Honey Bee Success Research Articles

The Influence of Environmental Factors on Site Selection Augment Breeding Success in Honey Bees: An Insight of Honey Bee Genetic Resource Conservation.

Honey bee reproductive behavior involves a complicated mating system that embodies a number of factors, including environmental and human-induced factors. Controlled breeding in isolated mating stations is a prerequisite to maintain the genetic resources of honey bees through natural mating. The concept of controlled mating is a challenge in most beekeeping operations due to its low mating success rate. Therefore, a detailed investigation into the suitability of isolated mating stations is of interest. Thus, we bred two subspecies of honey bees (Apis cerana koreana and Apis mellifera L.) in isolated mating stations (island) from 2021 to 2023 and in an open breeding station in 2023. Our results demonstrate that the highest percentage of the mating success rate in isolated mating stations was recorded in the Wido Island, which had the highest percentage of bare land, coniferous forests, deciduous forests, fields, and mixed forests. The mating success rate was higher in the summer and spring for A. cerana and A. mellifera, respectively. The mating success rate was higher in open mating compared to controlled mating (Island) and did not vary between pure-breeding and cross-breeding lines. Our findings suggested that mating stations with mixed forest and fields are potential sites for the successful breeding of honey bees.

Task specific behavior of Indian honey bee (Apis cerana indica) workers

The success of honey bees living in a colony is due to well-organized interaction among morphologically similar castes, the workers. Here, we investigated the behavior of marked worker bees (Apis cerana indica Fab.) after emergence. To have a distinct difference in behavior between early- and middle-adult bees, worker bees were divided into two groups: young-aged bees (YAB) and middle-aged bees (MAB). Four castes i.e., “cell cleaner”, “nurse bee” (YAB), “MAB”, and “forager bees” were identified in A. c. indica. Seventeen distinct behavioral tasks performed by the worker caste with advancing age were recorded. YAB were observed to be engaged in taking care of the brood, such as “capping”, “inspecting”, and “feeding the brood”, while MAB were observed to be engaged in “honey processing”, “building combs”, “guarding”, and other tasks. There were no significant differences in “inspecting cells” and “walking” between YAB and MAB. YAB were seen “In cell” comparatively higher on the combs. Tasks like “capping” are done only by YAB, while tasks like “head inside honey cells”, “building comb”, and “chewing wood” are performed by MAB. Except for a brief orientation flight, YAB never performed “guarding” or “foraging” outside the colony. Data indicated that MAB is also involved in feeding the broods. The transition from within-colony to outside-colony tasks was observed when workers were 18-20 days old. Additionally, worker bees performed a variety of duties concurrently on the same day. Thus, the worker caste of A. c. indica, which lacks physical difference, can organize and divide colony responsibilities.

Neurotransmitters receptors gene drive the olfactory learning behavior of honeybee

The neurotransmitters receptor gene are multifunctional modulators of behaviors in social insects, with significant effects among species and several dominant roles within the same species. Multiple amines receptors affect diverse behavioral and physiological processes in the honeybee. Apis mellifera ligustica is excellent bee species due to its remarkable learning abilities. Here we analyze whether changes in expression of neurotransmitters receptor genes are related to olfaction learning behavior. We present a behavioral experiment on honeybees’ appetitive olfactory conditioning and examine the relationship between learning success and neurotransmitters receptor gene expression. Bees were trained using proboscis extension response to discriminate learner and failed learner bees and examine the expression of neurotransmitters receptors genes in the brains of learner and failed-learner bees. Real-time quantitative PCR was performed to assess neurotransmitter expression levels. Our finding showed significant results in differentiating the learner and failed-learner bee. The expression level of AmDop1, AmDop2, AmDop3, AmOa1, AmTyr1 and 5-HT showed significantly higher expression in learner and failed-learner bees. Our finding suggests the critical role of neurotransmitters receptors in the olfactory learning behavior of A. mellifera. These significant neurotransmitters receptors could thus act together to define optimal motivational or attentional levels and improve learning success. This study revealed the dynamic modulation of neurotransmitters expression in the brain of learner and failed learner bees and suggested an essential role for neurotransmitters receptors gene in regulating the olfactory learning behavior in honeybees. We suggested that neurotransmitters receptors are expressed in the brain of bees and are likely to be directly influential in regulating olfactory learning success in honeybees.

