Perturbation of normal behaviors (e.g., nursing and foraging) in honey bee colonies by any external factors would immediately reduce the colony’s capacity for brood rearing, which can eventually lead to collapse of entire colony. To investigate the effects of brood rearing suppression in the biology of honey bee workers (nurse and forager), the gene-set enrichment analysis (GSEA) was performed for the transcriptomes of worker bees with or without their brood rearing being suppressed, from which functional profiles of pathways under influences by each condition were identified. Blocking of normal labor (i.e., nursing or foraging) induced the over-representation of pathways related with reshaping of worker bee physiology, suggesting that transition of labor is physiologically reversible. In addition, brood rearing suppression appeared to result in the reduction of neuronal excitability and aggressiveness in both forager and nurse, which would be necessary to manage the in-hive stress under unfavorable conditions

There are two different types of acetylcholinesterase (AChE1 and AChE2) in the western honeybee as in most of insects. It is suggested that soluble AmAChE1 might be related with a stress response as judged from its elevated expression level in honey bee workers when brood rearing was suppressed. In this study, to ensure the nature of AmAChE1 responding to stress factors, the expression patterns of AmAChE1 following heat shock, brood rearing suppression and chemical treatments (Imidacloprid and fluvalinate) were investigated. Also, several heat shock protein (hsp) genes (hsp10, hsp60, hsp70 and hsp90) known as general stress markers were tested as positive references. Heat shock induced expression of every tested hsp along with AmAChE1. In brood rearing-suppressed worker bees, 7 days old bees showed much higher expression level of AmAChE1 and hsp90 compared to control honey bees. However, treatment of imidacloprid and fluvalinate did not induce any apparent overexpression of these genes. These results confirm that both HSP and AmAChE1 genes generally respond to temperature and brood rearing suppression and further suggest that AmAChE1 can serve as a potential biomarker along with hsps for the detection of stress in honey bee colonies.

Two different types of acetylcholinesterae (AChE1 and AChE2) are present in majority of insects, including the Western honey bee. Out of the two honey bee AChEs (AmAChEs), the soluble AmAChE1 with little catalytic activity is widely distributed in both neuronal and non-neuronal tissues, including fat body. In this study, to identify stresss factors that can induce AmAChE expression, we tested various conditions that honey bees can encounter in natural setting, including heat shock, cold shock, bacterial challenge (Escherichia coli and Staphylococcus aureus) and Varroa mite infestations, and evaluated their effects on AmAChE expression. Among the stress factors tested, only heat shock condition induced AmAChE expression in a dose dependet manner. This finding suggests that one function of AmAChE1 is related with thermoregulations, especially against heat shock stress in honey bees.

Honey bee swarming is a natural phenomenon that occurs when the colony encounters changes in the in-hive (i.e. population size and queen condition) and environmental conditions. To better understand the molecular basis of swarming, we conducted the transcriptomic profiles of worker bees between before swarming [pre-swarming colony (PSC)] and after swarming [swarming group (SG) and remaining group (RG)]. Based on the gene set enrichment analysis (GSEA), we predicted the biological processes associated with swarming. In addition, we analyzed the composition of cuticular hydrocarbons (CHCs) by gas chromatography-mass spectrometry and compared their profiles between different bee groups. GSEA results showed that there were a little differences between PSC and RG while many of the pathways related with metabolism and protein processing were down regulated in SG relative to PSC and RG. CHCs profiling revealed a similar CHCs composition between PSC and RG but some differences in CHCs composition (i.e. heneicosane, octacosane, octacosanol) were detected between SG and RG. These differences in gene pathway and CHC composition were discussed with respect to physiological changes and social communication.

Colony collapse disorder (CCD), a phenomenon of honeybees disappearance, has been reported since 2006. Chronic exposure to neonicotinoid insecticides, particularly imidacloprid, has been suggested to impair forager’s ability for foraging and be a main cause of CCD. Recently, it has been reported that imidacloprid induces insulin resistance in animal cell line by blocking glucose uptake. Similarly to human insulin, insulin-like peptide (ILP) of insects is involved in maintaining blood glucose contents in hemolymph by regulating the concentration of trehalose and glycogen. Therefore, we have hypothesized that sublethal concentration of neonicotinoid may affect the metabolic pathway of honey bees as well. We investigated the transcription levels of the genes involved in the insulin/insulin-like signaling (IIS) pathway, such as AmILP and AmInR, following an acute or a chronic dietary exposure of sublethal concentrations of imidacloprid to foragers. In both experiments, honeybees showed increased expression levels of ILP and InR in a dose-dependent manner. Our results suggest that sublethal dose of imidacloprid likely upregulates IIS pathway, thereby rendering honey bees to become resistant to insulin.

