The Welsh dark bee (Apis mellifera mellifera) is not extinct

Due to past and present imports of Apis mellifera ligustica (Italian bees), Apis mellifera carnica (Carniolan bees) and the English Buckfast bee (a hybrid strain) across its entire natural range, Apis mellifera mellifera is now threatened with extinction by genetic pollution through hybridization. Whilst the status of remnant A. m. mellifera populations is well documented on the European mainland, few studies have been undertaken to identify surviving populations on the British Isles. A few A. m. mellifera stocks are thought to persist in Scotland and the southwest of England and recently, Ireland might appear to contain multiple non-hybridized A. m. mellifera populations. 163 young worker bees, representing 121 colonies from across Wales, were genetically screened in an attempt to identify remnant A. m. mellifera stocks, as part of a conservation breeding program. Recent studies have demonstrated that honey bees of local origin have significantly higher survival chances than honey bees of non-local origin due to their adaptation to their local environment, suggesting that conservation of locally adapted honey bees is a logistical and practical possibility to develop sustainable apiculture. Within this survey, we made use of a custom-tailored SNP genotype assay to estimate the extent of C lineage introgression in the ncDNA as well as sequencing of the tRNAleucox2 intergenic region of the mtDNA to check for the ancestry of the tested coloniesinfo:eu-repo/semantics/publishedVersio

DeepWings: a machine learning tool for identification of honey bee subspecies

DeepWings© is a software that uses Machine Learning for fully automated identification of Apis mellifera subspecies based on wing geometric morphometrics (WGM). Here, we examined the performance of DeepWings© under realistic conditions by processing 14,782 wing images with varying quality and produced by different operators. These images represented 2,593 colonies covering the native ranges of A. m. iberiensis (Portugal, Spain and historical introduction in the Azores), A. m. mellifera (Belgium, France, Ireland, Poland, Russia, Sweden, Switzerland, UK) and A. m. carnica (Croatia, Hungary, Romania). The classification probability obtained for the colonies was contrasted with the endemic subspecies distribution. Additionally, the association between WGM classification and that inferred from microsatellites and SNPs was evaluated for 1,214 colonies. As much as 94.4% of the wings were accepted and classified by DeepWings©. In the Iberian honey bee native range, 92,6% of the colonies were classified as A. m. iberiensis with a median probability of 91.88 (IQR = 22.52). In the Azores, 85.7% of colonies were classified as A. m. iberiensis, with a median probability of 84.16 (32.40). In the Dark honey bee native range, 41.1 % of the colonies were classified as A. m mellifera with a median probability of 99.36 (8.02). The low percentage of colonies matching the native subspecies was mainly due to the low values registered in Avignon (20.0%), Poland (32.9%), and Wales (41.2%). In contrast, most of the colonies analyzed in other locations of the native range of A. m. mellifera matched this subspecies: Belgium (100.0%), Groix (63.9%), Ouessant (72.7%), Ireland (78.0%), Russia (96.2%), Sweden (84.2%) and Switzerland (55.6%). In the colonies from Croatia, Hungary, and Romania, 88.0% of the samples were classified as A. m. carnica, with a median probability of 98.49 (6.76). The association between WGM and molecular data was highly significant but not very strong (Spearman r = 0.31, p < 0.0001). A good agreement between morphological and molecular methods was registered in samples originating from highly conserved M-lineage populations whereas in populations with historical records of foreign queen importations the agreement was weaker. In general, DeepWings© showed good performance when tested under realistic conditions. It is a valuable tool that can be used not only for honey bee breeding and conservation but also for research purposes.info:eu-repo/semantics/publishedVersio

Cistus ladanifer as a source of phenolic compounds with antifungal activity

A screening of the antifungal potential of phenolic extract of Cistus ladanifer from Northeast Portugal, against Candida species was performed. The extract was characterized by HPLC-DAD-ESI/MS. Phenolic acids and derivatives, ellagic acid derivatives and flavonoids, such as catechins, flavonols and flavones, were found in the sample, The most abudant group was ellagic acid derivatives in which punicalagin gallate, a derivative of punicalagin attached to gallic acid, was found in highest amount. These compounds could be related to the strong inhibition of C. albicans, C. glabrata and C. parapsilosis growth. Moreover, the best antifungal activity was against C. glabrata, where the studied extract was able to cause at least 3 Log of reduction at concentrations below 50μg/mL and a total growth inhibition at concentrations above 625 μg/mL

Virus Prevalence in Egg Samples Collected from Naturally Selected and Traditionally Managed Honey Bee Colonies across Europe

