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.

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.

Five heat shock protein 70 (hsp70) isoforms (hsc70-3, hsc70-4, hsc70-5, hsc70cb, hsp70Ab) of Apis mellifera were identified from Honeybee genome database. Specific primers for each isoform were designed for the quantitative realtime RT-PCR analysis, then analyzed transcript levels of the abdomen of adult workers (3-4 weeks old) in respond to heat shock and imidacloprid ingestion. Heat shock at 45°C for 1 h induced all 5 genes but highest in hsc70cb, hsp70Ab. Ingestion of imidacloprid pesticide did not change any hsp70 isoforms at 33°C but those bees also highly responsive to heat shock at 45°C. In addition, expression level of each hsp70 isoform was various and heat shock response of each isoform was tissue-specific. For example, hsc70-3 was highest in midgut, hsc70-4 was in hypopharyngeal gland, but hsp70Ab was in fat bodies. However, heat shock response of all 5 isoforms was the highest in the fat body than brain, hypopharyngeal gland, midgut, flight muscle and integument. Our results provide information for the understanding of complicated protective mechanism of honey bee against thermal stress.

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.

꿀벌은 화분매개 산업으로 가장 각광을 받고 있는 곤충 중 하나이다. 현재는 서양뒤열벌, 머리뿔가위벌 등이 화분매개로 많이 이용되며 앞으로 다른 화분매개 곤충을 연구하여 화분매개 산업을 발전 시켜나가 농가와의 시너지효과를 기대할 수 있다. 현대에 들어 화분매개 산업에 문제시 되는 농약의 독성에 대한 피해가 늘어나고 있는데 미래의 화분매개충이 될 확률이 높은 stingless bee와 꿀벌간의 급성 독성에 대한 차이를 알고자 태국 치앙마이 대학교에서 stingless bee를 포획하여 네오니코티노이드계 3종(Thiamethoxam, Imidacloprid, clothianidin과 카바메이트계 1종(Cabaryl)에 대해서 섭식독성 실험을 하였다. 농약별 추천 농도에 맞게 희석 한 후, 10배부터 100,000배 6단계로 나누어 처리 하였다. Stingless bee의 반수치사농도는 Thiamethoxam, Imidacloprid, clothianidin에 대해 각각 049, 5.84, 0.72 ppm이었고, Cabaryl 처리구에서는 처리후 14시간까지 추천농도에서도 20%대의 사망률을 보였다. 반면 A. mellifera의 반수치사농도는 각각 0.22, 1.97, 0.46, 53.6 ppm로 나타났다. A. mellifera 국내 개체군을 대상으로 한 연구에서는 0.19, 6.32, 0.22, 7.84 ppm으로 나타났다. 꿀벌의 경우 개체군간 차이는 매우 적었으며, stingless bee의 경우 독성이 상대적으로 낮게 나타났다.

꿀벌(honey bee)은 대표적인 화분매개곤충으로 산업적 가치가 높을 뿐만 아니라 생태계에서도 중요한 위치를 차지한다. 2006년 이후 꿀벌군집붕괴현상(CCD)으로 인해 수많은 꿀벌들이 죽었지만 아직까지 그 정확한 원인이 밝혀지지 않아 여전히 꿀벌들의 생존을 위협하고 있다. 이와 더불어 최근 기후변화에 의한 불확실한 환경조건 또한 꿀벌을 위협하는 요소들 중 하나이다. 본 실험에서는 이러한 외부 환경 조건에 대한 꿀벌의 생리적인 반응을 측정하기 위해서 heat shock protein (hsp) 유전자를 이용하였다. 꿀벌의 유전체 분석을 통하여 36개의 hsp 유전자를 선발하였다. 이들 중 hsp40, hsp70, grp78, hsp90를 선정하여 quantitative real-time PCR를 통해 발현량을 분석하였다. 고온 처리(40, 45, 50°C)를 했을 때 45°C에서 hsp 발현량이 가장 높았다. 그리고 조직별(지방체, 중장, 날개 근육)로는 날개근육에서 발현량이 가장 높았다. 적화제 섭식 시 hsp 발현량이 증가하였지만, 살충제 이미다클로프리드 섭식 시는 hsp 발현량이 감소하였다. 즉, 외부 스트레스에 대해 꿀벌 hsp 유전자들의 발현이 다양한 패턴을 나타냈다. 이를 바탕으로 스트레스에 반응하는 꿀벌의 생리에 대해 더 폭넓은 이해가 있을 것으로 예상된다.