Chronic High Glyphosate Exposure Delays Individual Worker Bee (Apis mellifera L.) Development under Field Conditions.

Simple SummaryGlyphosate-based herbicides (GBH) can be found worldwide throughout conventional agroecosystems due to their unique and effective mode of action. Their use is generally not considered harmful to honey bees, and, consequently, foragers may encounter food sources that are potentially contaminated with GBH residues. However, recent studies found GBH to cause sublethal effects in bees, and therefore give rise to concern. While most related research has addressed such effects under laboratory conditions, field-realistic approaches under free-flying conditions are scarce. Here, we explore if GBH influences several important performance parameters at the colony level using standard and modified regulatory testing methods. Colony conditions (i.e., colony weight gain, individual worker bee survival, and overwintering) were not affected when subjected to chronic GBH exposure in a realistic range (high and low). In line with previous laboratory results, the high range of treatments revealed a delayed brood development of workers and reduced hatching weight of adults when compared with the control group. However, we concluded that more drastic effects on honey bee health did not seem to appear, as a broad range of performance parameters remained completely unaffected. In future research, the underlying mechanisms of the developmental delay that was confirmed here should be carefully investigated.The ongoing debate about glyphosate-based herbicides (GBH) and their implications for beneficial arthropods gives rise to controversy. This research was carried out to cover possible sublethal GBH effects on the brood and colony development, adult survival, and overwintering success of honey bees (Apis mellifera L.) under field conditions. Residues in bee relevant matrices, such as nectar, pollen, and plants, were additionally measured. To address these questions, we adopted four independent study approaches. For brood effects and survival, we orally exposed mini-hives housed in the “Kieler mating-nuc” system to sublethal concentrations of 4.8 mg glyphosate/kg (T1, low) and 137.6 mg glyphosate/kg (T2, high) over a period of one brood cycle (21 days). Brood development and colony conditions were assessed after a modified OECD method (No. 75). For adult survival, we weighed and labeled freshly emerged workers from control and exposed colonies and introduced them into non-contaminated mini-hives to monitor their life span for 25 consecutive days. The results from these experiments showed a trivial effect of GBH on colony conditions and the survival of individual workers, even though the hatching weight was reduced in T2. The brood termination rate (BTR) in the T2 treatment, however, was more than doubled (49.84%) when compared to the control (22.11%) or T1 (20.69%). This was surprising as T2 colonies gained similar weight and similar numbers of bees per colony compared to the control, indicating an equal performance. Obviously, the brood development in T2 was not “terminated” as expected by the OECD method terminology, but rather “slowed down” for an unknown period of time. In light of these findings, we suggest that chronic high GBH exposure is capable of significantly delaying worker brood development, while no further detrimental effects seem to appear at the colony level. Against this background, we discuss additional results and possible consequences of GBH for honey bee health.

Colony Size, Rather Than Geographic Origin of Stocks, Predicts Overwintering Success in Honey Bees (Hymenoptera: Apidae) in the Northeastern United States.