Mortality of honeybees(Apis cerana) is a serious problem that beekeepers have to face periodically in Korea. The presence of RNA viruses, in addition to other pathogens may be one of its possible causes. In this work, we were detected Black queen cell virus (BQCV), Kashmir bee virus (KBV), Korean Sacbrood virus (KSBV), Ascosphaera apis, and Nosema in samples of Apis cerana. Honey bee viruses was detected KSBV(58.5 %), KBV(6.5 %), BQCV(70 %) in 2015 by RT(Revers transcriptase)-PCR. Sacbrood virus (SBV) is an important disease of A. cerana. A. apis can cause chock brood disease to honey bee. It was detected 10.3 % of A. cerana colonies by PCR. Also, Nosema cerana was detected 50.5%. Conclusively, investigated disease of the A. cerana, and confirmed virus that lead to bee disease, this is thought by valuable thing as data for development of beekeeping industry such as Colony Collapse cause searching examination.

Honey bee swarming is a naturally occurring phenomenon under the conditions of population increase, climate change and pollen deficit. However, unexpected swarming usually results in loss of bee colony, it poses a considerable trouble in bee keeping. In an attempt to search for molecular markers that can predict the swarming behavior, transcriptional profiling was conducted and compared between the heads of swarming group and the remaining group in the same honey bee colonies. A total of 25,551 transcripts were initially identified and 1,144 differentially expressed genes between the two groups were sorted by FC2 (fold change) cut-off value. Several transcripts, including 6 apidermin (structurally novel cuticular protein)-related, 16 cuticular and 3 odorant binding proteins, showed lower expression levels in the swarming group compared with the remaining group (FC range of –2.17 to –667.48, -2.04 to –54.34 and -2.08 to –21.34 respectively). Pathway analyses are currently in progress to understand the physiological and metabolic differences between swarming and remaining groups of honey bees.

Acetylcholinesterase 1 (AmAChE1) has low catalytic activity and is abundantly expressed in both neuronal and non-neuronal tissues. In previous experiments, we observed that AmAChE1 is rarely expressed in summer while highly expressed in winter. Through additional experiments, the expression of AmAChE1 was suggested to be associated with brood rearing status. Under the assumption that abnormal suppression of brood rearing activity may result in stressful condition in honey bee social community, it was further suggested that AmAChE1 is likely involved in stress management particularly during winter. We hypothesized that the increased docility usually observed in overwintering bees is likely an outcome of stress management in colony, which is mediated by AmAChE1 expression. To verify this, worker bees expressing abundant AmAChE1 were collected in early winter and injected with Amace1 dsRNA to knockdown Amace1. Then, the behavioral activity of the bees was investigated using the EthoVison video tracking system. Honey bees injected with Amace1 dsRNA showed significantly increased motility, which was strongly correlated with the suppressed expression level of AmAChE1 in the abdomen. No apparent reduced expression of AmAChE1 in the head was observed perhaps due to the limited efficacy of RNA interference in the blood-brain-barrier. Our finding suggests that behavioral activity can be regulated, at least, by AmAChE1 expression level in non-neuronal tissue (i.e., fatbody) perhaps via metabolic alteration.

