Apis Cerana Research Articles

The origin of materials deposited by Japanese honey bees at their hive entrances as a defense against giant hornets

Eastern honey bees (Apis cerana Fabricius, 1793) apply spots of materials derived from other organisms to the outside of their hive entrances as one of their defenses against giant hornets. In this study, we used DNA metabarcoding to identify the origin of such materials applied by Japanese honey bees (Apis cerana japonica Radoszkowski, 1877) and found them to be derived from mammals, birds, arthropods, and terrestrial plants. Our results show that this particular defensive behavior involves the use of a wider variety of taxa than previously known.

Decline in Honeybees and Its Consequences for Beekeepers and Crop Pollination in Western Nepal.

In understudied regions of the world, beekeeper records can provide valuable insights into changes in pollinator population trends. We conducted a questionnaire survey of 116 beekeepers in a mountainous area of Western Nepal, where the native honeybee Apis cerana cerana is kept as a managed bee. We complemented the survey with field data on insect-crop visitation, a household income survey, and an interview with a local lead beekeeper. In total, 76% of beekeepers reported declines in honeybees, while 86% and 78% reported declines in honey yield and number of beehives, respectively. Honey yield per hive fell by 50% between 2012 and 2022, whilst the number of occupied hives decreased by 44%. Beekeepers ranked climate change and declining flower abundance as the most important drivers of the decline. This raises concern for the future food and economic security of this region, where honey sales contribute to 16% of total household income, and where Apis cerana cerana plays a major role in crop pollination, contributing more than 50% of all flower visits to apple, cucumber, and pumpkin. To mitigate further declines, we promote native habitat and wildflower preservation, and using well-insulated log hives to buffer bees against the increasingly extreme temperature fluctuations.

Molecular detection of Lotmaria passim in intestine of Japanese honeybees (Apis cerana japonica)

ABSTRACTCrithidia mellificae and Lotmaria passim are trypanosomatids that infect honeybees, and many studies suggest that both parasites contribute to the decline in the honeybee population. The Japanese honeybee (Apis cerana japonica) is a native honeybee that inhabits various areas of Japan and is one of the most important pollinators. Both parasites have been well studied in the western honeybee (Apis mellifera) but have been poorly investigated in A. c. japonica. The present study investigated the presence of C. mellificae and L. passim in one feral and six managed A. c. japonica colonies at three different institutes. Five out of seven colonies were polymerase chain reaction‐positive for L. passim (71.4%); however, C. mellificae was not detected. Four of the five colonies were positive in both the midgut and hindgut, but one was positive only in the hindgut. A homology search and phylogenetic tree of the glycosomal glyceraldehyde‐3‐phosphate dehydrogenase (gGAPDH) and cytochrome b (Cytb) genes obtained in this study indicated that the sequences belonged to L. passim. The results of this study emphasize concerns regarding the health of this ecologically important pollinator and the importance of further investigation of the prevalence of L. passim in A. c. japonica in a wider area of Japan.

Determination of Mineral Content and Physico-Chemical Properties of Apis Honey from Karnataka State

The present investigation analyzed Apis honey samples of dorsata, cerana, mellifera and florea spp. from Coorg and Kolar districts of Karnataka. The physical parameters, pH, optical density, viscosity, and moisture contents were analyzed for the Apis honey samples and were found to comply with international standards. The efficacy of Apis honey in medical research chiefly depends on its mineral constituents. Hence, the total ash content was calculated using the Ivanov and Chevanakova methods. An atomic absorption spectrophotometer and flame photometer were used to quantify minerals in honey samples. The total ash range was between 0.24±0.2 to 0.65±0.1 per cent. The F-test and ANOVA values of the total ash content of honey samples were significant at 5% levels. Honey of Apis dorsata had 4.33±0.01 ppm±SD of Calcium and 1.69±0.02 ppm±SD of Magnesium; 0.004±0.0001 ppm±SD of Chromium 0.09±0.02 ppm±SD of Iron was found in honey of Apis florea. Likewise, honey of Apis cerana had Copper (0.05±0.002 ppm±SD), Manganese (0.08±0.002 ppm±SD), Phosphorus (0.49±0.02 ppm±SD), Potassium (40.44±0.09 ppm±SD) and Sodium (4.37±0.06 ppm±SD). Zinc (0.06±0.002 ppm±SD) was present in honey of A. mellifera. All the mineral nutrients studied were within the compliance range and determined to be statistically significant (p< 0.05). It was concluded that the Karnataka Apis honey maintains its good standards.