Honey bees (Apis mellifera L.) are key pollinators of agricultural crops. However, approximately 30% of managed colonies die each winter in the United States. There has been great interest in breeding for 'locally adapted stocks' which survive winter conditions in a particular region. Here, we evaluate the impact of geographic origin of stock on colony weight, population size, and overwintering survival. Comparing four different U.S. honey bee stocks (two bred in southern and two bred in northern regions) under standard beekeeping practices in three different apiary locations in central Pennsylvania, we examined possible adaptation of these stocks to temperate conditions. We confirmed the genotypic difference among the stocks from different geographic origins via microsatellite analysis. We found that stock or region of origin was not correlated with weight, population size, or overwintering success. However, overwintering success was influenced by the weight and population size the colonies reached prior to winter where higher colony weight is a strong predictor of overwintering survival. Although the number of locations used in this study was limited, the difference in average colony sizes from different locations may be attributable to the abundance and diversity of floral resources near the honey bee colonies. Our results suggest that 1) honey bees may use similar strategies to cope with environmental conditions in both southern and northern regions, 2) colonies must reach a population size threshold to survive adverse conditions (an example of the Allee effect), and 3) landscape nutrition is a key component to colony survival.

Wild, native bees and managed honey bees benefit from similar agricultural land uses

Although both managed and unmanaged bees are important pollinators of crops and wild plants, efforts to address questions about landscapes that best support pollinators often focus on either wild pollinators or honey bees. This study examined if there was concordance between the success of wild bee communities and managed honey bee colonies at sites varying in floral availability and disturbance level in a predominantly agricultural landscape. We also determined which agricultural land uses best supported wild bee communities. The study area in the state of North Dakota in Northern Great Plains in North America is home to understudied native bee communities as well as over ¼ of U.S. commercial honey bee colonies during the summer months. There is an assumption that honey bees can do well in agricultural areas but that wild bees need natural areas to thrive. We compared wild bee community success with health and survival of managed honey bees (data obtained from a related study) at six apiary locations over three years. We examined wild bee communities and surrounding land uses at 18 locations, three of which were spatially associated with each of six apiary locations. Wild bee abundance and species diversity were positively correlated with honey production, a measure of honey bee success, indicating that locations supporting successful honey bee colonies also supported successful wild bee communities. Grasslands, bee-forage crops, wooded areas, and wetlands were associated with increased abundance, species diversity, or functional diversity of wild bee communities. Crops not providing forage for bees, predominantly soybean, corn, and wheat, were associated with decreased functional diversity, decreased above-ground nesting bees and bees with shorter active season durations, and decreased honey bee survival. Pollinator conservation efforts retaining and enhancing grasslands, wooded areas, wetlands, and crops providing bee forage will likely support the growth, reproduction, and survival of diverse wild bee communities and the success of managed honey bees in areas dominated by intensive agriculture.

A common neonicotinoid pesticide, thiamethoxam, impairs honey bee flight ability

Pesticides can pose environmental risks, and a common neonicotinoid pesticide, thiamethoxam, decreases homing success in honey bees. Neonicotinoids can alter bee navigation, but we present the first evidence that neonicotinoid exposure alone can impair the physical ability of bees to fly. We tested the effects of acute or chronic exposure to thiamethoxam on the flight ability of foragers in flight mills. Within 1 h of consuming a single sublethal dose (1.34 ng/bee), foragers showed excitation and significantly increased flight duration (+78%) and distance (+72%). Chronic exposure significantly decreased flight duration (−54%), distance (−56%), and average velocity (−7%) after either one or two days of continuous exposure that resulted in bees ingesting field-relevant thiamethoxam doses of 1.96–2.90 ng/bee/day. These results provide the first demonstration that acute or chronic exposure to a neonicotinoid alone can significantly alter bee flight. Such exposure may impair foraging and homing, which are vital to normal colony function and ecosystem services.

Honey bee success predicted by landscape composition in Ohio, USA.