Tropilaelaps mercedesae is an ectoparasite of immature honey bees belonging to the genus Tropilaelaps (Acari: Laelapidae). T. mercedesae has become a major threat to the Western honey bee Apis mellifera in Asia, including Korea, and is expanding its geographical range to northern regions due to global warming. To establish gene resources of T. mercedesae, the whole transcriptome was analyzed by RNA sequencing. An mRNA-focused library was generated from total RNA extracted from the mixed stages using the TruSeq RNA Library Preparation kit and sequenced using the HiSeq 2000 platform. A total of 6.0 Gb reads were obtained with 85% Q30 value. Trimmed sequence data were de novo assembled using the CLC Assembly Cell v 4.2. A total of 64,868 non-duplicate contigs were finally obtained and annotated by the Blast2GO using the NCBI nr database. The most abundant species in the resulting 14,336 Blast hits (22.1%) was Metaseiulus occidentalis, a predatory mite, followed by Ixodes scapularis and Tribolium castaneum, suggesting that the T. mercedesae transcriptome matches well with closely related other arthropod species, including mites and ticks. In order to provide basic information for efficient control and monitoring of potential resistance in T. mercedesae, acaricide target genes were annotated and characterized. One voltage-sensitive sodium channel gene encoding the molecular target of fluvalinate, a pyrethroid acaricide most widely used for the control of T. mercedesae, was identified and its molecular properties were investigated. In addition, other acaricide target genes, including acetylcholinesterase and glutamate (or GABA)-gated chloride channel, were identified and characterized.

The acetylcholinesterase 1 (AmAChE1) of the honey bee is known to be abundantly expressed both in the central and peripheral nervous systems. AmAChE1 exists mostly in the soluble form with little catalytic activity and has non-neuronal functions. Our preliminary observation showed that AmAChE1 expression fluctuated between the forages and nurses. A more systematic expression profiling of AmAChE1 over a year cycle on a monthly basis revealed that AmAChE1 was predominantly expressed during the winter months with being moderately expressed during the rainy summer time. However, no significant difference in AmAChE1 expression was noticed between the nurse and forager workers. Interestingly, AmAChE1 expression was inhibited when bees were allowed for brooding by placing overwintering bee hives in strawberry green houses with the supplement of pollen diets whereas it was resumed when the bee hives were removed from the green houses, thereby suppressed brooding. To confirm whether brooding status is a main determining factor for the suppression of AmAChE1 expression, active bee hives were placed in a screen tent, thereby hindering foraging, until brooding was completely suppressed, and then allowed to restore brooding by removing the screen. The AmAChE1 expression in the head was up-regulated when brooding was suppressed whereas its expression was down-regulated when brooding was resumed. These finding demonstrates that AmAChE1 expression in the central nervous system (i.e., head) is related with brooding status of honey bee. To understand the connection between the AmAChE1 expression and other pathways related with brooding, currently in progress are the analyses of head transcriptomes of honey bee workers with or without their brooding suppressed.

Varroa destructor and Tropilaelaps mercedesae mites are ectoparasitic to honey bee having similar life cycle and damage symptoms. Both invade into the last instar larval cell and reproduce during capped brood period of honey bee development. Female adult mites escape from the comb cell on the back of the emerging adult bee (phoretic period) and invade another cell for reproduction. Objective of this study was to study the effect of competitive interaction on each parasitic mite species population. We assessed population monitoring of host and parasitic mites. Honey bee population was monitored by approximating sealed brood and adult bees based on the coverage of the combs. Parasitic mites were monitored by detection technique like sugar shake, stick board, and sealed brood. This monitoring continued at weekly interval during 2008, 2014, and 2015. Additionally Invasion distribution of each species was checked. We calculated carrying capacity, population growth rate, and competition parameter from population monitoring data. Single parasitic mite, Varroa occurred and infestation increased continuously throughout the year in 2008. Co-occurrence of Varroa and Tropilaelaps in honey bee colonies was studied in 2014 and 2015. Carrying capacity was higher in single parasite infesting honeybee than parasites in co-occurrence. While using sugar method, carrying capacity of Varroa alone was found higher than in its co-occurrence with Tropilaelaps. Population growth rate of Varroa when tested alone was higher than its co-occurrence with Tropilaelaps in sugar method. Population growth rate of Varroa and Tropilaepas was higher in sticky method than sugar methods when they were tested in co-occurrence. Population growth rate is higher in Tropilaelaps (0.09) than Varroa (0.05) when both are tested in co-occurrence. We calculated competition parameter of Varroa and Tropilaelaps which was 1.9 and 0.53, respectively. Negative effect on regulation of carrying capacity and population growth rate is due to interspecies competition. Varroa population was higher than Tropilaelaps because there was high intraspecies competition among Tropilaelaps. Single Varroa or its co-occurrence with Tropilaelaps both can destroy honeybee colonies.

