Here, we investigated antioxidant defense mechanism in the spermatheca of A. mellifera queens via RNA-seq analysis of spermathecae in both mated and virgin queens. We identified the genes encoding antioxidant proteins, which were differentially expressed in the spermatheca of mated queens. The concentrations of antioxidant proteins, such as superoxide dismutase 1 (SOD1), catalase, glutathione peroxidase (GTPX), and transferrin (Tf) together with the levels of ROS, H2O2, and iron were higher in the spermathecal fluid of mated queens as opposed to those in the spermathecal fluid of virgin queens; this indicated that increase in antioxidant protein concentration is an antioxidant defense mechanism occurring in the spermathecal fluid of mated queens against ROS; this mechanism involves conversion of ROS using antioxidant enzymes and Tf-mediated inhibition of the Fenton reaction occurring between Fe2+ and H2O2. Our data indicate that an increased expression of antioxidant proteins could facilitate prolonged storage and survival of sperms in the spermatheca of mated queens, suggesting the role of antioxidant proteins in antioxidative defense against ROS.

We investigated the effects of honey bee (Apis mellifera L.) colony size on the pollination of greenhouse-cultivated watermelon grown under the forcing cultivation system. The highest pollination activity of bees was observed (14.3 ± 5.0 honey bees/day) when the bee colony size was 10,000 honey bees, followed by 7,500 and 5,000 honey bees. There was a positive correlation between the bee colony size and pollination activity (R = 0.262). There was no significant difference in the fruit set with different honey bee colony sizes (88%–91%). However, the larger the bee colony size, the higher the number of seeds fertilized and the rate of seed fertilization (p > 0.05). The number of seeds and the content of sugar were negatively correlated (R = -0.714). Overall, we found that a colony size of 5,000 honey bees was the most effective for the pollination of watermelon grown under forcing cultivation.

Learning and memory are essential for animals like honey bee, in which foragers leave their nest to collect food and then successfully learn to navigate back to colony. Chronic environmental exposure of neoniconitiod highly affect pollinators like honey bee. We investigated the effect of neonicotinoid, thiacloprid and imidacloprid on learning, memory and mortality of pollen foragers based on their toxicity level. Individual Pollen foragers Apis mellifera were trained using a proboscis extension proboscis. We used three treatments: 50% sugar solution, 50% sugar contaminated thiacloprid and imidacloprid as unconditioned stimulus and 2M 1-nonanol as conditioned stimulus. Our result shows that there is no significant difference between control and thiacloprid treatment both in learning and mortality of honey bee. But we found difference in memory between subjects exposed to control and thiacloprid contamination. Whereas imidacloprid contamination significantly lowered learning, eradicate memory retention and higher mortality of honey bee. Even thiacloprid and imidacloprid are in the same chemical class of Neonicotinoid insecticides, their toxic level would be different resulting in differential ecological impact to honey bee colony.

Comparative toxicity of different groups of pesticides on Apis mellifera L. were tested in the laboratory. Commercial formulations dissolved in water from the highest dose level marked on the label were serially diluted to 10^(-6) times to carry out oral trials on each pesticide. Fungicide (Metconazole), herbicide (Glyphosate), acaricide (Amitraz) and 3 insecticides (organophosphate Fenitrothion, neonicotinoids of Thiacloprid and Thiamethoxam) were compared. Thiamethoxam and fenitrothion caused higher mortality, and amitraz showed intermediate level of mortality while herbicide and fungicide showed minimal impacts. Among neonicotinoids, Thiamethoxam was highly toxic but thiacloprid showed mortality less than 25% even at the highest concentration. LC50 values were estimated as Amitraz 197.70, Fenitrothion 2.20, and Thiamethoxam 0.188 ppm at 24 h after treatment. Fungicide, herbicide and a neonicotinoid thiacloprid were all showed low oral toxicity. This study confirmed that the old pesticide, organophosphate was highly toxic and two different toxic path way exist for neonicotinoid pesticides.

