Advances and knowledge gaps on climate change impacts on honey bees and beekeeping: A systematic review.

The Western honey bee Apis mellifera is a managed species that provides diverse hive products and contributing to wild plant pollination, as well as being a critical component of crop pollination systems worldwide. High mortality rates have been reported in different continents attributed to different factors, including pesticides, pests, diseases, and lack of floral resources. Furthermore, climate change has been identified as a potential driver negatively impacting pollinators, but it is still unclear how it could affect honey bee populations. In this context, we carried out a systematic review to synthesize the effects of climate change on honey bees and beekeeping activities. A total of 90 articles were identified, providing insight into potential impacts (negative, neutral, and positive) on honey bees and beekeeping. Interest in climate change's impact on honey bees has increased in the last decade, with studies mainly focusing on honey bee individuals, using empirical and experimental approaches, and performed at short-spatial (<10 km) and temporal (<5 years) scales. Moreover, environmental analyses were mainly based on short-term data (weather) and concentrated on only a few countries. Environmental variables such as temperature, precipitation, and wind were widely studied and had generalized negative effects on different biological and ecological aspects of honey bees. Food reserves, plant-pollinator networks, mortality, gene expression, and metabolism were negatively impacted. Knowledge gaps included a lack of studies at the apiary and beekeeper level, a limited number of predictive and perception studies, poor representation of large-spatial and mid-term scales, a lack of climate analysis, and a poor understanding of the potential impacts of pests and diseases. Finally, climate change's impacts on global beekeeping are still an emergent issue. This is mainly due to their diverse effects on honey bees and the potential necessity of implementing adaptation measures to sustain this activity under complex environmental scenarios.

La abeja occidental Apis mellifera es una especie manejada que proporciona diversos productos de la colmena y servicios de polinización, los cuales son cruciales para plantas silvestres y cultivos en todo el mundo. En distintos continentes se han registrado altas tasas de mortalidad, las cuales son atribuidas a diversos factores, como el uso de pesticidas, plagas, enfermedades y falta de recursos florales. Además, el cambio climático ha sido identificado como un potencial factor que afecta negativamente a los polinizadores, pero aún no está claro cómo podría afectar a las poblaciones de abejas melíferas. En este contexto, realizamos una revisión sistemática de la literatura disponible para sintetizar los efectos del cambio climático en las abejas melíferas y las actividades apícolas. En total, se identificaron 90 artículos que proporcionaron información sobre los posibles efectos (negativos, neutros y positivos) en las abejas melíferas y la apicultura. El interés por el impacto del cambio climático en las abejas melíferas ha aumentado en la última década, con estudios centrados principalmente en individuos de abejas melíferas, utilizando enfoques empíricos y experimentales y realizados a escalas espaciales (<10 km) y temporales (<5 años) cortas. Además, los análisis ambientales fueron basaron principalmente en datos a corto plazo (meteorológicos) y se concentraron sólo en algunos países. Variables ambientales como la temperatura, las precipitaciones y el viento fueron ampliamente estudiadas y tuvieron efectos negativos generalizados sobre distintos aspectos biológicos y ecológicos de las abejas melíferas. Además, las reservas alimenticias, las interacciones planta-polinizador, la mortalidad, la expresión génica y el metabolismo se vieron afectados negativamente. Entre los vacios de conocimiento cabe mencionar la falta de estudios a nivel de colmenar y apicultor, la escasez de estudios de predicción y percepción, la escasa representación de las grandes escalas espaciales y a mediano plazo, el déficit de análisis climáticos y la escasa comprensión de los impactos potenciales de plagas y enfermedades. Por último, las repercusiones del cambio climático en la apicultura mundial siguen siendo un tema emergente, que debe estudiarse en los distintos países. Esto se debe principalmente a sus diversos efectos sobre las abejas melíferas y a la necesidad potencial de aplicar medidas de adaptación para mantener esta actividad crucial en escenarios medioambientales complejos.

