Commercial Bee Research Articles

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.

Does pathogen spillover from commercially reared bumble bees threaten wild pollinators?

The conservation of insect pollinators is drawing attention because of reported declines in bee species and the ‘ecosystem services’ they provide. This issue has been brought to a head by recent devastating losses of honey bees throughout North America (so called, ‘Colony Collapse Disorder’); yet, we still have little understanding of the cause(s) of bee declines. Wild bumble bees (Bombus spp.) have also suffered serious declines and circumstantial evidence suggests that pathogen ‘spillover’ from commercially reared bumble bees, which are used extensively to pollinate greenhouse crops, is a possible cause. We constructed a spatially explicit model of pathogen spillover in bumble bees and, using laboratory experiments and the literature, estimated parameter values for the spillover of Crithidia bombi, a destructive pathogen commonly found in commercial Bombus. We also monitored wild bumble bee populations near greenhouses for evidence of pathogen spillover, and compared the fit of our model to patterns of C. bombi infection observed in the field. Our model predicts that, during the first three months of spillover, transmission from commercial hives would infect up to 20% of wild bumble bees within 2 km of the greenhouse. However, a travelling wave of disease is predicted to form suddenly, infecting up to 35–100% of wild Bombus, and spread away from the greenhouse at a rate of 2 km/wk. In the field, although we did not observe a large epizootic wave of infection, the prevalences of C. bombi near greenhouses were consistent with our model. Indeed, we found that spillover has allowed C. bombi to invade several wild bumble bee species near greenhouses. Given the available evidence, it is likely that pathogen spillover from commercial bees is contributing to the ongoing decline of wild Bombus in North America. Improved management of domestic bees, for example by reducing their parasite loads and their overlap with wild congeners, could diminish or even eliminate pathogen spillover.

Comparative Performance of Two Mite-Resistant Stocks of Honey Bees (Hymenoptera: Apidae) in Alabama Beekeeping Operations

The utility of USDA-developed Russian and varroa sensitive hygiene (VSH) honey bees, Apis mellifera L. (Hymenoptera: Apidae), was compared with that of locally produced, commercial Italian bees during 2004-2006 in beekeeping operations in Alabama, USA. Infestations of varroa mites, Varroa destructor Anderson & Truman (Acari: Varroidae), were measured twice each year, and colonies that reached established economic treatment thresholds (one mite per 100 adult bees in late winter; 5-10 mites per 100 adult bees in late summer) were treated with acaricides. Infestations of tracheal mites, Acarapis woodi (Rennie) (Acari: Tarsonemidae), were measured autumn and compared with a treatment threshold of 20% mite prevalence. Honey production was measured in 2005 and 2006 for colonies that retained original test queens. Throughout the three seasons of measurement, resistant stocks required less treatment against parasitic mites than the Italian stock. The total percentages of colonies needing treatment against varroa mites were 12% of VSH, 24% of Russian, and 40% of Italian. The total percentages requiring treatment against tracheal mites were 1% of Russian, 8% of VSH and 12% of Italian. The average honey yield of Russian and VSH colonies was comparable with that of Italian colonies each year. Beekeepers did not report any significant behavioral problems with the resistant stocks. These stocks thus have good potential for use in nonmigratory beekeeping operations in the southeastern United States.

Comparative Performance of Two Mite-Resistant Stocks of Honey Bees (Hymenoptera: Apidae) in Alabama Beekeeping Operations

