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The honey bee subspecies native to Saudi Arabia, Apis mellifera jemenitica Rutter, is currently being threatened by genetic pressure from exotic subspecies imported by commercial beekeepers. Uncontrolled interbreeding between native and exotic subspecies could dilute advantageous adaptations and give rise to new haplotypes that are not well suited for Saudi Arabia’s harsh climate. In this study, we analyzed the mitochondrial haplotypes and parasitization patterns by Varroa destructor mites in commercial beekeeping operations across Southwestern Saudi Arabia. We sampled 300 workers from five randomly chosen colonies at each of the eleven apiaries from December 2022 to February 2023. We extracted DNA from two workers per colony for analysis of the mitochondrial COI-COII region and assessed the remaining workers for mite infestation levels. We also haplotyped a subgroup of mites. All 55 colonies analyzed belonged to the A. m. jemenitica subspecies, which is part of the Z subgroup of the A lineage. Mitochondrial genome analysis revealed ten distinct haplotype sequences at four of the eleven locations. The average (± SEM) number of mites per 100 workers across all sites was 1.95 ± 0.96 and was below a 3% infestation threshold at nine of the eleven locations. All tested mites belonged to the Korean haplotype. The Al-Riyan, Al-Radha, and Khaitaa apiaries had both, no novel haplotypes, and the lowest Varroa mite infestation levels. This study could ultimately inform a colony selection process for the implementation of a breeding program aimed at improving honey bee productivity in Southwestern Saudi Arabia. [ABSTRACT FROM AUTHOR]

The tiny population of the endemic Maltese honey bee (A. m. ruttneri) is threatened by anthropogenic influences, such as urbanisation, habitat loss, and unsustainable agricultural practices, but most prominently by the importation of commercially important non-native stock. To obtain data on the colony life cycle parameters of A. m. ruttneri and to measure its apicultural performance in relation to imported A. m. ligustica under Maltese conditions, we conducted a comparative study between mid-2017 and early 2020. Over one full season, colonies of both subspecies (A. m. ruttneri (n = 15) vs. A. m. ligustica (n = 18)) were regularly assessed for survival, colony size, behaviour, and presence of diseases. The comparative assessments were completed in September 2018, but monitoring and sampling of the surviving colonies of A. m. ruttneri continued until March 2020. Our results clearly indicate that the tested group of sister queens of A. m. ruttneri is well adapted to the prevailing environmental conditions in Malta. The colonies survived significantly longer compared to the tested group of sister queens of A. m. ligustica and performed better in several parameters measured, their colony development, and health being well in tune with the environment. A. m. ruttneri received acceptable scores for behavioural traits (gentleness and calmness on the comb), showing potential for improvement by breeding. The results from this pioneering study clearly indicate that A. m. ruttneri, with its superior adaptation to Maltese conditions and the potential to improve by breeding, represents a prime option towards economically sound beekeeping on the Maltese archipelago. [ABSTRACT FROM AUTHOR]

Bees are important insects both environmentally and economically. Despite this, most bee species are poorly characterized regarding their morphology and nesting habits, which are relevant characteristics for planning management and conservation. Plebeia flavocincta is a stingless bee species that occurs in the Northeast region of Brazil and there is little knowledge about its morphology and nesting biology. Here, we morphologically characterize Plebeia flavocincta workers from 54 colonies and use seven colonies to describe the structure of the species’ nest. All nests were found in seasonally dry forest areas in different substrates, namely, hollow of native trees, wall, post, and wooden boxes. The structure of the species’ nest was detailed in terms of the number, shape, and area of the combs; brood cell size; size of food pots; nest size; and honey volume. Plebeia flavocincta is found in both natural and urban environments. The structure of the nest of Plebeia flavocincta is similar to that found in other species of the same genus. This is the first nest diagnosis study of the species. In addition, by establishing morphological data to recognize Plebeia flavocincta, this study provides useful information for management and conservation plans for the species. [ABSTRACT FROM AUTHOR]

The beekeeping sector is facing many challenges. One of the greatest is maintaining healthy colonies that produce high-quality products without any residues of veterinary medicines and with low environmental impact. The main enemy is the ectoparasitic mite Varroa destructor, the most significant honeybee pest and a key factor in high colony losses worldwide. In the previous four decades, three pillars of Varroa control have crystallized to be essential for sustainable management: apitechnical measures, chemical treatments, and resistant stocks of honey bees. In the long term, the latter is probably the most sustainable as it is a step to self-sustaining populations of feral and managed colonies. We recognize the significance of progress in knowledge of all three pillars to conquer Varroa and of their successful usage in accordance with local and global conditions and capabilities. In this review, we present a possible integration of the components of the three pillars of Varroa control strategies in the light of sustainable beekeeping and provide their linkage to the production of high-quality and safe honeybee products and maintaining healthy colonies. [ABSTRACT FROM AUTHOR]

