Honey bees are affected by a variety of factors, so they have to be thoroughly managed according to their lifestyle. The activity of the honey bee foragers represent an important parameter of the hive state. Here, the real-time and automatic monitoring system using dual infrared sensors was applied for counting the foraging activity of honey bees based on ICT. According to this study, this system is very accurate with a relative error of 3.98% / 4.43% compared to manual counting through video analysis. This system showed the scalability of the system through the internal and external temperature sensors connected through the main board and BLE module. Furthermore, the data measured through this system for one month were analyzed, the monthly average foraging activity and the number of lost foragers were measured (1.88% of outgoing bees), and at the same time, the foraging patterns according to the changes of temperature and time were analyzed. This study suggests that the development of apicultural, scientific and educational materials with more powerful real-time monitoring tools through expansion of a complex monitoring system and big data accumulation.

Sacbrood virus (SBV) caused significant colony collapse in Korean Apis cerana. Considering that hygienic behavior in honey bees confers colony-level resistance against brood diseases, we utilized this trait for selecting A. cerana colonies. In addition, the brood survival rate was evaluated after colonies were SBV-inoculated. Over four selective generations, dead brood removal and brood survivorship in selected colonies were higher than those in the unselected colonies (P < 0.01, 99.3 vs. 89.9% for removal of pin-killed pupae; P < 0.01, 99.0 vs. 63.9% for removal of SBV-killed larvae; and P < 0.01, 70.0 vs. 9.2% for brood survivorship). Following SBV-inoculation, selected colonies showed an increase in the number of surviving pupae and adults, whereas unselected colonies collapsed mostly. Our results confirm the feasibility of selecting SBV-resistant A. cerana.

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.

Honey bee, Apis mellifera L., have been widely used as a model organism for biological science because of its highly developed sociality, specialized labor division and passive population management. In order to examine the expression patterns of genes putatively involved in social development in honey bee, quantitative real-time PCR (qRT-PCR) that has been widely used to investigate the expression level of target gene can be used in honey bee study. However, the selection and validation of optimal reference genes is a crucial step prior to running qRT-PCR. In the present study, therefore, the seasonal expression stability of five candidate reference genes in the abdomen of forager and nurse was investigated using three programs (geNorm, NormFinder and BestKeeper), and selected reference genes were validated by the normalization of expression level of vg encoding vitellogenin. Although three programs revealed slightly different gene stability values, overall the combination of two genes (rpS18 and gapdh encoding ribosomal protein S18 and glyceraldehyde-3-phosphate dehydrogenase, respectively) was resulted in the most suitable use for normalization of the target gene in forager. However, a single gene, either rpL32 or rpS18 in the nurse or either rpL32, rpS18, or gapdh in the comparison between foragers and nurses, were suggested to be applied for normalization of seasonal and labor-specific gene expression by qRT-PCR.

The honey bee soluble acetylcholinesterase 1 (AmAChE1) is overexpressed under the overwintering and brood rearing-suppressed conditions. To investigate the role of AmAChE1 in regulating acetylcholine (ACh) titer, ACh concentrations both in the head (neuronal) and abdomen (non-neuronal) were analyzed. ACh titer was significantly lower in both tissues of worker bees under the overwintering and brood rearing-suppressed conditions compared to control bees. The expression levels of another two factors that regulate ACh titer, choline acetyltransferase (AmAChT) and acetylcholinesterase 2 (AmAChE2), were not altered as judged by qPCR and native PAGE, suggesting that the lower ACh titer was mainly regulated by AmAChE1. For precise verification of AmAChE1 as an ACh titer regulator, honey bees were put under brood rearing-suppressed condition to induce AmAChE1 and injected AmAChE1 dsRNA to knock down the gene. The ACh titer of AmAChE1-knocked down honey bees was 1.9 and 2.6 folds higher than that of control bees in head and abdomen, respectively. Taken together, in spite of its extremely low catalytic activity, the overexpression of AmAChE1 is likely to be related with the low level of ACh homeostasis, perhaps via ACh sequestration, under brood rearingsuppressed condition, and likely induce metabolic changes through ACh receptors-related pathways.

