae; and 7-day-old adult bee) of Bombus terrestris. When DEGs of different female castes were compared, it was found that there were more DEGs at the mid larval and adult stages than at other stages. Caste differentiation may be linked to candidate genes such as Vitellogenin, Kr-h1, Dnmt3, Hexamerin, Yellow, and Chymotrypsin-2. Additionally, the gene expression profiles were observed differently among the four development stages. Comparing one stage to the next showed that, more number of DEGs were found in queens than workers. In the investigation of how gene expression affects larval caste determination, WGCNA showed that five modules were closely associated with larval caste determination. The functions of genes were mainly enriched in energy metabolism and energy production within mitochondria, suggesting that the energy requirements during the larval development process varied between caste determination. The current study sheds light on the patterns of gene expression in the female caste of Bombus terrestris, which will be useful for future research on polyphenism through differential gene expressions.

The honeybee Apis cerana plays a crucial role as a pollinator, contributing significantly to biodiversity and supporting ecological processes [...]

Honey bee population inhabiting among different geographic regions often exhibit distinctive traits and phenotypes as a means of enhancing their adaptation to local environmental conditions. Morphological difference of worker was used to reflect the honey bee population locality adaptation and as one of the important markers of species evolution. Here, four comb cell and seven morphology characters of honey bee Apis cerana from two adjacent populations of Yunnan Province were measured to explore the effect of local adaptation on worker comb cell and morphology. Results showed that the characters of worker comb cell and morphology was significant difference between samples from these two local populations of A. cerana. It was separated into two groups which corresponding into the general A. cerana geographic population of Yungui Plateau and South Yunnan base on worker comb cell and morphology character. The worker comb cell size and morphology of A. cerana from Qujing were found to be significantly larger than those from Cangyuan. The indices that showed the most significantly different between populations were cell depth and right forewing length. Moreover, a strong positive correlation was observed between the cell diagonal diameter and the right forewing length, with a correlation coefficient 0.575. In conclusion, honey bee A. cerana population appear high variation in comb cell and morphology to adapt the locality environment. The forewing length of worker was the most significant variation indices between geographic populations, and could be as an indicator of worker cell and morphology among different A. cerana geographic populations.

Invasive populations often experience founder effects: a loss of genetic diversity relative to the source population, due to a small number of founders. Even where these founder effects do not impact colonization success, theory predicts they might affect the rate at which invasive populations expand. This is because secondary founder effects are generated at advancing population edges, further reducing local genetic diversity and elevating genetic load. We show that in an expanding invasive population of the Asian honey bee (Apis cerana), genetic diversity is indeed lowest at range edges, including at the complementary sex determiner, csd, a locus that is homozygous-lethal. Consistent with lower local csd diversity, range edge colonies had lower brood viability than colonies in the range centre. Further, simulations of a newly-founded and expanding honey bee population corroborate the spatial patterns in mean colony fitness observed in our empirical data and show that such genetic load at range edges will slow the rate of population expansion. Invasive populations often have low genetic diversity because they originated from a small number of founding individuals. This study shows that in an invasive honey bee, one consequence of low genetic diversity is a reduced rate of population expansion due to serial founder effects at range edges.

Oilseed rape is an economically important crop and provides a good nectar resource. In this study, the nectar secretion characteristics of five winter oilseed rape (Brassica napus L.) cultivars in China were examined throughout the daytime. The correlations of corolla opening size, air temperature and relative humidity with nectar production were also determined. Different daily patterns of nectar secretion were detected in flowers opening at different times of the day, and similar trends were observed among cultivars. The nectar volume and nectar sugar concentration in flowers that opened before 9:00 peaked on the first day. The nectar volume of flowers that opened at 11:00 peaked on the second day, and the nectar sugar concentration peaked on the first day. The total nectar yield of flowers opening before 9:00 (4.422–5.265 μl) was lower than that of flowers opening at 11:00 (7.982–10.646 μl). The average nectar sugar concentration of flowers opening before 9:00 (18.4–23.3%) was higher than that of flowers opening at 11:00 (15.3–17.5%). The nectar volume was positively correlated with air temperature and relative humidity, while the nectar sugar concentration was positively correlated with air temperature and negatively correlated with relative humidity. The nectar volume and nectar sugar concentration were positively correlated with corolla opening size. The glucose/fructose ratio ranged from 0.89 to 1.44. These results will contribute to a better understanding of the nectar secretion patterns of B. napus L. and will support further studies assessing the melliferous potential of B. napus L. and the temporal dynamics of plant-pollinator interactions.

