Commercial Honey Bee Research Articles

Genetic Characterization of Commercial Honey Bee (Hymenoptera: Apidae) Populations in the United States by Using Mitochondrial and Microsatellite Markers

Abstract Genetic diversity levels within and between the two commercial breeding areas in the United States were analyzed using the DraI restriction fragment length polymorphism of the COI-COII mitochondrial region and 10 polymorphic microsatellite loci. The western commercial breeding population (WCBP) and the southeastern commercial breeding population (SCBP) were sampled in 1993–1994 and again in 2004–2005. The goal of this study was to characterize the genetic composition of these populations and to measure potential changes in genetic diversity and composition across the sampling period. The mitochondrial DNA haplotypes C1 and C2, characteristic of the most popular bee strains (Italians and Carniolans, respectively) sold in the United States, were the dominant haplotypes at both sample dates. The frequency of Apis mellifera mellifera M haplotypes, M4, M7, and M7′, decreased during the 10-yr span. An A1 haplotype characteristic of Africanized bees was found in the SCBP from 2005. Microsatellite analysis showed there was a loss of alleles in both the WCBP and SCBP, but the losses were not significant due to simultaneous gains of new alleles into these populations between 1993 and 2005. Genetic differences that occurred between the 1993–1994 WCBP and SCBP were still detectable in these populations sampled a decade later, suggesting that these populations could be useful sources of diversity for each other in the future.

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.

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.

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.

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.

Varying degrees of Apis mellifera ligustica introgression in protected populations of the black honeybee, Apis mellifera mellifera, in northwest Europe

The natural distribution of honeybee subspecies in Europe has been significantly affected by human activities during the last century. Non-native subspecies of honeybees have been introduced and propagated, so that native black honeybee (Apis mellifera mellifera) populations lost their identity by gene-flow or went extinct. After previous studies investigated the remaining gene-pools of native honeybees in France and Spain, we here assess the genetic composition of eight northwest European populations of the black honeybee, using both mitochondrial (restriction fragment length polymorphisms of the intergenic transfer RNAleu-COII region) and nuclear (11 microsatellite loci) markers. Both data sets show that A. m. mellifera populations still exist in Norway, Sweden, Denmark, England, Scotland and Ireland, but that they are threatened by gene flow from commercial honeybees. Both Bayesian admixture analysis of the microsatellite data and DraI-RFLP (restriction fragment length polymorphism) analysis of the intergenic region indicated that gene-flow had hardly occurred in some populations, whereas almost 10% introgression was observed in other populations. The most introgressed population was found on the Danish Island of Laeso, which is the last remaining native Danish population of A. m. mellifera and the only one of the eight investigated populations that is protected by law. We discuss how individual admixture analysis can be used to monitor the restoration of honeybee populations that suffer from unwanted hybridization with non-native subspecies.

Commercial honey bees ( Apis mellifera) reduce the fecundity of an Australian native bee ( Hylaeus alcyoneus)

European honey bees used for commercial honey production represent a potential source of competition for floral resources with native nectar and pollen feeding insects. This study reports the results of an experiment run over two years on the impact of commercial honey bees on the fecundity of a solitary native bee, Hylaeus alcyoneus. Registered apiary sites were used as treatment sites (with honey bees) while control sites (without honey bees) were interspersed between. The fecundity of H. alcyoneus was measured using trap nests. We compared the number of nests produced, number of eggs per nest and emerging progeny mass of H. alcyoneus in sites with and without commercial bee hives. The number of nests produced by H. alcyoneus was 23% less (Wilcoxon’s T) at treatment sites than control sites. Analysis of individual measurement intervals using ANOVA was compromised by a general lack of power. This result highlights that even though honey bees have been present in certain areas for many years, competition with native bees may still be occurring.

Impact of the introduced honey bee (Apis mellifera) (Hymenoptera: Apidae) on native bees: A review

Abstract Interspecific competition for a limited resource can result in the reduction of survival, growth and/or reproduction in one of the species involved. The introduced honey bee (Apis mellifera Linnaeus) is an example of a species that can compete with native bees for floral resources. Often, research into honey bee/native bee competition has focused on floral resource overlap, visitation rates or resource harvesting, and any negative interaction has been interpreted as a negative impact. Although this research can be valuable in indicating the potential for competition between honey bees and native bees, to determine if the long‐term survival of a native bee species is threatened, fecundity, survival or population density needs to be assessed. The present review evaluates research that has investigated all these measurements of honey bee/native bee competition and finds that many studies have problems with sample size, confounding factors or data interpretation. Guidelines for future research include increasing replication and using long‐term studies to investigate the impact of both commercial and feral honey bees.

