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.

In the present study, the 17,694-bp long complete mitochondrial genome (mitogenome) of the dwarf honey bee, Apis florea (Hymenoptera: Apidae), is described with an emphasis on the noteworthy triplicated tRNAser(AGN) region and an extraordinary long A+T-rich region with repeat regions. The gene arrangement of A. florea mitogenome is identical to that of A. mellifera, but has triplicated tRNASer(AGN), each of which contains the precedent 44 bp-long and following another 64 bp-long repeats plus one complete first repeat abutting to tRNAMet. A total of 1,610-bp long two repeat regions in 1,987 bp-long A+T-rich region is composed of nearly identical 141 ~ 219-bp long five tandem repeats and 50 ~ 52-bp long 12 tandem repeats that are encompassed by three non-repeat sequences. One of the common interpretations for such repeat sequence is slipped-strand mispairing and unequal crossing-over events during DNA replication.

Worldwide studies on Apis cerana variation for biogeography and genetic diversity depended largely on a 86~93 bp-long mitochondrial non-coding region (internal spacer region) located between tRNALeu and COII (named as NC2), possibly due to higher variability among available markers. In order to incorporate the A. cerana occurring in South Korea into world extensive data, we also sequenced the NC2 from 118 A. cerana samples collected over nine Korean localities and 66 A. cerana samples over seven Asian localities, such as China, Vietnam, and Thailand. These data were combined with preexisting world data to scrutinize genetic relationships of A. cerana in South Korea to outside distributional range. Sequencing of 184 samples provided a total of ten haplotypes: five from Korea, six from China, one from Vietnam, and two from Thailand. Among them eight were new, whereas two were previously reported ones. Phylogenetic analysis of A. cerana NC2 haplotypes so far found including ours has confirmed the presence of four major groups of A. cerana (Asian mainland group, Sundaland group, Palawan group, and Luzon-Mindahnao group) and all haplotypes found in this study also were included in the Asian mainland group. In order to find further variable regions that can be used as sequence-based marker several mitochondrial non-coding regions and nuclear intron regions are in the middle of testing.

Nosema disease caused by Nosema apis which belongs to fungi is a major cause of honey production loss and is worldwide in distribution. N. apis infects the epithelial cells of the digestive system of adult honeybees. Nosema causes significant losses in population size of honeybee. There are about 25 thousand beekeepers caring for approximately 1,697,000 colonies in Korea. Honey production totaled almost 38,505 metric tons in 2010. This production was estimated to be worth about 274 billion Korean won. To determine infection level of nosema disease during the season, adult worker bees were collected from two colonies of experiment apiary from January to October. Our results indicate that the infection level of nosema disease was increased in spring and autumn. Also we initiated a survey of honeybee colonies on the blooming period of Acacia to determine the prevalence of N. apis. Twenty two hives owned by 18 beekeepers were sampled for this study. Bees were collected on 24th and 25th May of 2012. Nosema spore counts ranged from zero to 5,266,000 spores per bee. The average number of nosema spores per bee was calculated to be 1,375,000. Approximately 86% of the apiaries examined were infected with nosema, based on the presence of spores in the flowering period of Acacia. This indicates that nosema is the predominant species affecting honeybee colonies.

We investigated the molecular and kinetic properties of two acetylcholinesterases (AmAChE1 and AmAChE2) from the Western honey bee, Apis mellifera. Western blot analysis revealed that AmAChE2 has most of catalytic activity rather than AmAChE1, further suggesting that AmAChE2 is responsible for synaptic transmission in A. mellifera, in contrast to most other insects. AmAChE2 was predominately expressed in the ganglia and head containing the central nervous system (CNS), while AmAChE1 was abundantly observed not only in the CNS but also in the peripheral nervous system/non-neuronal tissues. Both AmAChEs exist as homodimers; the monomers are covalently connected via a disulfide bond under native conditions. However, AmAChE2 was associated with the cell membrane via the glycophosphatidylinositol anchor, while AmAChE1 was present as a soluble form. The two AmAChEs were functionally expressed with a baculovirus system. Kinetic analysis revealed that AmAChE2 has approximately 2,500-fold greater catalytic efficiency toward acetylthiocholine and butyrylthiocholine than AmAChE1, supporting the synaptic function of AmAChE2. In addition, AmAChE2 likely serves as the main target of the organophosphate (OP) and carbamate (CB) insecticides as judged by the lower IC50 values against AmAChE2 than against AmAChE1. When OP and CB insecticides were pre-incubated with a mixture of AmAChE1 and AmAChE2, asignificant reduction in the inhibition of AmAChE2 was observed, suggesting a protective role of AmAChE1 against xenobiotics. Taken together, based on their tissue distribution pattern, molecular and kinetic properties, AmAChE2 plays a major role in synaptic transmission, while AmAChE1 has non-neuronal functions, including chemical defense.

Climate change and global warming are directly effecting the population dynamics of insects of medical importance and insect pests of agricultural commodities during the last few years. The outbreak of some insect-borndiseases and decreasing yield of agricultural products are both caused and results of climate change are known everywhere in the world. Recent reports of honey bee diseases and out breaks, as well as increase in the incidence of CCD(Collapse Colonial Disease) are causing great concerns and pose big problem for our bee keepers in many countries in North America and Europe. These important infectious diseases are possible carried and propagated by bee mites primarily by Varroa mites, which have recently experienced increasing populations in USA and UK includes some European countries. Recently some Asian honey bees adapted to live in the urban areas as the example of Apis dorsata move to Mae Fah Luang Campus more than 30 colonies and even in Chulalonkorn Campus more than 10 colonies increase from few colonies in the the last few years. Apis florea have been found more than 161 colonies this year in Kanchanaburi (River Kwai province) this year(2009). The discussion of some wild honey bees migration will concentrate on research program of our bee research unit of the university in Thailand.

본 연구에서는 양봉사 내부환경을 보다 효율적으로 조절할 수 있는 환기팬 작동방식을 구명하기 위하여 시뮬레이션을 통해 얻어진 환기팬 작동방식에 대한 연 구결과를 양봉사에 직접 적용하여 실험을 실시하였으며, 양봉사 내부의 온도 및 습도변화에 대한 시율레이션과 실험결과를 비교 · 분석하여 양봉사 설계시 양봉사 열환경 해석 프로그램의 적용성을 검토하고, 실험결과를 이용하여 환기팬 작동방식별 양봉사 내부환경의 조절 성능을 분석하였다. 기 개발된 양봉사 열환경 해석 프로그램은 앞으로 양봉사 설계에 적절하게 이용할 수 있을 것으로 판단되었다. 외부기온이 비슷한 조건에서는 환기팬 작동방식 B의 경우가 A의 경우보다 양봉사의 내부온도가 대체로 더 낮았으며, 평균적으로 벌통 내부는 2.8℃, 양봉사 내부는 2.1℃ 더 낮았다. 이것은 Lee 등(1998b)이 제시한 환기팬 작동방식에 따라 양봉사 내부의 승온억제를 최고 2.8℃까지 할 수 있다는 내용을 뒷받침하는 실험결과이다. 환기팬 작동방식 A와 B 모두 꿀벌이 월동하기에 적합한 상대습도 범위 (50~75%) 였으나, 방식 B가 A 보다 양봉사 내부 습도의 최고 및 최저편차가 약 2%, 평균습도가 약 5% 적게 나타나 습도환경조절에 있어 좀 더 안정적인 것으로 판단되었다. 따라서 환기팬 작동방식 B는 A 에 비하여 양봉사 내부환경조절 성능이 더욱 우수하고 효율적인 것으로 판단되었다.