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The invasion of the Western honey bee, Apis mellifera, by Varroa destructor is attributed to two mitochondrial haplotypes (K and J) that shifted last century from their primary host the Eastern honey bee, A. cerana, in north-east Asia. Here, mitochondrial DNA sequences (cox1, cox3, atp6 and cytb: 2700 base pairs) were obtained from mites infesting both Eastern and Western honeybees (respectively 21 and 11 colonies) from Asia including regions where the shifts first occurred. A total of eighteen haplotypes were uncovered in Asia (11 on A. cerana and 7 on A. mellifera). Two new variants of the K haplotype and two of the J haplotype were found on Western honeybees in what appeared to be well-established infestations. New haplotypes may represent a potential threat to A. mellifera worldwide. The extreme lack of polymorphism in the K and J haplotypes outside of Asia, can now be plausibly explained as being due to genetic 'bottlenecks' that occurred in Asia before and after mites shifted from their original Eastern honeybee host. Apis mellifera / Apis cerana / Varroa / mitochondrial DNA/diversity

International audience; Pheromones are very important in animal communication. To learn more about the molecular basis of pheromone action, we studied the effects of a potent honey bee pheromone on brain gene expression. Brood pheromone (BP) caused changes in the expression of hundreds of genes in the bee brain in a manner consistent with its known effects on behavioral maturation. Brood pheromone exposure in young bees causes a delay in the transition from working in the hive to foraging, and we found that BP treatment tended to upregulate genes in the brain that are upregulated in bees specialized on brood care but downregulate genes that are upregulated in foragers. However, the effects of BP were age dependent; this pattern was reversed when older bees were tested, consistent with the stimulation of foraging by BP in older bees already competent to forage. These results support the idea that one way that pheromones influence behavior is by orchestrating large-scale changes in brain gene expression. We also found evidence for a relationship between cis and BP regulation of brain gene expression, with several cis-regulatory motifs statistically overrepresented in the promoter regions of genes regulated by BP. Transcription factors that target a few of these motifs have already been implicated in the regulation of bee behavior. Together these results demonstrate strong connections between pheromone effects, behavior, and regulation of brain gene expression.

The purpose of this study is to investigate the possibility to use acetylcholinesterase (AChE) as a biomarker of exposure to deltamethrin insecticide in the honeybee, Apis mellifera and to test its reliability in the presence of other contaminants, as carbamate insecticide. Joined actions of deltamethrin (pyrethroid) and pirimicarb (carbamate), alone or in association, are investigated on AChE activity in surviving and dead honeybees, with a special focus on the relative proportions of its membrane and soluble forms. At the 0.5X dose (12.5 ng of deltamethrin and/or 2.5 microg of pirimicarb per bee), the residual tissue AChE activity in dead bees was 78% with deltamethrin, 43% with pirimicarb and 33% with dual treatment. In surviving bees, tissue AChE activity represented 250%, and 270% of control AChE activity with deltamethrin and dual treatment, respectively. The analysis of membrane and soluble AChE forms revealed an increase in the soluble form in dead bees after deltamethrin and dual treatment. However, in vitro investigations showed no direct interaction of deltamethrin on soluble and membrane AChE activity. The results suggest that the action of deltamethrin on AChE activity, in honeybee intact organisms, could be due to indirect mechanisms. The duality of AChE response to deltamethrin exposure, exhibited by the possibility of increase (surviving bees) or decrease (dead bees) of its activity has been pointed out for the first time. The important increase in AChE activity in response to deltamethrin, not altered by pirimicarb treatment, suggests that AChE activity could represent a robust biomarker specific to deltamethrin exposure in living bees.

International audience; Two acetylcholinesterase (EC 3.1.1.7) membrane forms AChEm1 and AChEm2, have been characterised in the honey bee head. They can be differentiated by their ionic properties: AChEm1 is eluted at 220 mM NaCl whereas AChEm2 is eluted at 350 mM NaCl in anion exchange chromatography. They also present different thermal stabilities. Previous processing such as sedimentation, phase separation, and extraction procedures do not affect the presence of the two forms. Unlike AChEm1, AChEm2 presents reversible chromatographic elution properties, with a shift between 350 to 220 mM NaCl, depending on detergent conditions. Purification by affinity chromatography does not abolish the shift of the AChEm2 elution. The similar chromatographic behaviour of soluble AChE strongly suggests that the occurrence of the two membrane forms is not due to the membrane anchor. The two forms have similar sensitivities to eserine and BW284C51. They exhibit similar electrophoretic mobilities and present molecular masses of 66 kDa in SDS-PAGE and a sensitivity to phosphatidylinositol-specific phospholipase C in non-denaturing conditions, thus revealing the presence of a glycosyl-phosphatidylinositol anchor. We assume that bee AChE occurs in two distinct conformational states whose AChEm2 apparent state is reversibly modulated by the Triton X-100 detergent into AChEm1