Monitoring virus infections can be an important selection tool in honey bee breeding. A recent study pointed towards an association between the virus-free status of eggs and an increased virus resistance to deformed wing virus (DWV) at the colony level. In this study, eggs from both naturally surviving and traditionally managed colonies from across Europe were screened for the prevalence of different viruses. Screenings were performed using the phenotyping protocol of the 'suppressed in ovo virus infection' trait but with qPCR instead of end-point PCR and a primer set that covers all DWV genotypes. Of the 213 screened samples, 109 were infected with DWV, 54 were infected with black queen cell virus (BQCV), 3 were infected with the sacbrood virus, and 2 were infected with the acute bee paralyses virus. It was demonstrated that incidences of the vertical transmission of DWV were more frequent in naturally surviving than in traditionally managed colonies, although the virus loads in the eggs remained the same. When comparing virus infections with queen age, older queens showed significantly lower infection loads of DWV in both traditionally managed and naturally surviving colonies, as well as reduced DWV infection frequencies in traditionally managed colonies. We determined that the detection frequencies of DWV and BQCV in honey bee eggs were lower in samples obtained in the spring than in those collected in the summer, indicating that vertical transmission may be lower in spring. Together, these patterns in vertical transmission show that honey bee queens have the potential to reduce the degree of vertical transmission over time

Virus Prevalence in Egg Samples Collected from Naturally Selected and Traditionally Managed Honey Bee Colonies across Europe

Monitoring virus infections can be an important selection tool in honey bee breeding. A recent study pointed towards an association between the virus-free status of eggs and an increased virus resistance to deformed wing virus (DWV) at the colony level. In this study, eggs from both naturally surviving and traditionally managed colonies from across Europe were screened for the prevalence of different viruses. Screenings were performed using the phenotyping protocol of the &lsquo;suppressed in ovo virus infection&rsquo; trait but with qPCR instead of end-point PCR and a primer set that covers all DWV genotypes. Of the 213 screened samples, 109 were infected with DWV, 54 were infected with black queen cell virus (BQCV), 3 were infected with the sacbrood virus, and 2 were infected with the acute bee paralyses virus. It was demonstrated that incidences of the vertical transmission of DWV were more frequent in naturally surviving than in traditionally managed colonies, although the virus loads in the eggs remained the same. When comparing virus infections with queen age, older queens showed significantly lower infection loads of DWV in both traditionally managed and naturally surviving colonies, as well as reduced DWV infection frequencies in traditionally managed colonies. We determined that the detection frequencies of DWV and BQCV in honey bee eggs were lower in samples obtained in the spring than in those collected in the summer, indicating that vertical transmission may be lower in spring. Together, these patterns in vertical transmission show that honey bee queens have the potential to reduce the degree of vertical transmission over time

Comparison of two alternative store formats using a Malmquist-type index

This paper explores the differences in performance between two groups of retailing stores that operate with different formats. The study uses a Malmquist-type index to distinguish internal inefficiencies from those associated with the group (or format) characteristics. A fundamental characteristic of the new index is to compare groups in a static setting. The study described in this paper combines the use of the Malmquist index with statistical tests. The Malmquist-type index is decomposed into sub-indexes for comparing the efficiency spread between groups and the productivity differences between the best-practice frontiers of the groups. The hypothesis tests are used to verify if the differences between groups captured by the Malmquist-type index and its components are statistically significant. There are several methods based on DEA for comparing the performance of two groups, such as the program efficiency method and the comparison of efficiency distributions using statistical hypothesis tests. The method used in this paper is compared with the existing approaches to highlight its strengths and weaknesses. The applicability of the method is illustrated with a case study that compares the performance of heavy bazaar stores (that sell electrical appliances and consumer electronics) with different formats (megastores versus superstores). The study showed that the overall performance of megastores is better due to the effect of a more productive frontier. However, the efficiency spread is larger in megastores than in superstores meaning that there is scope for efficiency improvements

Conservation status of the endemic European Dark Honey Bee (Apis mellifera mellifera) in Belgium & Netherlands

Due to past and present imports of Apis mellifera ligustica (Italian bees), Apis mellifera carnica (Carniolan bees) and the Buckfast bee (a hybrid strain) across its entire natural range, the European Dark Honey bee (Apis mellifera mellifera) is currently threatened with extinction by genetic pollution through hybridization. In the past, genomic research has shown the European Dark Honey bee was still present in the Belgian Chimay area and on the Dutch North Sea Isle of Texel. However, as the risk of beekeepers importing non-native honey bees into the area remains, which could rapidly threaten the genetic integrity of the endemic honey bee population, monitoring hybridization is a key element in conservation and breeding. Within the framework of the Flemish Beekeeping Programme, 246 honey bee colonies originating from the Belgian population of Chimay (108) and the Dutch North Sea island populations of Texel (6) and Terschelling (132) were sampled in autumn 2021 to identify pure European Dark Honey bee colonies with which to support the Flemish A. m. mellifera breeding activities. The population of Terschelling, which has not been studied before, was included because local beekeepers claimed their colonies looked and behaved like European Dark Honey bees. Of each sampled honey bee colony 10 worker bees were used for this study, including measuring wing morphometrics (based on cubital index, discoidal shift angle and hantal index) and estimating the extent of C-lineage introgression in the ncDNA by applying a custom-tailored SNP genotype assay. Q-values for most sampled honey bee colonies were above 90% for M-lineage: 85 out of 108 colonies for Chimay; 106 out of 132 colonies for Terschelling and all 6 colonies for Texel. Both the populations of Chimay and Texel seem to be spared from intense hybridization over the past decades, whilst a novel remnant population of the European Dark Honey bee was found on the Isle of Terschelling. The correlation between wing morphometrics and molecular data was significant but very weak (Spearman r = 0.20, p = 0.002), indicating the SNP genotype assay is a more valuable tool for assisting in breeding and conservation activities.info:eu-repo/semantics/publishedVersio