Although it is believed that internal nutrient sensors play important roles in feeding behaviors, their molecular and neural mechanisms underlying of the modulation of physiological status and cell growth are poorly understood. Using a Ca2+ imaging experiments with heterologous expression systems, we show that one of the gustatory receptors in the western honey bee Apis mellifera is selectively tuned to amino acids. Remarkably, we report that this gustatory receptor of the honey bee is highly expressed in hypopharyngeal gland, which plays a role in caste differentiation as well as royal jelly production and secretion. Knocking down this gustatory receptor gene reduces cellular pathways responsible for nutritional sensing such as mTOR signals in hypopharageal gland. Furthermore, the interfering expression of this gustatory receptor gene not only alters morphological changes and developmental retardation of the hypopharyngeal gland, but it also blocks cellular growth signals to induce autophagy. This new report indicates that internal sensing and downstream signals detecting nutrients is essential for honey bee to maintain the cellular growth and development of internal organs essential for caste development and maintenance of social structure in the honey bee.

Several Mites are currently the most serious threat to the world bee industry. The ectoparasitic honey bee mites was originally confined to the Asian honey bee(Apis cerana etc.). Varroa destructor and Tropilaelaps clareae has plagued European honey bees, Apis mellifera. Differences in mite tolerance are reported between two honey bee species A. mellifera and A. cerana. We were amplified antimicrobial peptide cDNA genes (Defencin, Abaecin, Royalisin, Apidaecin and Hymenoptaecin) by RT-PCR. We explored the transcriptional response to mite parasitism in A. mellifera 4th instars larvae which differ in susceptibility to V. destructor and T. clareae, comparing parasitized and non-parasitized 4th instars larvae (worker and Drone) from same hive. Differential gene expression of worker bees and Drone bees induced by mites (V. destructor and T. clareae) infection was investigated by northern blot. Mites (V. destructor and T. clareae) parasitism caused changes in the expression of genes related to sex distinction. Bees tolerant to mites (V. destructor and T. clareae) were mainly characterized by differences in the expression of genes regulating antimicrobial gene expression. It provides a first step toward better understanding molecular expression involved in this differential sex distinction host-parasite relationship. We were detected bee virus in A. mellifera, comparing parasitized and non-parasitized 4th instars larvae (worker and Drone). Therefore, this result was demonstrated that mites were another possible route of horizontal transmission, as several viruses were detected in mites and their hosts.

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.

꿀벌(Apis mellifera)은 낮에 비상 활동을 하는 주행성(diurnal activity) 곤충에 해당한다. 꿀벌의 일주활동은 여러 환경요인에 영향을 받는 것으로 보인다. 환경요 인은 장소, 시간, 온도, 습도, 날씨 등의 기초적인 조건을 포함하며 더불어 오염원 상 황, 천적의 유무, 꽃꿀의 량, 패치의 분포 등이 포함될 수 있으며 이들 요인들은 꿀벌 일꾼들의 외부활동에 영향을 미치는 것으로 보인다. 꿀벌이 꽃꿀 채집활동이 하루 동안 어떻게 일어나는지 양상을 파악하는 일은 그들의 행동에 특정 환경요인이 개 체의 의사결정 메카니즘이 어떻게 변하는지를 파악하는데 기초 자료로 이용될 수 있으며, 그 자체의 데이터로써도 가치를 가진다. 본 연구는 이른 아침부터 저녁까 지 하루 동안 각 시간에 일벌들이 봉군에서 들고나는 행동의 패턴을 알기 위한 것이 다. 꿀벌의 활동을 파악하기 위해 온실에 봉군을 설치하고, 영상녹화 장치를 통해 행동을 녹화 하였다. 매일 죽는 개체의 수를 파악해 사망률을 측정하였고, 촬영시 간은 일출과 일몰 시간을 포함한 am06:00부터 pm08:00까지 찍었으며, 온/습도계 는 온실과 벌통 내부에 설치하여 10분 간격으로 측정하였고, 조도는 1시간 간격으 로 온실 내부 조도를 측정하였다. 특정 환경요인을 조작한 상황에서 본 실험을 통해 서 조사된 정형행동 패턴을 파악하기 위한 예비실험으로 실시하였다.