Varroa mites (Varroa destructor) are the most significant threat to beekeeping worldwide. They are directly or indirectly responsible for millions of colony losses each year. Beekeepers are somewhat able to control varroa populations through the use of physical and chemical treatments. However, these methods range in effectiveness, can harm honey bees, can be physically demanding on the beekeeper, and do not always provide complete protection from varroa. More importantly, in some populations varroa mites have developed resistance to available acaricides. Overcoming the varroa mite problem will require novel and targeted treatment options. Here, we explore the potential of gene drive technology to control varroa. We show that spreading a neutral gene drive in varroa is possible but requires specific colony-level management practices to overcome the challenges of both inbreeding and haplodiploidy. Furthermore, continued treatment with acaricides is necessary to give a gene drive time to fix in the varroa population. Unfortunately, a gene drive that impacts female or male fertility does not spread in varroa. Therefore, we suggest that the most promising way forward is to use a gene drive which carries a toxin precursor or removes acaricide resistance alleles. [ABSTRACT FROM AUTHOR]

Apocephalus borealis is a parasitoid of hymenopterans native to North America that also attacks introduced honey bees (Apis mellifera). Parasitism by this species has been associated with infested bees absconding the hive and dying outside. The flies can also harbour viral infections and nosematosis. Recently, nucleotide sequences identical to A. borealis were reported from bulk screenings of honey bees from Belgium and South Korea, although no adult flies have been collected. To predict the potential invasion risk of A. borealis across the world, we constructed a MaxEnt species distribution model based on occurrence data from North America submitted to the citizen science project ZomBee Watch (zombeewatch.org) and from museum specimens. The results have shown that extensive parts of Europe, the Mediterranean Basin, Asia Minor, southern Africa, eastern Asia, Australasia, and North and South America have high degrees of climatic suitability for invasion, suggesting that the fly could establish in these regions. The potential invasion range is expected to stay similar under different climate change scenarios. We discuss the status of A. borealis as an invasive species and measures that can be taken to reduce the risk of its introduction outside of North America. Our results highlight A. borealis as a potential threat to honey bee health worldwide that requires urgent attention of international veterinary bodies to prevent its spread. [ABSTRACT FROM AUTHOR]

Australia is one of the few countries where Apis mellifera are not infested by the parasitic mite Varroa destructor. In Australia a program called the 'Sugar Shake Team' has been implemented to detect an incursion of V. destructor, should it occur. The aim of this paper was to provide an estimate of the probability that V. destructor would be detected by the Sugar Shake Team program if an incursion had actually occurred (surveillance system sensitivity) using a scenario tree modelling approach. A secondary aim was to provide commentary on how surveillance for V. destructor incursions into Australia might be made more effective. Our analyses show that if one apiary in the study area was infested with V. destructor, there was only a 0.47% probability that infestation would be detected by the current program. We conclude that in its current form the Sugar Shake Team program does not provide protection to multi-billion-dollar beekeeping, pollination and agricultural industries in Australia. Surveillance for V. destructor can be made more effective by increasing the coverage and frequency of testing, deployment of additional sentinel hives and the use of sticky boards. [ABSTRACT FROM AUTHOR]

Multiple harmful factors cause chronic sub-lethal stress in managed honey bee colonies. In weak colonies, worker bees may not efficiently maintain the optimum temperature (33–36°C) in peripheral brood development areas. A short period at 25°C induces physiological adjustments and increases the mortality in honey bee brood reared in vitro. Molecular damage due to oxidative imbalance can be one of the main causes of mortality when organisms are under stress. Here, we demonstrate that in vitro rearing honey bee brood exposed 3 days at sub-optimal temperature (25°C) does not lead to H2O2 accumulation and oxidative protein damage. Cold-stressed honey bee brood showed increased levels of both total antioxidant status (TAS) and expression of peroxiredoxins PRX1 and PRX4, but not of catalase activity. Results indicate that specific antioxidant defenses induced in honey bee brood under moderated cold stress are enough to keep H2O2 levels under control and avoid major protein damages. It is concluded that the increase of mortality in cold-stressed brood are due to multifactor's, beyond uncontrolled oxidative injuries. [ABSTRACT FROM AUTHOR]

Black soldier fly larvae (Hermetia illucens) were discovered in a weak honey bee colony in Hailey, Idaho. The larvae were localized to the brood area and caused the affected comb to putrefy. Further communication with the beekeeper revealed that the colony recently returned from California and that the larvae likely originated there as well. In California, H. illucens are common and exist sympatrically with honey bees, yet there have been very few reports of damage. We therefore believe H. illucens are unlikely to cause damage to healthy colonies or significantly impact the apiculture industry. This report is the first published observation of H. illucens in Idaho and shows conclusively for the first time that H. illucens associates with honey bee colonies in North America. [ABSTRACT FROM AUTHOR]