The utility of USDA-developed Russian and varroa sensitive hygiene (VSH) honey bees, Apis mellifera L. (Hymenoptera: Apidae), was compared with that of locally produced, commercial Italian bees during 2004–2006 in beekeeping operations in Alabama, USA. Infestations of varroa mites, Varroa destructor Anderson & Truman (Acari: Varroidae), were measured twice each year, and colonies that reached established economic treatment thresholds (one mite per 100 adult bees in late winter; 5–10 mites per 100 adult bees in late summer) were treated with acaricides. Infestations of tracheal mites, Acarapis woodi (Rennie) (Acari: Tarsonemidae), were measured autumn and compared with a treatment threshold of 20% mite prevalence. Honey production was measured in 2005 and 2006 for colonies that retained original test queens. Throughout the three seasons of measurement, resistant stocks required less treatment against parasitic mites than the Italian stock. The total percentages of colonies needing treatment against varroa mites were 12% of VSH, 24% of Russian, and 40% of Italian. The total percentages requiring treatment against tracheal mites were 1% of Russian, 8% of VSH and 12% of Italian. The average honey yield of Russian and VSH colonies was comparable with that of Italian colonies each year. Beekeepers did not report any significant behavioral problems with the resistant stocks. These stocks thus have good potential for use in nonmigratory beekeeping operations in the southeastern United States.

Population Genetics of Commercial and Feral Honey Bees in Western Australia

Population Genetics of Commercial and Feral Honey Bees in Western Australia

Population Genetics of Commercial and Feral Honey Bees in Western Australia

Due to the introduction of exotic honey bee (Apis mellifera L.) diseases in the eastern states, the borders of the state of Western Australia were closed to the import of bees for breeding and other purposes > 25 yr ago. To provide genetically improved stock for the industry, a closed population breeding program was established that now provides stock for the majority of Western Australian beekeepers. Given concerns that inbreeding may have resulted from the closed population breeding structure, we assessed the genetic diversity within and between the breeding lines by using microsatellite and mitochondrial markers. We found that the breeding population still maintains considerable genetic diversity, despite 25 yr of selective breeding. We also investigated the genetic distance of the closed population breeding program to that of beekeepers outside of the program, and the feral Western Australian honey bee population. The feral population is genetically distinct from the closed population, but not from the genetic stock maintained by beekeepers outside of the program. The honey bees of Western Australia show three mitotypes, originating from two subspecies: Apis mellifera ligustica (mitotypes C1 and M7b) and Apis mellifera iberica (mitotype M6). Only mitotypes C1 and M6 are present in the commercial populations. The feral population contains all three mitotypes.

Decline and Conservation of Bumble Bees

Declines in bumble bee species in the past 60 years are well documented in Europe, where they are driven primarily by habitat loss and declines in floral abundance and diversity resulting from agricultural intensification. Impacts of habitat degradation and fragmentation are likely to be compounded by the social nature of bumble bees and their largely monogamous breeding system, which renders their effective population size low. Hence, populations are susceptible to stochastic extinction events and inbreeding. In North America, catastrophic declines of some bumble bee species since the 1990s are probably attributable to the accidental introduction of a nonnative parasite from Europe, a result of global trade in domesticated bumble bee colonies used for pollination of greenhouse crops. Given the importance of bumble bees as pollinators of crops and wildflowers, steps must be taken to prevent further declines. Suggested measures include tight regulation of commercial bumble bee use and targeted use of environmentally comparable schemes to enhance floristic diversity in agricultural landscapes.

Comparison of microsatellite DNA diversity among commercial queen breeder stocks of Italian honey bees in the United States and Italy

SummaryDeclines in the numbers of breeder honey bee queens and the concomitant loss of genetic diversity could potentially result in inbreeding, and increased susceptibility to pests and diseases. Genetic diversity of commercial Italian bee colonies in the United States and Italy was assessed using six variable microsatellite DNA loci. Worker bees were sampled from colonies of queen breeders in both countries (USA, n = 18; Italy, n = 24). Overall, allelic richness (mean alleles/locus), gene diversity (heterozygosity), and FIS (inbreeding coefficient) did not differ between the two groups. A total of 48 alleles were present among all colonies. Sampled colonies from each country had a total of 38 alleles, although alleles were present that were unique to each group. There were a total of 10 unique alleles among USA bees and 10 among Italian bees. Estimates of the level of genetic differentiation based on different allele frequency patterns among the USA and Italian bees were measured with the population genetic parameter FST. These estimates showed that bees from the USA and Italy were measurably distinct relative to the frequencies of the microsatellite alleles present in samples from each country. Overall allelic diversity levels were sufficiently high indicating that inbreeding does not appear to be an immediate threat to existing honey bee populations.