본 연구에서는 양봉농가에서 대량 생산이 가능하고 영양이 풍부한 꿀벌 수벌번데기를 새로운 식품원료로 사용 하기 위하여 유해 미생물과 곰팡이독소에 대한 안전성 시험을 수행하였다. 검사 시료는 국내 3지역의 양봉농가에서 직접 생산한 수벌번데기를 채취 후 곧바로 냉동 운반 하여 동결건조하여 사용하였다. 식품공전 시험법에 따라 대장균군(Coliforms), 살모넬라(Salmonella spp.), 황색포도 상구균(Staphylococcus aureus) 및 장출혈성대장균(Enterohemorrhage Escherichia coli)에 대한 검출 여부를 조사한 결과 280개의 벌통에서 채취한 수벌번데기 전부에서 전혀 검출되지 않았다. 또한 곰팡이 독소인 아플라톡신 B1 (aflatoxin), 오크라톡신 A (ochratoxin), 데옥시니발레놀 (deoxynivalenol) 그리고 제랄레논(zearalenone)이 수벌번데기에서 전혀 검출되지 않았다. 따라서 벌통 내 소비에서 채취하여 곧 바로 냉동보관 한 수벌번데기는 유해 미생물과 곰팡이 독소로부터 안전한 것으로 확인되어 식품원료 로 사용이 가능할 것으로 사료된다.

기후변화, 외래병해충발생, 밀원수 감소 등 여러 요인으로 인해 우리 나라의 양봉농가는 벌꿀생산량 및 농가소득이 감소하는 추세이다. 또한 밀원이 없는 시기에 가축용 사료가 아닌 고가의 식용설탕을 꿀벌의 인공사료로 급여하고 있어 농가는 ‘생산비 상승’과 ‘밀원수 부족’을 국내양봉업이 직면한 가장 큰 문제점으로 지적하고 있다. 이에 따른 양봉농가의 생산비를 절감하고 꿀벌의 생리·생태의 개선효과를 가지는 저가형 당액사료개발을 위해 농산부산물에서 추출한 천연당을 봉군에 적용시험을 추진하였다. 양파(OS-1, OS-2), 양배추(CS-1, CS-2), 바나나(Banana)부산물에서 추출한 천연당의 봉군당 평균먹이소모량(mL)은 설탕당액(대조구) 처리구와 비교시 바나나추출당액 급여구에서 5500.00±0.00, 5133.33±404.15로 유사하였다. 그러나 꿀벌의 봉세발달은 대조구에 비해 21006.7±2137, 17403.3±2257마리로 조사되어 낮은 경향을 나타내었고 수명조사 결과는 큰 차이가 없었다. 농산부산물을 이용한 천연당은 우선 꿀벌의 기호도 향상을 우선으로 개선시켜야 할 것으로 보인다.

농촌진흥청 개발 품종인 토종벌 신품종(질병저항성 우수계통)에 대해 전남지역에서의 형질특성(봉세발달, 마리당 수밀력, 청소력 등)을 조사하였다. 질병저항성 계통(RS)으로 육성된 토종벌의 유밀기 마리당 수밀력은 들어오는 일벌의 무게가 80.89±8.95mg, 나가는 일벌의 무게가 63.56±8.90mg으로 조사되었고, 비저항성계통(NRS)은 각각 83.22±1.39, 66.67±1.20mg으로 조사되어 RS에서 그 무게차가 0.7mg 더 높았으나 통계적 유의차는 없었다. Pin killed test에 의한 사충제거능력(청소력)은 제거하지 못한 유충잔존율이 RS에서 12시간과 24시간 경과시 14.00±10.39와 7.00±3.46으로, NRS에서는 20.33±14.29, 13.33±10.41%로 조사되었으며, 특히 RS와 NRS의 사충 비제거율이 24시간 경과하였을 때 4.67±2.08, 8.33±7.77%로 RS가 우수한 특성을 보였다. 신규여왕벌 입식 후 봉군세력발달은 NRS에 비하여 RS의 일벌수, 번데기 및 유충수의 발달율이 안정적이고 다소 빠르게 증가하였다.