In social insects, larvae are completely dependent on adults to complete their development. In honey bees (Apis mellifera L.), larval development requires that larvae engage workers in nursing tasks rather than allocating energy in other activities (Le Conte and Hefetz, 2008). Indeed, in the absence of any constraint, workers tend to become active reproductive individual. The queen inhibits worker ovary development via pheromones (Hoover et al., 2003; Wossler and Crewe, 1999), but the inhibition of worker ovary development seems superior when bees are exposed to unsealed brood (Kropacova and Haslbachova, 1970, 1971). Components of the brood pheromone have already been identified and consist of a blend of 10 esters (Le Conte et al., 1989, 1990). Two of these low volatility compounds have been demonstrated to partially decrease worker ovary development (Mohammedi et al., 1998; Pankiw and Garza, 2007). Thus, we asked whether brood emits volatile compounds that could also have an effect on worker ovary activation. We identified a new highly volatile molecule from the larvae E-β-ocimene, that inhibits worker ovary maturation. We used Solid Phase Microextraction (SPME) (65 μm Carbowax) to sample volatiles emitted by different larval instars. We analyzed 20 larvae at stage 1, 2–3 or 10 larvae at stage 4–5. Larvae were kept in a 15 mL closed vial for 20 min in an incubator at 34 ◦C and 50% humidity (N = 8

Dossier thématique : l'Abeille; National audience; Si nous voulions que l’Abeille fût indicatrice, au sens d’indicateur écologique, de quelque chose qui regarde l’humanité, par exemple de sa responsabilité vis-à-vis de la planète, eh bien nous sommes servis ! La recherche occidentale est aujourd’hui mobilisée pour empêcher la disparition de l’Abeille qui est l’abeille apicole, l’abeille domestique, l’espèce Apis mellifera1. Et cette disparition n’est pas pensable sans celles de toutes les autres abeilles (les apiformes), puis des insectes pollinisateurs et finalement des plantes qui dépendent le plus du service écologique de la pollinisation réalisée par les insectes ! L’Abeille présente des symptômes inquiétants, mais quelle Abeille ? L’Abeille a deux figures : des populations sauvages et des populations élevées par l’humain. C’est dans les ruchers de l’apiculture que les symptômes sont décrits par les apiculteurs et en termes d’élevage (cheptel, production, état sanitaire, soins, etc.). Ses symptômes sont-ils ceux de l’ambassadrice auprès de l’humanité d’une faune sauvage menacée, ou bien ceux d’un animal d’élevage mal protégé des calamités ?

Article first published online: 1 MAY 2012; International audience; Honey bee societies (Apis mellifera), the ectoparasitic mite Varroa destructor, and honey bee viruses that are vectored by the mite, form a complex system of host–parasite interactions. Coevolution by natural selection in this system has been hindered for European honey bee hosts since apicultural practices remove the mite and consequently the selective pressures required for such a process. An increasing mite population means increasing transmission opportunities for viruses that can quickly develop into severe infections, killing a bee colony. Remarkably, a few subpopulations in Europe have survived mite infestation for extended periods of over 10 years without management by beekeepers and offer the possibility to study their natural host–parasite coevolution. Our study shows that two of these “natural” honey bee populations, in Avignon, France and Gotland, Sweden, have in fact evolved resistant traits that reduce the fitness of the mite (measured as the reproductive success), thereby reducing the parasitic load within the colony to evade the development of overt viral infections. Mite reproductive success was reduced by about 30% in both populations. Detailed examinations of mite reproductive parameters suggest these geographically and genetically distinct populations favor different mechanisms of resistance, even though they have experienced similar selection pressures of mite infestation. Compared to unrelated control colonies in the same location, mites in the Avignon population had high levels of infertility while in Gotland there was a higher proportions of mites that delayed initiation of egg-laying. Possible explanations for the observed rapid coevolution are discussed.