Chemical miticides are used routinely in honey bee colonies worldwide as treatment for the parasitic mite Varroa destructor, but there have been very few long-term colony-level field studies of the impacts of miticides on the bees themselves. Lab-based studies with individual bees or bees in small groups have highlighted many negative effects of miticides on bee behaviour and physiology; hence, there is an urgent need to better understand the consequences of miticides on honey bee colonies in an apicultural setting. Here we compared effects of commercial treatments of the miticides tau-fluvalinate and thymol, and controls, on honey bee colonies and bee foraging behaviour over five months, from autumn through winter in Sydney, Australia. Since V. destructor does not occur in Sydney, in this study, we could isolate the direct effects of the miticides from indirect effects resulting from reduced mite load. We found the autumn treatment of either miticide caused no significant change in bee adult or brood population or size of food stores. The average temperature in the thymol group differed from the temperature in the control group and was lower during winter. Neither miticide reduced bee longevity. Tau-fluvalinate caused bees to start foraging earlier in life and perform shorter trips, but no other effects on foraging behaviour were documented. To conclude, in Sydney, Australia, limited negative effects of autumn thymol or tau-fluvalinate treatments were observed on bees or bee colony performance. [ABSTRACT FROM AUTHOR]

A longitudinal study was carried out in order to evaluate Nosema spp. spore counts in two key moments of the year (late autumn and spring) in honeybee colonies from five eco-regions of Argentina. Three hundred and sixty colonies were randomly selected and the infestation level of Nosema spp. and Varroa destructor was assessed in autumn and spring of 2015. In addition, a questionnaire concerning all management practices applied in the colonies was answered by the beekeepers. Generalized linear mixed effect models were performed to determine the relationship between risk factors associated with Nosema spp. spore counts in each eco-region. Data were scanned to identify colonies cluster with a higher probability of achieving high values of Nosema spp. abundance for each sampling period. Spatial distribution of colonies with a higher risk of achieving high Nosema spp. abundance seems to be explained by geographical conditions associated to climatic conditions and some management practices implemented in each eco-region. [ABSTRACT FROM AUTHOR]

Traditional beekeeping has been playing important socio-economic roles in Ethiopia for millennia. The country is situated in northeast Africa, where ranges of major evolutionary lineages of Apis mellifera adjoin. However, studies on the classification and distribution of subspecies and lineages of honey bees in the country are partly inconsistent, either proposing multiple subspecies and lineages or a unique A. m. simensis. This study was conducted with the aim of elucidating Ethiopian honey bees in reference to African subspecies and major global lineages using wing geometric morphometrics and COI-COII mitochondrial DNA analyses. For this purpose, 660 worker bees were collected from 66 colonies representing highland, midland, and lowland zones in different locations. Both methods indicated that the samples from this study form a distinct cluster together with A. m. simensis reference. In addition, forewing venation patterns showed that most of the Ethiopian samples are separate from all reference subspecies, except A. m. simensis. Analysis of COI-COII sequences revealed five DraI haplotypes (Y2, Y1, A1, and O5'), of which one was new denoted as Y3. Moreover, centroid size strongly associated with elevation. In conclusion, the results supported that Ethiopian honey bees are distinct both at lineage and subspecies levels; however, there is an indication of lineage O in the north. [ABSTRACT FROM AUTHOR]

The aim of the research was to determine the influence of acetamiprid and deltamethrin on the mortality and behaviour of honeybees of the same variety, coming from the same source and estimated to be in good condition by a professional beekeeper, but in different years and under different weather conditions. Results of research conducted in field isolators in oilseed rape fields in the years 2012–2018 showed no acetamiprid influence either on the mortality or on the behaviour of honeybees. Deltamethrin activity differed from a lack of influence through causing mortality and a weaker condition of honeybee colonies to the destruction of the colony. This demonstrates the relative safety of acetamiprid to honeybees and the high risk of deltamethrin use. The differences in the bee colonies' reaction to deltamethrin are probably caused by the high acute toxicity of this active ingredient, genetically dependent, variable metabolic capabilities of particular bee colonies, or coexistence of a variety of different stressors—mainly pathogens. [ABSTRACT FROM AUTHOR]

Research and development of new natural and safe veterinary medicaments to treat honey bee varroosis caused by Varroa destructor Anderson and Trueman is an important step on the path to embarking on organic beekeeping. In the present research, field experiments were conducted to evaluate the efficacy of a new plant-based formulation against varroa mite and its safety for the honey bees during the summer and autumn of 2018 in Shirvan, North Khorasan, Iran. It was found that the corrected efficacy of this formulation in the summer (48.70%) was significantly higher than that in the autumn (29.08%). These results proved the importance of ambient temperature on the varroacidal effectiveness of the formulation. An acceptable safety margin for eggs, larvae, adult workers, and queen bees was observed after employing the formulation over a 4-week treatment period in the summer experiment. The effects of the formulation on the enzyme activities and the amounts of energy reserves of the treated bees are also discussed. [ABSTRACT FROM AUTHOR]

Agrochemicals and biocides are suspected to cause a dysbiosis of honey bee microbiota, decreasing colonies ability to respond to the environment. As a first step to investigate agriculture and beekeeping impact, hives bacteriomes from an anthropized environment (Agri-env) were compared to that of pristine's (Prist-env). 16S rRNA sequencing evidenced differences in richness and composition between sample types (Gut (G), Brood (B), Bee-bread (BB)) and environments. Higher opportunist loads and shifts toward taxa capable of metabolizing insecticides were observed in G and B at Agri-env, while beneficial bacteria were enriched in Prist-env. Bacteria in BB did not differ, the acidity of the niche outweighing the influence of external factors. Results showed the environment plays a major role in shaping honey bee microbiota, the agricultural realm inducing a bacterial disruption that would let to colonies vulnerability. In contrast, a less susceptible bee will be promoted in less anthropized locations. [ABSTRACT FROM AUTHOR]