Physicochemical and antioxidant properties of Apis cerana honey from Lombok and Bali Islands.

Limited honey production worldwide leads to higher market prices, thus making it prone to adulteration. Therefore, regular physicochemical analysis is imperative for ensuring authenticity and safety. This study describes the physicochemical and antioxidant properties of Apis cerana honey sourced from the islands of Lombok and Bali, showing their unique regional traits. A comparative analysis was conducted on honey samples from Lombok and Bali as well as honey variety from Malaysia. Moisture content was found slightly above 20% in raw honey samples from Lombok and Bali, adhering to the national standard (SNI 8664:2018) of not exceeding 22%. Both honey types displayed pH values within the acceptable range (3.40-6.10), ensuring favorable conditions for long-term storage. However, Lombok honey exhibited higher free acidity (78.5±2.14 meq/kg) than Bali honey (76.0±1.14 meq/kg), surpassing Codex Alimentarius recommendations (≤50 meq/kg). The ash content, reflective of inorganic mineral composition, was notably lower in Lombok (0.21±0.02 g/100) and Bali honey (0.14±0.01 g/100) compared to Tualang honey (1.3±0.02 g/100). Electric conductivity, indicative of mineral content, revealed Lombok and Bali honey with lower but comparable values than Tualang honey. Hydroxymethylfurfural (HMF) concentrations in Lombok (14.4±0.11 mg/kg) and Bali (17.6±0.25 mg/kg) were slightly elevated compared to Tualang honey (6.4±0.11 mg/kg), suggesting potential processing-related changes. Sugar analysis revealed Lombok honey with the highest sucrose content (2.39±0.01g/100g) and Bali honey with the highest total sugar content (75.21±0.11 g/100g). Both honeys exhibited lower glucose than fructose content, aligning with Codex Alimentarius guidelines. The phenolic content, flavonoids, and antioxidant activity were significantly higher in Lombok and Bali honey compared to Tualang honey, suggesting potential health benefits. Further analysis by LC-MS/MS-QTOF targeted analysis identified various flavonoids/flavanols and polyphenolic/phenolic acid compounds in Lombok and Bali honey. The study marks the importance of characterizing the unique composition of honey from different regions, ensuring quality and authenticity in the honey industry.

Odorant Receptors Expressing and Antennal Lobes Architecture Are Linked to Caste Dimorphism in Asian Honeybee, Apis cerana (Hymenoptera: Apidae).

Insects heavily rely on the olfactory system for food, mating, and predator evasion. However, the caste-related olfactory differences in Apis cerana, a eusocial insect, remain unclear. To explore the peripheral and primary center of the olfactory system link to the caste dimorphism in A. cerana, transcriptome and immunohistochemistry studies on the odorant receptors (ORs) and architecture of antennal lobes (ALs) were performed on different castes. Through transcriptomesis, we found more olfactory receptor genes in queens and workers than in drones, which were further validated by RT-qPCR, indicating caste dimorphism. Meanwhile, ALs structure, including volume, surface area, and the number of glomeruli, demonstrated a close association with caste dimorphism. Particularly, drones had more macroglomeruli possibly for pheromone recognition. Interestingly, we found that the number of ORs and glomeruli ratio was nearly 1:1. Also, the ORs expression distribution pattern was very similar to the distribution of glomeruli volume. Our results suggest the existence of concurrent plasticity in both the peripheral olfactory system and ALs among different castes of A. cerana, highlighting the role of the olfactory system in labor division in insects.

