7 research outputs found

    Estimating the density of honeybee colonies across their natural range to fill the gap in pollinator decline censuses

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    Although pollinator declines are a global biodiversity threat, the demography of the western honeybee (Apis mellifera) has not been considered by conservationists because it is biased by the activity of beekeepers. To fill this gap in pollinator decline censuses and to provide a broad picture of the current status of honeybees across their natural range, we used microsatellite genetic markers to estimate colony densities and genetic diversity at different locations in Europe, Africa, and central Asia that had different patterns of land use. Genetic diversity and colony densities were highest in South Africa and lowest in Northern Europe and were correlated with mean annual temperature. Confounding factors not related to climate, however, are also likely to influence genetic diversity and colony densities in honeybee populations. Land use showed a significantly negative influence over genetic diversity and the density of honeybee colonies over all sampling locations. In Europe honeybees sampled in nature reserves had genetic diversity and colony densities similar to those sampled in agricultural landscapes, which suggests that the former are not wild but may have come from managed hives. Other results also support this idea: putative wild bees were rare in our European samples, and the mean estimated density of honeybee colonies on the continent closely resembled the reported mean number of managed hives. Current densities of European honeybee populations are in the same range as those found in the adverse climatic conditions of the Kalahari and Saharan deserts, which suggests that beekeeping activities do not compensate for the loss of wild colonies. Our findings highlight the importance of reconsidering the conservation status of honeybees in Europe and of regarding beekeeping not only as a profitable business for producing honey, but also as an essential component of biodiversity conservation.This project was funded by the BEESHOP European network (FOOD-CT-2006-022568) and the National Research Foundation of South Africa

    Evolutionarily diverse origins of deformed wing viruses in western honey bees

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    Novel transmission routes can allow infectious diseases to spread, often with devastating consequences. Ectoparasitic varroa mites vector a diversity of RNA viruses, having switched hosts from the eastern to western honey bees (Apis cerana to Apis mellifera). They provide an opportunity to explore how novel transmission routes shape disease epidemiology. As the principal driver of the spread of deformed wing viruses (mainly DWV-A and DWV-B), varroa infestation has also driven global honey bee health declines. The more virulent DWV-B strain has been replacing the original DWV-A strain in many regions over the past two decades. Yet, how these viruses originated and spread remains poorly understood. Here, we use a phylogeographic analysis based on whole-genome data to reconstruct the origins and demography of DWV spread. We found that, rather than reemerging in western honey bees after varroa switched hosts, as suggested by previous work, DWV-A most likely originated in East Asia and spread in the mid-20th century. It also showed a massive population size expansion following the varroa host switch. By contrast, DWV-B was most likely acquired more recently from a source outside East Asia and appears absent from the original varroa host. These results highlight the dynamic nature of viral adaptation, whereby a vector's host switch can give rise to competing and increasingly virulent disease pandemics. The evolutionary novelty and rapid global spread of these host-virus interactions, together with observed spillover into other species, illustrate how increasing globalization poses urgent threats to biodiversity and food security

    Distribution and variability of deformed wing virus of honeybees (Apis mellifera L.) in the Middle East and North Africa

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    Three hundred and eleven honeybee samples from 12 countries in the Middle East and North Africa (MENA) (Jordan, Lebanon, Syria, Iraq, Egypt, Libya, Tunisia, Algeria, Morocco, Yemen, Palestine, and Sudan) were analyzed for the presence of deformed wing virus (DWV). The prevalence of DWV throughout the MENA region was pervasive, but variable. The highest prevalence was found in Lebanon and Syria, with prevalence dropping in Palestine, Jordan, and Egypt before increasing slightly moving westwards to Algeria and Morocco Phylogenetic analysis of a 194 nucleotide section of the DWV Lp gene did not identify any significant phylogenetic resolution among the samples, although the sequences did show consistent regional clustering, including an interesting geographic gradient from Morocco through North Africa to Jordan and Syria. The sequences revealed several clear variability hotspots in the deduced amino acid sequence, which furthermore showed some patterns of regional identity. Furthermore, the sequence variants from the Middle East and North Africa appear more numerous and diverse than those from Europe