The ectoparasite V. destructor is one of the major threats to Western honeybees' production (A. mellifera) worldwide, causing colony losses and reducing bees' productivity and pollinating capacity. Since parasitism produces high energy consumption in hosts, the aim of this study was to compare the effects of this ectoparasite on energy expenditure and survival rate in honeybees. Newborn bees were kept in chambers at 32 °C and 55% humidity with food ad libitum. Individual bees were taken at random and grouped into three treatments: T0 (no mites), T1 (one mite), and T2 (two mites). After the mites had fed on the bees, the metabolic rate (CO2 production = VCO2) was individually measured at 32 °C for 3 h. We also measured survival rate, using the same groups for 8 days. A significant effect of the number of mites on VCO2 was found (T0 = 3.14 μLCO2 min−1, T1 = 4.03 μLCO2 min−1 and T2 = 6.44 μLCO2 min−1, F(2) = 25.81, p < 0.001). The treatments did not affect significantly the bees' survival (p = 0.283), despite the survival rates recorded were 57.5% in T0, 42.5% in T1, and 40.0% in T2. V. destructor clearly increases the energetic cost of living in bees and provoking a reduction of the survival rate even when this value was not significant statistically. [ABSTRACT FROM AUTHOR]

In vitro rearing of honey bees is becoming a widely employed procedure. Nevertheless, few studies have assessed its impact on brood development considering nutritional and social differences between both in vitro and in-hive rearing contexts. We compared developmental parameters between these two contexts using an intra-frame grafting procedure. We confirmed a grafting effect on development. However, pre-imaginal survival did not depend on the rearing procedure. The correlation in mortality between groups of larvae (exposed or not to grafting) was independent of the rearing context suggesting transmission of inheritable and infectious factors. In addition, the comparison between contexts showed that in vitro larvae had delayed molting and achieved emergence 1.57 days later. Furthermore, in vitro imagoes emerged with lower weight and shorter wing length than in-hive bees. Our results strengthen the idea that there is an in vitro phenotype as a consequence of phenotypic plasticity. [ABSTRACT FROM AUTHOR]

Viral infections are commonly associated with honey bee (Apis mellifera) colony mortality. Using metagenomics, we previously identified 8 viruses from populations of honey bees and 11 other bee species around the world. These viruses had not been previously been described as bee-infecting viruses, and belong to viral families that are not commonly described in bees. To provide a fine-scale characterization of these viruses in the USA, we screened bees from the 2015 USDA National Honey Bee Disease Survey. Two viruses are widespread, and thus likely require further characterization, while four may represent emerging or under surveyed infections. We also compare different approaches for screening samples for viral infections. This study demonstrates the importance of creating and maintaining large-scale collections for the broader research community. [ABSTRACT FROM AUTHOR]

Bees are vital pollinators, but are faced with numerous threats that include loss of floral resources and emerging parasites amongst others. Urbanisation is a rapidly expanding driver of land-use change that may interact with these two major threats to bees. Here we investigated effects of urbanisation on food store quality and colony health in honeybees (Apis mellifera) by sampling 51 hives in four different land-use categories: urban, suburban, rural open and rural wooded during two seasons (spring and autumn). We found positive effects of urban land use on colony strength and richness of stored pollen morphotypes, alongside lower late-season Nosema sp. infection in urban and suburban colonies. Our results reveal that honeybees exhibit lower colony performance in strength in rural areas, adding to the growing evidence that modern agricultural landscapes can constitute poor habitat for insect pollinators. [ABSTRACT FROM AUTHOR]

Various reports recently informed about the effects of contaminated or adulterated wax foundations as a main cause of poor brood and colony development. Beekeepers reported that affected colonies were showing a holey brood pattern and a decline in population size. Twenty-five samples of wax foundations were collected from different sources in Germany. Samples were analyzed using a multi-residue analysis for 147 insecticides, acaricides, and varroacides to investigate the actual load of contamination in beeswax. Furthermore, the effect of selected contaminated and/or adulterated wax foundations on colony and brood development of honeybees was evaluated under field conditions. Our results show that 38 active substances in total were found in the wax samples. Acaricides used in-hive were the most frequently detected contaminants at high concentrations. Trace concentrations of plant protection products and biocides were also found. In the field trials, a significant influence of stearin-adulterated wax on population size, the number of capped brood cells, and termination rate was found compared with the reference. No detectable effects of other treatments on the investigated parameters were observed. [ABSTRACT FROM AUTHOR]

