scholarly journals Exposure of Larvae of the Solitary Bee Osmia bicornis to the Honey Bee Pathogen Nosema ceranae Affects Life History

Insects ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 380 ◽  
Author(s):  
Bramke ◽  
Müller ◽  
McMahon ◽  
Rolff
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Growth Parameters ◽  
Physiological State ◽  
Nosema Ceranae ◽  
Wild Plants ◽  
Physiological Status ◽  
Viable Spore ◽  
Wild Bees ◽  
Osmia Bicornis

Wild bees are important pollinators of wild plants and agricultural crops and they are threatened by several environmental stressors including emerging pathogens. Honey bees have been suggested as a potential source of pathogen spillover. One prevalent pathogen that has recently emerged as a honey bee disease is the microsporidian Nosema ceranae. While the impacts of N. ceranae in honey bees are well documented, virtually nothing is known about its effects in solitary wild bees. The solitary mason bee Osmia bicornis is a common pollinator in orchards and amenable to commercial management. Here, we experimentally exposed larvae of O. bicornis to food contaminated with N. ceranae and document spore presence during larval development. We measured mortality, growth parameters, and timing of pupation in a semi-field experiment. Hatched individuals were assessed for physiological state including fat body mass, wing muscle mass, and body size. We recorded higher mortality in the viable-spore-exposed group but could only detect a low number of spores among the individuals of this treatment. Viable-spore-treated individuals with higher head capsule width had a delayed pupation start. No impact on the physiological status could be detected in hatched imagines. Although we did not find overt evidence of O. bicornis infection, our findings indicate that exposure of larvae to viable N. ceranae spores could affect bee development.

scholarly journals Silencing the Honey Bee (Apis mellifera) Naked Cuticle Gene (nkd) Improves Host Immune Function and Reduces Nosema ceranae Infections

2016 ◽  
Vol 82 (22) ◽  
pp. 6779-6787 ◽  
Author(s):  
Wenfeng Li ◽  
Jay D. Evans ◽  
Qiang Huang ◽  
Cristina Rodríguez-García ◽  
Jie Liu ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Immune Function ◽  
Honey Bee ◽  
Honey Bees ◽  
Nosema Ceranae ◽  
Negative Regulator ◽  
Mrna Levels ◽  
Content Type ◽  
Bee Disease

ABSTRACTNosema ceranaeis a new and emerging microsporidian parasite of European honey bees,Apis mellifera, that has been implicated in colony losses worldwide. RNA interference (RNAi), a posttranscriptional gene silencing mechanism, has emerged as a potent and specific strategy for controlling infections of parasites and pathogens in honey bees. While previous studies have focused on the silencing of parasite/pathogen virulence factors, we explore here the possibility of silencing a host factor as a mechanism for reducing parasite load. Specifically, we used an RNAi strategy to reduce the expression of a honey bee gene,naked cuticle(nkd), which is a negative regulator of host immune function. Our studies found thatnkdmRNA levels in adult bees were upregulated byN. ceranaeinfection (and thus, the parasite may use this mechanism to suppress host immune function) and that ingestion of double-stranded RNA (dsRNA) specific tonkdefficiently silenced its expression. Furthermore, we found that RNAi-mediated knockdown ofnkdtranscripts inNosema-infected bees resulted in upregulation of the expression of several immune genes (Abaecin,Apidaecin,Defensin-1, andPGRP-S2), reduction ofNosemaspore loads, and extension of honey bee life span. The results of our studies clearly indicate that silencing the hostnkdgene can activate honey bee immune responses, suppress the reproduction ofN. ceranae, and improve the overall health of honey bees. This study represents a novel host-derived therapeutic for honey bee disease treatment that merits further exploration.IMPORTANCEGiven the critical role of honey bees in the pollination of agricultural crops, it is urgent to develop strategies to prevent the colony decline induced by the infection of parasites/pathogens. Targeting parasites and pathogens directly by RNAi has been proven to be useful for controlling infections in honey bees, but little is known about the disease impacts of RNAi silencing of host factors. Here, we demonstrate that knocking down the honey bee immune repressor-encodingnkdgene can suppress the reproduction ofN. ceranaeand improve the overall health of honey bees, which highlights the potential role of host-derived and RNAi-based therapeutics in controlling the infections in honey bees. The information obtained from this study will have positive implications for honey bee disease management practices.

scholarly journals Significance of Apoidea as Main Pollinators. Ecological and Economic Impact and Implications for Human Nutrition

Diversity ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 280
Author(s):  
Peter Hristov ◽  
Boyko Neov ◽  
Rositsa Shumkova ◽  
Nadezhda Palova
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Agricultural Production ◽  
Genetic Resource ◽  
Economic Value ◽  
Wild Plants ◽  
Insect Pollination ◽  
Economic Sectors ◽  
Pollination Services ◽  
Total Economic Value