Long-term effect of temperature on honey yield and honeybee phenology.

There is growing concern about declines in pollinator species, and more recently reservations have been expressed about mismatch in plant-pollinator synchrony as a consequence of phenological change caused by rising temperatures. Long-term changes in honeybee Apis mellifera phenology may have major consequences for agriculture, especially the pollinator market, as well as for honey production. To date, these aspects have received only modest attention. In the current study, we examine honeybee and beekeeping activity in southern Poland for the period 1965-2010, supplemented by hive yields from a beekeeper in southern UK in the same period. We show that despite negative reports on honeybee condition, and documented climate change, the studied apiary managed to show a marked increase in honey production over the 46 year study period, as did that from the UK. The proportion of the annual yield originating from the first harvest decreased during the study period and was associated with rising temperatures in summer. Honeybee spring phenology showed strong negative relationships with temperature but no overall change through time because temperatures of key early spring months had not increased significantly. In contrast, increasing yields and an increased number of harvests (and hence a later final harvest and longer season) were detected and were related to rising temperatures in late spring and in summer.

Temporal Variation in Honey Production by the Stingless Bee Melipona subnitida (Hymenoptera: Apidae): Long-Term Management Reveals its Potential as a Commercial Species in Northeastern Brazil.

Even though stingless beekeeping has a great potential as a sustainable development tool, the activity remains essentially informal, technical knowledge is scarce, and management practices lack the sophistication and standardization found in apiculture. Here, we contributed to the further development of stingless beekeeping by investigating the long-term impact of management and climate on honey production and colony survival in the stingless bee Melipona subnitida Ducke (1910). We analyzed a 10-yr record of 155 M. subnitida colonies kept by a commercial honey producer of northeastern Brazil. This constitutes the longest and most accurate record available for a stingless bee. We modeled honey production in relation to time (years), age, management practices (colony division and food supplementation), and climatic factors (temperature and precipitation), and used a model selection approach to identify which factors best explained honey production. We also modeled colony mortality in relation to climatic factors. Although the amount of honey produced by each colony decreased over time, we found that the probability of producing honey increased over the years. Colony divisions decreased honey production, but did not affect honey presence, while supplementary feeding positively affected honey production. In warmer years, the probability of producing honey decreased and the amount of honey produced was lower. In years with lower precipitation, fewer colonies produced honey. In contrast, colony mortality was not affected by climatic factors, and some colonies lived up to nine years, enduring extreme climatic conditions. Our findings provide useful guidelines to improve management and honey production in stingless bees.

Nectar Characteristics and Honey Production Potential of Five Rapeseed Cultivars and Two Wildflower Species in South Korea.

The growing beekeeping industry in South Korea has led to the establishment of new honey plant complexes. However, studies on honey production from each species are limited. This study aimed to assess the honey production potential of various Brassica napus cultivars and two wildflower species. The nectar characteristics of B. napus varied significantly among the cultivars. Absolute sugar concentrations differed among the cultivars, but sugar composition ratios were similar. In contrast, the amino acid content remained relatively uniform regarding percentage values, irrespective of the absolute concentrations. Estimations of honey potential production per hectare (kg/ha) resulted in the following ranking among cultivars: 'JM7003' (107.1) > 'YS' (73.0) > 'JM7001' (63.7) > 'TL' (52.7) > 'TM' (42.4). The nectar volume of Pseudolysimachion rotundum var. subintegrum and Leonurus japonicus increased during the flowering stage. P. rotundum var. subintegrum was sucrose-rich and L. japonicus was sucrose-dominant. Both species predominantly contained phenylalanine, P. rotundum var. subintegrum had glutamine as the second most abundant amino acid, and L. japonicus had tyrosine. The honey production potential was 152.4 kg/ha for P. rotundum var. subintegrum and 151.3 kg/ha for L. japonicus. These findings provide a basis for identifying food resources for pollinators and selecting plant species to establish honey plant complexes.

