Nucleus Colonies Research Articles

Effects of Vitamin Supplements in a Pollen Substitute on Some Characteristics of Bee Nucleus Colonies

This study aimed to evaluate the effects of vitamin supplementation in a pollen substitute on the performance of honey bee colonies (Apis mellifera mellifera). Twenty nucleus colonies housed in Langstroth-Ruth hives were randomly selected and fed a diet consisting of corn gluten, sugar, and brewer’s yeast residuals, yielding 21.0% crude protein, 7.1% crude fat, and 1.7% crude ash. This diet was enriched with a vitamin mixture at doses of 1, 2, and 3 grams. Control group I received a sugar-water syrup (1:1, w/v), while control group II received the basic diet without vitamin supplementation. The three experimental groups were given the diet with varying amounts of the vitamin mixture. Results indicated that experimental group II demonstrated colony strength comparable to experimental group I but significantly higher than the control group by 14.6-49.4%, and 34.3% higher than experimental group III (P<0.05). Queen bee egg yield increased significantly, with control group II showing a 27.5% increase, experimental group I showing 52.1% increase, experimental group II showing 67.6% increase, and experimental group III showing 28.5% increase on July 28th. Similar trends were observed on August 28th, with respective increases of 30.2%, 32.5%, 37.4%, and 14.7% compared to control group I. Additionally, honey yields for experimental group II were significantly higher by 25.8-57.9% compared to the control groups and 46.8% higher than experimental group III (P<0.05). These findings suggest that vitamin-enriched pollen substitutes positively impact colony strength, queen bee egg laying, and honey production, underscoring the potential benefits of such supplementation in beekeeping practices.

Reduced parasite burden in feral honeybee colonies

Abstract Bee parasites are the main threat to apiculture and since many parasite taxa can spill over from honeybees (Apis mellifera) to other bee species, honeybee disease management is important for pollinator conservation in general. It is unknown whether honeybees that escaped from apiaries (i.e. feral colonies) benefit from natural parasite‐reducing mechanisms like swarming or suffer from high parasite pressure due to the lack of medical treatment. In the latter case, they could function as parasite reservoirs and pose a risk to the health of managed honeybees (spillback) and wild bees (spillover). We compared the occurrence of 18 microparasites among managed (N = 74) and feral (N = 64) honeybee colony samples from four regions in Germany using qPCR. We distinguished five colony types representing differences in colony age and management histories, two variables potentially modulating parasite prevalence. Besides strong regional variation in parasite communities, parasite burden was consistently lower in feral than in managed colonies. The overall number of detected parasite taxa per colony was 15% lower and Trypanosomatidae, chronic bee paralysis virus, and deformed wing viruses A and B were less prevalent and abundant in feral colonies than in managed colonies. Parasite burden was lowest in newly founded feral colonies, intermediate in overwintered feral colonies and managed nucleus colonies, and highest in overwintered managed colonies and hived swarms. Our study confirms the hypothesis that the natural mode of colony reproduction and dispersal by swarming temporally reduces parasite pressure in honeybees. We conclude that feral colonies are unlikely to contribute significantly to the spread of bee diseases. There is no conflict between the conservation of wild‐living honeybees and the management of diseases in apiculture.

Best Management Practices Increase Profitability of Small-Scale US Beekeeping Operations.

Little is known about the economics of small-scale beekeeping, due in part because many of these beekeepers are motivated by personal enjoyment and not profit. These beekeepers, however, represent more than 90% of US beekeeping population, so economic analysis of this majority group is warranted. Understanding how management practices impact colony profitability in small apiaries can inform beekeeper management decisions. Best management practices (BMPs) can increase colony productivity and survival, but often require additional labor and materials compared to less intensive beekeeping practices. Here, we investigate the impact of BMPs on the profitability of small-scale beekeeping. We found that BMPs required higher costs in labor and materials, but that they also produced higher revenue from honey and nucleus colony production. As a result, after three years, BMP apiaries were 8 times more profitable than less intensively managed apiaries. The increased profitability in BMP apiaries is largely attributed to improved colony health and survival due to more active Varroa management and reduced Varroa and viral loads. These results can inform small scale beekeeper budgeting and management, and also support extension efforts to increase BMP adoption.

