Honey bee plays an important role in pollinating plants. Recently, however, declines in honey bee populations have been reported in many countries, and pesticides have been pointed out as one of the factors contributing to honey bee loss. To determine the effects of pesticides on honey bee behavior, we investigated the homing ability of honey bee exposed to four pesticides (acetamiprid, imidacloprid, fenitrothion, and carbaryl). In addition, the changes in expression levels of genes associated with ‘learning and memory’ (cGMP-dependent protein kinase foraging, Kruppel homolog 1, Adenlyate cyclase 3, Early growth response protein 1, Hormone receptor 38) were examined after pesticide treatment in forager bee. The four pesticides tested in this study generally reduced the homing ability of foragers. In the examination of gene expression, learning and memory-related genes were induced by the exposure to acetamiprid, imidacloprid, and carbaryl, whereas fenitrothion decreased the expression of these genes in honey bee. Although further studies are needed, this suggests that pesticides may have negative effects on honey bee behavior and behavior-related gene expression.
등검은말벌은 우리나라 뿐 아니라 유럽지역에 침입한 꿀벌의 중요한 포식해충이다. 양봉가들이 살충제를 활용하여 밀도 억제를 시도하고 있으나 아직까지 실현가능하고 과학적 방법과 적용 가능성이 정형화되지 않았다. 본 연구는 양봉가들이 주로 사용하는 살충제를 가지고, 등검은 말벌의 유충과 성충의 살충율과 반응 패턴을 조사하였다. Clothianidin, Dinotefuran, Carbosulfan은 처리 후 30분 내 70% 이상의 살충률을 보 였으며, Bifenthrin, Cartap hydrochloride의 상대적으로 살충률이 낮았다. Clothianidin, Dinotefuran, Carbosulfan의 반수치사약량(LD50)은 각 0.29, 0.65, 2.21 μg/bee이었다. 5령 유충에 대한 24시간 간격으로 3회 연속 섭식 처리를 했을 때, 2일이후에 약효가 나타났고 72시간 후에는 모두 70% 이상 살충률을 보였다. 등검은말벌의 반수치사약량은 양봉꿀벌의 것보다 10-100배 더 높았다. 향후 이 살충제를 말벌 방제에 이용할 수 있을지 추가적 검토가 필요하다.
South Korea experienced a significant decline in honey bee populations starting in 2021, which continued for two years until the winter of 2022. To investigate the potential causes of this decline, we conducted a virome analysis, considering viruses as possible culprits. Samples were collected during two periods: April-May 2022 and May-June 2023. From libraries contsructed from their total RNA, we secured a total of 25 raw FASTQ files by high-throughput sequencing. In the honey bees collected in 2022, we identified eight previously unreported honey bee viruses including Lake Sinai viruses, one novel honey bee-related virus, and one novel plant-related virus. In the subsequent sampling in 2023, we found that most of the viruses identified in 2022 were still present. Additionally, the novel honey bee virus reported in 2022 was also found in the 2023 collections, along with three more honey bee-related novel viruses. Notably, numerous plant viruses were detected in honey bees collected during the flowering season. This analysis suggests that the viruses observed in South Korean honey bees are likely distributed nationwide. These findings provide fundamental data for future research on honey bee viruses in South Korea.
The honey bee, Apis mellifera, has a defense system, including detoxification, antioxidation, and immunity pathways, against external stimulation such as chemicals, stress, and pathogens. However, pesticides, particularly neonicotinoids and butenolids, have been recently reported to alter physiological changes in honey bee. In this study, we investigated the expression levels of eight genes categorized into detoxification (CYPQ3), antioxidation (CAT and SOD2), and immune system (Abaecin, Apidaecin, Defensin1, Defensin2, and Hymenoptaecin), in five tissues (Head, Thorax, Gut, Fat body, and Carcass) of honey bee treated with three pesticides (Acetamiprid, Imidacloprid, and Flupyradifurone) using quantitative real-time PCR. Gene expression patterns was varied depending on the type of pesticides and tissues. However, among eight genes, the expression levels of CYPQ3 was notably induced, but those of AMPs were generally reduced by all pesticides tested in this study in five tissues. These suggest that CYPQ3-mediated detoxification pathway is induced, but AMP-mediated immune system might be disrupted when honey bee is exposed to neonicotinoids and butenolid.