Greenhouse Gas (GHG) Emissions from Honey Production: Two-Year Survey in Italian Beekeeping Farms.

The objective of this study was to quantify the climate change (CC) impact of the honey supply chain in different beekeeping systems and farms, over two consecutive years. The CC impact category is quantified as kg CO2 equivalent and it evaluates the GHG emissions, mainly CO2, N2O, and CH4. The results ranged from 0.44 to 3.18 (p = 0.039) kg CO2e/kg honey with higher values in 2021 than 2020. The main contributors to climate change of the honey supply chain are represented by transport and supplemental feeding inputs. The beekeeping system (migratory or stationary) influenced CC: the contribution to CC for stationary farms was estimated at 0.58 kg CO2e/kg honey and 2.48 for migratory ones (p < 0.001). Given the close connection between honey yield and LCA results due to the unit of measurement of impact, i.e., kg of honey produced, an index was developed (wildflower honey climate index) as a simple benchmark tool for prediction of honey yield in the survey context. Using the data from the present study, we found that the index is positively related to honey yield (r = 0.504; p < 0.05) but negatively related to supplemental feeding (r = -0.918; p < 0.01) and overall carbon footprint (r = -0.657; p < 0.05). Further studies are needed to better explain the effects of weather on honey production, as well as environmental impact.

Plant Species as Potential Forage for Honey Bees in the Al-Baha Mountain Region in Southwestern Saudi Arabia.

The contribution of bee forages in the form of nectar, pollen, and propolis to beekeeping development depends on plant species diversity. The data concerning the increase in honey production in southwestern Saudi Arabia, which was unexpected with the deterioration of the vegetation cover, becomes a concrete background for this study, which planned to list the bee plant species contributing as sources of nectar, pollen, and propolis. The sampling method followed a purposive random sampling approach, and 20 × 20 m plots were considered with a total of 450 sample plots. Bee forage plants were identified based on flower morphology and honey bees' actions during floral visits at active foraging hours. A checklist of bee forages containing 268 plants species belonging to 62 families was documented. The number of pollen source plants (122) was more than nectar (92) and propolis (10) source plants. Regarding seasonal distribution, spring and winter were relatively good seasons for honey bees in terms of pollen, nectar, and propolis availability. Generally, this study is an essential step towards understanding, conserving, and rehabilitating plant species providing nectar, forage, and propolis to honey bees in Al-Baha Region of Saudi Arabia.

Observation of Genetic Gain with Instrumental Insemination of Honeybee Queens.

Controlling mating in the honeybee (Apis mellifera) is part of one of the greatest challenges for the beekeeping industry's genetic selection programs due to specific characteristics of their reproduction. Several techniques for supervising honeybee mating with relative effective control have been developed over the years to allow honeybee selection. As part of this project, we compared the genetic gains for several colony performance traits, obtained using the BLUP-animal method, according to the selection pressure applied in controlled reproduction (directed fertilization versus instrumental insemination). Our results show similar genetic gains for hygienic behavior and honey production between colonies whether queens were fertilized naturally or via instrumental insemination, as well as similar or lower genetic gains for colonies with queens inseminated for spring development. In addition, we noticed greater fragility in queens following insemination. These findings show that instrumental insemination is an effective tool for reproductive control in genetic selection and for estimating breeding values more precisely. However, this technique does not result in queens of superior genetic quality for commercial purposes.

Nosema ceranae Infections in Honey Bees (Apis mellifera) Treated with Pre/Probiotics and Impacts on Colonies in the Field.