Wild and managed bees provide pollination services to crops and wild plants, as well as a variety of other services beneficial to humans. Honey bees are the most economically valuable pollinator worldwide. It has been calculated that 9.5% of the total economic value of agricultural production comes from insect pollination, thus amounting to just under USD 200 billion globally. More than 100 important crops depend on pollination by honey bees. The latter pollinate not only a wide number of commercial crops but also many wild plants, some of which are threatened by extinction and constitute a valuable genetic resource. Moreover, as pollinators, honey bees play a significant role in every aspect of the ecosystem by facilitating the growth of trees, flowers, and other plants that serve as food and shelter for many large and small creatures. In this paper, we describe how the reduction in honey bee populations affects various economic sectors, as well as human health.

scholarly journals Exposure of honey bee larvae to thiamethoxam and its interaction with Nosema ceranae infection in adult honey bees

2020 ◽  
Vol 256 ◽  
pp. 113443 ◽  
Author(s):  
Tanja Tesovnik ◽  
Minja Zorc ◽  
Marko Ristanić ◽  
Uroš Glavinić ◽  
Jevrosima Stevanović ◽  
...  
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Nosema Ceranae ◽  
Honey Bee Larvae

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

2021 ◽  
Vol 8 (6) ◽  
pp. 107
Author(s):  
Shane S. Klassen ◽  
William VanBlyderveen ◽  
Les Eccles ◽  
Paul G. Kelly ◽  
Daniel Borges ◽  
...  
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Nosema Ceranae ◽  
Future Research ◽  
First Year ◽  
Winter Mortality ◽  
Treatment Frequency ◽  
Honey Production ◽  
Sugar Syrup ◽  
Second Year

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

scholarly journals Prevalence and distribution of Nosema ceranae in Croatian honeybee colonies

2010 ◽  
Vol 55 (No. 9) ◽  
pp. 457-462 ◽  
Author(s):  
I. Tlak Gajger ◽  
O. Vugrek ◽  
D. Grilec ◽  
Z. Petrinec
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Microscopic Examination ◽  
Honey Bees ◽  
Nosema Ceranae ◽  
Negative Effects ◽  
Microsporidian Parasite ◽  
Nosema Species ◽  
Nosema Disease ◽  
Bee Colonies

Nosema disease of European honey bees afflicts bees worldwide. Nosema ceranae is a recently described microsporidian parasite of the honey bee (Apis mellifera) and its geographical distribution is not well known. The disease may have many negative effects on bee colonies and cause high losses for apiculture and consequently in agriculture. With this in mind, a total of 204 samples of dead bees from different localities in Croatia were selected and investigated for distribution, prevalence and diversity of N. ceranae infection, using light microscopic examination and multiplex PCR. Our results show that N. ceranae is the only nosema species found to infect honeybees in our geographically varied collection. The nucleotide sequences of amplicons from Nosema-infested honeybee samples were 100% identical with the N. ceranae sequence deposited in the GenBank database. N. ceranae infected bees were found in samples collected from each of 21 districts, and in all three climatic areas, i.e., mediterranean, mountain, and continental parts regions of Croatia.

scholarly journals Impact of honeybee (Apis mellifera L.) density on wild bee foraging behaviour

2016 ◽  
Vol 60 (1) ◽  
pp. 49-62 ◽  
Author(s):  
Georgios Goras ◽  
Chrysoula Tananaki ◽  
Maria Dimou ◽  
Thomas Tscheulin ◽  
Theodora Petanidou ◽  
...  
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Foraging Behaviour ◽  
Northern Greece ◽  
Wild Bees ◽  
Honey Production ◽  
Visitation Frequency ◽  
Before And After ◽  
Bee Foraging ◽  
Visit Duration

Abstract Honey bees are globally regarded as important crop pollinators and are also valued for their honey production. They have been introduced on an almost worldwide scale. During recent years, however, several studies argue their possible competition with unmanaged pollinators. Here we examine the possible effects of honey bees on the foraging behaviour of wild bees on Cistus creticus flowers in Northern Greece. We gradually introduced one, five, and eight honey-bee hives per site, each containing ca. 20,000 workers. The visitation frequency and visit duration of wild bees before and after the beehive introductions were measured by flower observation. While the visitation frequencies of wild bees were unaffected, the average time wild bees spent on C. creticus increased with the introduction of the honey-bee hives. Although competition between honey bees and wild bees is often expected, we did not find any clear evidence for significant effects even in honey-bee densities much higher than the European-wide average of 3.1 colonies/km2.

scholarly journals Possible Spillover of Pathogens between Bee Communities Foraging on the Same Floral Resource

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 122
Author(s):  
Anne Dalmon ◽  
Virgine Diévart ◽  
Maxime Thomasson ◽  
Romain Fouque ◽  
Bernard E. Vaissière ◽  
...  
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Population Decline ◽  
Virus Transmission ◽  
Wild Bees ◽  
Deformed Wing Virus ◽  
Wild Bee ◽  
Pollinator Community ◽  
Floral Resource ◽  
Paralysis Virus