The hypopharyngeal gland (HPG) of the honeybee worker produces royal jelly (RJ) and has a developmental cycle closely related to the division of labor. In this study, we investigated to compare the HPG acini diameter of differently aged worker bees with high royal jelly producing colony (HRC) or less producing colony (LRC). Additionally, we also evaluated whether the fresh weight of the head is a reliable indicator of the developmental status of HPG. The HRC showed a significantly higher RJ production about two-times as compared with those of the LRC. We measured the HG-diameters on days 1, 3, 6, 9, 12, 15. The microscopic analysis revealed that the acini size of the HRC was significantly larger than the LRC. In addition, the acini diameter of HRC was 15% longer than the LRC on the first day after emerging. It was shown that the fastest development during 3 days which is preparing for nurse the brood. The HPG acini diameters increased in both colonies in a similar fashion until day 12 and then decreased. We also compared the fresh head weight of the experimental colonies, differences were similar to the development of HPG. Therefore, high royal jelly production may have a positive correlation between HPG acini size and the fresh head weight.

Royal jelly (RJ) is a well-known functional and medicinal food for human health promotion. Major royal jelly proteins (MRJPs), which are the major protein components in RJ, exhibit antimicrobial activities. However, the identities of the MRJPs of RJ responsible for its antioxidant effects have remained unclear. Here, we report that honeybee (Apis cerana) MRJP 2 (AcMRJP2) acts as an antimicrobial and antioxidant agent in RJ. Using recombinant AcMRJP2, which was produced in baculovirus-infected insect cells, we established the antimicrobial and antioxidant roles of MRJP 2. AcMRJP2 bound to the surfaces of bacteria, fungi, and yeast, which then induced structural damage in the microbial cell walls and led to a broad spectrum of antimicrobial activities. AcMRJP2 protected mammalian and insect cells via the direct shielding of the cell against oxidative stress, which led to reduced levels of caspase-3 activity and oxidative stress-induced cell apoptosis, followed by increased cell viability. Moreover, AcMRJP2 exhibited DNA protection activity against reactive oxygen species (ROS). Our data indicate that AcMRJP2 could play a crucial role as an antimicrobial agent and antioxidant in RJ, suggesting that MRJP 2 is a component responsible for the antimicrobial and antioxidant activities of RJ.

RNA interference (RNAi) has been considered as an alternative strategy to control agricultural pest whereby double-stranded RNA triggers a potent and specific inhibition of its homologous mRNA. Since small dsRNAs are required for various RNAi applications, there is a need for cost-effective methods for producing large quantities of high-quality dsRNA. In this study, Bacillus thuringiensis (Bt) based dsRNA production platform was established under control of sporulation-dependent promoter and vp1 gene of Sacbrood virus (SBV) was introduced. The dsRNA against vp1 gene produced from the Bt suppressed the replication of SBV. In addition, the dsRNA was assembled into inulin coated-nanoparticle to increase stability of dsRNA in environment.

Honeybees (Apis mellifera) are defend on feeds for their larvae and adult bees` healthy life. The nectar is carbohydrate source for making energy. We are extract several sugars from plants for using carbohydrate source to bee. 3 sugar source was extracted from plants (watermelon, cabbage, and mandarin). Almost sample showed high level of insecticidal rate and low level feed intake rate. We were selected 2 type of cabbage sugar syrup that low level insecticidal rate and high level feed intake rate (No 6 cabbage(+fructose) was mixed with 10% fructose and No. 7 cabbage(+pollen) was made with 10 % pollen). Cabbage sugar solution has much more impurities than purified sugar. So, No.6 and No 7 sample can do up-regulation of antimicrobial genes (apideacin, defencin, abacin, and hymenopteacin). Cabbage sugar solution has much more impurities than purified sugar. Our results suggest that up-regulation of antimicrobial genes might be involved in worker through carbohydrate impurities related immune pathways.