Apis cerana Fabricius, 1793 in Sumatra: Haplotype Variations of Mitochondrial DNA and the Molecular Relationship with the Asian Honey Bees (Hymenoptera: Apidae)

Honey bee Apis cerana is widely distributed in Asia and the Indonesian archipelago, including Sumatra. We studied the molecular variations of A. cerana using cytochrome c oxidase subunits 1 and 2 genes (cox1 and cox2) and the cox1/cox2 intergenic spacers (igs) in several altitudes in the six provinces of Sumatra. We explored the haplotype distributions of those three mtDNA markers for A. cerana in the low-, mid-, and highlands of Sumatra. We also analyzed their relationship with A. cerana in Sundaland and Asia using those markers. Our study revealed 12 new haplotypes of A. cerana cox1 in Sumatra, while nine and eight new haplotypes for cox2 and igs, respectively. Apis cerana in North Sumatra, Lampung, and South Sumatra had the three highest haplotype variations. Most of the specific haplotypes of inter-colony A. cerana from Sumatra were found in the lowlands, while most were in the highlands for intra-colony variations. We found low gene flow among populations of A. cerana in Sumatra. One haplotype, Sumatra4 cox2 from North Sumatra, was the same as Java3 haplotype, presumably due to anthropogenic impact. The molecular phylogenetic tree of A. cerana in the Sundaland revealed that A. cerana from Sumatra has a close relationship to those of Borneo compared to Java.

Socialization of Apis Cerana Honey Bee Cultivation to Improve the Economy of the Kanagarian Community Malai Iii Koto Sungai Geringging Padang Pariaman

The Apis cerana honey bee is a natural resource that may be developed for beekeeping in Nagari Malai III Koto, Sungai Geringging District, Padang Pariaman, West Sumatra. The potential of these bees is developed, either as a single business as a honey producer or integrated with various types of plants. The main supporting factors for Apis cerana beekeeping are the presence of bee colonies found in people's gardens and the availability of abundant food throughout the year produced by plantation, fruit, and forestry crops. In addition, there are human resources from academics and professionals scattered in various regions. The prospect of Apis cerana honey beekeeping needs to be socialized to the farming community through counseling so that the potential of Apis cerana bees can be maximized. The socialization was carried out by means of counseling and demonstration methods to farmers and their families as the target audience and accompanied by the government of Nagari Malai III Koto. The results obtained that socialization carried out by extension and demonstration methods could disseminate information, increase the knowledge and interest of farmers and farming families about Apis cerana honey beekeeping

Pollinators diversity and pollination effects on yield attributes of sunflower (Helianthus annuus Linnaeus) in Odisha, India

In the study on the diversity of pollinators and their pollination efficiency in sunflower (Helianthus annuus L.) under field condition of Odisha during 2021-22, recorded 18 species of pollinators. Indian honeybee, Apis cerana indica F. (Hymenoptera, Apidae) was found to be the major one among the insect pollinators. The experiment conducted for two years with three different treatments viz., open pollination (OP), managed A. cerana indica pollination (HB) and pollinator exclusion (PE) for better yield and quality revealed that both quantitative and qualitative parameters were significantly higher in OP sunflower crops followed by crops pollinated by A. cerana indica. Significantly higher seed yield, 1000 seed weight, percentage of seed filling and number of seed per capitulum were recorded in these treatments. These findings indicate OP and HB increase 33 per cent more yield in sunflower.