Impacts of indoor mass storage of two densities of honey bee queens (Apis mellifera) during winter on queen survival, reproductive quality and colony performance

Spring imports of queen honey bees (Apis mellifera L.) are essential to replace winter colony losses in Canada, but contribute to the spread of treatment-resistant strains of pathogens and undesirable genetic traits. A possible alternative to these imports is the mass storage of queens during winter. By overwintering a strong colony (queen bank) containing large numbers of mated queens isolated in cages, beekeepers could acquire local queens early in the spring. In this study, we tested the efficacy of overwintering queen banks at two different queen densities (40 and 80). In the 40-queen banks (40 QB), 74.2% of queens survived the 6-month overwintering period, while 42.1% of queens survived in the 80-queen banks (80 QB). When compared to queens overwintered free in their colony, queens from bank colonies were smaller and lighter in early spring but had similar sperm viability and sperm count. Overwintering queens in banks did not have an impact on their acceptance in a nucleus colony but reduced their oviposition in the initial weeks following their introduction. After several days in nucleus colonies, queens from banks had regained a size and weight similar to that of queens overwintered normally, suggesting that they could perform well over a complete beekeeping season. This study achieved promising results and highlights the potential of this technique for the beekeeping industry in Canada and worldwide.

Using Nucs in Beekeeping Operations

This revised 9-page illustrated fact sheet by James D. Ellis discusses the merits of using nucleus colonies, or nucs, which are smaller versions of full-sized Langstroth hives. The publication explains how to create and manage nucs and how to use them to control swarming, strengthen production colonies, re-queen hives, hive swarms, produce queens to sell to other beekeepers, and in general strengthen and expand a beekeeping operation. Published by the UF Department of Entomology and Nematology. http://edis.ifas.ufl.edu/in869
 Original Publication: Ellis, James, and Catherine Nalen. 2010. “The Advantages of Using Nucs in Beekeeping Operations”. EDIS 2010 (7). https://journals.flvc.org/edis/article/view/118804.

Chemical and cultural control of Tropilaelaps mercedesae mites in honeybee (Apis mellifera) colonies in Northern Thailand.

At least two parasitic mites have moved from Asian species of honeybees to infest Apis mellifera. Of these two, Varroa destructor is more widespread globally while Tropilaelaps mercedesae has remained largely in Asia. Tropilaelaps mites are most problematic when A. mellifera is managed outside its native range in contact with Asian species of Apis. In areas where this occurs, beekeepers of A. mellifera treat aggressively for Tropilaelaps and Varroa is either outcompeted or is controlled as a result of the aggressive treatment regime used against Tropilaelaps. Many mite control products used worldwide may in fact control both mites but environmental conditions differ globally and thus a control product that works well in one area may be less or ineffective in other areas. This is especially true of volatile compounds. In the current research we tested several commercial products known to control Varroa and powdered sulfur for efficacy against Tropilaelaps. Additionally, we tested the cultural control method of making a hive division to reduce Tropilaelaps growth in both the parent and offspring colony. Making a split or nucleus colony significantly reduced mite population in both the parent and nucleus colony when compared to un-manipulated control colonies. The formic acid product, Mite-Away Quick Strips®, was the only commercial product that significantly reduced mite population 8 weeks after initiation of treatment without side effects. Sulfur also reduced mite populations but both sulfur and Hopguard® significantly impacted colony growth by reducing adult bee populations. Apivar® (amitraz) strips had no effect on mite or adult bee populations under the conditions tested.

Bee Smitten in Cuba

For the last few years I have been keeping bees along the East Coast of the United States. My operation is small, consisting of only a couple hundred overwintered nucleus colonies and at most 100 p...

Field Residues and Effects of the Insect Growth Regulator Novaluron and Its Major Co-Formulant N-Methyl-2-Pyrrolidone on Honey Bee Reproduction and Development.