Haploid males of hymenopteran species produce gametes through an abortive meiosis I followed by meiosis II that can either be symmetric or asymmetric in different species. Thus, one spermatocyte could give rise to two spermatids with either equal or unequal amounts of cytoplasm. It is currently unknown what molecular features accompany these postmeiotic sperm cells especially in species with asymmetric meiosis II such as bees. Here we present testis single-cell RNA sequencing datasets from the honeybee (Apis mellifera) drones of 3 and 14 days after emergence (3d and 14d). We show that, while 3d testes exhibit active, ongoing spermatogenesis, 14d testes only have late-stage spermatids. We identify a postmeiotic bifurcation in the transcriptional roadmap during spermatogenesis, with cells progressing toward the annotated spermatids (SPT) and small spermatids (sSPT), respectively. Despite an overall similarity in their transcriptomic profiles, sSPTs express the fewest genes and the least RNA content among all the sperm cell types. Intriguingly, sSPTs exhibit a relatively high expression level for Hymenoptera-restricted genes and a high mutation load, suggesting that the special meiosis II during spermatogenesis in the honeybee is accompanied by phylogenetically young gene activities.

Pollen is essential to the development of honey bees. The nutrients in bee pollen vary greatly among plant species. Here, we analyzed the differences in the amino acid compositions of pear (Pyrus bretschneideri), rape (Brassica napus), and apricot (Armeniaca sibirica) pollens and investigated the variation in hemolymph metabolites and metabolic pathways through untargeted metabolomics in caged adult bees at days 7 and 14. The results showed that the levels of five essential amino acids (isoleucine, phenylalanine, lysine, methionine, and histidine) were the highest in pear pollen, and the levels of four amino acids (isoleucine: 50.75 ± 1.93 mg/kg, phenylalanine: 87.25 ± 2.66 mg/kg, methionine: 16.00 ± 0.71 mg/kg and histidine: 647.50 ± 24.80 mg/kg) were significantly higher in pear pollen than in the other two kinds of bee pollen (p < 0.05). The number of metabolites in bee hemolymph on day 14 (615) was significantly lower than that on day 7 (1466). The key metabolic pathways of bees, namely, “sphingolipid metabolism (p = 0.0091)”, “tryptophan metabolism (p = 0.0245)”, and “cysteine and methionine metabolism (p = 0.0277)”, were significantly affected on day 7. There was no meaningful pathway enrichment on day 14. In conclusion, pear pollen had higher nutritional value among the three bee pollens in terms of amino acid level, followed by rape and apricot pollen, and the difference in amino acid composition among bee pollens was reflected in the lipid and amino acid metabolism pathways of early adult honey bee hemolymph. This study provides new insights into the physiological and metabolic functions of different bee pollens in bees.

近年来,沧源佤族自治县(以下简称"沧源县")结合山多林密的特征,着力加快发展蜜蜂产业,在中国东方航空集团有限公司(以下简称"东航")、中国农业科学院蜜蜂研究所(以下简称"蜜蜂所")以及正大蜂业(云南)有限公司(以下简称"正大蜂业")的大力支持与帮助下,经过各级各部门的共同努力,取得了一定成效,切实为助力乡村振兴做出积极贡献.基于实地调研结果,本文介绍沧源县资源优势和蜜蜂产业发展现状,分析沧源县发展蜜蜂产业存在的主要问题与困难,旨在促进当地蜜蜂产业的发展.

Oilseed rape is the third-largest source of vegetable oil and the second-largest source of protein meal in the world. Pollinators are vital in the production of oilseed rape. However, pollination efficiency could be influenced by the morphology and foraging behaviors of pollinators. To evaluate the effect of pollinator size and foraging behavior on pollination efficiency, the intertegular distances (ITDs) of five bumble bees (Bombus pyrosoma, B. lantschouensis, B. melanurus, B. sichelii and B. sibiricus) and two honey bees (Apis mellifera and A. cerana) were evaluated. Their foraging activities and single visit depositions (SVDs) on oilseed rape were observed and counted. The ITDs of bumble bees were significantly larger than honey bees (P < 0.05). The single-visit duration of A. mellifera (2.43 +/- 0.06 s) was significantly longer than other bees (P < 0.05). The interval time of the A. cerana was longer than other bees (P < 0.05). Larger bees tended to deposit more pollen on stigmas at each visit than smaller bees. The interspecific ITD of bees had a positive effect on SVD (P < 0.001). There was no correlation between ITD and SVD among individuals of the same species. In conclusion, the size of bees had a positive impact on pollination efficiency. Bees with a greater ITD deposited substantially more pollen and had a significantly shorter interval between flowers. Understanding the foraging behavior and pollination efficiency of these bee species and developing habitats to support them should enable growers to achieve resilient production.