Shifts in plant‐invertebrate interactions between wild and ex situ conservation populations of a critically endangered tree

Abstract Ex situ conservation is an effective approach to prevent the extinction of endangered species. Biotic interactions (e.g. herbivory and pollination) are critical to ex situ conservation success, including plant establishment, survival and reproduction. However, shifts in biotic interactions between wild and ex situ populations are still poorly understood. We compared herbivory and pollination characteristics between the only wild population (WP) and three ex situ populations (LP, local population, nearby WP; NP, north population, ca. 850 km; and SP, south population, ca. 750 km) of a critically endangered tree species (Sinojackia huangmeiensis) to explore the latitudinal changes in plant‐invertebrate interactions. Larvae of the Limacodidae family were the dominant herbivores in WP, LP and NP, while the only herbivore observed in SP was snail. Compared to WP, the leaf herbivory rate was unchanged in LP but decreased in NP and SP. Leaf defence traits (total phenols, tannins, leaf thickness and leaf dry matter content) increased or remained unchanged in the three ex situ populations. A pollinator (Apis cerana) of S. huangmeiensis was present in the four populations. NP and SP lacked some pollinators that were found in both WP and LP, but they shared one pollinator that was not observed in WP and LP. The pollinator visiting frequency increased in SP, while it did not change significantly in LP and NP. Synthesis and applications. Our results suggested that both herbivory and pollination of Sinojackia huangmeiensis changed in ex situ populations, with complete or partial changes in herbivores, leaf herbivory rate, pollinators, pollinator visiting frequency and fruit set in the two distant ex situ populations. This work provides a unique empirical study of shifts in both antagonistic and mutualistic biotic interactions between wild and ex situ populations. We emphasized that it is essential to integrate herbivore and pollinator management in future ex situ conservation of plant species.

Identification of the cytochrome P450 gene AccCYP6A13 in Apis cerana cerana and its response to environmental stress

Cytochrome P450 plays a crucial role in regulating insect growth, development, and resisting a variety of stresses. Insect metamorphosis and response to external stress are altered by deleting CYP450 genes. In this study, we identified and analyzed a novel gene of CYP450 family, AccCYP6A13, from Apis cerana cerana, and explored its role in the response of Apis cerana cerana to adverse external stressors. It was found that the expression of AccCYP6A13 was spatiotemporal specificity. The expression level increased with age and reached its highest value in the adult stage. The primarily expressiong location were legs, brain, and epidermis of honeybees. Stress conditions can affect the expression of AccCYP6A13 depending on treatment times. RNA interference experiments have shown that knocking down AccCYP6A13 reduces antioxidant activity and deactivates detoxification enzymes, resulting in oxidative damage accumulation and a decline in detoxification capability in bees, as well as inhibiting numerous antioxidant genes. Additionally, knockdown of the AccCYP6A13 gene in Apis cerana cerana resulted in increased sensitivity to pesticides and increased mortality when treated with neonicotinoid pesticides such as thiamethoxam. AccCYP6A13 overexpression in a prokaryotic system further confirmed its role in resistance to oxidative stress. To summarize, AccCYP6A13 may play an essential role in the normal development and response to environmental stress in Apis cerana cerana. Furthermore, this study contributed to the theoretical understanding of bee resistance biology.

Temporal and Spatial Foraging Activity of Indian Honey Bee (Apis cerana indica F.) at Different Migratory Sites

Migratory beekeeping increases honey production and reduces the feeding costs of stationary beekeeping during longer dearth periods. This study discerns the influence of environmental conditions on the foraging behavior of the Indian honey bee, Apis cerana indica F., at different migratory sites in Southern India. The total number of foraging bees, pollen foraging efficiency, and nectar foraging efficiency were estimated. Furthermore, the influence of environmental factors, including temperature, relative humidity, rainfall, and solar radiation, was recorded to identify its impact on the foraging behavior of honey bees. Among the climatic factors, maximum temperature (>30 °C) was the most crucial, negatively affecting bee activity with correlation coefficients of -0.83, -0.34, and -0.33 for outgoing bees, nectar, and pollen collectors, respectively. The relative humidity showed a positive impact on the frequency of worker bees moving out of the hive (r = 0.79), those coming in with nectar (r = 0.27), and pollen (r = 0.29). Rainfall hampered foraging activity, while solar radiation was found to have no significant effect on bee activity. Diurnal variations showed peak activity of bee foragers between 6.00 and 10.00 am. The visits by honey bees were significantly higher at low temperatures, solar radiation, precipitation, and high relative humidity. They made about 90% of their flower visits in the early morning, although plenty of bee flora was available throughout the day. Also, the environmental conditions at different sites strongly influenced the foraging behavior. However, the honey bees still focused their activities on favorable conditions depending on their biology and fixed their daily foraging patterns, improving beekeeping and honey production throughout the year.