Available online 19 April 2012; International audience; Social removal is often an adaptive response for preventing the entry and spread of parasitic infection between kin members of a group. Social isolation via removal or the switching of social tasks has also been observed in insect societies; however, the underlying mechanisms are unclear. We tested in honeybees the role of the immune system in physiological and behavioral modulation. Forager bees are often located in the outer area of the colony, and thus have reduced contacts with individuals of high importance, who are located in the inner area of the colony (e.g. queen and brood). We thus expected that an immune challenge would induce a forager profile. This was confirmed by measuring brain (foraging and malvolio gene expression), physiological (hypopharyngeal glands size) and behavioral (queen attendance) parameters of nurse/forager profiles after a treatment with an immune-activator (lipopolysaccharides). Our results support the idea that the interplay between the brain and immune system may be an important regulatory factor of social immunity in insects

International audience; Here, scientists from 19 European countries, most of them collaborating in Working Group 4: “Diversity and Vitality” of COST Action FA 0803 “Prevention of honey bee COlony LOSSes” (COLOSS), review the methodology applied in each country for discriminating between honey bee populations. Morphometric analyses (classical and geometric) and different molecular markers have been applied. Even if the approach has been similar, however, different methodologies regarding measurements, landmarks or molecular markers may have been used, as well as different statistical procedures. There is therefore the necessity to establish common methods in all countries in order to have results that can be directly compared. This is one of the goals of WG4 of the COLOSS project; Científicos de 19 países europeos, la mayoría de ellos colaboradores del Grupo de Trabajo 4: "Diversidad y Vitalidad" de la Acción COST FA 0803 "Prevención de la mortalidad de colmenas" (COLOSS), revisan aquí la metodología aplicada en cada país para discriminar a las poblaciones de abejas. Se han aplicado análisis morfométricos (clásico y geométrico) y distintos marcadores moleculares. Incluso si el enfoque ha sido el mismo, se han usado diferentes metodologías en relación a las medidas, puntos de referencia o marcadores moleculares, así como diferentes procedimientos estadísticos. Por lo tanto, existe la necesidad de establecer métodos comunes en todos los países para tener resultados que puedan ser directamente comparados. Este es uno de los objetivos del GT4 del proyecto COLOSS.

Diplôme : Master; Like all bees (Apiformes), honey bees (Apis mellifera) feed on pollen which they must harvest to bring to their nest. To do so, pollen is acquired in flowers, brushed, gathered and compacted with nectar or honey into the corbiculae of the hind legs. The behaviours used during pollen manipulation and compaction have already been described repeatedly, but mainly based on visual observations. My goal was to record, describe and analyse these behaviours based on the recordings with a high speed camera. With these recordings, an ethogram of 12 behaviors was compiled, each behaviour with an average duration of only 17 to 73/100 of a second. The presence of some behaviours already described was confirmed, others were not, and some new behaviours were recorded such as the brushing of the mid legs by the front legs and, in strict nectar foragers, the brushing of the external surface of the hind legs by the mid legs. The analysis of the frequency distribution of these 12 behaviours highlighted a significant difference between foragers with pollen loads in their corbiculae and strict nectar foragers. This study is one of the first ones done on bees with this approach and it showed its possibilities as well as its limits when working under natural conditions; Comme toutes les abeilles (Apiformes), les abeilles domestiques (Apis mellifera) se nourrissent de pollen qu’elles doivent donc récolter pour le rapporter à leur nid. Pour se faire, le pollen est obtenu dans les fleurs, brossé, rassemblé et compacté avec du nectar ou du miel dans les corbicules des pattes postérieures. Les comportements impliqués dans la manipulation et l’agrégation du pollen ont déjà été souvent décrits, mais principalement à partir d’observations réalisées à l’oeil nu. Mon objectif était d’observer, de décrire et d’analyser ces comportements en utilisant une caméra à haute vitesse. A partir de ces enregistrements, un éthogramme de 12 comportements a été établi, chacun d’eux avec une durée moyenne de seulement 17 à 73 centièmes de seconde. La présence de certains comportements déjà décrits dans la littérature a été confirmée, d’autres ont été infirmé, et de nouveaux comportements ont été observés comme le brossage des pattes médianes par les pattes antérieures et, chez les butineuses de nectar strictes, le brossage de l’extérieur des pattes postérieures par les pattes médianes. L’analyse de la distribution des fréquences de ces 12 comportements a mis en évidence une différence significative entre les mouvements des pattes des butineuses qui possèdent des pelotes et ceux des butineuses strictes de nectar. Cette étude est l’une des premières effectuées sur abeilles avec cette approche et elle en montre les possibilités, mais aussi les limites en conditions naturelles.