Owing to the recent declines in honey bee (Apis mellifera L.) populations, there is a need for field and laboratory studies to investigate threats to pollinator health. This study examines the hypothesis that the organophosphate alternative, Rimon 0.83EC, can have consequences to honey bee health by combining newly acquired field residue data, laboratory bioassays, and colony level feeding studies. Following label rate applications of Rimon 0.83EC to apple trees, average residue concentrations of the active ingredient, novaluron, were found to be 3.38 ppm in tree-collected pollen. Residues of the major co-formulant in Rimon 0.83EC, N-methyl-2-pyrrolidone (NMP), were below the limit of detection in the field, but a growth chamber study described here found that NMP can persist in pollen for up to 7 d with average concentrations of 69.3 ppm. Concurrent larval rearing studies found novaluron and NMP to be toxic to developing honey bees at doses as low as 100 ppb and 100 ppm, respectively. Nucleus colony feeding studies found that chronic exposure to Rimon 0.83EC at doses as low as 200 ppm (18.6 ppm novaluron) can result in interruptions to brood production that can last for up to 2 wk after exposure. Taken together, these data indicate the use of Rimon 0.83EC on blooming flowers is a significant threat to honey bee reproduction, and suggest the need for more strict and clear usage guidelines.

Colony Level Prevalence and Intensity of Nosema ceranae in Honey Bees (Apis mellifera L.).

Nosema ceranae is a widely prevalent microsporidian parasite in the western honey bee. There is considerable uncertainty regarding infection dynamics of this important pathogen in honey bee colonies. Understanding the infection dynamics at the colony level may aid in development of a reliable sampling protocol for N. ceranae diagnosis, and provide insights into efficient treatment strategies. The primary objective of this study was to characterize the prevalence (proportion of the sampled bees found infected) and intensity (number of spores per bee) of N. ceranae infection in bees from various age cohorts in a colony. We examined N. ceranae infection in both overwintered colonies that were naturally infected with N. ceranae and in quadruple cohort nucleus colonies that were established and artificially inoculated with N. ceranae. We also examined and quantified effects of N. ceranae infection on hypopharyngeal gland protein content and gut pH. There was no correlation between the prevalence and intensity of N. ceranae infection in composite samples (pooled bee samples used for analysis). Our results indicated that the prevalence and intensity of N. ceranae infection is significantly influenced by honey bee age. The N. ceranae infection prevalence values from composite samples of background bees (unmarked bees collected from four different locations in a colony) were not significantly different from those pertaining to marked-bee age cohorts specific to each sampling date. The foraging-aged bees had a higher prevalence of N. ceranae infection when compared to nurse-aged bees. N. ceranae did not have a significant effect on hypopharyngeal gland protein content. Further, there was no significant difference in mean gut pH of N. ceranae infected bees and non-infected bees. This study provides comprehensive insights into N. ceranae infection dynamics at the colony level, and also demonstrates the effects of N. ceranae infection on hypopharyngeal gland protein content and midgut pH.

Introduction of Aethina tumida (Coleoptera: Nitidulidae) in the regions of Calabria and Sicily (southern Italy)

AbstractAethina tumida (small hive beetle, SHB) was first detected in September 2014 in Calabria region, southern Italy, and in a single apiary in Sicily in November 2014. In September 2015, SHB was again recorded in Calabria, and in 2016, only sentinel honey bee nucleus colonies were found to be infested. Its phylogenetic relationship and possible origin were investigated comparing the cox1 sequences with the corresponding region available in the GenBank database. The neighbour-joining method revealed that the first Italian specimen belonged to a group also containing an African specimen from Cameroon. The Italian specimens differ from the SHBs spread worldwide and are split into two different groups: group B1 includes the AfricCam3 sequence and the first SHB identified in Calabria; group B2 includes specimens from Calabria and the only one from Sicily which share identical cox1 sequences. SHB in Italy appears to have been introduced from Africa and includes independent or contemporary incursions in the two concerned regions. The most likely scenario is that SHB was introduced into Calabria followed by man-mediated migration to Sicily.

Metal contaminant accumulation in the hive: Consequences for whole-colony health and brood production in the honey bee (Apis mellifera L.).

