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This article discusses a new defensive behavior called "wing-slapping" exhibited by Japanese honey bees against invading ants. The study observed Japanese honey bee colonies being invaded by Japanese pavement ants and recorded the bees' defensive behaviors using a high-speed camera. The results showed that the bees slap the ants with their wings through direct contact. The study also found that the effectiveness of wing-slapping varied among different ant species. The article suggests that wing-slapping may have evolved as a low-energy defense against ant incursion, but further research is needed to understand the evolution of defensive behaviors in honey bees. The study highlights the potential risks posed by invasive ants to honey bee populations and calls for more attention to the defensive behaviors of bees against ants. [Extracted from the article]

Several studies have reported fragmentary evidence that climate change is altering the phenology and behavior of honey bees. We compiled records of off-season swarming of the Japanese honey bee (Apis cerana japonica) between autumn and winter to improve our understanding of the impact of climate change on the subspecies’ swarming phenology. Based on a survey of 311 beekeepers, eleven off-season swarming records were collected, with ten of them are from 2020 onward. The beekeepers who reported off-season swarming records had eight to twenty years of beekeeping experience, and they declared that they were witnessing off-season swarming for the first time, suggesting a recent increase. One possible factor contributing to the increase in off-season swarming is the temperature rise, as average autumn and winter temperatures in Japan have been increasing.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Apis cerana is widely adapted to vast areas that stretch from Russia to Sundaland (Indonesia) through Palawan in the Philippines. By using mitochondrial DNA of the cytochrome oxidase subunit 1 (COX1) gene, the cytochrome oxidase subunit 2 (COX2) gene, and the COX1-COX2 intergenic regions (IGS), as well as the nuclear major royal jelly protein 2 (mrjp2) gene, we aimed to explore the number of new haplotypes of A. cerana in Indonesia and the genetic variations of A. cerana in Indonesia, particularly between Sundaland A. cerana with the Moluccas and West Papua. These studies found three main findings; the first is the 11 A. cerana new haplotypes in total for the COX1, COX2, IGS, and mrjp2 gene sequences. The maximum likelihood phylogenetic tree agreed with the haplotype cluster. Apis cerana in West Papua and the Moluccas clustered in the same clade with the Sundaland A. cerana from Java, Banten, and Belitung, that suggests common origin of these bees. The third finding is genetic distances of COX1 gene between A. cerana in Java and those from West, East, South Kalimantan, Sabah, and Sarawak were approximately 4% which is similar to genetic distance between Indonesian A. cerana (A. cerana javana) and East Asia (A. cerana cerana and A. cerana japonica). The genetic distance also proved the separation of the Indonesian A. cerana lineage with the Indo-Malayan lineage (Sabah, Sarawak, and Kalimantan) from previous studies. This result gives rise to the possibility of the emerging new subspecies of A. cerana in Kalimantan. [ABSTRACT FROM AUTHOR]

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., (© 2024. The Author(s).)

The biology of Apis cerana F., the Asian honey bee, is far less known than that of its sister species Apis mellifera L. The arrival of A. cerana in North Queensland has prompted the need to better understand the ecology and biology of this species in an invasive context. We evaluated the colour, shape and spontaneous landing preferences of free flying A. cerana using artificial shape of equal surface. A. cerana displayed a stable and marked preference toward yellow regardless of the season (wet or dry). However, for other colours, different preference patterns were observed depending on the season suggesting a learned preference. Bees had a strong preference for star shaped U.V. nectar guides regardless of the season. Conversely to A. mellifera, A. cerana appeared to minimise the perimeter surface ratio in its landing choice choosing circular over jagged surfaces. However, when tested using polygons and circle of same area and thus very similar perimeters the choice pattern showed no minimisation of perimeter/surface ratio. Surprisingly, bees had a clear preference towards odd number apex shapes and 3/4 of landings occurring on the heptagon, despite the rarity of such 7-lobed flowers in nature. [ABSTRACT FROM AUTHOR]

