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

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.

Download Full-text

Resistance of native honey bees from Rhodope Mountains and lowland regions of Bulgaria to Nosema ceranae and viral pathogens

BULGARIAN JOURNAL OF VETERINARY MEDICINE ◽

10.15547/bjvm.2201 ◽

2020 ◽

Vol 23 (2) ◽

pp. 206-217

Author(s):

R. Shumkova ◽

B. Neov ◽

A. Georgieva ◽

D. Teofanova ◽

G. Radoslavov ◽

...

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Honey Bees ◽

Viral Infections ◽

Viral Pathogens ◽

Deformed Wing Virus ◽

Queen Cell ◽

Kashmir Bee Virus ◽

Paralysis Virus ◽

Bee Viruses

The Western honey bee (Apis mellifera L., Hymenoptera: Apidae) is a species of fundamental economic, agricultural and environmental importance. The aim of this study was to compare the prevalence of some parasitic and viral pathogens in local honey bees from the Rodope Mountains and plain regions. To achieve this goal, molecular screening for two of the most distributed Nosema spp. and molecular identification of six honey bee viruses – Deformed wing virus (DWV), Acute bee paralysis virus (ABPV), Chronic bee paralysis virus (CBPV), Sacbrood virus (SBV), Kashmir bee virus (KBV), and Black queen cell virus (BQCV) was performed. Molecular analysis was carried out on 168 honey bee samples from apiaries situated in three different parts of the country where a mix of different honey bee subspecies were reared. In South Bulgaria (the Rhodope Mountains), a local honey bee called Apis mellifera rodopica (a local ecotype of A. m. macedonica) was bred, while in the other two regions (plains) different introduced subspecies existed. The results showed that the samples from the lowland regions in the country were outlined with the highest prevalence (70.5%) of N. ceranae, while those from the mountainous parts had the lowest rate (5.2%). Four of the honey bee viruses were identified – DWV (10/5.9%), followed by SBV (6/3.6%) and ABPV (2/1.2%), and one case of BQCV. In conclusion, the local honey bee A. m. rodopica (despite the higher number of samples) has shown lower prevalence of both nosemosis and viral infections. Therefore, this honey bee has to be preserved as a part of the national biodiversity.

Download Full-text

Nationwide Screening for Bee Viruses and Parasites in Belgian Honey Bees

Viruses ◽

10.3390/v12080890 ◽

2020 ◽

Vol 12 (8) ◽

pp. 890

Author(s):

Severine Matthijs ◽

Valérie De Waele ◽

Valerie Vandenberge ◽

Bénédicte Verhoeven ◽

Jacqueline Evers ◽

...

Keyword(s):

Viral Load ◽

Real Time ◽

Honey Bee ◽

Honey Bees ◽

High Viral Load ◽

Deformed Wing Virus ◽

Bee Health ◽

Honey Bee Health ◽

Varroa Mites ◽

Paralysis Virus

The health of honey bees is threatened by multiple factors, including viruses and parasites. We screened 557 honey bee (Apis mellifera) colonies from 155 beekeepers distributed all over Belgium to determine the prevalence of seven widespread viruses and two parasites (Varroa sp. and Nosema sp.). Deformed wing virus B (DWV-B), black queen cell virus (BQCV), and sacbrood virus (SBV) were highly prevalent and detected by real-time RT-PCR in more than 95% of the colonies. Acute bee paralysis virus (ABPV), chronic bee paralysis virus (CBPV) and deformed wing virus A (DWV-A) were prevalent to a lower extent (between 18 and 29%). Most viruses were only present at low or moderate viral loads. Nevertheless, about 50% of the colonies harbored at least one virus at high viral load (>107 genome copies/bee). Varroa mites and Nosema sp. were found in 81.5% and 59.7% of the honey bee colonies, respectively, and all Nosema were identified as Nosema ceranae by real time PCR. Interestingly, we found a significant correlation between the number of Varroa mites and DWV-B viral load. To determine the combined effect of these and other factors on honey bee health in Belgium, a follow up of colonies over multiple years is necessary.