Diplôme : Licence Professionnelle; Le travail présenté dans ce document est le fruit d'un stage de 5 mois au sein de l'I.N.R.A d'Avignon, dans le laboratoire Pollinisation et Ecologie des Abeilles. Ce stage a été réalisé dans le cadre de la licence professionnelle Aménagement du Territoire et Urbanisme, spécialité Géomatique, de l'I.U.T. de Provence de Digne-les-Bains. La problématique de ce stage est d'élaborer une procédure de calcul d'indices paysagers à partir d'outils SIG, pour des études d'impact du contexte paysager sur les communautés d'abeilles. L'élaboration de cette procédure a donc été le fil rouge du stage. Pour réaliser cette mission, les moyens utilisés sont le logiciel ArcGis pour le traitement des données d'occupations du sol vecteurs et rasters, le logiciel R pour le traitement des données ASCII provenant des rasters traités précédemment, et le logiciel Fragstats qui a permis de calculer les indices paysagers à partir des fichiers ASCII. La méthode élaborée, elle a ensuite été réutilisée pour deux projets scientifiques du laboratoire: le projet Bio2M et le projet Tournesol

BackgroundIn honey bee colony, the brood is able to manipulate and chemically control the workers in order to sustain their own development. A brood ester pheromone produced primarily by old larvae (4 and 5 days old larvae) was first identified as acting as a contact pheromone with specific effects on nurses in the colony. More recently a new volatile brood pheromone has been identified: E-β-ocimene, which partially inhibits ovary development in workers.Methodology and principal findingOur analysis of E-β-ocimene production revealed that young brood (newly hatched to 3 days old) produce the highest quantity of E-β-ocimene relative to their body weight. By testing the potential action of this molecule as a non-specific larval signal, due to its high volatility in the colony, we demonstrated that in the presence of E-β-ocimene nest workers start to forage earlier in life, as seen in the presence of real brood.Conclusions/significanceIn this way, young larvae are able to assign precedence to the task of foraging by workers in order to increase food stores for their own development. Thus, in the complexity of honey bee chemical communication, E-β-ocimene, a pheromone of young larvae, provides the brood with the means to express their nutritional needs to the workers.

BUTS DE L'ETUDE : Etudier les effets du nombre d’abeilles, de la présence de QMP (phéromone mandibulaire de la reine) et de la résistance naturelle au Varroa sur la résistance de l’abeille Apis mellifera au parasite Nosema ceranae. --METHODES & TECHNIQUES : Expériences en laboratoire dans des cagettes avec les différents facteurs. Analyse statistique avec le logiciel XLStat. --RESULTATS : Le Nosema augmente la mortalité dans les groupes de 30 et 100 abeilles avec ou sans QMP. La QMP diminue la mortalité des cagettes de 5 abeilles et améliore leur résistance au parasite. Les cagettes de 5 abeilles ont une mortalité plus élevée. Pas d’effets des facteurs sociaux sur la consommation de nourriture, ni sur le nombre de spores. Pas de différence de mortalité et de nombre de spores de Nosema entre les ruches naturellement résistantes au Varroa et les non résistantes. --CONCLUSIONS : Utiliser des cagettes de 30 abeilles car les cagettes de 100 donnent les mêmes résultats et les cagettes de 5 sont plus sensibles à la mortalité. Les abeilles par petits groupes sont sans doute plus stressées que les groupes plus gros et ont par conséquent besoin de QMP pour survivre, AIMS OF THE STUDY : To study the effects of the number of bees, the presence of QMP (queen mandibular pheromone) and natural resistance towards Varroa on resistance to the parasite Nosema ceranae in the honey bee (Apis mellifera) --MATERIALS & METHODS : Cage experiments in laboratory using the different factors. Statistical analyses using XlStat software. --RESULTS : Nosema increases mortality in cages of 30 and 100 bees, with or without QMP. QMP decreases the mortality of bees in cage of 5 and increases their resistance to the parasite. No effects of social factors on the rate of sugar consumption, nor on the number of spores in the bees. No difference in the mortality or number of spores between the naturally Varroa-resistant hives and the non resistant ones. --CONCLUSIONS : Using 30 bees per cage gives the same result as using cages of 100 bees and is less sensitive to mortality than using cages of 5 bees. It is possible that bees in small groups are more stressed than larger groups and therefore need QMP in order to survive.