Most Korean beekeepers have moved from south to north of Korea to collect nectar from black locust (Robinia pseudoacacia) flowers for 2 months. This provided a valuable opportunity to sample bees originating from diverse areas in one location. We initiated a survey of honeybee (Apis mellifera) colonies on the blooming period of Acacia to determine the prevalence of Nosema apis and black queen cell virus (BQCV) in 2013. Nosema causes significant losses in population size of honeybees. Sixteenth hives were sampled for this study. Bees were collected on the 4th and 13th of May, 2013. Nosema spore counts ranged from zero to 1,948,333 spores per bee. The average number of nosema spores per bee was calculated to be 450,000. Approximately 94% of the apiaries examined were infected with nosema, based on the presence of spores in the flowering period of Acacia. Also nosema is thought to be associated with black queen cell virus. RT-PCR analysis shows that BQCV infection rate was 100%. This indicates that nosema and BQCV is the predominant species affecting honeybee colonies.

서양종꿀벌(Apis mellifera)과 동양종꿀벌(Apis cerana)에서 온도 스트레스(4℃, 37℃)에 의한 Cu-Zn superoxide dismutase (SOD1)과 thioredoxin reductase (TrxR) 유전자발현 정도를 비교하였다. 그 결과 두 종 모두 처리 후 5시간까지 SOD1과 TrxR의 발현이 급격히 증가하다 차츰 감소하는 경향을 보였다. 스트레스 성 물질(MV, H2O2) 주입에서는 H2O2보다 MV에 의해 현저히 SOD1과 TrxR의 발 현이 증가하였다. 온도스트레스와 물질주입 스트레스 조건하에서 SOD1과 TrxR 의 효소활성을 측정한 결과, 발현시간보다 좀 더 늦은 시간대에서 최대 활성을 보였 다. 그리고 서양종꿀벌과 동양종꿀벌의 SOD1과 TrxR의 단백질 발현 특성을 구명 하기 위하여 E. coli expression system을 이용하였다. 그 결과 SOD1은 약 16 kDa 정도, TrxR은 약 60 kDa 정도의 위치에서 밴드가 관찰되었으며 항체를 이용한 Western blot 결과에서도 동일한 위치에서 밴드를 detection 하였다.

To substitute for bluebottle fly, Chrysomyia megacephala which is being used for pollinator in mango fruit, and improve the pollinating effect of mango fruit which is also being increased as high value added crop recently in Jeju island of korea, 2 kinds of pollinator were used in analyzing and surveying of foraging activities on mango fruit in Seogwipo province. This study was conducted using 3 species of pollinator, Apis mellifera, Bombus terrestris and Chrysomyia megacephala with 3 treatment in vinyl-house condition respectively. Species of mango fruit, Irwin, was used in this experiment. A number of foraging activity of Apis mellifera and Bombus terrestris in hive showed highest 11 AM, and showed normal foraging activity in high temperature condition(28℃). Pollinating ratio of Bombus terrestris was shown 100% and over 95% in case of Apis mellifera. This ratio suggest that the 2 species of insects is effective as pollinator on mango fruit compared with bluebottle fly. Daily pollinating activity of Apis mellifera and Bombus terrestris was shown peak in 11 AM, but showed even activity from 9 AM to 3 PM in case of Chrysomyia megacephala. The pollinating characteristics of 3 species depends on illuminance but temperature, especially in case of Bombus terrestris was more affected by change of illuminance. Visiting time of Bombus terrestris and Apis mellifera on this flower was shown 2.8 and 3.4 seconds respectively. But Chrysomyia megacephala showed longer 10 times with 32.5 seconds than other insects. This results suppose that Chrysomyia megacephala showed as resting behavior for almost time on the flower not foraging activity to pollinate.