Download Full-text

Nationwide Screening for Important Bee Viruses in Belgian Honey Bees

Proceedings ◽

10.3390/proceedings2020050054 ◽

2020 ◽

Vol 50 (1) ◽

pp. 54

Author(s):

Severine Matthijs ◽

Nick De Regge

Keyword(s):

Viral Load ◽

Honey Bee ◽

Honey Bees ◽

Clinical Symptoms ◽

Deformed Wing Virus ◽

Ct Value ◽

Increased Risk ◽

The Impact ◽

Bee Colonies ◽

Paralysis Virus

The ecological and economic importance of bees for pollination and biodiversity is well established. The health of bees is, however, threatened by a multitude of factors, including viruses. In this study, we screened 557 colonies from 155 beekeepers distributed all over Belgium to monitor the prevalence and distribution of seven widespread viruses in Belgian honey bees (Apis mellifera). Several of these viruses have been linked with an increased risk for colony loss. Although these viruses can severely impact honey bees and can even cause the death of larvae or adults, colonies with a low viral load usually appear asymptomatic (covert infection). The presence of viruses was determined by real-time RT-PCR. The three most prevalent viruses in Belgian honey bees are Deformed wing virus B (DWV-B or VDV-1), Black queen cell virus (BQCV), and Sacbrood virus (SBV). These viruses were found in more than 90% of the honey bee colonies, but often with a high Ct value, which indicates that they are present at low viral loads (less than 3 log10 genome copies per bee). In certain colonies, however, DWV-B, BQCV, or SBV was detected with a low Ct value, representing a high viral load (in some cases, more than 7 log10 genome copies per bee) and with an increased likelihood of development of clinical symptoms. Deformed wing virus A (DWV-A), Acute bee paralysis virus (ABPV), and Chronic bee paralysis virus (CBPV) were found in less than 40% of the colonies. Kashmir bee virus (KBV) was not found in any of the analyzed Belgian honey bees. Most of the honey bee colonies are infected with multiple viruses, albeit with low virus loads. The impact of viruses can however become critical in the presence of other detrimental factors such as parasites (Nosema sp., Varroa sp.) and pesticides.

Download Full-text

Reduced nest development of reared Bombus terrestris within apiary dense human-modified landscapes

Scientific Reports ◽

10.1038/s41598-021-82540-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ivan Meeus ◽

Laurian Parmentier ◽

Matti Pisman ◽

Dirk C. de Graaf ◽

Guy Smagghe

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Bombus Terrestris ◽

Global Scale ◽

Bumble Bees ◽

Wild Bees ◽

Wild Bee ◽

Important Trait ◽

Competition For Resources ◽

Biomass Increase

AbstractWild bees are in decline on a local to global scale. The presence of managed honey bees can lead to competition for resources with wild bee species, which has not been investigated so far for human-modified landscapes. In this study we assess if managed honey bee hive density influence nest development (biomass) of bumble bees, an important trait affecting fitness. We hypothesize that domesticated honey bees can negatively affect Bombus terrestris nest development in human-modified landscapes. In Flanders, Belgium, where such landscapes are dominantly present, we selected 11 locations with landscape metrics ranging from urban to agricultural. The bee hive locations were mapped and each location contained one apiary dense (AD) and one apiary sparse (AS) study site (mean density of 7.6 ± 5.7 managed honey bee hives per km2 in AD sites). We assessed the effect of apiary density on the reproduction of reared B. terrestris nests. Reared B. terrestris nests had more biomass increase over 8 weeks in apiary sparse (AS) sites compared to nests located in apiary dense (AD) sites. This effect was mainly visible in urban locations, where nest in AS sites have 99.25 ± 60.99 g more biomass increase compared to nest in urban AD sites. Additionally, we found that managed bumble bee nests had higher biomass increase in urban locations. We conclude that the density of bee hives is a factor to consider in regard to interspecific competition between domesticated honey bees and bumble bees.

Download Full-text

The relationship between managed bees and the prevalence of parasites in bumblebees

10.7287/peerj.preprints.309v2 ◽

2014 ◽

Cited By ~ 1

Author(s):