In Japanese honey bees Apis cerana japonica, infestations of the tracheal mite Acarapis woodi have spread rapidly over the mainland of Japan, causing damage and the collapse of colonies. Meanwhile, infestations by mites in Apis mellifera have hardly been observed in Japan. In this study, we assessed and compared the susceptibility of the two species, A. cerana and A. mellifera, using an inoculation assay. We found that migrating female mites entered the tracheae of more newly emerged bees in both species but more frequently in A. cerana than in A. mellifera. Hence, the higher susceptibility in A. cerana is proposed as a factor causing the explosive epidemic of tracheal mites in only A. cerana in Japan. Moreover, we compared grooming behaviors between the two bee species using an observation assay as a preliminary experiment, although the bees were not exposed to the presence of tracheal mites. From these observations, the frequency of autogrooming (self-grooming) on the thorax in A. cerana was lower than that in A. mellifera. The difference in susceptibility to the mite between these two species may be due to the difference in grooming behavior frequency. [ABSTRACT FROM AUTHOR]

Background: Varroa mites are widely considered the biggest honey bee health problem worldwide. Until recently, Varroa jacobsoni has been found to live and reproduce only in Asian honey bee (Apis cerana) colonies, while V. destructor successfully reproduces in both A. cerana and A. mellifera colonies. However, we have identified an island population of V. jacobsoni that is highly destructive to A. mellifera, the primary species used for pollination and honey production. The ability of these populations of mites to cross the host species boundary potentially represents an enormous threat to apiculture, and is presumably due to genetic variation that exists among populations of V. jacobsoni that influences gene expression and reproductive status. In this work, we investigate differences in gene expression between populations of V. jacobsoni reproducing on A. cerana and those either reproducing or not capable of reproducing on A. mellifera, in order to gain insight into differences that allow V. jacobsoni to overcome its normal species tropism. Results: We sequenced and assembled a de novo transcriptome of V. jacobsoni. We also performed a differential gene expression analysis contrasting biological replicates of V. jacobsoni populations that differ in their ability to reproduce on A. mellifera. Using the edgeR, EBSeq and DESeq R packages for differential gene expression analysis, we found 287 differentially expressed genes (FDR ≤ 0.05), of which 91% were up regulated in mites reproducing on A. mellifera. In addition, mites found reproducing on A. mellifera showed substantially more variation in expression among replicates. We searched for orthologous genes in public databases and were able to associate 100 of these 287 differentially expressed genes with a functional description. Conclusions: There is differential gene expression between the two mite groups, with more variation in gene expression among mites that were able to reproduce on A. mellifera. A small set of genes showed reduced expression in mites on the A. mellifera host, including putative transcription factors and digestive tract developmental genes. The vast majority of differentially expressed genes were up-regulated in this host. This gene set showed enrichment for genes associated with mitochondrial respiratory function and apoptosis, suggesting that mites on this host may be experiencing higher stress, and may be less optimally adapted to parasitize it. Some genes involved in reproduction and oogenesis were also overexpressed, which should be further studied in regards to this host shift. [ABSTRACT FROM AUTHOR]

The first record of tracheal mites, Acarapis woodi, in Japan was made in 2010. These mites have since caused serious damage to the colonies of Japanese honey bees, Apis cerana japonica. In the present study, to control the mites on Japanese honey bees with l-menthol, an agent used for European honey bees, Apis mellifera, we investigated (1) the seasonality of menthol efficacy, (2) the overwintering mortality of menthol-treated colonies, and (3) the menthol residue in honey under field conditions in cooperation with private beekeepers of Japanese honey bees. Seasonal menthol efficacy was tested by applying 30 g of l-menthol for 1 month in different seasons. Mite prevalence was measured by dissecting the honey bee thorax. Overwintering mortality was monitored during winter after checking the mite prevalence in autumn, and was compared with that of untreated colonies reported in our previous study. The residual level of menthol in honey was measured by GC-MS. The results showed that the menthol-treated colonies had a smaller rate of increase in mite prevalence than the untreated colonies. The effects of menthol were highest in March and April. The winter mortality was depressed by menthol treatment. Honey samples extracted from the menthol-treated colonies included 0.4 ppm of menthol residue on average. Our findings suggest that menthol treatment is effective for controlling the tracheal mites on Japanese honey bees. [ABSTRACT FROM AUTHOR]