Honeybees (Apis mellifera) adapted themselves to different geographical and climatical conditions since they had been introduced in Korea. Beekeepers have tried to breed valuable lineages with artificial insemination or conventional mating techniques. However, evaluation of breeding resultants still relies on timeconsuming observation data. Genetical characterization of breeds has proven its usefulness to preserve genetic resources of livestock. In recent years, microsatellites are most commonly used to evaluate population structures and diversities of living organisms in that the characteristics of locus specificity, rich polymorphism, abundant and random distribution over the genome, and their co-dominant inheritance. Determining classic genetic distances using neutral, highly polymorphic microsatellite markers is a reliable method to investigate genetic relationships and breed differentiation. This methodology can be used to establish preservation priorities for livestock breeds. The final aim of this study was to develop potent markers for assessing genetic structure of lineages after artificial insemination. In this study, the genetic structure of ten microsatellite markers were sequenced or analysed with polymerase chain reaction for eleven European honeybee populations. The results may help to develop reliable microsatellite markers for more efficient preservation strategies of valuable honeybee breeds.

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.

The time-zone of pollinating activity according to numbers of Apis mellifera hive released in the strawberry(Maehyang var.) houses was together from 9A.M. to 4P.M., and the peak times of pollinating activity were between 11A.M and 1P.M.. The effects on pollinating activity according to numbers of A .mellifera hive released in the strawberry houses were ordered 5bee combs(11,000heads), 4bee combs(8,800heads) and 3bee combs(6,600heads). The rate of workers lost in A. mellifera hives with 5bee combs and 4bee combs during the strawberry cultivating period were lower than that of 3bee combs. The rates of fruit set by pollinating activity according to numbers of A.mellifera hive released in the strawberry houses were same level with 99%. The fruit qualities; No. of seeds, sugar content and rate of normal fruit set were same level, but fruit weight was ordered 5bee combs in 16.9g, 4bee combs in 16.4g and 3bee combs in 15.6g. The rate of marketable fruit of 4bee combs and 5bee combs were 5% to 9% higher than that of 3bee combs, respectively.

Toxicity of seven environment friendly agricultural materials (EFAM), which have been used in the domestic market were evaluated on honeybee (Apis mellifera) and asian multicolored ladybird beetle (Harmonia axyridis). Three EFAMs made from plant extract agents (Wangjoongwang Eco, Bogum Eco and Bestop Eco) and four EFAMs made from microbial utilizing agents (Worldstar Eco, Goodmorning, Bluechip and Cameleon) were investigated as EFAMs. In evaluation of toxicity on honeybee, the RT25 values of 3 EFAMs made from plant extract agents ranged from 1 to 3 days. Therefore, honeybee should be released 1-3 days after application of these EFAMs. Meanwhile, the four agricultural materials made from microbial utilizing agents did not show any mortality against honeybee. In evaluating the toxicity to adult and larva ladybird beetles, all seven EFAMs made from plant extract agents and microbial utilizing agents to show any mortality.

Since the ancient times the therapeutic application of honeybee venom (BV) is practised and persisted until the present days. Resistant bacteria are in emergence and some drugs no longer have an antimicrobial action. To purify the melittin known as antibacterial peptide, five major peptidergic subfractions were separated, purified and identified from the whole BV. We investigated the antibacterial activity of whole BV and purified melittin against Staphylococcus aureus by the minimum inhibitory concentrations (MIC) and the postantibiotic effect (PAE). The MIC of whole BV for S. aureus was 0.06 ㎍/㎖, respectively. The MIC of melittin was 0.06 ㎍/㎖ on S. aureus. The in vitro PAE of whole BV and isolated melittin were determined using E. coli and S. aureus. The PAE of whole BV against S. aureus were 3.45 h (1×MIC). The PAE of melittin against S. aureus was 4.35 h (1 × MIC). Also both whole BV and melittin killed S. aureus at 5 × MIC. The regrowth wasn't observed after 18 h. These results suggest that whole BV and melittin will be developed a novel antibacterial drug.