Brood Pheromone Regulates Foraging Activity of Honey Bees (Hymenoptera: Apidae)

Brood pheromone modulated the foraging behavior of commercial honey bee, Apis mellifera L., colonies pollinating a 10-ha market garden of cucumber, Cucurbita pepo L., and zucchini, Cucumis saticus L., in Texas in late autumn. Six colonies were randomly selected to receive 2000 larval equivalents of brood pheromone and six received a blank control. The ratio of pollen to nonpollen foragers entering colonies was significantly greater in pheromone-treated colonies 1 h after treatment. Pheromone-treated foragers returned with pollen load weights that were significantly heavier than controls. Pollen returned by pheromone-treated foragers was 43% more likely to originate from the target crop. Number of pollen grains washed from the bodies of nonpollen foragers from pheromone-treated colonies was significantly greater than controls and the pollen was 54% more likely to originate from the target crop. Increasing the foraging stimulus environment with brood pheromone increased colony-level foraging and individual forager efforts. Brood pheromone is a promising technology for increasing the pollination activity and efficiency of commercial honey bee colonies.

Brood pheromone regulates foraging activity of honey bees (Hymenoptera: Apidae).

Brood pheromone modulated the foraging behavior of commercial honey bee, Apis mellifera L., colonies pollinating a 10-ha market garden of cucumber, Cucurbita pepo L., and zucchini, Cucumis saticus L., in Texas in late autumn. Six colonies were randomly selected to receive 2000 larval equivalents of brood pheromone and six received a blank control. The ratio of pollen to nonpollen foragers entering colonies was significantly greater in pheromone-treated colonies 1 h after treatment. Pheromone-treated foragers returned with pollen load weights that were significantly heavier than controls. Pollen returned by pheromone-treated foragers was 43% more likely to originate from the target crop. Number of pollen grains washed from the bodies of nonpollen foragers from pheromone-treated colonies was significantly greater than controls and the pollen was 54% more likely to originate from the target crop. Increasing the foraging stimulus environment with brood pheromone increased colony-level foraging and individual forager efforts. Brood pheromone is a promising technology for increasing the pollination activity and efficiency of commercial honey bee colonies.

Does the recently introduced bumblebee Bombus terrestris (Apidae) threaten Australian ecosystems?

Abstract Native vegetation near Hobart in Tasmania was investigated to determine whether it was being invaded by the recently introduced large earth bumblebee, Bombus terrestris (Linnaeus, 1758). This species was found to be established in high numbers in a variety of vegetation types from coastal heath, through sclerophyll forest, and subalpine shrubberies up to an altitude of 1100 m. Hence, it has the potential to spread through much of Tasmania and temperate, mesic regions of mainland Australia. It is highly polylectic, foraging on at least 66 native plant species from 21 families. While the most heavily visited species produced abundant nectar, the lack of pre‐dation on this species also allowed it to forage economically on small flowers in clusters. This foraging profile overlapped with those of all anthophilous insect families, all bee subgenera, and all species of nectarivorous birds which were encountered. Therefore, B. terrestris has the potential to compete with most native anthophiles and commercial honeybees. As it forages from some plant taxa which are not visited by the European honeybee, Apis mellifera Linnaeus, 1758, this species is impacting on plant‐pollinator relationships which have previously been free from the effects of exotic bees.

Blessing or curse? Varroa mite impacts Africanized bee spread and beekeeping

Africanized honey bees were first detected in California in October 1994. Since then, they have established a foothold in the Imperial Valley and have spread toward San Diego and into Palm Springs. However, their spread has been much slower than originally expected. What has slowed them? The best guess is Varroa jacobsoni, an exotic ectoparasite of honey bees recently introduced into North America. The effects of varroa on Africanized honey bees may be both a blessing and a curse; the latter is especially true if Africanized bees become resistant to varroa and commercial honey bees do not.