Sacbrood disease is a viral disease on honey bee larvae Apis cerana. Diseased larvae fail to pupae and to be dead at old larvae and pre-pupae stage. Currently, there is no remedy to control sacbrood disease. In this study we conducted to observe sacbrood disease on Apis cerana colonies from June to September, 2014 at the A. cerana apiary of NAAS, and using biological measure to treat this disease. Our study results were showed that sacbrood disease infected A. cerana colonies in all months of observation. The percentage of infected colonies was from 33.3% up to 100%. Controlling sacbrood disease by requeen measure, the percentage of recovered colonies was 57.1 % while of this by cage queen measure was only 28.6 %.

In this study we conducted to rear worker honey bee (Apis cerana) from larvae to adult stage in the laboratory by using plastic well plates. Our study results were showed that honey bee larvae Apis cerana could be reared in the laboratory. The adult worker bee started to emerge on day 17 from grafting. The emergence of worker bee peak on day 18 and declined thereafter. The average survival rate from larvae to pre-pupae stage was 74.6%. The average survival rates from pre-pupae to adult stage and from larvae to adult stage were 40.7 % and 30.4 % respectively.

Asian is rich in honey bee species and genetic diversity. Among the difference native honey bee species, Apis cerana is very diversity of subspecies and distribution as well. Until now, nine A. cerana subspecies have been named. However, natural diversity of this species is being declined by threats such as pest, disease, deforestation, pesticide positioning and climate change. Therefore, the understanding of morphological characteristics of A. cerana is viral for maintaining biological diversity. In this paper we give an overview of method that are used for distinguish honey bee A. cerana subspecies and ecotype that can contribute to recognize genetic origin of colonies for conservation and breeding purpose. Base on morphmetric method currently in use, we outline strategies for sampling and measuring morphological characteristics on A. cerana.

RDA(Rural Development Administration of Agriculture) and YIRI(Yecheon-gun Industrial Insect Research Institute) was development of 3 strains crossbred honey bee(Apis mellifera) for increasing honey production(HP). The overall goal of this research is to improve the honey production of queen honey bees. This will enhance the economic value of the nation’s honey bees for honey production, and hazard resistance. Our main objective of this research is to test of honey bees(A. mellifera) that have increased as well as being good honey producers and resistance of disease in jeon-nam province. The new honey bee(A. mellifera) stock were identified ability of increasing honey production by comparing with rearing practice colony. The new honey bee(A. mellifera) stock can produce more than 30~50% honey(HP; 12.31 kg) comparing with rearing practice colonies(control 1; 8.17 kg, and control 2; 9.53 kg). Furthermore, we are calculated the number of worker bee per colony. Population of worker bee in new honey bee(A. mellifera) stock are 2,849 (colony 1), 8,860 (colony 2) and 10,451 (colony 3), it was more then 1.2~3.7 fold comparing with controls.

The effects of a newly developed flower thinning formulation (FTF) on the vitality of the honey bee Apis mellifera were examined by measuring the activities of various digestive enzymes in adult worker bees. First, direct spraying of the FTF solution did not cause any behavioral changes or lethal effects for the honey bees based on 24 h observation. Second, oral ingestion of a sugar solution containing the FTF did not produce any significant change in the activities of amylase, proteinases, lipase, or acetylcholine esterase (AChE) in the worker bees 6 h or 24 h after treatment. Meanwhile, a commercial formulation containing sulfur compounds showed slightly reduced activities for several digestive enzymes and AChE, although no behavioral disturbance. Thus, the results of the present study suggest that the FTF is not toxic for honey bees, in terms of contact and ingestion. Therefore, this newly developed FTF can be used for flower thinning without any detrimental effects on pollinating insects.