Foraging honey bees (Apis mellifera L.) can routinely travel as far as several kilometers from their hive in the process of collecting nectar and pollen from floral patches within the surrounding landscape. Since the availability of floral resources at the landscape scale is a function of landscape composition, apiculturists have long recognized that landscape composition is a critical determinant of honey bee colony success. Nevertheless, very few studies present quantitative data relating colony success metrics to local landscape composition. We employed a beekeeper survey in conjunction with GIS-based landscape analysis to model colony success as a function of landscape composition in the State of Ohio, USA, a region characterized by intensive cropland, urban development, deciduous forest, and grassland. We found that colony food accumulation and wax production were positively related to cropland and negatively related to forest and grassland, a pattern that may be driven by the abundance of dandelion and clovers in agricultural areas compared to forest or mature grassland. Colony food accumulation was also negatively correlated with urban land cover in sites dominated by urban and agricultural land use, which does not support the popular opinion that the urban environment is more favorable to honey bees than cropland.

Effect of a Fungicide and Spray Adjuvant on Queen-Rearing Success in Honey Bees (Hymenoptera: Apidae)

Commercial producers of honey bee queens (Apis mellifera L.) have reported unexplained loss of immature queens during the larval or pupal stage. Many affected queen-rearing operations are situated among the almond orchards of California and report these losses in weeks after almond trees bloom. Almond flowers are a rich foraging resource for bees, but are often treated with fungicides, insecticides, and spray adjuvants during bloom. Anecdotal reports by queen producers associate problems in queen development with application of the fungicide Pristine (boscalid and pyraclostrobin) and spray adjuvants that are tank-mixed with it. To test the effect of these compounds on queen development, a new bioassay was developed in which queens are reared in closed swarm boxes for 4 d, until capping, with nurse bees fed exclusively on artificially contaminated pollen. Pollen was treated with four concentrations of formulated Pristine (0.4, 4, 40, and 400 ppm), a spray adjuvant (Break-Thru, 200 ppm), the combination of Pristine and spray adjuvant (400:200 ppm), the insect growth regulator insecticide diflubenzuron (100 ppm) as a positive control, or water as negative control. Chemical analysis revealed that low concentrations of pyraclostrobin (50 ppb), but no boscalid, were detectable in royal jelly secreted by nurse bees feeding on treated pollen. No significant difference in queen development or survival was observed between any of the experimental treatments and the negative control. Only diflubenzuron, the positive control, caused a substantial reduction in survival of immature queens.

Hive Relocation Does Not Adversely Affect Honey Bee (Hymenoptera: Apidae) Foraging

Honey bees,Apis mellifera, face major challenges including diseases and reduced food availability due to agricultural intensification. Additionally, migratory beekeeping may subject colonies to a moving stress, both during the move itself and after the move, from the bees having to forage in a novel environment where they have no knowledge of flower locations. This study investigated the latter. We moved three colonies housed in observation hives onto the campus from a site 26 km away and compared their foraging performance to three similarly sized colonies at the same location that had not been moved. We obtained data on (1) foraging performance by calculating distance by decoding waggle dances, (2) hive foraging rate by counting forager departure rate, (3) forage quality by assessing sugar content of nectar from returning foragers, and (4) forager success by calculating the proportion of bees returning to the nest entrance with nectar in their crop. We repeated this 3 times (August 2010, October 2010, and June 2011) to encompass any seasonal effects. The data show no consistent difference in foraging performance of moved versus resident hives. Overall the results suggest that moving to a new location does not adversely affect the foraging success of honey bees.

Effects of Horizon Landmarks on Homing Success in Honey Bees

A hypothesis is proposed and field data presented indicating that in long-distance navigation, honey bee foragers use horizon landmarks to determine the direction of their home site. Metal tags were recaptured from marked foragers released at various distances and directions from their nests located in mountainous or flat terrain. The proportion of tagged foragers returning to their nests decreased as distances of the release points from the natal colony increased. However, the fraction of returns versus distance differed according to site horizon features. Twice as many foragers returned to their home nests located in mountainous terrain as compared to returns in flat terrain. Maximum distances from which honey bee foragers found their nests were about 5 km in flat terrain with no skyline features and about 9 km in a mountainous region. The data support the hypothesis that orientation cues relied on by foragers for distance navigation include deformations in the landscape horizon when available. A search...