Detection and removal of brood infested with eggs and larvae of small hive beetles (Aethina tumida Murray) by Russian honey bees

SummaryThe response of Russian honey bees to brood infested with small hive beetle (SHB) eggs and larvae was compared to that of a commercial stock (predominantly of A. m. ligustica). Test brood was grouped as follows: a) NoP = no perforation either of capping or cell wall; b) PWall = perforation of cell wall only; c) PCap = perforation of capping only; and d) PBoth = capping and cell wall perforations. All perforations were made by SHB. Our results showed that brood cells with perforations of the cell wall (PWall and PBoth) had the highest infestation (76.53 ± 2.10%) and number of eggs (58.46 ± 2.85 eggs). Because PCap showed low levels of infestation (29.17 ± 3.31% and 15.60 ± 1.31 eggs per infested cell), we calculated brood removal based on data from PWall and PBoth groups. Within 6 h, both stocks removed the contents of 39.24 ± 4.94% of PWall cells. A higher removal rate of 50.51 ± 5.80% was observed in PBoth cells. These two groups of brood had the highest numbers of eggs per infested cell (50–70 eggs). Eggs hatched after the 6 h observation and subsequent hygienic removal was of brood infested with larvae. At 20 h, additional 56.41 ± 4.62% (PWall) and 42.04 ± 4.91% (PBoth) removal rates were observed. Overall, the cumulative removal rates for both stocks were similar with means of 85.11 ± 2.98% and 84.32 ± 4.29% for the commercial and Russian honey bees, respectively. In conclusion, we observed that both honey bee stocks were able to detect eggs inside the sealed brood cells and remove them with the infested brood.

Cryptic species diversity in a widespread bumble bee complex revealed using mitochondrial DNA RFLPs

Cryptic species diversity is thought to be common within the class Insecta, posing problems for basic ecological and population genetic studies and conservation management. Within the temperate bumble bee (Bombus spp.) fauna, members of the subgenus Bombus sensu stricto are amongst the most abundant and widespread. However, their species diversity is controversial due to the extreme difficulty or inability morphologically to identify the majority of individuals to species. Our character-based phylogenetic analyses of partial CO1 (700 bp) from 39 individuals spread across their sympatric European ranges provided unequivocal support for five taxa (3–22 diagnostic DNA base pair sites per species). Inclusion of 20 Irish specimens to the dataset revealed ≥2.3% sequence divergence between taxa and ≤1.3% within taxa. We developed a PCR-RFLP based method for unequivocally distinguishing amongst the four cryptic European taxa of this subgenus, B. cryptarum, B. lucorum, B. magnus and B. terrestris, and used it to analyse 391 females of the former three species collected across Ireland, all of which could be unambiguously assigned to species. Bombus lucorum was the most widely distributed and abundant of the cryptarum–lucorum–magnus species complex, comprising 56% of individuals, though it was significantly less abundant at higher altitudes (>200 m) whilst B. cryptarum was relatively more abundant at higher altitudes. Bombus magnus was rarely encountered at urban sites. Both B. lucorum and B. terrestris are nowadays reared commercially for pollination and transported globally. Our RFLP approach to identify native fauna can underpin ecological studies of these important cryptic species as well as the impact of commercial bumble bees on them.