Lately, CRISPR-Cas9 has become one of the most essential tools to understand gene’s function. In the honeybee, however, the application of CRISPR technology has been hindered by various factors leading to very few reports of success in genome editing. Among these, collection of honeybee embryos for microinjection has been a time-consuming procedure, mainly limiting the applicability of the genome editing technique to honeybees. To improve the drawbacks of the conventional plastic plug-based system, we have developed a film-assisted honeybee embryo collection system (FECS) using transparent film as a detachable bottom layer. In this new system, eggs are laid on the detachable film surface and collected in a batch, and thus no additional alignment is required for microinjectoin. As the film can be easily replaced with in a few seconds, embryo collection can be repeated continuously after a single caging of a queen. Also, unlike conventional plug-based systems, the new system utilizes 100% of the eggs laid by the queen, thereby increases the yield three times in theory. The main unit of the system can be printed with ordinary SLA/DLP type 3D printer and the stl file for 3D printing will be distributed online.

미포장충류(Nosema spp. (NS))는 양봉꿀벌에 심각한 문제를 야기시키는 기생충으로 효과적인 방제물질의 선발이 무엇보다 중요하다. 본 연구는 노제마병과 기타 꿀벌의 발생유행시기의 구명과 더불어 3가지 노제마병 방제물질(M1 = 벌꿀희석의 레몬쥬스; M2 = 설탕시럽 혼합의 카모마일 추출물; M3 = 설탕시럽 혼합의 항생물질 스트리베트)을 평가하고자 수행하였다. 꿀벌 성충과 유충집단의 질병 유행시기를 년간 조사하였으며, 야외 및 실험실 조건에서 노제마병에 대한 M1, M2, M3의 효과를 평가하였다. 조사결과 극소수의 꿀벌 성충과 유충 질병이 발견되었다. 노제마 병은 겨울과 봄 기간 저온과 고습조건에서 검출되었다. 포장실험에서 M2는 36.66%까지 발병억제 능력을 보였으며, 반면M3는 23.33%, M1는 13.33%의 억제효과를 보였다. 실내실험에서 M2가 방제효과가 가장 좋았고, 그 다음 M1와 M3 이었다. 3가지 방제물질은 병에 감염된 꿀벌성충의 생존력을 크게 높이는 것으로 나타났다. 본 연구는 노제마병 방제를 위한 천연물질로 카모마일의 잠재적 방제효과를 제시하고 있다.

The honey bee, Apis mellifera ligustica (Hymenoptera: Apidae), strain with a high hygienic behavior (HHB) has been bred for several years in Korea, and a diagnosis system to distinguish it from low hygienic behavior (LHB) strain has been necessitated. Thus, complete mitogenome of the two strains were sequenced through Next-Generation Sequencing technique to detect SNPs. Comparison of the mitogenome sequences from the two strains of A. m. ligustica have detected 23 SNPs in 11 PCGs and these were further confirmed the presence of SNPs using each 10 individuals selected randomly from each strain, indicating that these SNP markers might be useful to diagnose the honeybee strains with the HHB. Therefore, mitogenome sequences are promising genome source to detect SNP markers, particularly for inbred female iso-lines.

Honey bee has been widely used as a model insect for biological sciences because of its sociality and specialized labor division. For the investigation of the seasonal and labor-dependent expression patterns of genes putatively involved in its sociality, quantitative real-time PCR (qRT-PCR) can be applied to quantify gene expression level and selection of reliable reference gene(s) for normalization is an accurate step. In this study, using three softwares (geNorm, NormFinder and BestKeeper), we evaluated seasonal expression stabilities of four reference genes that have been widely used for qRT-PCR in forager and nurse heads. Among four candidates, two genes, rpS18 and gapdh, were suggested to be the optimal reference genes for qRT-PCR.