Pesticides are indispensable in contemporary agriculture but are mainly attributed to honey bee population decline. In order to understand the approximate physiological response to pesticides, honey bees were exposed to seven pesticides (Acetamiprid, Imidacloprid, Flupyradifurone, Carbaryl, Fenitrothion, Amitraz, and Bifenthrin), and expression changes of the genes categorized into four physiological functions (insecticide targets, immune-, detoxification-, and reactive oxygen species response-related gene) were analyzed in the head and abdomen of honey bee exposed to pesticides using quantitative PCR. Based on the heat map analysis, immune-related genes seem to be more up-regulated by pesticide exposure in head than abdomen. Among detoxification genes, only cytochrome P450 families were up-regulated in head. Interestingly, regardless of the insecticide target, expressions of Nicotinic acetylcholine receptor beta 1 and Acetylcholinesterase 1 were notably induced by pesticide exposure in head. Heat map analysis expressing the transcription profiles of various genes in the head and abdomen of the honey bee exposed to various pesticides can be used to diagnose pesticide damage in honey bees in the future.
The adult of honey bee, Apis mellifera, performs an age-dependent division of labor with nurse bees and foragers. Foragers fly outside the hive to collect pollen and nectar, while nurses feed and care for the larvae and queen inside the hive. Foragers are considered to be frequently exposed to agrochemicals, although nurses, stayed inside the hive, are potentially exposed to pesticides through application of miticides and pesticidecontaminated food provided by forager. Therefore, physiological effects of pesticides to nurses should be elucidated to understand the adverse effects of the chemicals on entire honey bee colony. In this study, we investigated the expression changes of the genes associated with labor division (task genes) and the nursing behavior of nurse bees fed four pesticides: acetamiprid (ACE), carbaryl (CB), imidacloprid (IMI), and fenitrothion (FEN). When nurses were exposed to ACE, IMI, and FEN, expression levels of task genes were up- and down-regulated, and their nursing behaviors were also suppressed and enhanced, respectively. CB did not alter the gene expression levels, however increased nursing behavior. These suggest the potential of pesticide that breaks the balance of labor distribution in honey bee colony.
The foraging behavior of honey bees can be attributed to the nutritional incentives they gain from their activities. Nevertheless, a persistent question has revolved around how the nutritional composition undergoes alterations during the process of converting pollen into bee bread. We embarked on a comprehensive investigation of nutritional shifts, spanning from fresh pollen to bee-pollen, pollen patties, and bee bread. Our research findings unveiled that pollen exhibited notably higher levels of individual amino acids, resulting in significantly elevated overall amino acid content compared to bee-collected pollen. While we provided pollen patty to the honey bee colony, initially, during the first 3 to 7 days, there were no substantial discrepancies in the total amino acid content between bee bread and the pollen patty. Intriguingly, unlike most amino acids, we detected a distinct pattern of higher proline content in bee bread compared to bee-pollen or the pollen patty. This shift in amino acid composition likely stems from the incorporation of nectar and other secretions during the bee bread-making process. Moreover, over a span of approximately 14 days within hive conditions, the amino acid content in bee bread increased. Conversely, in terms of fatty acid contents, they were found to be lower in bee bread than those in the pollen patty, with no significant temporal differences observed. Regarding mineral content, bee bread, in general, contained fewer minerals than bee pollen and pollen patties. In conclusion, the transformation of pollen into bee bread involves dynamic alterations in nutrient contents, influenced by both intrinsic bee-related factors and external factors within the hive environment.
2022년 3월12일 제천시의 발표(구체화)에 따르면 제천지역 내 양봉 농가를 대상으로 꿀벌생육실태를 확인한 결과 전체 벌통에서 절반 수준의 꿀벌이 사라진 것을 확인하였다. 이는 이전부터 국내 남부에서 진행되어 오던 꿀벌집단실종 현상의 한계선이 지구온난화로 인해 북쪽으로 이동하고 있다고 언론에서 집중 조명된 적이 있다. 이러한 현상이 과연 한반도 온난화에 의한 것인지의 여부를 파악하고자 원인분석 및 실험을 진행하였다. 먼저 꿀벌실종이 일어난 연도와 달을 중심으로 제천지역내의 기온, 일교차, 강수, 일조량 등 다양한 환경조건 중 예전 과 비교하여 급격한 변화가 일어난 요인을 조사하였으며 이러한 급격한 변화가 일어나는 요인이 꿀벌의 집단실 종에 미칠 수 있는 가능성을 분석하였다. 다른 요인분석으로 미국, 유럽 등에서 꿀벌실종의 주요 원인으로 주목받 고 있는 네오니코티노이드계(Neonicotinoids) 살충제를 이용해 꿀벌에 미치는 영향을 실험하였으며, 생존한계 농도를 측정하였다. 또한 국내 살충제의 연도별 사용량을 간접 비교함으로써 꿀벌실종의 주요요인을 찾고자 하였다. 분석결과 충북제천 꿀벌의 실종은 기온의 상승보다는 일조량이 큰 영향을 미친 것으로 보이며, 향후 일조량에 따른 벌집내부의 온도변화 및 꿀벌의 활동성 변화에 초점을 맞추어 꿀벌실종에 대한 장기적인 상관관 계를 살펴보아야 할 것으로 생각된다.