The beekeeping potential of Sub-Himalayan West Bengal, India: A palynological assessment of honey

SummaryFifty honey samples (both squeezed and extracted) collected from the eastern Himalayan part of West Bengal, India were analyzed for their pollen content. Among these honey samples, forty-eight were from Apis cerana indica and two from Apis florea. Eighteen honey samples were identified as unifloral, of which 17 were from Apis cerana indica. The predominant pollen types were Rosa sp., Ageratum conyzoides, Rubus ellipticus, Prunus sp., Millettia pulchra, Trifolium repens, Primula sp., Schima wallichii, Fragaria sp., Potentilla sp. (during summer), Ageratum conyzoides, Schima wallichii, Sedum multicaule, (during autumn) and Aristolochia sp., Rosa sp. (during winter). In one sample from Apis florea, Trifolium repens predominated (during summer). Three honey flow periods (HFP-I-III) are recognized in this area. HFP-I (March-June) is the principal flow period while HFP-II (July-October) and HFP-III (November-February) are secondary. On the basis of Absolute Pollen Count (APC), Group I, Group II and Group III honeys are recognized from this region. K-means clustering of the honey samples from summer, autumn and winter seasons were carried out, establishing that variation in honey samples is possibly due to different pollen content and not controlled by their season of production. The study also explores the suitability for establishing commercial bee keeping in the remote areas of the eastern Himalayan part of West Bengal, India.

Quantitative determination of trans- 10-Hydroxy-2-Decenoic Acid (10-HDA) in Brazilian royal jelly and commercial products containing royal jelly

SummaryWe report the analysis of Brazilian commercial bee products using high performance liquid chromatography, and a faster method, to detect trans-10-Hydroxy-2-Decenoic Acid or 10-Hydroxy-2-E-decenoic acid (10-HDA) in royal jelly. Determination was carried out using aqueous phosphoric acid 0.1% (pH 2.5)/methanol (50/50) as the mobile phase, and a LiChrospher® RP-18 column with detection at 215 nm. A good linearity was shown between the concentration of 10-HDA and peak area in the concentration range of 5.0–50.0 mg/L (r 0.99, n = 5). The within-day and between-day relative standard deviation (RSD) were1 % and 3 %, respectively.

Can commercially imported bumble bees out‐compete their native conspecifics?

Summary Although invasive species are major topics of research, little consideration has been given to the implications of introducing non‐native subspecies or beneficial organisms such as pollinators. However, the extensive trade in bumble bees as pollinators of glasshouse crops involves both. Within regions in Europe, the importation of non‐native commercially reared subspecies of Bombus terrestris could endanger native bumble bees through competitive displacement and/or hybridization. This study made a direct ecological comparison between commercially imported and native B. terrestris colonies growing in the wild in the UK. In particular, using a paired design, we compared the nectar‐foraging performance and reproductive outputs of commercial and native colonies growing under identical field conditions. Commercial colonies performed well in the field, with substantially higher nectar‐foraging rates than native colonies in four out of five locations. Nectar‐foraging performance was positively correlated with forager size, with commercial bees being consistently larger than native bees. All seven commercial colonies studied produced gynes (new queens), with two colonies each producing in excess of 50. In contrast, only two out of seven native colonies produced gynes, and those only produced small numbers (five in total). Males were produced by all colonies but there were no significant differences in numbers between commercial and native subspecies. Synthesis and applications. The high reproductive success of commercial colonies indicates that there is an appreciable risk that they will become established and spread within the UK. Furthermore, their superior foraging ability and large colony size could lead them to out‐compete native bumble bees. Clearly the invasive potential of non‐native subspecies and/or beneficial organisms should not be overlooked. With respect to the current importation of commercial bumble bees, we strongly recommend a precautionary approach: native species and subspecies should be locally reared and the use/disposal of bees should be strictly regulated.

Effects of Three-Dimensional and Color Patterns on Nest Location and Progeny Mortality in Alfalfa Leafcutting Bee (Hymenoptera: Megachilidae)