Comprehensive analysis of the microbiome in Apis cerana honey highlights honey as a potential source for the isolation of beneficial bacterial strains.

Honey is a nutritious food made by bees from nectar and sweet deposits of flowering plants and has been used for centuries as a natural remedy for wound healing and other bacterial infections due to its antibacterial properties. Honey contains a diverse community of bacteria, especially probiotic bacteria, that greatly affect the health of bees and their consumers. Therefore, understanding the microorganisms in honey can help to ensure the quality of honey and lead to the identification of potential probiotic bacteria. Herein, the bacteria community in honey produced by Apis cerana was investigated by applying the next-generation sequencing (NGS) method for the V3-V4 hypervariable regions of the bacterial 16S rRNA gene. In addition, lactic acid bacteria (LAB) in the honey sample were also isolated and screened for in vitro antimicrobial activity. The results showed that the microbiota of A. cerana honey consisted of two major bacterial phyla, Firmicutes (50%; Clostridia, 48.2%) and Proteobacteria (49%; Gammaproteobacteria, 47.7%). Among the 67 identified bacterial genera, the three most predominant genera were beneficial obligate anaerobic bacteria, Lachnospiraceae (48.14%), followed by Gilliamella (26.80%), and Enterobacter (10.16%). Remarkably, among the identified LAB, Lactobacillus kunkeei was found to be the most abundant species. Interestingly, the isolated L. kunkeei strains exhibited antimicrobial activity against some pathogenic bacteria in honeybees, including Klebsiella spp., Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa and Staphylococcus aureus. This underscores the potential candidacy of L. kunkeei for developing probiotics for medical use. Taken together, our results provided new insights into the microbiota community in the A. cerana honey in Hanoi, Vietnam, highlighting evidence that honey can be an unexplored source for isolating bacterial strains with potential probiotic applications in honeybees and humans.

Comparative Study of Amino Acids in the Different Stages of Honey Bee

Apiculture is the practice of keeping bees as well as the manufacturing of honey and beeswax. Nectar is the main source of carbohydrates for honey bees. The amount of nectar needed pet colony depends on how concentrated the sugars are in the nectar. A worker bee needs 11 mg of dry sugar each day, which translates to about 22 µl of 50% sugar syrup per bee per day. In order to make honeybees grow satisfactorily enough feed must be provided, and feed should have all the necessary nutrients for the growth of honeybees. The important nutrients such as amino acids, lipids, carbohydrates, and requirements of vitamins and minerals are necessary for the growth and development of honeybees. During development, several structural, physiological, and biochemical changes occur takes place in an organism from stage to stage. There is a variation in the quality of all biochemical components. In the present study, the free amino acids from the eggs, larvae, pupae, and adult honeybee Apis cerana indica and also honey have been analyzed. This work was carried out by adopting the technique of paper chromatography. The developed chromatograms were dried and the spots were identified by spraying with (O.IN) Ninhydrin in acetone. The Rf values were calculated and compared with the Rf values of the standard amino acids. The presence of amino acids in different life stages of honeybee and honey were analyzed and compared.

Roles of DNA Methylation in Color Alternation of Eastern Honey Bees (Apis cerana) Induced by the Royal Jelly of Western Honey Bees (Apis mellifera).