Food shortage, along with biotic stressors, contributes to winter honey bee colony losses. In autumn, to support honey bee colonies and prepare them for the winter season, beekeepers can supply homemade syrups which could contain compounds with possible negative side effects. In this study, we investigated the toxicity of one of those compounds (e.g., hydroxymethylfurfural, HMF) at doses consistent with literature data both to healthy bees and bees challenged with their most important parasite (i.e., Varroa destructor). To strengthen available data on HMF concentration in sugar syrups, we also investigated HMF formation in homemade 2:1 inverted sugar syrup, considering, in particular, the influence of temperature or boiling time on different homemade sugar syrups according to their acidity. Finally, we studied the effects of the acidity of sugar syrups on honeybee survival, and tested whether or not sucrose inversion through acidification is really necessary. We show that doses of HMF similar to those reported as sublethal in the literature appear to be non-toxic even to mite infested bees. However, the amount of HMF that can be found in homemade syrups, which increases with temperature and acidity, can be much higher and can cause significant bee mortality. Moreover, we highlighted the detrimental effect of syrups acidity on honeybee survival, suggesting that the addition of lemon or any other acidifying substance to invert the sucrose could be harmful and not necessary. Our results suggest a responsible approach to homemade colony nutrition. [ABSTRACT FROM AUTHOR]

The absence of a full pedigree can hinder selective breeding efforts. In honeybees, definitive maternity and especially paternity of queens is difficult to determine, even under managed mating schemes (e.g. using artificial insemination) due to the negative effects of single-drone mating on colony fitness. Here we genotyped 388 living queens from two beekeeping operations using Genotyping-by-Sequencing (GBS). We evaluate two methods to call single-nucleotide polymorphism (SNPs), Tassel 5 and Stacks, for their ability to supply SNPs that can recover known relationships. While Stacks discovered more SNPs (29,433), SNPs called with Tassel 5 (16,757) were found to be more accurate for the derivation of relationships. This methodology presents a low-cost genotyping approach and can be used to support commercial honeybee breeding schemes. [ABSTRACT FROM AUTHOR]

Over the past decade, the importance of the beekeeping activities has been emphasized in the field of biodiversity, ecosystems, agriculture, and human health. Thus, deciding correct beekeeping activities seems essential to maintain and improve productivity and efficiency. Due to this importance, considering the economic contributions of beekeeping to the rural area, the need for suitability analysis concept has been revealed. At this point, multicriteria decision analysis (MCDA) and geographical information system (GIS) integration provides efficient solutions to the complex structure of decision-making process for beekeeping activities. In this study, site suitability analysis for beekeeping via analytical hierarchy process (AHP), the technique for order of preference by similarity to ideal solution (TOPSIS), and vise kriterijumska optimizacija I kompromisno resenje (VIKOR) was carried out to increase honey productivity and compare MCDA techniques for Konya city in Turkey. Slope, elevation, aspect, distance to water resources, roads and settlements, precipitation, and flora criteria were included to determine suitability. The requirements, expectations, and limitations of beekeeping activities were specified with the participation of experts and stakeholders. The final suitability maps resulted from each method were validated with existing 117 beekeeping locations and Turkish Statistical Institute 2015 beekeeping statistics for Konya province. Considering existing beekeeper locations, AHP has 82%, VIKOR 88%, and TOPSIS 91% overlapping rates with the suitability maps. According to the correlation R values between total beekeeper count and suitability rates, VIKOR has 0.70, TOPSIS 0.68 and AHP 0.66. [ABSTRACT FROM AUTHOR]

A scientific note on the "Liebefeld Method" to estimate honey bee colony strength: its history, use, and translation Keywords: Apis mellifera; colony development; colony strength; colony estimation; honey bee health EN Apis mellifera colony development colony strength colony estimation honey bee health 422 427 6 06/25/20 20200601 NES 200601 Electronic supplementary material The online version of this article (10.1007/s13592-019-00728-2) contains supplementary material, which is available to authorized users. Quantifying colony strength Researchers have long been interested in understanding the population dynamics of honey bee colonies. Apis mellifera, colony development, colony strength, colony estimation, honey bee health. [Extracted from the article]

The aim of this study was to assess potential harmful lethal and sublethal effects of commercial plant protection product containing Bacillus amyloliquefaciens QST 713 (formerly subtilis) spores on winter adult honeybees according to OECD 245 (2017). Caged winter honeybees fed 10 days with a sucrose solution (50% w/w) ad libitum spiked with a maximum application field rate of 1/1 and its 1/10 showed no dose-dependent mortality under laboratory conditions; the No Observed Effect Concentration (NOEC) appears to be higher than or equal 4 × 107 colony-forming unit (CFU)/ml diet, resp. 4 × 1010 CFU/l diet. Although the results of Denaturing Gradient Gel Electrophoresis (DGGE) analysis showed no significant changes in the composition of gut bacterial community between untreated control and experimental groups after 10 days of chronic exposure, the expression of genes encoding antimicrobial peptides was decreased in one/both treated groups in comparison with untreated control group; significantly lower results of expression were detected in genes for Apidaecin, Defensin-1, and Hymenoptaecin. Despite no direct lethal effect of commercial plant protection product containing Bacillus amyloliquefaciens, QST 713 was observed in adult bees following chronic exposure; the decrease in some immunity parameters observed in tested winter bees may potentially impair bee colony health and survival. [ABSTRACT FROM AUTHOR]

