An Insight Into the microRNA Profile of the Ectoparasitic Mite Varroa destructor (Acari: Varroidae), the Primary Vector of Honey Bee Deformed Wing Virus

The remarkably adaptive mite Varroa destructor is the most important honey bee ectoparasite. Varroa mites are competent vectors of deformed wing virus (DWV), and the Varroa-virus complex is a major determinant of annual honey bee colony mortality and collapse. MicroRNAs (miRNAs) are 22-24 nucleotide non-coding RNAs produced by all plants and animals and some viruses that influence biological processes through post-transcriptional regulation of gene expression. Knowledge of miRNAs and their function in mite biology remains limited. Here we constructed small RNA libraries from male and female V. destructor using Illumina’s small RNA-Seq platform. A total of 101,913,208 and 91,904,732 small RNA reads (\u3e18 nucleotides) from male and female mites were analyzed using the miRDeep2 algorithm. A conservative approach predicted 306 miRNAs, 18 of which were upregulated and 13 downregulated in female V. destructor compared with males. Quantitative real-time PCR validated the expression of selected differentially-expressed female Varroa miRNAs. This dataset provides a list of potential miRNA targets involved in regulating vital Varroa biological processes and paves the way for developing strategies to target Varroa and their viruses

Effects of Coumaphos and Imidacloprid on Honey Bee (Hymenoptera: Apidae) Lifespan and Antioxidant Gene Regulations in Laboratory Experiments

The main objective of this study was to test comparatively the effects of two common insecticides on honey bee Apis mellifera worker’s lifespan, food consumption, mortality, and expression of antioxidant genes. Newly emerged worker bees were exposed to organophosphate insecticide coumaphos, a neonicotinoid imidacloprid, and their mixtures. Toxicity tests were conducted along with bee midgut immunohistological TUNEL analyses. RT-qPCR assessed the regulation of 10 bee antioxidant genes linked to pesticide toxicity. We tested coumaphos at 92,600 ppb concentration, in combination with 5 and 20 ppb imidacloprid. Coumaphos induced significantly higher bee mortality, which was associated with down regulation of catalase compared to coumaphos and imidacloprid (5/20 ppb) mixtures, whereas, both imidacloprid concentrations independently had no effect on bee mortality. Mixture of coumaphos and imidacloprid reduced daily bee consumption of a control food patty to 10 mg from a coumaphos intake of 14.3 mg and 18.4 and 13.7 mg for imidacloprid (5 and 20) ppb, respectively. While coumaphos and imidacloprid mixtures induced down-regulation of antioxidant genes with noticeable midgut tissue damage, imidacloprid induced intensive gene up-regulations with less midgut apoptosis

Honey Bee Survival and Pathogen Prevalence: From the Perspective of Landscape and Exposure to Pesticides

In order to study the in situ effects of the agricultural landscape and exposure to pesticides on honey bee health, sixteen honey bee colonies were placed in four different agricultural landscapes. Those landscapes were three agricultural areas with varying levels of agricultural intensity (AG areas) and one non-agricultural area (NAG area). Colonies were monitored for different pathogen prevalence and pesticide residues over a period of one year. RT-qPCR was used to study the prevalence of seven different honey bee viruses as well as Nosema sp. in colonies located in different agricultural systems with various intensities of soybean, corn, sorghum, and cotton production. Populations of the parasitic mite Varroa destructor were also extensively monitored. Comprehensive MS-LC pesticide residue analyses were performed on samples of wax, honey, foragers, winter bees, dead bees, and crop flowers for each apiary and location. A significantly higher level of varroa loads were recorded in colonies of the AG areas, but this at least partly correlated with increased colony size and did not necessarily result from exposure to pesticides. Infections of two viruses (deformed wing virus genotype a (DWVa) and acute bee paralysis virus (ABPV)) and Nosema sp. varied among the four studied locations. The urban location significantly elevated colony pathogen loads, while AG locations significantly benefited and increased the colony weight gain. Cotton and sorghum flowers contained high concentrations of insecticide including neonicotinoids, while soybean and corn had less pesticide residues. Several events of pesticide toxicity were recorded in the AG areas, and high concentrations of neonicotinoid insecticides were detected in dead bees

RFID Technology Serving Honey Bee Research: A Comprehensive Description of a 32-Antenna System to Study Honey Bee and Queen Behavior