Virus prevalence in egg samples collected from naturally selected and traditionally managed honey bee colonies across Europe

Monitoring virus infections can be an important selection tool in honey bee breeding. A recent study pointed towards an association between the virus-free status of eggs and an increased virus resistance to deformed wing virus (DWV) at the colony level. In this study, eggs from both naturally surviving and traditionally managed colonies from across Europe were screened for the prevalence of different viruses. Screenings were performed using the phenotyping protocol of the ‘suppressed in ovo virus infection’ trait but with qPCR instead of end-point PCR and a primer set that covers all DWV genotypes. Of the 213 screened samples, 109 were infected with DWV, 54 were infected with black queen cell virus (BQCV), 3 were infected with the sacbrood virus, and 2 were infected with the acute bee paralyses virus. It was demonstrated that incidences of the vertical transmission of DWV were more frequent in naturally surviving than in traditionally managed colonies, although the virus loads in the eggs remained the same. When comparing virus infections with queen age, older queens showed significantly lower infection loads of DWV in both traditionally managed and naturally surviving colonies, as well as reduced DWV infection frequencies in traditionally managed colonies. We determined that the detection frequencies of DWV and BQCV in honey bee eggs were lower in samples obtained in the spring than in those collected in the summer, indicating that vertical transmission may be lower in spring. Together, these patterns in vertical transmission show that honey bee queens have the potential to reduce the degree of vertical transmission over time

Virus Prevalence in Egg Samples Collected from Naturally Selected and Traditionally Managed Honey Bee Colonies across Europe

Monitoring virus infections can be an important selection tool in honey bee breeding. A recent study pointed towards an association between the virus-free status of eggs and an increased virus resistance to deformed wing virus (DWV) at the colony level. In this study, eggs from both naturally surviving and traditionally managed colonies from across Europe were screened for the prevalence of different viruses. Screenings were performed using the phenotyping protocol of the ‘suppressed in ovo virus infection’ trait but with qPCR instead of end-point PCR and a primer set that covers all DWV genotypes. Of the 213 screened samples, 109 were infected with DWV, 54 were infected with black queen cell virus (BQCV), 3 were infected with the sacbrood virus, and 2 were infected with the acute bee paralyses virus. It was demonstrated that incidences of the vertical transmission of DWV were more frequent in naturally surviving than in traditionally managed colonies, although the virus loads in the eggs remained the same. When comparing virus infections with queen age, older queens showed significantly lower infection loads of DWV in both traditionally managed and naturally surviving colonies, as well as reduced DWV infection frequencies in traditionally managed colonies. We determined that the detection frequencies of DWV and BQCV in honey bee eggs were lower in samples obtained in the spring than in those collected in the summer, indicating that vertical transmission may be lower in spring. Together, these patterns in vertical transmission show that honey bee queens have the potential to reduce the degree of vertical transmission over time.</jats:p

Virus Prevalence in Egg Samples Collected from Naturally Selected and Traditionally Managed Honey Bee Colonies across Europe

Monitoring virus infections can be an important selection tool in honey bee breeding. A recent study pointed towards an association between the virus-free status of eggs and an increased virus resistance to deformed wing virus (DWV) at the colony level. In this study, eggs from both naturally surviving and traditionally managed colonies from across Europe were screened for the prevalence of different viruses. Screenings were performed using the phenotyping protocol of the ‘suppressed in ovo virus infection’ trait but with qPCR instead of end-point PCR and a primer set that covers all DWV genotypes. Of the 213 screened samples, 109 were infected with DWV, 54 were infected with black queen cell virus (BQCV), 3 were infected with the sacbrood virus, and 2 were infected with the acute bee paralyses virus. It was demonstrated that incidences of the vertical transmission of DWV were more frequent in naturally surviving than in traditionally managed colonies, although the virus loads in the eggs remained the same. When comparing virus infections with queen age, older queens showed significantly lower infection loads of DWV in both traditionally managed and naturally surviving colonies, as well as reduced DWV infection frequencies in traditionally managed colonies. We determined that the detection frequencies of DWV and BQCV in honey bee eggs were lower in samples obtained in the spring than in those collected in the summer, indicating that vertical transmission may be lower in spring. Together, these patterns in vertical transmission show that honey bee queens have the potential to reduce the degree of vertical transmission over time