The mite Varroa destructor is an important honey bee parasite that causes substantial losses of honey bee colonies worldwide. Evolutionary theory suggests that the high densities at which honey bees are managed in large-scale beekeeping settings will likely select for mites with greater growth and virulence, thereby potentially explaining the major damage done by these mites. We tested this hypothesis by collecting mites from feral bee colonies, "lightly" managed colonies (those from small-scale sedentary operations), and "heavily" managed colonies (those from large-scale operations that move thousands of colonies across the US on a yearly basis). We established 8 apiaries, each consisting of 11 colonies from a standardized lightly managed bee background that were cleared of mites, and artificially infested each apiary with controlled numbers of mites from feral, lightly managed, or heavily managed bees or left uninoculated as negative control. We monitored the colonies for more than 2 years for mite levels, colony strength (adult bee population, brood coverage, and honey storage), and survival. As predicted by evolutionary theory, we found that colonies inoculated with mites from managed backgrounds had increased V. destructor mite levels relative to those with mites from feral colonies or negative controls. However, we did not see a difference between heavily and lightly managed colonies, and these higher mite burdens did not translate into greater virulence, as measured by reductions in colony strength and survival. Our results suggest that human management of honey bee colonies may favor the increased population growth rate of V. destructor, but that a range of potential confounders (including viral infections and genotype-by-genotype interactions) likely contribute to the relationship between mite reproduction and virulence. [ABSTRACT FROM AUTHOR]

Deformed wing virus and Varroa destructor virus-1 have a high percentage of nucleotide identity and might be considered as closely related viruses: DWV genotype A (DWV-A) and DWV genotype B (DWV-B) respectively. They have been implicated in overwinter colony losses in association with Varroa destructor infestations that vectored both DWV variants. In this study, we performed experimental inoculations of honeybee pupae with viral suspensions prepared from honeybee heads naturally infected by either DWV-A or DWV-B. Two outcomes were observed: the inoculated pupae exhibited either higher rates of bees with deformed wings or higher mortality rates than control bees. For both DWV variants, the viral loads quantified in the head of inoculated bees were significantly greater than those in control bees (p < 0.01). These outcomes were not correlated to the virus genotype (DWV-A or DWV-B) detected in the inocula by RT-quantitative PCR targeting the VP3 coding sequence (RT-qPCR). However, the highest mortality rates found in our study were correlated with an increase in sacbrood virus (SBV) load. Despite the fact that only either DWV-A or DWV-B was expected to be inoculated, we observed increased mortality in honeybees that were infected with both DWV and SBV. [ABSTRACT FROM AUTHOR]

Effects of pesticides have been debated as one of the causes of worldwide declines of bee populations. Improving the risk assessment of pesticides on bees is important to halt these declines. Pesticide risk assessment today mainly focuses on one bee species, the honey bee. Because of differences in life cycles among bee species, this risk assessment needs to be adapted to take these differences into account. For both the adult and larval life stages, development of test protocols for solitary bees is required. Here, we summarize the current knowledge on larval tier 1 tests based on the first test protocols for solitary bee larvae available in the literature. As the ecology and rearing of solitary bees of the genus Osmia spp. are well known, we propose this genus as a model species in a first step to develop protocols for solitary species. In addition, we discuss guidelines, relevant endpoints, and research needs for the development of a standardized oral toxicity test protocol of solitary bee larvae. [ABSTRACT FROM AUTHOR]

Ground-nesting bees are largely undervalued, both in terms of their use as model species for behavioural studies, and in terms of their agricultural benefit as pollinators in crop systems. But, why? One potential barrier limiting their use as model species may be our understanding of how to effectively establish and maintain ground-nesting bees in the laboratory. Here we review how artificial nests are used to study ground-nesting bees and provide guidelines for building, starting and maintaining artificial nests. Ultimately, appropriate design and maintenance of artificial nests will allow researchers to explore a suite of interesting questions related to this important group of pollinating insects, from natural history to the origins of eusociality and the effects of environmental contaminants. [ABSTRACT FROM AUTHOR]

Rearing honey bee, Apis mellifera L., larvae in vitro is a popular risk assessment tool because many uncontrollable factors (e.g., weather conditions, food availability) that bias field studies can be eliminated in the laboratory. However, modern in vitro rearing techniques suffer variable survival rates and OECD guidelines specify a minimum of 70% survival to adult emergence in the untreated negative controls for the test to be considered valid. We hypothesized that the colony from which larvae are sourced for in vitro-rearing risk assessments may affect the survival percentage of those larvae in vitro. To test this hypothesis, we compared the survival rates of brood reared in vitro to that of brood reared by their parental colony to determine if source colony affects brood survival in vitro. Colony-reared and in vitro-reared brood survival percentages were calculated for each of the 14 colonies. There was not a statistically detectable difference in the survival percentage to adult emergence of colony-reared and in vitro-reared bees. Furthermore, the colony-reared brood survival percentage at day 11 (prepupal stage) was predictive of the survival percentage to adult emergence of in vitro-reared bees. We suggest that the 11-day brood survival percentage should be used when selecting suitable colonies for use as source colonies for in vitro-rearing risk assessments. Based on our results, colonies with brood survival percentages of ≥ 80% are suitable colonies from which to source larvae for in vitro-rearing risk assessments. [ABSTRACT FROM AUTHOR]