Peter Graystock ◽

Dave Goulson ◽

William O Hughes

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Parasite Prevalence ◽

Wild Bees ◽

Deformed Wing Virus ◽

Nosema Bombi ◽

Crithidia Bombi ◽

Parasite Spillover ◽

The Impact ◽

The Relationship

Honey bees and, more recently, bumblebees have been domesticated and are now managed commercially primarily for crop pollination, mixing with wild pollinators during foraging on shared flower resources. There is mounting evidence that managed honey bees or commercially produced bumblebees may affect the health of wild pollinators such as bumblebees by increasing competition for resources and the prevalence of parasites in wild bees. Here we screened 764 bumblebees from around five greenhouses that either used commercially produced bumblebees or did not, as well as bumblebees from 10 colonies placed at two sites either close to or far from a honey bee apiary, for the parasites Apicystis bombi, Crithidia bombi, Nosema bombi, N. ceranae, N. apis and deformed wing virus. We found that A. bombi and C. bombi were more prevalent around greenhouses using commercially produced bumblebees, while C. bombi was 18% more prevalent in bumblebees at the site near to the honey bee apiary than those at the site far from the apiary. Whilst these results are from only a limited number of sites, they support previous reports of parasite spillover from commercially produced bumblebees to wild bumblebees, and suggest that the impact of stress from competing with managed bees or the vectoring of parasites by them on parasite prevalence in wild bees needs further investigation. It appears increasingly likely that the use of managed bees comes at a cost of increased parasites in wild bumblebees, which is not only a concern for bumblebee conservation, but which may impact other pollinators as well.

Download Full-text

Analysis of Pollination Services Provided by Wild and Managed Bees (Apoidea) in Wild Blueberry (Vaccinium angustifolium Aiton) Production in Maine, USA, with a Literature Review

Agronomy ◽

10.3390/agronomy10091413 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1413

Author(s):

Sara L. Bushmann ◽

Francis A. Drummond

Keyword(s):

Honey Bee ◽

Crop Yield ◽

Honey Bees ◽

Fruit Set ◽

Bumble Bees ◽

Wild Bees ◽

Vaccinium Angustifolium ◽

Wild Bee ◽

Bee Communities ◽

Wild Blueberry

Maine is the largest producer of wild blueberry (Vaccinium angustifolium Aiton) in the United States. Pollination comes from combinations of honey bees (Apis mellifera (L.)), commercial bumble bees (Bombus impatiens Cresson), and wild bees. This study addresses (1) previous research addressing wild-blueberry pollination, (2) effects of wild-bee and honey-bee activity densities on fruit set, yield, and crop value, (3) the economic value of wild-bee communities, and (4) economic consequences of pollinator loss. Bee communities were sampled in 40 fields over three years (2010–2012) and bee activity densities were estimated for bumble bees, honey bees, and other wild bees. These data were applied to an economic model to estimate the value of bee taxa. Bumble bees and honey bees predicted fruit set and reduced its spatial heterogeneity. Other wild bees were not significant predictors of fruit set. Yield was predicted by fruit set and field size, but not pest management tactics. Our analysis showed that disruption in supply of honey bees would result in nearly a 30% decrease in crop yield, buffered in part by wild bees that provide “background” levels of pollination. Honey-bee stocking density and, thus, the activity density of honey bees was greater in larger fields, but not for wild bees. Therefore, a decrease in crop yield would be greater than 30% for large fields due to the proportionally greater investment in honey bees in large fields and a relatively lower contribution by wild bees.

Download Full-text

The relationship between managed bees and the prevalence of parasites in bumblebees

10.7287/peerj.preprints.309 ◽

2014 ◽

Cited By ~ 1

Author(s):

Peter Graystock ◽

Dave Goulson ◽

William O Hughes

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Parasite Prevalence ◽

Wild Bees ◽

Deformed Wing Virus ◽

Nosema Bombi ◽

Crithidia Bombi ◽

Parasite Spillover ◽

The Impact ◽

The Relationship

Download Full-text

Landscape structure affects the sunflower visiting frequency of insect pollinators

Scientific Reports ◽

10.1038/s41598-021-87650-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Károly Lajos ◽

Ferenc Samu ◽

Áron Domonkos Bihaly ◽

Dávid Fülöp ◽

Miklós Sárospataki

Keyword(s):