Diplôme : IUT

Dans une colonie d’abeilles sans reine ni couvain, les ouvrières tendent à devenir fertiles et investir leur énergie dans la ponte d’oeuf non-fécondés. Afin de maintenir une certaine stabilité dans l’organisation de la colonie et prévenir ce détournement de l’investissement énergétique des ouvrières, la reine garantie son statut de seule reproductrice et le couvain accapare le soin des ouvrières. Pour cela, ils émettent des phéromones peu volatiles. La phéromone mandibulaire (principalement le 9-ODA) émis par la reine ainsi qu’un mélange de 10 esters émis par le couvain. Ces composés permettent une castration chimique partielle des ouvrières. Cependant, parmi les deux facteurs de régulation de la maturation ovarienne des ouvrières, il semble que la présence de couvain soit le plus actif. Nous nous sommes donc demandé si les larves ne pourraient pas émettre des molécules très volatiles ayant un rôle sur le développement ovarien des ouvrières. Les composés volatiles larvaires ont donc été prélevés par Microextraction sur phase solide (SPME), puis analysés et identifiés par GC-MS. Le pic majeur retrouvé dans tous les échantillons est une molécule hautement volatile, l’E-β- ocimene. Nous avons testé l’effet de cette molécule sur la croissance des ovaires d’ouvrières élevées en cagette. Les résultats indiquent un effet inhibiteur significatif de l’E-β-ocimene sur le développement ovarien des ouvrières. Cette nouvelle phéromone, dont les effets sont identiques à ceux produits par la phéromone mandibulaire de la reine, montre que différents acteurs, utilisant différentes phéromones, peuvent induire un même effet sur le même organisme cible. De nouveaux tests sont nécessaires pour comprendre si les trois phéromones décris ici, régulant la fertilité de la colonie d’abeilles, peuvent agir ensemble pour une castration chimique totale des ouvrières

Dans une colonie d’abeilles sans reine ni couvain, les ouvrières tendent à devenir fertiles et investir leur énergie dans la ponte d’oeuf non-fécondés. Afin de maintenir une certaine stabilité dans l’organisation de la colonie et prévenir ce détournement de l’investissement énergétique des ouvrières, la reine garantie son statut de seule reproductrice et le couvain accapare le soin des ouvrières. Pour cela, ils émettent des phéromones peu volatiles. La phéromone mandibulaire (principalement le 9-ODA) émis par la reine ainsi qu’un mélange de 10 esters émis par le couvain. Ces composés permettent une castration chimique partielle des ouvrières. Cependant, parmi les deux facteurs de régulation de la maturation ovarienne des ouvrières, il semble que la présence de couvain soit le plus actif. Nous nous sommes donc demandé si les larves ne pourraient pas émettre des molécules très volatiles ayant un rôle sur le développement ovarien des ouvrières. Les composés volatiles larvaires ont donc été prélevés par Microextraction sur phase solide (SPME), puis analysés et identifiés par GC-MS. Le pic majeur retrouvé dans tous les échantillons est une molécule hautement volatile, l’E-β- ocimene. Nous avons testé l’effet de cette molécule sur la croissance des ovaires d’ouvrières élevées en cagette. Les résultats indiquent un effet inhibiteur significatif de l’E-β-ocimene sur le développement ovarien des ouvrières. Cette nouvelle phéromone, dont les effets sont identiques à ceux produits par la phéromone mandibulaire de la reine, montre que différents acteurs, utilisant différentes phéromones, peuvent induire un même effet sur le même organisme cible. De nouveaux tests sont nécessaires pour comprendre si les trois phéromones décris ici, régulant la fertilité de la colonie d’abeilles, peuvent agir ensemble pour une castration chimique totale des ouvrières