Alternatives to the antibiotic fumagillin for the control of Nosema ceranae, a gut parasite of the honey bee, are needed. The prebiotics eugenol, chitosan, and naringenin and the probiotic Protexin® (Enterococcus faecium) provided in sugar syrup or protein patty either in spring or fall were evaluated for their effects on N. ceranae infection, colony population, honey yield and winter survivorship using field colonies. In the first year, spring treatments with eugenol, naringenin, and Protexin® significantly reduced N. ceranae infection and increased honey production, while Protexin® also increased adult bee populations and chitosan was ineffective. Fall treatments increased survivorship and decreased N. ceranae infection the following spring. In the second year, selected compounds were further tested with a larger number of colonies per treatment and only protein patty used in the spring and sugar syrup in the fall. Protexin® and naringenin significantly decreased N. ceranae infections and increased the population of adult bees after spring treatment, but did not affect honey yields. There were no differences between treatments for colony winter mortality, but surviving colonies that had been treated with Protexin® and naringenin were significantly more populated and had lower N. ceranae spore counts than control, non-treated colonies. Protexin® and naringenin were the most promising candidates for controlling N. ceranae and promoting honey bee populations, warranting further investigation. Future research should investigate the optimal colony dose and treatment frequency to maximize colony health.

Expanding the reach: ethnobotanical knowledge and technological intensification in beekeeping among the Ogiek of the Mau Forest, Kenya.

BACKGROUND: Initiatives for beekeeping intensification across the tropics can foster production and income, but the changes triggered by the introduction of modern beehives might permeate traditional knowledge and practices in multiple ways, and as such should be investigated and understood. We conducted an ethnobotanical study in the Eastern part of the Mau Forest among Ogiek beekeepers who customarily practice forest beekeeping and who are involved in a project aimed at the modernization of their beekeeping activities. We aimed to document the beekeeping-associated ethnobotanical knowledge, exploring the relationships and complementarity between modern and traditional knowledge and practices. METHODS: Field research was carried out through semi-structured interviews with 30 Ogiek beekeepers and 10 additional stakeholders. We collected ethnobotanical data about plants used for beekeeping purposes, and ethnographic information on traditional and modern beekeeping systems. RESULTS: We report 66 plant species, distributed across 36 botanical families representing 58 genera, important as melliferous, for the construction and placing of hives, attracting bees, and harvesting and storing honey. Dombeya torrida (J.F.Gmel.) Bamps, Juniperus procera Hochst. ex Endl., and Podocarpus latifolius (Thunb.) R.Br. ex Mirb. are the species with the most mentions and the highest number of uses. Our study reveals that the Ogiek possess a detailed knowledge of the forest's flora, its importance and uses and that this knowledge underpins beekeeping practices. Under the influence of external actors, the Ogiek have progressively adopted modern versus traditional log hives and moved beekeeping out of the forest into open areas of pastures and crop fields. Beekeepers are also experimenting with combinations of practices borrowed from modern and traditional beekeeping systems, particularly in the field of hive construction and in the criteria to set up apiaries. CONCLUSIONS: The study indicates a complementarity and an incipient hybridization of traditional and modern beekeeping, in a way that suggests that modern beehives are instrumental in expanding the reach of beekeeping into deforested and cultivated areas. The study also points to the existence of a rift in the effects of beekeeping intensification on the livelihoods of the Ogiek and on their relationship with the forest. We argue that this intensification might be improving the former but weakening the latter, carrying the associated risk of erosion of traditional forest-based ethnobotanical knowledge.

Economics of technical efficiency in white honey production: Using stochastic frontier production function.

This study estimates and compares technical efficiency levels among beekeeping projects with various production capacities using a sample drawn from Fayoum Governorate in Egypt. The study also compares among beekeeping's most important economic indicators, estimates the optimum production amount, and investigates why technical efficiency in Egyptian beekeeping is declining. We conclude that the average cost to produce one ton of honey decreases when production capacity increases. Furthermore, the average total, net return, and return on investment of one Egyptian pound increases when production capacity increases. Moreover, the results of a stochastic frontier production function indicate an increased return to scale. Finally, the results of maximum likelihood estimation show that technical inefficiency helps explain the deviation of actual from optimal production amounts.

The Effect of Diet on the Composition and Stability of Proteins Secreted by Honey Bees in Honey.