Background: Long non-coding RNAs (lncRNAs) are a class of RNAs that do not encode proteins. Recently, lncRNAs have gained special attention for their roles in various biological process and diseases. Results: In an attempt to identify long intergenic non-coding RNAs (lincRNAs) and their possible involvement in honey bee development and diseases, we analyzed RNA-seq datasets generated from Asian honey bee (Apis cerana) and western honey bee (Apis mellifera). We identified 2470 lincRNAs with an average length of 1011 bp from A. cerana and 1514 lincRNAs with an average length of 790 bp in A. mellifera. Comparative analysis revealed that 5 % of the total lincRNAs derived from both species are unique in each species. Our comparative digital gene expression analysis revealed a high degree of tissue-specific expression among the seven major tissues of honey bee, different from mRNA expression patterns. A total of 863 (57 %) and 464 (18 %) lincRNAs showed tissue-dependent expression in A. mellifera and A. cerana, respectively, most preferentially in ovary and fat body tissues. Importantly, we identified 11 lincRNAs that are specifically regulated upon viral infection in honey bees, and 10 of them appear to play roles during infection with various viruses. Conclusions: This study provides the first comprehensive set of lincRNAs for honey bees and opens the door to discover lincRNAs associated with biological and hormone signaling pathways as well as various diseases of honey bee. [ABSTRACT FROM AUTHOR]

Background: Long non-coding RNAs (lncRNAs) are a class of RNAs that do not encode proteins. Recently, lncRNAs have gained special attention for their roles in various biological process and diseases. Results: In an attempt to identify long intergenic non-coding RNAs (lincRNAs) and their possible involvement in honey bee development and diseases, we analyzed RNA-seq datasets generated from Asian honey bee (Apis cerana) and western honey bee (Apis mellifera). We identified 2470 lincRNAs with an average length of 1011 bp from A. cerana and 1514 lincRNAs with an average length of 790 bp in A. mellifera. Comparative analysis revealed that 5 % of the total lincRNAs derived from both species are unique in each species. Our comparative digital gene expression analysis revealed a high degree of tissue-specific expression among the seven major tissues of honey bee, different from mRNA expression patterns. A total of 863 (57 %) and 464 (18 %) lincRNAs showed tissue-dependent expression in A. mellifera and A. cerana, respectively, most preferentially in ovary and fat body tissues. Importantly, we identified 11 lincRNAs that are specifically regulated upon viral infection in honey bees, and 10 of them appear to play roles during infection with various viruses. Conclusions: This study provides the first comprehensive set of lincRNAs for honey bees and opens the door to discover lincRNAs associated with biological and hormone signaling pathways as well as various diseases of honey bee. [ABSTRACT FROM AUTHOR]