Honey bees are challenged with declining colony numbers, generally called ‘Colony Collapse Syndrome’ (CCS). This issue is certainly a syndrome because it is due to a range of threats, including parasitic mites, exposure to agricultural chemicals and various viruses, among other things. We posed the hypothesis the CCS could also be due to declining nutritional qualities, which may relate to digestive physiology. Because there is no information on honey bee lipid nutrition and digestion, we characterized a digestive phospholipase A2 in honey bee midguts. In this paper, I will report on some of our findings. With a focus on students, I will also use this report to share thoughts on presenting and writing for international audiences.

Nosema disease caused by the microsporidia Nosema apis and Nosema ceranae are a honey bee pathogen parasitizing. Nosema disease symptoms include digestive and absorption disorders because the spores damage epithelial tissue and potentially causing colony death. Recently, N. ceranae has been reported as an important threat to honey bee health. Turmeric (Curcuma longa L.) Curcuma tonga L. belongs to the family Zingiberaceae and is a perennial, tropical herb. Turmeric, the powdered rhizome, is used for medicinal purposes. The aim of this study was to evaluate the potential of Turmeric (Curcuma longa L.) for the control of N. ceranae in honeybees. For the study, we infected with N. ceranae spore through dosed and fed with the turmeric extraction at difference concentration. The data show that the turmeric extraction was not toxic for bee at least at 1% and the bees fed with 0.5 % turmeric extraction had significantly lower infection rates. This data suggest that turmeric could be useful in alternative strategies for the control of N. ceranae.

In this study, we investigated the nutritional composition including proximate, amino acid, vitamin, minerals, and the antioxidant activity of green tea (Camellia sinensis) pollen grains collected by Apis mellifera bees, for use as a health food. The crude protein and fat content was estimated at 26.14% and 3.49%, respectively. Eighteen amino acids were identified in green tea pollen, including 8 essential amino acids and 10 non-essential amino acids. The predominant amino acids were glutamic acid, proline and aspartic acid accounting for about 33.3% of total free amino acids. The concentration of vitamin C was the highest value of 35.7%, followed by B3 and B2 among the detected vitamins. The predominant minerals were potassium (790.32 mg/100g), followed by phosphorus (707.52 mg/100g) and sulfur (302.67 mg/100g), whereas copper, zinc and sodium were detected as minor elements. The antioxidant activity and phenolic content accounted for 33.8% at 500 μg/mL extract and 2.55 μg/mg, respectively.

Among two different acetylcholinesterase (AmAChE1 and AmAChE2) of the western honey bee, the soluble AmAChE1might be related with a stress response as judged from its over-expression in honey bee workers when brood rearingwas suppressed. In this study, to ensure the nature of AmAChE1 responding to stress factors, the expression patternsof AmAChE1 were investigated following various treatments, including varroa mite infestation, bacterial challenge, broodrearing suppression, thermal stresses, chemical treatments, ultraviolet B irradiation, starvation, water restriction and crowdingstress. In addition, transcription profiles of four heat shock protein genes known as general stress markers and vitellogeningene, which is induced in several stress conditions, were tested as positive references. In every tested condition, onlybrood rearing suppression and heat shock were related with the expression of AmAChE1.

Honey bee swarming is a natural phenomenon that occurs by changes of colony (i.e. population size and queen condition) and environment conditions. As cuticular hydrocarbons (CHCs) are known to be involved in the communication between honey bee nest-mates, we investigated and compared the CHC profiles of worker bees from individual colonies of 9-days before swarming (PPSC), a day before swarming (PSC), swarming (SG) and remaining (non-swarming) (RG). A total of 53 CHCs were identified by GC-MS, among which 11 compounds showed significantly differential expression patterns between swarming states. Before swarming (between PPSC and PSC), detection levels of 4 CHCs were significantly different, suggesting that production of some CHCs changed prior to swarming for swarming preparation. Six CHCs were deferentially produced between PSC and RG. The differential profiles of CHCs with respect to different swarming states are currently under investigation.