Sacbrood virus (SBV) is one of the most destructive honey bee virus. The virus causes failure to pupate and kills honey bee larvae. The infacted larvae`s color is change to brown. At the end, honey bee colony is destructed. Recently Korean Scabrood virus(KSBV) caused a great loss of Korean honey bee(Apis cerena) colonies for short period. Therefore, We need a highly rapid diagnosis method for rapid detection of KSBV. In this study, We need amicro-scale chip-based real-time PCR system (GeneChecker®). This system was developed for rapid, specific PCR based diagnosis. This system has uncommonly fast heating and cooling system. So We was able to detecting of KSBV in Apis cerena in short time. This system needs small reaction volume(total 10ul). This volume include SsoFast™ Evagreen Supermix and serially diluted cDNA templates showed a high sensitivity of 101copies.That machine can setting each PCR stage time. A specific detection primer set (KSBV-123-F/R) was used to amplify a unique 123bp DNA fragment. This PCR assays using serially diluted cDNA templates showed a high sensitivity of 101 copies. When applied to KSBV-positve samples, the result showed high specifity. The minimum diagnosis time was 9m 47s (30cycle). The amplied positive samples appear red fluorescent color. This novel detection method could be used a PCR-based diagnositic tool (GeneChecker®). The results showed high sensitivity and specifity in short time. And this diagnosis method is expected to be applied to rapidly detect various pathogens.

Black queen cell virus (BQCV), one of the most prevalent viruse, causes the death of queen larvae and pupae. The RNA-dependent RNA polymerases (RdRPs) are central components in the life cycle of RNA viruses that catalyzes the replication of RNA from an RNA template without DNA stage. Inhibition of RdRP gene is importantly significant for application of monoclonal antibody generation as a diagnosis tool for identifying BQCV infection in honey bee..In this study, the presence of BQCV in honey bee samples was confirmed by PCR using BQCV F/R primer set to multiply of 700 bp DNA fragment. For ampification of BQCV Rdrp gene, a primer set attached BamHI/SalI restriction site was designed based on the best homogenization between BQCV RdRP sequences in NCBI, a PCR product containing BQCV RdRP gene with 1576 bp in length was amplified. Furthermore, BQCV RdRP gene will be cloned into pBlueXcm vector for future researches.

We sequenced 17,329 bp of mitochondrial genome (mitogenome) of the black dwarf honey bee, Apis andreniformis (Hymenoptera: Apidae), that lacks ~200 bp of the A+T-rich region for the completion of the genomic sequence. The gene arrangement of A. andreniformis mitogenome is identical to that of A. cerana. However, the genome contains 5 additional tRNALeu(CUN) located 4 copies between tRNAMet and tRNAGln, and 1 copy between tRNAGln and tRNAAla, along with the typical sets of genes (13 protein-coding genes, 22 tRNAs, and 2 rRNAs) including regular tRNALeu(CUN) and the A+T-rich region (at least 923 bp). Only 1 copy of tRNALeu(CUN) differed by 1 bp from other 4 copies of tRNALeu(CUN). Each additional tRNALeu(CUN) is followed by nearly identical 68-bp long repeat sequence (95.6% identity). All 13 protein coding genes have typical start codons found in insect mitochondrial PCGs (2 ATA, 9 ATT, and 2 ATG).

With over 7 billion people on the planet, agriculture faces immense pressure to meet global demands for food. One third of consumed food relies on insect pollination with by far, the predominate pollinator being the honey bee, Apis mellifera. Although future challenges facing agriculture will come from multiple domains, one of the immediate challenges is honey bee decline. Stress associated with transportation, pesticide exposure nutritional limitations, various diseases and pests have all been recognized as potential factors in honey bee decline. With the prospect of future global changes in climate, honey bees will also face changes in forage availability and overwintering potential. At the level of the individual colony, research has shown that honey bee health is directly correlated to genetic diversity. Increased colony diversity is associated with lower disease intensity, increased disease resistance, greater workforce productivity and thermoregulation stability. Genetic diversity at the population level serves as the raw material for selective breeding in agriculturally important plants and animals, including the honey bee. Honey bees are not native to Korea, however, and importation and founder events associated with the establishment of honey bees represent a series of genetic bottlenecks that limits the diversity of introduced honey bee populations. Fortunately, Apis mellifera consists of around 28 recognized subspecies within its native range, each with specific adaptations to climatic selective pressures endemic to its own location. Climate change is expected to be bring a high degree of uncertainty in the future to climate expression in various locations. Fortunately, the honey bee has a wide breadth of diversity contained within various subspecies and careful importation and evaluation of specific stocks may be highly useful as we enter climate uncertainty in the future. With the recognition that agro-ecosystems are highly interconnected and multifaceted, one of the greatest challenges facing agriculture is preserving and improving honey bee health.