Metal pollution has been increasing rapidly over the past century, and at the same time, the human population has continued to rise and produce contaminants that may negatively impact pollinators. Honey bees (Apis mellifera L.) forage over large areas and can collect contaminants from the environment. The primary objective of the present study was to determine whether the metal contaminants cadmium (Cd), copper (Cu), lead (Pb), and selenium (Se) can have a detrimental effect on whole-colony health in the managed pollinator A. mellifera. The authors isolated small nucleus colonies under large cages and fed them an exclusive diet of sugar syrup and pollen patty spiked with Cd, Cu, Pb, and Se or a control (no additional metal). Treatment levels were based on concentrations in honey and pollen from contaminated hives around the world. They measured whole-colony health including wax, honey, and brood production; colony weight; brood survival; and metal accumulation in various life stages. Colonies treated with Cd or Cu contained more dead pupae within capped cells compared with control, and Se-treated colonies had lower total worker weights compared to control. Lead had a minimal effect on colony performance, although many members of the hive accumulated significant quantities of the metal. By examining the honey bee as a social organism through whole-colony assessments of toxicity, the authors found that the distribution of toxicants throughout the colony varied from metal to metal, some caste members were more susceptible to certain metals, and the colony's ability to grow over time may have been reduced in the presence of Se. Apiaries residing near metal-contaminated areas may be at risk and can suffer changes in colony dynamics and survival.

Susceptibility of small honey bee colonies to invasion by the small hive beetle, Aethina tumida (Coleoptera, Nitidulidae)

AbstractWeak and small honey bee colonies are supposed to be more susceptible to infestations by the small hive beetle [Aethina tumida, small hive beetle (SHB)]. To test this, we established 24 nucleus colonies [12 with and 12 without previous SHB removal (= screening)]. Four weeks later, we compared beetle numbers and the occurrence of SHB reproduction to the corresponding full‐sized colonies. Full‐sized colonies with no screening were infested with significantly more SHBs than all other groups (mean ± standard deviation = 46.9 ± 26.7). Regardless of this, none of the full‐sized colonies showed damage or evidence of SHB reproduction. In contrast, five nucleus colonies collapsed and SHB larvae were found in an additional seven colonies. Our study demonstrates that SHB infestation levels which are harmless to full‐sized colonies may have a negative impact on small nucleus colonies.

Comparing Alternative Methods for Holding Virgin Honey Bee Queens for One Week in Mailing Cages before Mating

In beekeeping, queen honey bees are often temporarily kept alive in cages. We determined the survival of newly-emerged virgin honey bee queens every day for seven days in an experiment that simultaneously investigated three factors: queen cage type (wooden three-hole or plastic), attendant workers (present or absent) and food type (sugar candy, honey, or both). Ten queens were tested in each of the 12 combinations. Queens were reared using standard beekeeping methods (Doolittle/grafting) and emerged from their cells into vials held in an incubator at 34C. All 12 combinations gave high survival (90 or 100%) for three days but only one method (wooden cage, with attendants, honey) gave 100% survival to day seven. Factors affecting queen survival were analysed. Across all combinations, attendant bees significantly increased survival (18% vs. 53%, p<0.001). In addition, there was an interaction between food type and cage type (p<0.001) with the honey and plastic cage combination giving reduced survival. An additional group of queens was reared and held for seven days using the best method, and then directly introduced using smoke into queenless nucleus colonies that had been dequeened five days previously. Acceptance was high (80%, 8/10) showing that this combination is also suitable for preparing queens for introduction into colonies. Having a simple method for keeping newly-emerged virgin queens alive in cages for one week and acceptable for introduction into queenless colonies will be useful in honey bee breeding. In particular, it facilitates the screening of many queens for genetic or phenotypic characteristics when only a small proportion meets the desired criteria. These can then be introduced into queenless hives for natural mating or insemination, both of which take place when queens are one week old.

Breeding for hygienic behaviour in honeybees (Apis mellifera) using free-mated nucleus colonies

Gains in hygienic behaviour based on maternal selection of queens were evaluated among four commercial beekeeping operations in northern Alberta, Canada over four generations. While the proportion of breeding colonies expressing the trait increased with each subsequent generation, levels of hygienic behaviour among progeny remained relatively unchanged. Estimated breeding values for the final generation of progeny confirmed only a slight effect of selection; the expected average increase in the removal of frozen brood in the next generation was determined to be 0.17% at 24 h and 0.34% at 48 h. This modest increase may be explained by the low (24 h, h2 = 0.17) to moderate (48 h, h2 = 0.25) heritability of hygienic behaviour in our population. Our work implies that year-to-year comparisons of breeding colonies may not be an accurate predictor of selection gains within honeybee populations and that honey producers in this region may need to focus selection within elite breeding populations.