ABSTRACT In alfalfa, Medicago sativa L., seed production where high bee densities are released, alfalfa leafcutting bee, Megachile rotundata (F.) (Hymenoptera: Megachilidae), females may enter several nesting holes before locating their nests. Such levels of "wrong hole" visits lead to an increase in the time spent by females locating their own nests, thereby decreasing alfalfa pollination efficiency and possibly healthy brood production. The objectives of this study were to determine the effect of different nesting board configurations in commercial alfalfa leafcutting bee shelters (separating nesting boards, applying a three-dimensional pattern to the boards, applying a color contrast pattern, or applying a combination of three-dimensional and color contrast patterns) on nest location performance, on the incidence of chalkbrood disease, and on the incidence of broodless provisions. Separating the nesting boards inside shelters improved the ability of females to locate their nests. An increase in nest location performance also occurred in boards with the three-dimensional pattern and the combined three-dimensional and color contrast pattern, compared with the uniform board (a standard configuration currently used commercially). The percentage of provisioned cells that were broodless was not statistically different between treatments, but the percentage of larvae infected with chalkbrood decreased by half in the three-dimensional board design, compared with the uniform board.

Effects of Three-Dimensional and Color Patterns on Nest Location and Progeny Mortality in Alfalfa Leafcutting Bee (Hymenoptera: Megachilidae)

ABSTRACT In alfalfa, Medicago sativa L., seed production where high bee densities are released, alfalfa leafcutting bee, Megachile rotundata (F.) (Hymenoptera: Megachilidae), females may enter several nesting holes before locating their nests. Such levels of "wrong hole" visits lead to an increase in the time spent by females locating their own nests, thereby decreasing alfalfa pollination efficiency and possibly healthy brood production. The objectives of this study were to determine the effect of different nesting board configurations in commercial alfalfa leafcutting bee shelters (separating nesting boards, applying a three-dimensional pattern to the boards, applying a color contrast pattern, or applying a combination of three-dimensional and color contrast patterns) on nest location performance, on the incidence of chalkbrood disease, and on the incidence of broodless provisions. Separating the nesting boards inside shelters improved the ability of females to locate their nests. An increase in nest location performance also occurred in boards with the three-dimensional pattern and the combined three-dimensional and color contrast pattern, compared with the uniform board (a standard configuration currently used commercially). The percentage of provisioned cells that were broodless was not statistically different between treatments, but the percentage of larvae infected with chalkbrood decreased by half in the three-dimensional board design, compared with the uniform board.

Plight of the bumble bee: Pathogen spillover from commercial to wild populations

Pathogen spread or ‘spillover’ can occur when heavily infected, domestic hosts interact with closely-related wildlife populations. Commercially-produced bumble bees used in greenhouse pollination often have higher levels of various pathogens than wild bumble bees. These pathogens may spread to wild bees when commercial bees escape from greenhouses and interact with their wild counterparts at nearby flowers. We examined the prevalence of four pathogens in wild bumble bee populations at locations near and distant to commercial greenhouses in southern Ontario, Canada. Bumble bees collected near commercial greenhouses were more frequently infected by those pathogens capable of being transmitted at flowers (Crithidia bombi and Nosema bombi) than bees collected at sites away from greenhouses. We argue that the spillover of pathogens from commercial to wild bees is the most likely cause of this pattern and we discuss the implications of such spillover for bumble bee conservation.

Effects of parasitic mites and protozoa on the flower constancy and foraging rate of bumble bees

Parasites can affect host behavior in subtle but ecologically important ways. In the laboratory, we conducted experiments to determine whether parasitic infection by the intestinal protozoan Crithidia bombi or the tracheal mite Locustacarus buchneri alters the foraging behavior of the bumble bee Bombus impatiens. Using an array of equally rewarding yellow and blue artificial flowers, we measured the foraging rate (flowers visited per minute, flower handling time, and flight time between flowers) and flower constancy (tendency to sequentially visit flowers of the same type) of bees with varying intensities of infection. Bumble bee workers infected with tracheal mites foraged as rapidly as uninfected workers, but were considerably more constant to a single flower type (yellow or blue). In contrast, workers infected with intestinal protozoa showed similar levels of flower constancy, but visited 12% fewer flowers per minute on average than uninfected bees. By altering the foraging behavior of bees, such parasites may influence interactions between plants and pollinators, as well as the reproductive output of bumble bee colonies. Our study is the first to investigate the effects of parasitic protozoa and tracheal mites on the foraging behavior of bumble bees, and provides the first report of Crithidia bombi in commercial bumble bees in North America.