The fields of electronics and information technology have witnessed rapid development during the last decades, providing significant technical support to the field of biological sciences. Radio-Frequency Identification (RFID) technology has been used to automate the monitoring of animal location and behaviors in a wide range of vertebrate and invertebrate species, including social insects such as ants and honey bees (Apis mellifera L.). This technology relies on electromagnetic fields to identify and track transponders attached to objects automatically. Implementing new technologies to serve research purposes could be time consuming and require technical expertise from entomologists and researchers. Herein, we present a detailed description on how to harness RFID technology to serve honey bee research effectively. We describe how to build and operate a 32-antenna RFID system used to monitor various honey bee behaviors such as foraging, robbing, and queen and drone mating, which can be used in other social insects as well. Preliminary data related to queen nuptial flights were obtained using this unit and presented in this study. Virgin queens labeled with ≈5 mg transponders performed multiple (one to four) nuptial/orientation flights a day (9 a.m. to 5 p.m.) ranging from 8 to 145 s each. Contrary to virgin queens, no hive exit was recorded for mated queens. At full capacity, this unit can monitor up to 32 honey bee colonies concurrently and is self-sustained by a solar panel to work in remote areas. All materials, hardware, and software needed to build and operate this unit are detailed in this study, offering researchers and beekeepers a practical solution and a comprehensive source of information enabling the implementation of RFID technology in their research perspective

Analyse de la diversité moléculaire et morphométrique des populations d'abeilles de Syrie Apis mellifera syriaca (application à la conservation et à la sélection des populations d'abeilles)

Pour étudier la diversité génétique et morphométrique des populations d'abeille syrienne Apis mellifera syriaca, nous avons réalisé un échantillonnage de 1800 colonies d'abeilles couvrant trois pays différents: la Syrie, le Liban et l'Irak. Une abeille par colonie a été échantillonnée et conservée individuellement dans de l'alcool absolu. Ces abeilles ont été disséquées et les ailes conservées pour d'éventuelles analyses morphométriques. L'extraction des ADN totaux a été effectuée sur les thorax de ces abeilles. Chaque échantillon a ensuite été analysé pour deux marqueurs moléculaires: i) l'ADN mitochondrial, ii) 14 Loci microsatellites. Concernant le premier marqueur moléculaire, une CAPS (Cleaved Amplified Polymorphisms) a été effectuée dans la région intergénique non codante située entre les sous unités I et II du gène de la Cytochrome Oxydase (COI-COII). Cette analyse a permis l'identification de 18 nouveaux haplotypes spécifiques de l abeille syrienne Apis mellifera syriaca inconnus auparavant et qui forment un sous groupe (nommé Z) de la lignée évolutive africaine (A). Ces haplotypes Z qui appartiennent à la lignée africaine et non pas à la lignée orientale comme cela a été décrit dans des études précédentes ont été ultérieurement séquencés et soumis à GenBank sous les numéros d'accès suivants: HM236202 - HM236219. D autre part, les résultats moléculaires des populations d abeilles de Syrie ont identifié, dans plusieurs régions syriennes, des importations d abeilles étrangères comme mellifera, ligustica et carnica. Les populations d abeilles de Syrie se trouvent dans une zone géographique influencée par deux lignées évolutives: la lignée orientale (O) au Nord et la lignée africaine (A) au Sud. La Syrie est située dans une zone d introgression naturelle entre ces deux lignées expliquant l incohérence des résultats trouvés dans la littérature. Cette influence se traduit par une forte introgression allélique de la lignée orientale dans les populations syriennes du Nord tandis que les populations du Sud, caractérisées par les haplotypes Z, appartiennent majoritairement à la lignée africaine (A). L approche de la morphométrie géométrique confirme clairement les résultats moléculaires obtenus dans cette étude et s avère une approche prometteuse pour la caractérisation des sous-espèces d abeilles mellifèresPARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF

Non-Invasive Genotyping of Honey Bee Queens Apis mellifera L.: Transition of the DraI mtDNA COI-COII Test to In Silico

The honey bee Apis mellifera L. colony is headed by a single and indispensable queen, whose duty it is to ensure brood production and provide pheromonal stability within the colony. This study presents a non-invasive method that allows the identification of the queen maternal lineage and subspecies using the remaining tissue of her clipped wing. The DraI mtDNA COI-COII (DmCC) test was applied to various sizes of queen and worker wings and the results were compared with data obtained from other bee tissues. Furthermore, we propose a new method allowing in silico transition of the DmCC test and haplotype identification based on extended sequencing of the tRNAleu and COII genes. Our results show that DNA extracted by Chelex 10% from one-third of a queen’s wing is deemed adequate for a successful identification of her maternal evolutionary lineage, haplotype and subspecies. The in silico method proposed in this study fully adheres to the established guidelines of the DmCC, provides a universal standard for haplotype identification, and offers faster and more precise results by reconciling both cleaved amplified polymorphic sequences (CAPS) and Sanger sequencing approaches