Major royal jelly proteins (MRJPs), important protein components of bee royal jelly (RJ) and exclusive nourishments for queen, exhibit various biological and pharmacological activities. RJ is one of the most studied bee products, but the crucial roles for MRJP2 as an antimicrobial and antioxidant agents remain largely unknown. Here we demonstrated the antimicrobial and antioxidant functions of the Asiatic honeybee (Apis cerna) MRJP2 (AcMRJP2). Recombinant AcMRJP2 of approximately 53 kDa was expressed in baculovirus-infected insect cells, and it exhibited antimicrobial activity against bacteria, fungi, and yeast via binding to microbial surfaces and inducing structural damage in microbial cell walls. AcMRJP2 protected mammalian and insect cells against oxidative damage through shielding of cell membranes. Interestingly, AcMRJP2 exhibited DNA protection activity and DPPH radical-scavenging activity. Altogether, our data demonstrated that AcMRJP2 functions as antimicrobial and antioxidant agents.

Honeybee (Apis mellifera) egg-yolk protein vitellogenin (Vg) plays roles in immunity, antioxidation, and life span beyond reproduction, but it also acts as an allergen Api m 12 in venom. Here we established antimicrobial and antioxidant roles of honeybee Vg in the body and venom. Using the cDNA encoding Vg identified from Asiatic honeybee (A. cerana) workers, recombinant A. cerana Vg (AcVg) protein of approximately 180 kDa was produced in baculovirus-infected insect cells. In A. cerana worker bees, AcVg was expressed in the fat body and venom gland and was present in the secreted venom. AcVg induced structural damage in microbial cell walls via binding to microbial surfaces and exhibited antimicrobial activity against bacteria and fungi. AcVg protected mammalian and insect cells against oxidative damage through direct shielding of cell membranes. Interestingly, AcVg exhibited DNA protection activity against reactive oxygen species (ROS). Furthermore, the transcript level of AcVg was upregulated in the fat body, but not in the venom gland, of worker bees with antimicrobial peptides and antioxidant enzymes in response to microbial infection and oxidative stress. Our data indicate that AcVg is involved in innate immunity upon infection and in a defense system against ROS, supporting a crucial role of honeybee Vg as an antimicrobial and antioxidant agent in the body and venom.

We compared the fruit set and the quality of the Asian pear (Pyrus pyrifolia Nakai cv. Niitaka) among flowers pollinated by insect pollinators such as the honeybee(Apis mellifera) and bumblebee(Bombus terrestris) and pollinated artificial. The hand pollination rate was 1.3 times higher than bumblebee and 1.9 times higher than the honeybee pollination rate. Moreover, the artificially pollinated flowers produced fruit that was 5 to 10% higher in weight, 2 to 3% larger in size, and had a higher fruit shape index(L/D) than pollinated by the insect pollinators. On economic analysis, net profit from insect pollinator was 93.5 to 97.1% of net profit from hand pollination. Therefore, artificial pollination is more efficient than insect pollination in 'Niitaka' pear. However, regarding fruit quality and net profit, these results suggest that bee pollinator can be an good alternative to hand pollination in pear cv. Niitaka.

The population of managed honeybees has been dramatically declining the recent past in worldwide. N. ceranae causessignificant detriment to honey production and results in economic losses critically. In our knowledge, Fumagillin is theonly antibiotic approved for control of nosemosis in honeybees. In this study, to select isolate with anti-Nosema activityagainst N. ceranae. Entomopathogenic fungi cultural filtrates were screened using in vitro polar tube germination assay.These fungi cultural filtrates were used to evaluate the safety of honeybees and their inhibition of nosemosis. As a result,P. marquandii 364 and Pochonia sp. 60 showed inhibitory activity on the growth of N. ceranae in honeybees and didnot significantly affect the survival rate of honeybees. These may be employed as antibiotic agents and a good featureto be used in the development of new biocontrol agents of nosemosis.