Pyrrolizidine Alkaloids of Echium vulgare Honey Found in Pure Pollen

The pyrrolizidine alkaloids previously identified in floral honey attributed to Echium vulgare (Boraginaceae) have been detected (8000-14 000 ppm) in pure pollen collected from the anthers of Echium vulgare. Pyrrolizidine alkaloids and/or their N-oxides were isolated from the aqueous acid extracts of pollen by use of strong cation-exchange, solid-phase extraction and identified by liquid chromatographic/mass spectrometric (LCMS) analysis. The pyrrolizidine alkaloids in the pollen are present mainly as the N-oxides. In addition to seven previously described pyrrolizidine alkaloids and/or their N-oxides (echimidine, acetylechimidine, uplandicine, 9-O-angelylretronecine, echiuplatine, leptanthine, and echimiplatine), one unidentified (echivulgarine), but previously found in honey, and two previously undescribed (vulgarine and 7-O-acetylvulgarine) pyrrolizidine alkaloids and/or their N-oxides were identified in the pollen. Tentative structures for these unidentified pyrrolizidine alkaloids are proposed on the basis of the mass spectrometric data and biogenetic considerations. The implications of these results for identifying the source and subsequent concentrations of pyrrolizidine alkaloids in honeys and commercial bee pollen are briefly discussed.

American black bears and bee yard depredation at Okefenokee Swamp, Georgia

Abstract We studied American black bears (Ursus americanus), on the northwest periphery of Okefenokee Swamp in southeast Georgia, to assess landowner attitudes toward bears, estimate the extent of damage to commercial honey bee operations by bears, and evaluate methods to reduce bear depredations to apiaries. We collected 8,351 black bear radiolocations and identified 51 bee yards on our study area. Twenty-seven of 43 home ranges contained ≥1 bee yard, averaging 11.3 and 5.1 bee yards/home range of males (n = 7) and females (n = 20), respectively. From 1996 to 1998, we documented 7 instances of bears raiding bee yards within our study area and 6 instances in adjacent areas. All but 1 of the 13 raided yards were enclosed by electric fencing. In the 12 cases of damage to electrically fenced yards, however, the fences were not active because of depleted batteries. Based on compositional analysis, bear use of areas 800–1,400 m from bee yards was disproportionately greater than use 0–800 m from bee yards. Bear...

The primary melliferous flora and other aspects associated with beekeeping within State forests of New South Wales as determined by surveys of beekeepers

Summary The State forests of New South Wales (NSW) are a very important resource for the NSW beekeeping industry. In 1995/96, 3749 occupation permits were issued for bee fanning, and this number increased to 3843 in 1997. On average, 100–120 beehives were periodically placed on each occupation permit site, the number and location being determined by the flowering of species which beekeepers regarded as reliable producers of nectar and pollen. Commercial apiaries were also periodically placed adjacent to State forests, allowing the bees to fly to the floral resources of these forests. The fraction of sites located on private property in this way varied from 5% to 57%, depending on the forestry district, with an average of 34%. Thus the actual number of commercial honey bees accessing the State forest floral resources was much higher than occupation permits indicated. The main floral species of importance for beekeeping within the NSW coastal forests were Banksia ericifolia, Corymbia maculata, C. variegata, Eucalyptus muelleriana, E paniculata, E. sidemphloia, Lophostemon confertus, E. acmenoides and E. longifolia. The ironbark group of eucalypts was a major source of nectar for honey bees throughout the State forests of NSW. The main tablelands species were E. viminalis and E. pauciflora, although as there are fewer forest districts on the tablelands the frequency of mention across more than one forest district was reduced. The species of importance in the western forests included C. trachyphloia, E. camaldulensis, E. crebra, E. largiflorens, E. microcarpa, E. sideroxylon and E. fibrosa. This paper provides a collective anecdote of the most important nectar—and pollen-producing flora of value to commercial beekeepers within the forests under the management of Forests NSW.