RFID Technology Serving Honey Bee Research: A Comprehensive Description of a 32-Antenna System to Study Honey Bee and Queen Behavior

The fields of electronics and information technology have witnessed rapid development during the last decades, providing significant technical support to the field of biological sciences. Radio-Frequency Identification (RFID) technology has been used to automate the monitoring of animal location and behaviors in a wide range of vertebrate and invertebrate species, including social insects such as ants and honey bees (Apis mellifera L.). This technology relies on electromagnetic fields to identify and track transponders attached to objects automatically. Implementing new technologies to serve research purposes could be time consuming and require technical expertise from entomologists and researchers. Herein, we present a detailed description on how to harness RFID technology to serve honey bee research effectively. We describe how to build and operate a 32-antenna RFID system used to monitor various honey bee behaviors such as foraging, robbing, and queen and drone mating, which can be used in other social insects as well. Preliminary data related to queen nuptial flights were obtained using this unit and presented in this study. Virgin queens labeled with ≈5 mg transponders performed multiple (one to four) nuptial/orientation flights a day (9 a.m. to 5 p.m.) ranging from 8 to 145 s each. Contrary to virgin queens, no hive exit was recorded for mated queens. At full capacity, this unit can monitor up to 32 honey bee colonies concurrently and is self-sustained by a solar panel to work in remote areas. All materials, hardware, and software needed to build and operate this unit are detailed in this study, offering researchers and beekeepers a practical solution and a comprehensive source of information enabling the implementation of RFID technology in their research perspective

Interplay Between Selenium, Selenoprotein Genes, and Oxidative Stress in Honey Bee \u3ci\u3eApis mellifera\u3c/i\u3e L.

The honey bee, Apis mellifera L., is a major pollinator insect that lacks novel “selenoprotein genes”, rendering it susceptible to elevated levels of Selenium (Se) occurring naturally in the environment. We investigated the effects of two inorganic forms of Se on biological traits, oxidative stress, and gene regulation. Using bioassay arenas in the laboratory, one-day old sister bees were fed ad libitum 4 different concentrations of selenate and selenite, two common inorganic forms of Se. The transcription levels of 4 honey bee antioxidant genes were evaluated, and three putative selenoprotein-like genes (SELENOT, SELENOK, SELENOF) were characterized as well as Sbp2, a Selenium binding protein required for the translation of selenoproteins mRNA. Oxidative stress and Se residues were subsequently quantified in honey bee bodies throughout the experiment. Se induced higher oxidative stress in treated honey bees leading to a significantly elevated protein carbonyl content, particularly at the highest studied concentrations. Early upregulations of Spb2 and MsrA were identified at day 2 of the treatment while all genes except SELENOT were upregulated substantially at day 8 to alleviate the Se-induced oxidative stress levels. We determined that doses between 60 and 600 mg.Se.L−1 were acutely toxic to bees (\u3c48 h) while doses between 0.6 and 6 mg.Se.L−1 led to much lower mortality (7–16)%. Furthermore, when fed ad libitum, Se residue data indicated that bees tolerated accumulation up to 0.12 µg Se bee−1 for at least 8 days with a Se LC50 of ∼6 mg/L, a field realistic concentration found in pollen of certain plants in a high Se soil environment

Genetic assessment of Algerian honeybee populations by microsatellite markers

International audienceAbstractThe genetic diversity and structure of 414 honeybee workers from eight different populations in Algeria were analyzed using 14 polymorphic DNA microsatellite loci. The results showed that the honeybee populations were characterized by substantial genetic variation in terms of the average number of alleles and the degree of heterozygosity. Most populations were at Hardy–Weinberg equilibrium. Phylogenetic and population structure analyses confirmed the African origin of the studied Algerian populations and clustered them in a group distinct from evolutionary lineages West Mediterranean (M), North Mediterranean (C), and Oriental (O). Structure analyses revealed weak allelic introgression from both lineages M and C. High genetic variability was found within the Algerian populations. Two honeybee subspecies, Apis mellifera intermissa and Apis mellifera sahariensis, were present. However, to delimit the natural spread area of A. mellifera sahariensis, more samples from southern Algerian are needed