Background: The honey bee is an important model system for increasing understanding of molecular and neural mechanisms underlying social behaviors relevant to the agricultural industry and basic science. The western honey bee, Apis mellifera, has served as a model species, and its genome sequence has been published. In contrast, the genome of the Asian honey bee, Apis cerana, has not yet been sequenced. A. cerana has been raised in Asian countries for thousands of years and has brought considerable economic benefits to the apicultural industry. A cerana has divergent biological traits compared to A. mellifera and it has played a key role in maintaining biodiversity in eastern and southern Asia. Here we report the first whole genome sequence of A. cerana. Results: Using de novo assembly methods, we produced a 238 Mbp draft of the A. cerana genome and generated 10,651 genes. A. cerana-specific genes were analyzed to better understand the novel characteristics of this honey bee species. Seventy-two percent of the A. cerana-specific genes had more than one GO term, and 1,696 enzymes were categorized into 125 pathways. Genes involved in chemoreception and immunity were carefully identified and compared to those from other sequenced insect models. These included 10 gustatory receptors, 119 odorant receptors, 10 ionotropic receptors, and 160 immune-related genes. Conclusions: This first report of the whole genome sequence of A. cerana provides resources for comparative sociogenomics, especially in the field of social insect communication. These important tools will contribute to a better understanding of the complex behaviors and natural biology of the Asian honey bee and to anticipate its future evolutionary trajectory. [ABSTRACT FROM AUTHOR]

Background: The honey bee is an important model system for increasing understanding of molecular and neural mechanisms underlying social behaviors relevant to the agricultural industry and basic science. The western honey bee, Apis mellifera, has served as a model species, and its genome sequence has been published. In contrast, the genome of the Asian honey bee, Apis cerana, has not yet been sequenced. A. cerana has been raised in Asian countries for thousands of years and has brought considerable economic benefits to the apicultural industry. A cerana has divergent biological traits compared to A. mellifera and it has played a key role in maintaining biodiversity in eastern and southern Asia. Here we report the first whole genome sequence of A. cerana. Results: Using de novo assembly methods, we produced a 238 Mbp draft of the A. cerana genome and generated 10,651 genes. A.cerana-specific genes were analyzed to better understand the novel characteristics of this honey bee species. Seventy-two percent of the A. cerana-specific genes had more than one GO term, and 1,696 enzymes were categorized into 125 pathways. Genes involved in chemoreception and immunity were carefully identified and compared to those from other sequenced insect models. These included 10 gustatory receptors, 119 odorant receptors, 10 ionotropic receptors, and 160 immune-related genes. Conclusions: This first report of the whole genome sequence of A. cerana provides resources for comparative sociogenomics, especially in the field of social insect communication. These important tools will contribute to a better understanding of the complex behaviors and natural biology of the Asian honey bee and to anticipate its future evolutionary trajectory. [ABSTRACT FROM AUTHOR]

Honey bees and wild bees provide critical pollination services to agricultural ecosystems; however, the relative contributions of different bee taxa are not well understood. The natural habitats surrounding farmland support food and nesting resources for wild bees and therefore play an important role in the maintenance of crop pollination. In this study, we selected Cucurbita pepo L. (squash) as a model crop to investigate the relative importance of honey bees and bumblebees in pollinating the crop. Thirteen fields, which were surrounded by a gradient of natural habitat, were investigated on the Yunnan-Guizhou Plateau in China. We measured the visit densities of honey bees and bumblebees, the number of pollen grains deposited in a single visit by the two bee taxa, as well as the overall pollen grains deposited on stigmas during a flowering day, and then used Bayesian inference to decouple the pollen grains deposited by either the honey bees or the bumblebees. Compared with honey bees, bumblebees deposited a higher number of pollen grains on stigmas in a single visit, but had a lower visit density than honey bees. Meanwhile, the bumblebee visit density increased along the proportion of natural habitat, while the honey bee visit density was not affected by the surrounding natural habitat. Data simulations using Bayesian inference showed that on a flowering day, the number of pollen grains deposited by bumblebees increased with the proportion of natural habitat in the surrounding landscape, but the number of pollen grains deposited by honey bees did not. Moreover, the total numbers of pollen grains deposited by honey bees or bumblebees alone were all below 2000 (the critical level to satisfy the pollination requirement of this crop). Pollen calculations demonstrated that the number of pollen grains deposited by the two bee taxa was greater than 2000 in fields surrounded by more than 13% natural habitat (grasslands and forests). The results revealed that bumblebees ensured C. pepo pollination in combination with honey bees in the highland agricultural ecosystems. [ABSTRACT FROM AUTHOR]