Honey bees have a very interesting phenomenon where the larval diets of two different honey bee species are exchanged, resulting in altered phenotypes, namely, a honey bee nutritional crossbreed. This is a classical epigenetic process, but its underlying mechanisms remain unclear. This study aims to investigate the contribution of DNA methylation to the phenotypic alternation of a Apis mellifera-Apis cerana nutritional crossbreed. We used a full nutritional crossbreed technique to rear A. cerana queens by feeding their larvae with A. mellifera royal-jelly-based diets in an incubator. Subsequently, we compared genome-wide methylation sequencing, body color, GC ratio, and the DMRs between the nutritional crossbreed, A. cerana queens (NQs), and control, A. cerana queens (CQs). Our results showed that the NQ's body color shifted to yellow compared to the black control queens. Genome methylation sequencing revealed that NQs had a much higher ratio of mCG than that of CQs. A total of 1020 DMGs were identified, of which 20 DMGs were enriched into key pathways for melanin synthesis, including tryptophan, tyrosine, dopamine, and phenylalanine KEGG pathways. Three key differentially methylated genes [OGDH, ALDH(NAD+) and ALDH7] showed a clear, altered DNA methylation in multiple CpG islands in NQs compared to CQs. Consequently, these findings revealed that DNA methylation participates in A. cerana-A. mellifera nutritional crossbreeding as an important epigenetic modification. This study serves as a model of cross-kingdom epigenetic mechanisms in insect body color induced by environmental factors.

Evaluation of Probiotic Bacteria Isolated from Indigenous Honeybee Species of Pakistan

The honey bee gut is inhabited by many useful bacteria such as Lactic Acid Bacteria (LAB). These LAB possess active probiotic properties that are beneficial to other animals and even humans. The LAB is declared as generally recognized as safe (GRAS). The LAB is non-pathogenic and produces different metabolites having antimicrobial potential. In the current study LAB species isolated from four honey bee species (Apis melifera, Apis dorsata, Apis cerana, and Apis florae) prevalent in Pakistan were identified and investigated for their probiotic potential. The strains were identified using morphological, biochemical, and molecular techniques as genus Lactobacillus and Lactococcus. Current results confirmed that the honey bee gut has a rich source of lactic acid bacteria. Isolated strains were further evaluated for their ability to resist physiological stresses encountered in the human gastrointestinal tract. Safety testing of the isolates such as hemolytic assay revealed that these isolates have γ-hemolytic activity and were adjudged to be safe. Hence the present study concluded that honey bee gut is thesource of potential probiotic bacteria and can be used in pharmaceuticals, fermented foods, and nutraceuticals and may be used as a natural food preservative

The potential of honey from Apis cerana in preventing chronic inflammation by downregulating the NF-?B pathway

Chronic inflammation is an inflammatory condition that persists over a long period of time causing tissue damage and contributing to the development of chronic diseases such as arthritis, heart disease, or certain autoimmune conditions. The protein that plays a role in this regulation is the up-regulation of NF-?B, this is the aim of this research, namely to determine the potential of the compounds contained in A.cerana honey to bind with NF-?B. The research stages carried out were preparing the NF-?B protein structure database, protein preparation using the Yasara application, structure preparation and optimization using the Chemaxon application, as well as validating the molecular docking method and docking of compounds from A.cerana honey on the NF-?B protein using the PLANT application. The research results show that Ellagic acid, Taxifolin, Quercetin and Chrysin have affinity and form hydrogen bonds with the NF-?B protein. The binding energy between Ellagic acid, Taxifolin, Quercetin and Chrysin with the NF-?B protein respectively is 78,822; -64.89; -64,872 and -64,935. Ellagic acid, Taxifolin, Quercetin and Chrysin have potential anti-inflammatory activity through binding to the NF-?B protein, thereby preventing the inflammatory process.

Dynamics and regulatory role of circRNAs in Asian honey bee larvae following fungal infection