Marking small hive beetles with thoracic notching: effects on longevity, flight ability and fecundity

We tested two marking techniques for adult small hive beetles (SHB): dusting and thoracic notching. The use of blue and red chalk dusts to mark beetles was not persistent and caused early death of SHB with an average survival of 52.6 ± 23.8 and 13.9 ± 7.3 days, respectively. In contrast, notched beetles survived longer (mean = 353.6 ± 5.3 days) with the last beetle dying after 383 days. Likewise, notched beetles (presumed to be injured because of oozing hemolymph from the notched area) also lived long with an average of 193.6 ± 38.8 days. Notching also resulted in a high rate of recovery; 81% for beetles introduced directly into a nucleus colony, and 59% and 66% for a nucleus colony and pole traps, respectively, for beetles released inside a screen tent. These high recovery rates confirmed that notching did not interfere with the beetles’ ability to fly. However, it appeared that notched females laid more eggs than those that were not notched both with multiple (171.70 ± 11.20 vs 126.87 ± 10.27 eggs per day) and single (70.02 ± 5.45 vs 57.97 ± 5.12 eggs per day) pairs for a period of 1–3 days. Whether or not notching affects lifetime fecundity of females was not assessed in this study. Nevertheless, notching is a permanent mark for SHB and thus, may be useful in many ecological studies or in studying the efficacy of lures and traps for SHB control.

Advantages of Using Nucs in Beekeeping Operations

ENY153, a 6-page illustrated fact sheet by James D. Ellis and Catherine Zettel Nalen, discusses the merits of nucleus colonies, which are smaller versions of full-sized Langstroth colonies — creating a nuc, rearing queens for nucs, reasons to use them, and problems associated with them. Published by the UF Department of Entomology and Nematology, September 2010. ENY153/IN869: Using Nucs in Beekeeping Operations (ufl.edu)

Individual forager profits in Apis mellifera unaffected by a range of colony Varroa destructor densities

The parasitic mite Varroa destructor Anderson and Trueman negatively affects honey bee health, flight activity, and foraging behavior, all of which can be expected to affect foraging energetics. We tested this hypothesis in a 3-year field study. In each year, four-frame nucleus colonies with varying loads of varroa were placed under cages with mature rabbiteye blueberry plants, Vaccinium ashei. Individual bee weights consistently decreased as colony varroa populations increased, affirming that the design produced a range of colony mite effects. However, average forager flower handling times and nectar ingestion rates were unaffected by changes in colony varroa levels. Moreover, there were no significant effects of colony varroa levels on individual net foraging energy gain determined per flower, per second handling time, or per second total foraging time. We conclude that individual forager profits in Apis mellifera are unaffected by the range of colony V. destructor densities used in this study. These results are relevant to the question of the extent to which foraging of individuals relates to colony state in social Hymenoptera.

Comparative Resistance of Russian and Italian Honey Bees (Hymenoptera: Apidae) to Small Hive Beetles (Coleoptera: Nitidulidae)