꿀벌에 대한 중요성이 인식되고 도시양봉의 수요가 증가하는 가운데 도시양봉에 최적화된 벌통을 제작하였 다. 꿀벌과 도시양봉에 대한 설문를 진행한 결과, 분봉으로 인한 민원이 도시양봉을 하는 데 가장 큰 저해요소로 꼽혔다. 이에 분봉을 방지하여 시민과 어우러질 수 있으며 친환경적인 벌통을 제작하는 데 초점을 맞췄다. 분봉을 방지하기 위해서는 여왕벌의 이탈을 감지하는 자성 센서와 벌들이 분봉을 하고자 하는 욕구인 분봉열을 감지하 는 온도 센서를 설치하여 효율을 파악하였다. 더불어 최근 이상기후로 인한 잦은 폭우와 고열을 견디기 위하여 밀랍을 이용한 벌통 코팅을 진행하였다. 벌통의 바닥에는 트레이를 서랍처럼 분리 설치할 수 있도록 함으로써 무더운 기온에서는 손쉽게 트레이를 빼서 환기에 중점을 두고, 그 외의 조건에서는 트레이를 끼워둠으로써 바닥 에 떨어진 꿀벌의 사체를 주기적으로 수거하여 유전자 분석을 함으로써 꿀벌의 건강 상태를 점검할 수 있도록 하였다. 꿀벌이 해당 벌통으로 인하여 스트레스를 받는지 꿀벌의 주요 스트레스 마커 유전자의 상대적 발현량을 조사한 결과, 일반적인 벌통에서의 발현량 수준과 큰 차이가 없는 것을 확인할 수 있었다. 이처럼 새로이 디자인된 벌통을 이용한다면 이상기후에서도 도시양봉을 하는 데 기여할 수 있을 것으로 기대된다.
양봉꿀벌은 한 마리 여왕벌을 중심으로 일벌 및 수벌들이 군집을 이루고 있는 사회성 곤충이다. 꿀벌은 여왕벌 이 깨어나면 처녀비행 (반경 2.4~7.4km )을 하여 공중에서 여러 마리의 수벌들과 교미를 한 후, 자신의 봉군 내부로 돌아와 평생을 살아가는 생태적 특성을 가지고 있다. 이와 같은 이유로 계통 증식 또는 품종 육종에서 외부의 오염원을 차단하기 위해서는 여왕벌과 수벌이 격리된 지역에서 교미가 이루어져야 한다. 본 연구는 여왕벌과 수벌이 격리될 수 있는 국내 도서지역을 중심으로 격리교미 연구를 2020년부터 2023년 봄부터 가을까지 수행하 였으며, 육종을 위한 격리교미의 효율성을 분석하고자 하였다. 도서지역은 전남 - 낙월도, 전북 - 위도, 왕등도, 식도에서 수행되었으며, 섬 크기, 경관 환경 요인, 교미 시기 등에 의해 격리교미의 성공률이 어떻게 변하는지를 확인하였다.
Humans have lived in relationship with bees for a very long time. In addition, as essential pollinators, Bee also contribute to biodiversity by promoting the reproduction of various plant species, and play an important role in global food security. Therefore, strong and thriving bee populations are essential for maintaining healthy ecosystems and sustaining food production systems. However, the population of these bees is currently rapidly decreasing due to various causes such as climate change, abnormal temperatures, infectious diseases, and predators. In this presentation, we will learn about the microorganisms that affect bees, including bacteria and fungi, among the various causes of the decline in the bee population, and study their control.
Over the course of two winters, the significant decline in honey bee populations in Korea has emerged as a major social issue. This phenomenon is expected as attributed to factors such as the failure of pest control due to the pesticide resistance of the Varroa mite. This mite can transmit some viruses that infect honey bees, and these viruses are among the primary causes of the globally occurring colony collapse disorder. Traditional diagnostic methods like (RT-)PCR and ELISA are not ideal for identifying pathogens that are newly emerging or have undergone mutations. To detect any novel or mutated viruses beyond those that have been primarily diagnosed in Korea, we introduced virome analysis technology in the field of honey bees. Employing this method with high-throughput sequencing techniques, we were able to identify all existing viruses within individual or group samples. We discovered that the Lake Sinai virus, which has been reported worldwide but not in Korea, has already significantly spread within the country. Additionally, we were able to confirm the prevalence of viruses previously reported in Korea, such as the recently dominant Black Queen Cell Virus. Through this virome analysis, we can provide foundational data for determining the direction and countermeasures for virus diagnosis.