Evaluation of Australian commercial honey bees for hygienic behaviour, a critical character for tolerance to chalkbrood

Chalkbrood of honey bees (Apis mellifera) is caused by Ascosphaera apis, and is new to Australia. As yet, no treatment or prophylaxis is available for this disease. The best prospects for control are likely to come from the use of 'hygienic' bees, those with a strong genetic tendency to uncap and remove dead pupae, together with good beekeeping practice. Ten strains of Australian commercial honey bee were evaluated for hygienic behaviour. Dead pupae were inserted into the colonies and checked after 3, 5 and 7 days for the number of pupae removed. Most colonies (80%) were non-hygienic and hence likely to be susceptible to chalkbrood. However, 2 strains provided good overall performance in the test and comprised 1 or 2 colonies that were highly hygienic. Colonies were evaluated 3 times, and the good performance of these colonies was repeatable across trials. These data suggest that hygienic behavioural morphs exist in Australia's commercial bee strains, and it is unnecessary to obtain breeding stock from overseas for this reason alone. Selective breeding, with relatively simple techniques which can be used by beekeepers and queen breeders, should produce suitable genotypes.

Genetic Analysis of Commercial Honey Bees (Hymenoptera: Apidae) from the Southeastern United States

Approximately 3.2 million honey bee colonies are maintained by beekeepers in the United States and many are headed by commercially bred queens. We used mitochondrial DNA (mtDNA) and allozyme variation to characterize 142 breeder queen colonies from 22 apiaries in the southeastern United States that produced ≈483,900 commercial honey bee queens in 1993. Analysis of mtDNA haplotypes showed that 4% of the 142 commercial breeder queen colonies were maternal descendants of Apis mellifera mellifera, a subspecies that was imported into the United States by the 17th century but is no longer used commercially. The other 96% were probably descendants of A. m. ligustica. or A. m. carnica, subspecies imported in the 19th century which are still sold as commercial strains. Malate dehydrogenase allele frequencies for the 142 breeder queen colonies were determined to be Mdh65 = 0.50, Mdh80 = 0.23, and Mdh100 = 0.27. Five other enzymes known to be polymorphic in adult honey bees were invariant. Significant genetic differences between commercial and feral populations suggest that the feral population may represent a novel source of genetic variation for breeding programs.

Identification and Certification of Africanized Honey Bees

We investigate via computer simulation the effectiveness of regulating the process of Africanization of commercial honey bee populations in North America following the establishment of an Africanized feral population. Our results show that regulatory programs designed with the specific objective of identification and certification of non-Africanized, commercial colonies within an Africanized environment are not effective except under a narrow set of unlikely conditions. Under the conditions of our model, even low levels of immigration of Africanized drones into non-Africanized areas results in a high percentage of Africanization and a high probability of error of classification. We discuss the limitations of such programs, the kinds of data necessary to assess the likelihood of their success, and recommend a more effective direction for future research.

NON‐SUSCEPTIBILITY OF APIS MELLIFERA TO CULICINOMYCES CLAVISPORUS

AbstractThe commercial honey bee Apis mellifera was exposed to the mosquito pathogenic fungus Culicinomyces clavisporus. The examination of adults and larvae, sampled from an inoculated hive failed to detect any evidence of fungal invasion. Adult bees maintained in the laboratory at 27 °C and fed a fungal suspension were also found to be not susceptible.

Growth Regulator Survey for Activity in Inducing Parthenocarpy in the Highbush Blueberry1

Abstract An effective growth regulator treatment for inducing fruit set and parthenocarpic development in the highbush blueberry would restore a number of once productive varieties to profitable commercial use. The decline in productiveness of varieties such as Coville, Earliblue and Jersey has paralleled the decline in native pollinating insects such as the bumblebee (4). The use of commercial honeybees has not solved the fruit set problem in many cases because the problem varieties appear to be less attractive to the domesticated bees than are the fruitful varieties (4).

Growth Regulator Survey for Activity in Inducing Parthenocarpy in the Highbush Blueberry1

Abstract An effective growth regulator treatment for inducing fruit set and parthenocarpic development in the highbush blueberry would restore a number of once productive varieties to profitable commercial use. The decline in productiveness of varieties such as Coville, Earliblue and Jersey has paralleled the decline in native pollinating insects such as the bumblebee (4). The use of commercial honeybees has not solved the fruit set problem in many cases because the problem varieties appear to be less attractive to the domesticated bees than are the fruitful varieties (4).