To compare resistance to small hive beetles (Coleoptera: Nitidulidae) between Russian and commercial Italian honey bees (Hymenoptera: Apidae), the numbers of invading beetles, their population levels through time and small hive beetle reproduction inside the colonies were monitored. We found that the genotype of queens introduced into nucleus colonies had no immediate effect on small hive beetle invasion. However, the influence of honey bee stock on small hive beetle invasion was pronounced once test bees populated the hives. In colonies deliberately freed from small hive beetle during each observation period, the average number of invading beetles was higher in the Italian colonies (29 +/- 5 beetles) than in the Russian honey bee colonies (16 +/- 3 beetles). A similar trend was observed in colonies that were allowed to be freely colonized by beetles throughout the experimental period (Italian, 11.46 +/- 1.35; Russian, 5.21 +/- 0.66 beetles). A linear regression analysis showed no relationships between the number of beetles in the colonies and adult bee population (r2 = 0.1034, P = 0.297), brood produced (r2 = 0.1488, P = 0.132), or amount of pollen (P = 0.1036, P = 0.295). There were more Italian colonies that supported small hive beetle reproduction than Russian colonies. Regardless of stock, the use of entrance reducers had a significant effect on the average number of small hive beetle (with reducer, 16 +/- 3; without reducer, 27 +/- 5 beetles). However, there was no effect on bee population (with reducer, 13.20 +/- 0.71; without reducer, 14.60 +/- 0.70 frames) or brood production (with reducer, 6.12 +/- 0.30; without reducer, 6.44 +/- 0.34 frames). Overall, Russian honey bees were more resistant to small hive beetle than Italian honey bees as indicated by fewer invading beetles, lower small hive beetle population through time, and lesser reproduction.

The effect of honey bee worker brood cell size on Varroa destructor infestation and reproduction

SummaryThe effect of honey bee (Apis mellifera) worker brood cell size on cell infestation and reproductive success of Varroa destructor in New Zealand was determined by establishing ten nucleus colonies with mosaic frames, each consisting of cells drawn from five different foundation sizes. When the brood were 18–20 days old, 1636 cells were individually uncapped and the number of adult and deutonymph female mites were recorded. The internal width of each brood cell was also measured. The data were analysed according to the imprint size of the “foundation” specified by the supplier, and the “measured” internal width of each individual drawn brood cell. The “foundation” cell size had no significant effect on the reproductive success of V. destructor, but the proportion of cells that were infested by adult female mites was significantly different. A significantly higher proportion of the cells drawn from the 4.8 mm imprint “foundation” were infested compared to those of the other sizes.“Measured” brood cell size had no significant effect on mite reproduction or infestation.

Destroying managed and feral honey bee (Apis mellifera) colonies to eradicate honey bee pests

This paper reports on trials conducted to kill managed and feral honey bee (Apis mellifera) colonies to eradicate unwanted honey bee pests. The effectiveness of Pestigas‐P™ (natural pyrethrum) for the destruction of managed colonies was assessed. Pestigas‐P™ was effective when applied as a single 15‐s spray into an empty three‐quarter‐depth super and across the top of the frames. This allowed the gas to filter throughout the hive. Piperonyl butoxide (wax = 42.28 mg/kg, honey = 0.34 mg/kg, propolis = 9.2 mg/kg, floor scrapings = 270.34 mg/kg) and pyrethrum (wax = 21.3 mg/kg, honey = 0.06 mg/ kg, propolis = 6.8 mg/kg, floor scrapings = 172.4 mg/kg) residues were found in the hive but after 4 weeks these had no detectable effect on newly introduced honey bee colonies. Combined analyses of attractiveness, toxicity, and lethal time trials identified Ascend® 200SC (a.i. fipronil) as effective for depopulating feral honey bee colonies in New Zealand using poisoned baits. Ascend® 200SC is a slow acting stomach toxin. The effect of Ascend® on feral honey bee colonies was assessed in Canterbury, New Zealand in 2003. Nucleus colonies were placed between bait stations set out in a 4km2 grid. The stations were pre‐baited with sugar syrup which was replaced with sugar syrup containing fipronil (0.05 ml/litre) once 300 bees were foraging from a single bait station. In the autumn trial all 20 colonies died within 13 days of poisoning. After 6 weeks the effect of poisoned hives on the survival of newly introduced colonies was assessed. Five colonies were placed next to 10 poisoned hives in the original eradication area, five colonies were placed with 10 poisoned hives at least 4km from the original area, and an additional 10 colonies were placed at least 4km from the original area and 4 km apart. Introduced colonies are likely to die if they consume the stored fipronil in poisoned colonies. This persistent poisoning action increases the likelihood of a honey bee eradication attempt being successful, as the colonies that are not killed in the first round of poisoning may be poisoned by robbing honey containing fipronil from a previously poisoned hive. Fipronil remained toxic in honey for at least 26 months when stored at 0°C, 5°C, and 25°C.