annexes : 30 p. Diplôme : DUT; mellifera); a problem which our different experiments tried to answer. In this project, we tested the effects of multiple stresses with varying parameter, specifically their effects on honey bee hypopharyngeal glands, which are important for larvae nourishment. In our first experiment, we tested honey bee mortality with the systemic insecticide Imidacloprid and the microssporidian Nosema. Within this experiment, we noticed these two stresses elevated the level of mortality. Addiotionally, we wanted to examine what occurred the glandular level; that is to say, to determine whether augmentation in hypopharyngeal gland size and protein quantity as a result of the two stresses could be quantified. Our study shows that hypopharyngeal glands are more atrophied in honey bees after they have been exposed to Nosema and Imidacloprid treatments. We would like to show that honey bbes exposed to these treatments, and thus those that possess atrophied glands, produce less protein. To do this, it will be necessary to perform additional experimentation where the new project design is adapted to better fit the needs of the specific experiment; Depuis quelques années nous avons pu voir une hécatombe des abeilles et nos différentes expériences ont tenté de répondre au problème de la mortalité des abeilles (Apis mellifera). A partir de ce constat, nous avons voulu tester les effets de quelques stress sur différents paramètres notamment sur les glandes hypopharyngiennes qui sont importantes pour nourrir les larves. Lors de notre première expérience, nous avons testé la mortalité des abeilles face à différents paramètres tels qu’un pesticide, l’imidaclopride et une microspore nommée Nosema. Grâce à cette expérience nous avons observé que ces deux paramètres avaient une influence sur la mortalité observée. Par la suite, nous avons voulu examiner ce qui se passé au niveau des glandes hypopharyngiennes, si nous pouvions remarquer une réaction face à nos deux paramètres à deux niveaux qui sont : la taille des glandes, la quantité de protéine présente dans ces glandes. Cette expérience nous as permis de remarquer que lors de la dissection, les glandes hypopharyngiennes sont beaucoup plus atrophiées lorsque les abeilles sont exposées au traitement du Nosema et de l’imidaclopride associé. Nous aurions souhaité démontrer que lorsque les abeilles sont exposées à ce traitement, les glandes hypopharyngiennes par leur atrophie produisent moins de protéines. Or la manipulation n’a pas marché au niveau des dosages des protéines. Il faudrait reprendre cette expérience en changeant le protocole expérimental pour le dosage des protéines

8 annexes, 24 p. Diplôme : IUT

Depuis quelques années nous avons pu voir une hécatombe des abeilles et nos différentes expériences ont tenté de répondre au problème de la mortalité des abeilles (Apis mellifera). A partir de ce constat, nous avons voulu tester les effets de quelques stress sur différents paramètres notamment sur les glandes hypopharyngiennes qui sont importantes pour nourrir les larves. Lors de notre première expérience, nous avons testé la mortalité des abeilles face à différents paramètres tels qu’un pesticide, l’imidaclopride et une microspore nommée Nosema. Grâce à cette expérience nous avons observé que ces deux paramètres avaient une influence sur la mortalité observée. Par la suite, nous avons voulu examiner ce qui se passé au niveau des glandes hypopharyngiennes, si nous pouvions remarquer une réaction face à nos deux paramètres à deux niveaux qui sont : la taille des glandes, la quantité de protéine présente dans ces glandes. Cette expérience nous as permis de remarquer que lors de la dissection, les glandes hypopharyngiennes sont beaucoup plus atrophiées lorsque les abeilles sont exposées au traitement du Nosema et de l’imidaclopride associé. Nous aurions souhaité démontrer que lorsque les abeilles sont exposées à ce traitement, les glandes hypopharyngiennes par leur atrophie produisent moins de protéines. Or la manipulation n’a pas marché au niveau des dosages des protéines. Il faudrait reprendre cette expérience en changeant le protocole expérimental pour le dosage des protéines, mellifera); a problem which our different experiments tried to answer. In this project, we tested the effects of multiple stresses with varying parameter, specifically their effects on honey bee hypopharyngeal glands, which are important for larvae nourishment. In our first experiment, we tested honey bee mortality with the systemic insecticide Imidacloprid and the microssporidian Nosema. Within this experiment, we noticed these two stresses elevated the level of mortality. Addiotionally, we wanted to examine what occurred the glandular level; that is to say, to determine whether augmentation in hypopharyngeal gland size and protein quantity as a result of the two stresses could be quantified. Our study shows that hypopharyngeal glands are more atrophied in honey bees after they have been exposed to Nosema and Imidacloprid treatments. We would like to show that honey bbes exposed to these treatments, and thus those that possess atrophied glands, produce less protein. To do this, it will be necessary to perform additional experimentation where the new project design is adapted to better fit the needs of the specific experiment