The use of pesticides on crops contributes to the decline of bee populations, and in this sense, bioactive nutrients have been studied to counteract this effect. We suppose that caffeine might be one of these nutrients. We exposed honey bees (Apis mellifera L.) to 0.7 or 2.0 ng/mL imidacloprid, 5.0 μg/mL caffeine in syrup, or 5.0 μg/mL caffeine in syrup plus 0.7 or 2.0 ng/mL imidacloprid. After 72 h, the oxidative status and the food intake were verified. Imidacloprid increased glutathione peroxidase and catalase activities. Caffeine alone or with 2.0 ng/mL imidacloprid also stimulated the activity of glutathione peroxidase but did not alter the effect of the insecticide on the catalase activity. A significant reduction in the concentration of the thiol group of proteins was observed in the two imidacloprid-fed groups, and the addition of caffeine protected these groups. Imidacloprid increased the malondialdehyde concentration while the addition of caffeine partially decreased this effect. Food intake was higher for bees treated with 2.0 ng/mL imidacloprid. Our results show that imidacloprid increased the food intake resulting in oxidative damage, which was partially reversed by caffeine. From these findings, it is inferred that caffeine treatments can be used to mitigate the sublethal effects of this insecticide on honey bees. [ABSTRACT FROM AUTHOR]

Nosema ceranae is a unicellular fungal parasite of honey bees and causes huge losses for apiculture. Until present, no study on N. ceranae long non-coding RNAs (lncRNAs) was documented. Here, we sequenced purified spores of N. ceranae using strand-specific library construction and high-throughput RNA sequencing technologies. In total, 83 novel lncRNAs were predicted from N. ceranae spore samples, including lncRNAs, long intergenic non-coding RNAs (lincRNAs), and sense lncRNAs. Moreover, these lncRNAs share similar characteristics with those identified in mammals and plants, such as shorter length and fewer exon number and transcript isoforms than protein-coding genes. Finally, the expression of 12 lncRNAs was confirmed with RT-PCR, confirming their true existence. To our knowledge, this is the first evidence of lncRNAs produced by a microsporidia species, offering novel insights into basic biology such as regulation of gene expression of this widespread taxonomic group. [ABSTRACT FROM AUTHOR]

Apitoxin harvesting is a stressful practice for honey bees Apis mellifera L. due to the release of alarm pheromones that alter communication and behaviour and may also affect their physiology. Thus, the goal of this research was to verify the effects of apitoxin harvesting on the development of the hypopharyngeal glands (HGs), evaluating the number and area of acini. For this, ten beehives were subjected to one of two treatments: T1, without apitoxin harvest and T2, with apitoxin harvested by an electric collector. We collected ten 6-day-old honey bees in each treatment once every month (October through December). The HGs were removed and were processed for morphological-stereological analysis. The worker bees from hives subjected to treatment T2 showed a smaller acinar area and lower number of acini than those from hives subjected to treatment T1. Thus, apitoxin harvest negatively affects the structure of the hypopharyngeal glands, consequently affecting the production of royal jelly. [ABSTRACT FROM AUTHOR]

Diapause control and colony initiation are among the major problems encountered in the rearing of bumble bee colonies in small-scale rearing. In this study, we used Bombus terrestris queens obtained from commercial colonies to investigate (1) the diapause survival in virgin and mated queens, (2) the diapause and colony initiation performance of mated bumble bee queens in relation to the pre-diapause weight and (3) the effect of pupae's sex on colony initiation. We found that diapause survival is negatively affected by mating and by the low pre-diapause weight, but first egg deposition and development of the first adult worker were delayed in heavy queens. We found no significant differences in the egg-laying success in relation to pupae's sex; however, queens stimulated with queen pupae laid more eggs per cell and developed a first brood larger than those stimulated with male pupae. Our results can be useful in small-scale rearing, including the rearing of wild queens for conservation purposes. [ABSTRACT FROM AUTHOR]

Pesticides are a possible cause of pollinator decline and honey bee colony losses experienced in several countries in recent years. In the past years, many north-west Italian beekeepers reported the presence of dead brood in field apiaries during neonicotinoid-coated maize sowing; therefore, a possible role of these insecticides was suspected. The objective of this study was to test this hypothesis. Laboratory repeated dose toxicity tests on in vitro reared larvae were carried out using thiamethoxam. The repeated treatment median lethal concentration (LC) and the median lethal dose (LD) 14 and 19 days after grafting were calculated and resulted of the same order of magnitude of realistic brood exposure under a worst-case scenario. Various sublethal effects, like brownish larvae, duplication of the pupal integument, delay in development, and deformed adults were also observed. [ABSTRACT FROM AUTHOR]