Landscape Structure ◽

Honey Bees ◽

Agricultural Landscape ◽

Edge Density ◽

Wild Bees ◽

Natural Habitats ◽

Mass Flowering ◽

Positive Effects ◽

Pollinator Community ◽

Foraging Ranges

AbstractMass-flowering crop monocultures, like sunflower, cannot harbour a permanent pollinator community. Their pollination is best secured if both managed honey bees and wild pollinators are present in the agricultural landscape. Semi-natural habitats are known to be the main foraging and nesting areas of wild pollinators, thus benefiting their populations, whereas crops flowering simultaneously may competitively dilute pollinator densities. In our study we asked how landscape structure affects major pollinator groups’ visiting frequency on 36 focal sunflower fields, hypothesising that herbaceous semi-natural (hSNH) and sunflower patches in the landscape neighbourhood will have a scale-dependent effect. We found that an increasing area and/or dispersion of hSNH areas enhanced the visitation of all pollinator groups. These positive effects were scale-dependent and corresponded well with the foraging ranges of the observed bee pollinators. In contrast, an increasing edge density of neighbouring sunflower fields resulted in considerably lower visiting frequencies of wild bees. Our results clearly indicate that the pollination of sunflower is dependent on the composition and configuration of the agricultural landscape. We conclude that an optimization of the pollination can be achieved if sufficient amount of hSNH areas with good dispersion are provided and mass flowering crops do not over-dominate the agricultural landscape.

Download Full-text

Comparing Survival of Israeli Acute Paralysis Virus Infection among Stocks of U.S. Honey Bees

Insects ◽

10.3390/insects12010060 ◽

2021 ◽

Vol 12 (1) ◽

pp. 60

Author(s):

Shilpi Bhatia ◽

Saman S. Baral ◽

Carlos Vega Melendez ◽

Esmaeil Amiri ◽

Olav Rueppell

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Virus Infections ◽

Israeli Acute Paralysis Virus ◽

Immune Genes ◽

Starting Point ◽

Bee Health ◽

Honey Bee Health ◽

Survival Differences ◽

Paralysis Virus

Among numerous viruses that infect honey bees (Apis mellifera), Israeli acute paralysis virus (IAPV) can be linked to severe honey bee health problems. Breeding for virus resistance may improve honey bee health. To evaluate the potential for this approach, we compared the survival of IAPV infection among stocks from the U.S. We complemented the survival analysis with a survey of existing viruses in these stocks and assessing constitutive and induced expression of immune genes. Worker offspring from selected queens in a common apiary were inoculated with IAPV by topical applications after emergence to assess subsequent survival. Differences among stocks were small compared to variation within stocks, indicating the potential for improving honey bee survival of virus infections in all stocks. A positive relation between worker survival and virus load among stocks further suggested that honey bees may be able to adapt to better cope with viruses, while our molecular studies indicate that toll-6 may be related to survival differences among virus-infected worker bees. Together, these findings highlight the importance of viruses in queen breeding operations and provide a promising starting point for the quest to improve honey bee health by selectively breeding stock to be better able to survive virus infections.

Download Full-text

Detection of Lotmaria passim, Crithidia mellificae and Replicative Forms of Deformed Wing Virus and Kashmir Bee Virus in the Small Hive Beetle (Aethina tumida)

Pathogens ◽

10.3390/pathogens10030372 ◽

2021 ◽

Vol 10 (3) ◽

pp. 372

Author(s):

Antonio Nanetti ◽

James D. Ellis ◽

Ilaria Cardaio ◽

Giovanni Cilia

Keyword(s):

Honey Bee ◽

Aethina Tumida ◽

Small Hive Beetle ◽

Deformed Wing Virus ◽

Queen Cell ◽

Kashmir Bee Virus ◽

Acute Bee Paralysis Virus ◽

Bee Virus ◽

Paralysis Virus ◽

Lotmaria Passim

Knowledge regarding the honey bee pathogens borne by invasive bee pests remains scarce. This investigation aimed to assess the presence in Aethina tumida (small hive beetle, SHB) adults of honey bee pathogens belonging to the following groups: (i) bacteria (Paenibacillus larvae and Melissococcus plutonius), (ii) trypanosomatids (Lotmaria passim and Crithidia mellificae), and (iii) viruses (black queen cell virus, Kashmir bee virus, deformed wing virus, slow paralysis virus, sacbrood virus, Israeli acute paralysis virus, acute bee paralysis virus, chronic bee paralysis virus). Specimens were collected from free-flying colonies in Gainesville (Florida, U.S.A.) in summer 2017. The results of the molecular analysis show the presence of L. passim, C. mellificae, and replicative forms of deformed wing virus (DWV) and Kashmir bee virus (KBV). Replicative forms of KBV have not previously been reported. These results support the hypothesis of pathogen spillover between managed honey bees and the SHB, and these dynamics require further investigation.

Download Full-text