Honey proteins are essential bee nutrients and antimicrobials that protect honey from microbial spoilage. The majority of the honey proteome includes bee-secreted peptides and proteins, produced in specialised glands; however, bees need to forage actively for nitrogen sources and other basic elements of protein synthesis. Nectar and pollen of different origins can vary significantly in their nutritional composition and other compounds such as plant secondary metabolites. Worker bees producing and ripening honey from nectar might therefore need to adjust protein secretions depending on the quality and specific contents of the starting material. Here, we assessed the impact of different food sources (sugar solutions with different additives) on honey proteome composition and stability, using controlled cage experiments. Honey-like products generated from sugar solution with or without additional protein, or plant secondary metabolites, differed neither in protein quality nor in protein quantity among samples. Storage for 4 weeks prevented protein degradation in most cases, without differences between food sources. The honey-like product proteome included several major royal jelly proteins, alpha-glucosidase and glucose oxidase. As none of the feeding regimes resulted in different protein profiles, we can conclude that worker bees may secrete a constant amount of each bee-specific protein into honey to preserve this highly valuable hive product.

Brevibacillus laterosporus isolated from the digestive tract of honeybees has high antimicrobial activity and promotes growth and productivity of honeybee's colonies.

The development of novel antimicrobial drugs, as well as the discovery of novel compounds able to promote honeybee's growth, represents major challenges for modern entomology. The main aim of this study was to investigate whether Brevibacillus laterosporus isolated from the digestive tract of Saudi honeybees, Apis mellifera, was able to stimulate colony strength parameters of honeybees and to evaluate its ability to produce antimicrobial agents. Honeybees were collected in Dirab, Riyadh Region, Saudi Arabia, and microorganisms were isolated and identified by 16S ribosomal RNA analysis. Microscopic identification of the microorganism in its native state was facilitated by atomic force microscopy at high-resolution imaging. Active biological compounds were produced by submerged fermentation with B. laterosporus. The fermented broth was subjected to extraction and purification, and then semi-pure compounds were analyzed by gas chromatography-mass spectrometry. The effectiveness of the crude extract and semi-pure compounds as antimicrobial agents was evaluated by susceptibility assays. More than 22% of the microorganisms isolated from the digestive tract of healthy honeybees have been identified as B. laterosporus, this kind of species has a unique shape and morphological structure. The cyclic dipeptide cyclo(Leu-Pro) produced by B. laterosporus showed biological activity against several pathogenic microorganisms. Furthermore, the total counts of workers, closed brood, and open brood, as well as the production of bee pollen and honey, were better in honeybees treated with a B. laterosporus suspension. The data indicated that the B. laterosporus strain isolated from a healthy honeybee might be a novel probiotic and a producer of important biological compounds.

Pollen Collection, Honey Production, and Pollination Services: Managing Honey Bees in an Agricultural Setting.

Hybrid canola seed production is an important pollination market in Canada; typically both honey bees (Apis mellifera L. (Hymenoptera: Apidae)) and Alfalfa Leafcutting bees (Megachile rotundata Fab. (Hymenoptera: Megachilidae)) are concurrently managed to ensure pollination in this high-value crop. Beekeepers are paid to provide pollination services, and the colonies also produce a honey crop from the canola. Pollen availability from male-fertile plants is carefully managed in this crop to provide an abundance of pollen to fertilize male-sterile ('female') plants. This abundance of pollen represents an underutilized resource for beekeepers, and an opportunity to diversify the hive-products produced for market in this management system. We used a commercial-style pollen trap to collect pollen from colonies twice weekly for the duration of canola pollination, and compared the honey production and amount of sealed brood in colonies with pollen traps to those without pollen traps. We found that while pollen trapping reduced honey production, there was no negative impact on brood production, and at current market prices, the per-hive revenue was higher in colonies from which pollen was trapped. Pollen trapping honey bee colonies in the context of hybrid canola pollination, therefore, offers beekeepers an opportunity to diversify their products and increase their revenue.

A novel GIS-based approach to assess beekeeping suitability of Mediterranean lands.