Non-coding RNA (ncRNA) plays a vital part in the regulation of immune responses, growth, and development in plants and animals. Here, the identification, characteristic analysis, and molecular verification of circRNAs in Apis cerana cerana worker larval guts were conducted, followed by in-depth investigation of the expression pattern of larval circRNAs during Ascosphaera apis infection and exploration of the potential regulatory part of differentially expressed circRNAs (DEcircRNAs) in host immune responses. A total of 3178 circRNAs in the larval guts of A. c. cerana were identified, with a length distribution ranging from 15 to 96,007 nt. Additionally, 155, 95, and 86 DEcircRNAs were identified in the in the 4-, 5-, and 6-day-old larval guts following A. apis infection. These DEcircRNAs were predicted to target 29, 25, and 18 parental genes relevant to 12, 20, and 17 GO terms as well as 144, 114, and 61 KEGG pathways, including 5 cellular and 4 humoral immune pathways. Complex competing endogenous RNA (ceRNA) regulatory networks were detected as being formed among DEcircRNAs, DEmiRNAs, and DEmRNAs. The target DEmRNAs were engaged in 36, 47, and 47 GO terms as well as 331, 332, and 331 pathways, including 6 cellular and 6 humoral immune pathways. Further, 19 DEcircRNAs, 5 DEmiRNAs, and 3 mRNAs were included in the sub-networks relative to 3 antioxidant enzymes. Finally, back-splicing sites within 15 circRNAs and the difference in the 15 DEcircRNAs’ expression between uninoculated and A. apis–inoculated larval guts were confirmed based on molecular methods. These findings not only enrich our understanding of bee host–fungal pathogen interactions but also lay a foundation for illuminating the mechanism underlying the DEcircRNA-mediated immune defense of A. c. cerana larvae against A. apis invasion.Key points• The expression pattern of circRNAs was altered in the A. cerana worker larval guts following A. apis infection.• Back-splicing sites within 15 A. cerana circRNAs were verified using molecular approaches. DEcircRNAs potentially modulated immune responses and antioxidant enzymes in A. apis–challenged host guts.

Whole-Genome Resequencing-Based Qualitative Trait Locus Mapping Correlated yellow with the Mutant Color in Honeybees, Apis cerana cerana.

The honeybee, Apis cerana cerana (Ac), is an important pollinator and has adapted to the local ecological environment with relevant coloration. The cuticle coloration of the brown (br) mutant is brown instead of black in wild-type individuals. Therefore, this study aimed to identify and characterize the gene responsible for the br mutation. Genome resequencing with allele segregation measurement using Euclidean distance followed by Lowess regression analysis revealed that the color locus linked to the mutation was located on chromosome 11. A 2-base deletion on exon 4 was identified in the g7628 (yellow) gene after genome assembly and sequence cloning. In addition, the cuticle color of the abdomen of worker bees changed from black to brown when a defect was induced in the yellow gene using short interfering RNA (siRNA); however, the survival rate did not decrease significantly. These results indicate that the yellow gene participated in the body pigmentation, and its defect was responsible for the br mutation. This study promotes the understanding of the molecular basis of body coloration in honeybees, enriching the molecular mechanisms underlying insect pigmentation.

Japanese honey bees (Apis cerana japonica) have swarmed more often over the last two decades

The impacts of temperature increase are a concern for honey bees, which are major pollinators of crops and wild plants. Swarming is the reproductive behavior of honey bees that increases colony numbers. Honey bee colonies sometimes swarm multiple times, with each swarming termed a “swarming event” and a series of these events called a “swarming cycle.” The number of swarming events per swarming cycle varies widely depending on climatic conditions and subspecies, and the recent temperature increase due to global warming might be affecting the number of swarming events per swarming cycle of native honey bees. We clarified long-term changes in the number of swarming events per swarming cycle of Japanese honey bees (Apis cerana japonica) by collecting beekeepers’ swarming logbooks. The survey showed that between 2000 and 2022, Japanese honey bees swarmed 1 to 8 times per swarming cycle. Generalized linear model analysis indicated that year had a significant positive effect (coefficient, 0.03; 95% CI, 0.01–0.04); that is, the number of swarming events per swarming cycle showed a moderate increase over time. In addition, we found that colonies swarmed more often in a cycle when the swarming process began in early spring, especially in March. Considering the notably strong trend in Japan of warmer temperatures in March, the number of swarming events per swarming cycle may be increasing because reproduction is beginning earlier in the year. Further analyses are needed to verify the causal relationship of temperature increase on the number of swarming events per swarming cycle.