Viruses are known to contribute to bee population decline. Possible spillover is suspected from the co-occurrence of viruses in wild bees and honey bees. In order to study the risk of virus transmission between wild and managed bee species sharing the same floral resource, we tried to maximize the possible cross-infections using Phacelia tanacetifolia, which is highly attractive to honey bees and a broad range of wild bee species. Virus prevalence was compared over two years in Southern France. A total of 1137 wild bees from 29 wild bee species (based on COI barcoding) and 920 honey bees (Apis mellifera) were checked for the seven most common honey bee RNA viruses. Halictid bees were the most abundant. Co-infections were frequent, and Sacbrood virus (SBV), Black queen cell virus (BQCV), Acute bee paralysis virus (ABPV) and Israeli acute paralysis virus (IAPV) were widespread in the hymenopteran pollinator community. Conversely, Deformed wing virus (DWV) was detected at low levels in wild bees, whereas it was highly prevalent in honey bees (78.3% of the samples). Both wild bee and honey bee virus isolates were sequenced to look for possible host-specificity or geographical structuring. ABPV phylogeny suggested a specific cluster for Eucera bees, while isolates of DWV from bumble bees (Bombus spp.) clustered together with honey bee isolates, suggesting a possible spillover.

scholarly journals Reproduction of Distinct Varroa destructor Genotypes on Honey Bee Worker Brood

Insects ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 372 ◽  
Author(s):  
Wenfeng Li ◽  
Cheng Wang ◽  
Zachary Y. Huang ◽  
Yanping Chen ◽  
Richou Han
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Southern China ◽  
Reproductive Rate ◽  
Wild Plants ◽  
Dependent Manner ◽  
New Host ◽  
Varroa Mites ◽  
Worker Brood

Honey bees play important roles in pollination for many crops and wild plants, but have been facing great threats posed by various pathogens and parasites. Among them, Varroa destructor, an obligate ectoparasite of honey bees, is considered the most damaging. Within the last century, V. destructor shifted from the original host, the Asian honey bee Apis cerana to the new host, the European honey bee A. mellifera. However, the reproduction of Varroa mites, especially of different haplotypes in the two hosts, is still largely unknown. In this study, we first investigated the existing Varroa haplotypes in local colonies in southern China, and then compared the reproduction of different haplotypes on the worker brood of both the original and new hosts by artificial inoculation. We confirmed that there are two haplotypes of V. destructor in southern China, one is the Korea haplotype and the other is the China haplotype, and the two types parasitized different honey bee species. Although Varroa females from A. mellifera (Korea haplotype) are able to reproduce on the worker brood of both honey bee species, they showed better reproductive performance in the new host A. mellifera with significantly higher fecundity (number of offspring per mother mite) and reproductive rate (number of adult daughters per mother mite), suggesting that this parasite gains higher fitness after host shift. The data further showed that a short stay of Varroa females inside the A. cerana worker cells decreased their fecundity and especially the reproductive rate in a time-dependent manner, suggesting that the A. cerana worker cells may inhibit Varroa reproduction. In contrast, Varroa mites derived from A. cerana colonies (China haplotype) were entirely sterile in A. mellifera worker cells during two sequential inoculations, while the control mites from A. mellifera colonies (Korea haplotype) reproduced normally. In addition, all the infertile mites were found to defecate on the abdomen of bee pupae. We have revealed that two haplotypes of V. destructor exhibit differential reproduction on the worker brood of the original and new host honey bees, providing novel insights into the diversity and complexity of the reproduction of V. destructor.

scholarly journals RNA Interference-Mediated Knockdown of Genes Encoding Spore Wall Proteins Confers Protection against Nosema ceranae Infection in the European Honey Bee, Apis mellifera

2021 ◽  
Vol 9 (3) ◽  
pp. 505
Author(s):  
Nan He ◽  
Yi Zhang ◽  
Xin Le Duan ◽  
Jiang Hong Li ◽  
Wei-Fone Huang ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Rna Interference ◽  
Honey Bee ◽  
Honey Bees ◽  
Therapeutic Potential ◽  
Spore Wall ◽  
Nosema Ceranae ◽  
Host Responses ◽  
Colony Losses ◽  
Nosema Disease

Nosema ceranae (Opisthosporidia: Microsporidia) is an emergent intracellular parasite of the European honey bee (Apis mellifera) and causes serious Nosema disease which has been associated with worldwide honey bee colony losses. The only registered treatment for Nosema disease is fumagillin-b, and this has raised concerns about resistance and off-target effects. Fumagillin-B is banned from use in honey bee colonies in many countries, particularly in Europe. As a result, there is an urgent need for new and effective therapeutic options to treat Nosema disease in honey bees. An RNA interference (RNAi)-based approach can be a potent strategy for controlling diseases in honey bees. We explored the therapeutic potential of silencing the sequences of two N. ceranae encoded spore wall protein (SWP) genes by means of the RNAi-based methodology. Our study revealed that the oral ingestion of dsRNAs corresponding to SWP8 and SWP12 used separately or in combination could lead to a significant reduction in spore load, improve immunity, and extend the lifespan of N. ceranae-infected bees. The results from the work completed here enhance our understanding of honey bee host responses to microsporidia infection and highlight that RNAi-based therapeutics are a promising treatment for honey bee diseases.

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