Colony losses of managed honeybees have raised a major concern, and surveys of colony losses were conducted around the globe to understand the apicultural situation. Up to now, most studies have focused on the mortality of the Western honeybee ( Apis mellifera); however, little is known about the mortality of its eastern counterpart-the Eastern honeybee ( Apis cerana). Here, we report the survey results of A. cerana colony losses in three consecutive years (2011-2012, 2012-2013, and 2013-2014) in China. Colony losses were low overall (12.8%, 95% CI 11.9-13.7%) but varied among years, provinces, and types of apiaries. We used generalized linear mixed effects models to estimate the effects of possible risk factors and found that queen problems (queenless or drone-laying queens) were associated with colony losses. Further analyses showed that differences in mortality among different types of apiaries may be contributable to the differences in queen problems. This is the first survey of colony losses of A. cerana. [ABSTRACT FROM AUTHOR]

Internal temperatures of honey bee hives kept at different sites in North Dakota were monitored before and during winter to evaluate the effects of treatment, in the form of exposure to commercial pollination, and location on colony health. In October, hives exposed to commercial pollination during the summer had fewer adult bees and less brood than hives kept near natural forage, as well as lower average temperatures throughout winter. Within-day temperature variability was higher among hives exposed to commercial agriculture than for those kept near natural forage, indicating reduced temperature control. Fungicides, insecticides, varroacides, and an herbicide were detected in bee bread and wax samples; no major differences were observed either in the diversity or in the concentrations of agrochemicals with the exception of chlorpyrifos at one site. Varroa and Nosema densities were low overall. Data from the same site used in successive years showed significantly more brood the first year, as well as lower temperature variability; high levels of chlorpyrifos were detected in bee bread of colonies in the second year. Colony average temperature and temperature variability were informative with respect to colony phenology and post-winter status. [ABSTRACT FROM AUTHOR]

Honeybees are essential components to modern agriculture and economy. However, a continuous increase in cases of colony losses and colony depopulation are being reported worldwide. This critical situation has put the fragile equilibrium between bees and plants on the edge. As a consequence, several scientists have begun to focus their lines of research on this issue. Most researchers agree that there is no single explanation for the observed colony losses. Instead, these losses result from a synergistic interaction between different stressors. South America is not the exception; several cases of colony losses and colony depopulation were reported by beekeepers throughout the continent, yet no accurate data has been published to date. Therefore, this article attempts to analyze the past and present situation of honeybee health in South America, specifically in Argentina, Chile, Uruguay, Brazil, and Venezuela. Furthermore, it is intended to serve as a comparison to future colony losses, as well as to provide guidance for future hypothesis-driven research on the causes of colony mortality. We evaluate the impact of the main parasites and pathogens affecting honeybee colonies and discuss the role of each with respect to reported honeybee losses. We also contemplate the main challenges that each nation must confront with regards to honeybee health. [ABSTRACT FROM AUTHOR]

With increased globalisation and homogenisation, the maintenance of genetic integrity in local populations of agriculturally important species is of increasing concern. The western honeybee ( Apis mellifera) provides an interesting perspective as it is both managed and wild, with a large native range and much larger introduced range. We employed a newly created 95 single nucleotide polymorphism (SNP) test to characterise the genetic ancestry of the Australian commercial and feral honeybee populations. We found that most individuals were hybrids of mainly Western and Eastern European ancestry. Introductions of bees from North Africa are known from the historical record, and we show here the presence of alleles of African ancestry in some Australian bees, at levels comparable to those seen in the commercial populations of European-derived bees in North America. [ABSTRACT FROM AUTHOR]

Samples of bees and honey from 101 apiaries were collected in the West African Republic of Benin. Visual inspection revealed high Varroa destructor and Aethina tumida infestations and low Oplostomus fuligineus infestations. A pathogen screen based on bacterial/fungal cultures or microscopic examinations revealed the absence of American and European foulbrood, chalkbrood disease, acariosis and nosemosis. However, 13 bee samples (15.47 %) were found to be infected by viruses as determined by PCR-based techniques. Acute bee paralysis virus (ABPV; 8.33 %) and Black queen cell virus (4.76 %) were the most common. From the former we found a strain with an unusual molecular signature of the capsid region, which was taxonomically positioned between ABPV and Israeli acute paralysis virus. We also discovered Lake Sinai virus (LSV; 3.57 %) for the first time in Africa. Eight honey samples collected in regions where cotton was cultivated were subjected to multi-residue and quality control analyses. [ABSTRACT FROM AUTHOR]

Recent declines of bee populations have led to great interest in preserving bee species and fuel efforts to develop solitary species for pollination purposes. Xylophilous solitary bees can be easily reared in artificial nests tubes for commercial agricultural as well as wild plant pollination. The impact of the dimensions of these artificial nest tubes on reproduction parameters was studied in the red mason bee, Osmia bicornis (L.), in a long-term study. Increasing tube diameter positively affected both progeny sex ratio and body size. Sex ratio, but not progeny body mass, was negatively affected by short tube length. Building costs rose with increasing diameter accompanied by deteriorated efficiency of tube space utilization. Although female bees used a wide spectrum of nest dimensions, artificial nest tubes of 8-10 mm internal diameter and a length of at least 150 mm were optimal. [ABSTRACT FROM AUTHOR]