    Evolutionarily diverse origins of deformed wing viruses in western honey bees

    Get PDF
    Novel transmission routes can allow infectious diseases to spread, often with devastating consequences. Ectoparasitic varroa mites vector a diversity of RNA viruses, having switched hosts from the eastern to western honey bees (Apis cerana to Apis mellifera). They provide an opportunity to explore how novel transmission routes shape disease epidemiology. As the principal driver of the spread of deformed wing viruses (mainly DWV-A and DWV-B), varroa infestation has also driven global honey bee health declines. The more virulent DWV-B strain has been replacing the original DWV-A strain in many regions over the past two decades. Yet, how these viruses originated and spread remains poorly understood. Here, we use a phylogeographic analysis based on whole-genome data to reconstruct the origins and demography of DWV spread. We found that, rather than reemerging in western honey bees after varroa switched hosts, as suggested by previous work, DWV-A most likely originated in East Asia and spread in the mid-20th century. It also showed a massive population size expansion following the varroa host switch. By contrast, DWV-B was most likely acquired more recently from a source outside East Asia and appears absent from the original varroa host. These results highlight the dynamic nature of viral adaptation, whereby a vector's host switch can give rise to competing and increasingly virulent disease pandemics. The evolutionary novelty and rapid global spread of these host-virus interactions, together with observed spillover into other species, illustrate how increasing globalization poses urgent threats to biodiversity and food security

    The Invasion of the Dwarf Honeybee, Apis florea, along the River Nile in Sudan

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    The spread of the dwarf honeybee, Apis florea, in Sudan along the river Nile in a linear fashion provides a good model for studying the population dynamics and genetic effects of an invasion by a honeybee species. We use microsatellite DNA analyses to assess the population structure of both invasive A. florea and native Apis mellifera along the river Nile. The invasive A. florea had significantly higher population densities than the wild, native A. mellifera. Nevertheless, we found no indication of competitive displacement, suggesting that although A. florea had a high invasive potential, it coexisted with the native A. mellifera along the river Nile. The genetic data indicated that the invasion of A. florea was established by a single colony

    Distribution and variability of deformed wing virus of honeybees (Apis mellifera) in the Middle East and North Africa.

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    Three hundred eleven honeybee samples from twelve countries in the Middle East and North Africa (MENA) (Jordan, Lebanon, Syria, Iraq, Egypt, Libya, Tunisia, Algeria, Morocco, Yemen, Palestine and Sudan) were analyzed for the presence of deformed wing virus (DWV). The prevalence of DWV throughout the MENA region was pervasive, but variable. The highest prevalence was found in Lebanon and Syria, with prevalence dropping in Palestine, Jordan and Egypt before increasing slightly moving westwards to Algeria and Morocco Phylogenetic analysis of a 194 nucleotide section of the DWV Lp gene did not identify any significant phylogenetic resolution among the samples, although the sequences did show consistent regional clustering, including an interesting geographic gradient from Morocco through North Africa to Jordan and Syria. The sequences revealed several clear variability hotspots in the deduced amino acid sequence, that furthermore showed some patterns of regional identity. Furthermore, the sequence variants from the Middle East and North Africa appear more numerous and diverse than those from Europe. This article is protected by copyright. All rights reserved

    Effect of Storage Time and Floral Origin on the Physicochemical Properties of Beeswax and the Possibility of Using It as a Phase Changing Material in the Thermal Storage Energy Technology

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    Beeswax is a natural product that is primarily produced by honey bees of the genus Apis. It has many uses in various kinds of industries, including pharmacy and medicine. This study investigated the effect of storage and floral origin on some physicochemical properties of four beeswax samples. The floral origin of the beeswax samples was determined microscopically and the investigated physical properties were the melting point, color, surface characteristics and thermal behavior. The studied chemical constituents were the acid value, ester value, saponification value and the ester/acid ratio. The FT-IR, SEM, EDX, XRD and TGF techniques were applied to meet the objectives of this study. The physical properties of the beeswax were affected by the storage period and floral origin. The melting point of the beeswax samples significantly increased with the increase in the storage time, from 61.5 ± 2.12 °C for the 3 month sample to 74.5 ± 3.54 °C for the 2 year stored sample (p-value = 0.027). The acid values of the 3 month, 6 month, 1 year and 2 years stored samples were 19.57 ± 0.95, 22.95 ± 1.91, 27 ± 1.91 and 34.42 ± 0.95 mgKOH/g, respectively. The increase in the acid value was significant (p-value = 0.002). The ester values of the studied beeswax samples significantly increased with the increase in storage time as follows: 46.57 ± 2.86 mgKOH/g for the 3 month stored sample, 66.14 ± 3.82 mgKOH/g for the 6 month stored sample, 89.77 ± 0.95 mgKOH/g for the one year stored sample and 97.19 ± 1.91 mgKOH/g for the 2 year stored sample (p-value ≤ 0.001). Similarly, the saponification value and the carbon percentages increased with the increase in storage time. Unlike the results of the chemical components, the oxygen percentage decreased with the increase in storage time as follows: 11.24% (3 month), 10.31% (6 month), 7.97% (one year) and 6.74% (two year). The storage and floral origin of beeswax significantly affected its physicochemical properties in a way that qualify it to act as a phase changing material in the thermal storage energy technology
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