Honeybees are critically important for the environment and to the economy. However, there are in substantial decline worldwide, leading to serious threat to the stability and yield of food crops. Beekeeping is of pivotal importance, combining the wide economical aspect of honey production and the important ecological services provided by honeybees. In this scenario, the prompt identification of beekeeping areas is strategic, since it maximised productivity and lowered the risks of colony losses. Fuzzy logic is an ideal approach for problem-solving tasks, as it is specifically designed to manage problems with a high degree of uncertainty. This research tested a novel GIS-based approach to assess beekeeping suitability of lands located in Calabria (Southern Italy), without relying to Analytic Hierarchy Process - Multiple Criteria Decision Making (AHP-MCDM), thus avoiding the constraints due to the technique and decision makers' influences. Furthermore, the data used here were completely retrieved from open access sources, highlighting that our approach is characterized by low costs and can be easily reproduced for a wide arrays of geographical contexts. Notably, the results obtained by our experiments were validated by the actual beekeeping reality. Besides beekeeping, the use of this system could not only be applied in beekeeping land suitability evaluations, but may be successfully extended to other types of land suitability evaluations.

Assessment of bacterial quality of honey produced in Tamale metropolis (Ghana).

The bacterial quality of honey from different production sites within Tamale metropolis, Ghana, was estimated using standard microbiological methods. Honey samples were bought from six different production sites within Tamale metropolis and labeled. Samples that were taken from location B recorded the least mean bacterial count of 6.0×104 colony forming units/mL with samples taken from location D showing the highest, 1.1×105 colony forming units/mL. However, samples from production sites E and F recorded no bacteria growth. Bacteria isolated included Escherichia coli, Staphylococcus spp., Shigella spp., Streptococcus spp., and Bacillus spp. The pH values of honey samples from the various locations were found to be directly correlated to the average bacteria load. The variation in bacteria load and species at the various production sites and the absence of bacteria growth in two production sites is an indication of the differences in production practices, as well as hygienic conditions at these sites. The presence of these isolates is a cause for concern as pathogenic strains of these bacteria can cause serious health related problems.

Screening alternative therapies to control Nosemosis type C in honey bee (Apis mellifera iberiensis) colonies.

Nosemosis type C caused by the microsporidium Nosema ceranae is one of the most widespread of the adult honey bee diseases, and due to its detrimental effects on both strength and productivity of honey bee colonies, an appropriate control of this disease is advisable. Fumagillin is the only veterinary medicament recommended by the World Organization for Animal Health (OIE) to suppress infections by Nosema, but the use of this antibiotic is prohibited in the European Union and few alternatives are available at present to control the disease. In the present study three therapeutic agents (Nosestat®, Phenyl salicylate and Vitafeed Gold®) have been tested to control N. ceranae infection in honey bee colonies, and have been compared to the use of fumagillin. None of the products tested was effective against Nosema under our experimental conditions. Low consumption of the different doses of treatments may have had a strong influence on the results obtained, highlighting the importance of this issue and emphasizing that this should be evaluated in studies to test therapeutic treatments of honey bee colonies.

Geographic variation in the growth of domesticated honey bee stocks: disease or economics?

Declines in the stocks of domesticated honey bees in some countries have been attributed to disease, which is at odds with an increasing global trend in the total number of hives. Based on data on annual growth rates in hive numbers and honey production for 87 countries, we tested the hypothesis that geographic heterogeneity in the growth of the domesticated honey bee population can be attributed to disease. In contrast to predictions of this hypothesis, changes in honey production varied in proportion to changes in hive number. Also, growth in honey production was not more spatially heterogeneous than growth in hive numbers, as expected under a scenario of contagious pests. We argue that although disease aggravates production costs, it has less effect on changes in national hive numbers than labor costs, so that geographic variation in the growth of the global honey bee stock reflects the global division of human labor that is a hallmark of economic globalization, rather than persistent and pervasive biological causes.