Diplôme : DUT

Diplôme : Master; Face aux importantes pertes des colonies d’abeilles domestiques qui n’ont pas d’explication concluante, l’hypothèse de l’interaction entre différents facteurs comme les pesticides et les parasites semble être la plus vraisemblable prenant en compte l’exposition des abeilles dans leur milieu naturel non seulement à un facteur mais au plusieurs contraintes à la fois. Dans ce contexte, l’objectif a été l’étude des effets de l’interaction entre l’insecticide imidaclopride et les microsporidies Nosema spp. chez l’abeille, notamment les conséquences sur la mortalité, la consommation journalière de sirop et la charge de spores. La première partie de cette recherche a permis la sélection d’une dose de spores de Nosema spp. de 2x105 spores/abeille qui assure la survie pendant les premières étapes de vie mais avec un développement précoce de spores. Dans un second temps deux expériences ont été conduites, la première a permis d’évaluer la mortalité et la consommation de sirop de trois doses d’imidaclopride (0,7, 7 et 70 μg/kg) seules et en combinaison avec Nosema spp. La seconde expérience a permis la mesure de la charge de spores notamment de la dose 7 μg/kg en combinaison avec Nosema spp. Toutes les expérimentations ont été conduites sur des abeilles naissantes dans des conditions de laboratoire. On a constaté des effets de l’interaction entre l’imidaclopride et Nosema spp. chez l’abeille, en relation avec l’augmentation de la mortalité et de la consommation de nourriture. D’autre part, on a pu envisager que l’imidaclopride a un impact négatif sur la germination des spores ce qui peut avoir une influence sur la charge de spores, un sujet qui doit être étudié plus approfondi. Les mécanismes qui sont à la base des effets observés sont encore inconnus, c’est pourquoi, ces facteurs sont en cours d’analyse afin de mieux comprendre l’origine des effets de l’interaction entre l’imidaclopride et Nosema spp. chez l’abeille.

Diplôme : Master; The dramatic depopulation of honey bee colonies has not yet been associated to a single culprit, although many potential contributing factors have been identified. In an attempt to address the impact of an association of two factors on the honey bee, Apis mellifera, we studied the effects of a joint exposure to the microsporidian Nosema and the systemic insecticide imidacloprid, in the context of parasitisation by the mite Varroa destructor. Young adult bees were exposed to doses found in the field, in a lab rearing experiment. Survival, feeding behaviour, and specific activity of two immunity-related enzymes were investigated. Parasitisation by Nosema combined with sublethal intoxication to imidacloprid triggered energetic stress and mortality. The association of these two factors did not affect phenoloxidase specific activity, but decreased the activity of glucose oxidase. These results reveal a weakening of the jointly treated bees, suggesting that the depopulation phenomenon is likely to be triggered by multifactorial causes and that the two factors studied were amongst.

Face aux importantes pertes des colonies d’abeilles domestiques qui n’ont pas d’explication concluante, l’hypothèse de l’interaction entre différents facteurs comme les pesticides et les parasites semble être la plus vraisemblable prenant en compte l’exposition des abeilles dans leur milieu naturel non seulement à un facteur mais au plusieurs contraintes à la fois. Dans ce contexte, l’objectif a été l’étude des effets de l’interaction entre l’insecticide imidaclopride et les microsporidies Nosema spp. chez l’abeille, notamment les conséquences sur la mortalité, la consommation journalière de sirop et la charge de spores. La première partie de cette recherche a permis la sélection d’une dose de spores de Nosema spp. de 2x105 spores/abeille qui assure la survie pendant les premières étapes de vie mais avec un développement précoce de spores. Dans un second temps deux expériences ont été conduites, la première a permis d’évaluer la mortalité et la consommation de sirop de trois doses d’imidaclopride (0,7, 7 et 70 μg/kg) seules et en combinaison avec Nosema spp. La seconde expérience a permis la mesure de la charge de spores notamment de la dose 7 μg/kg en combinaison avec Nosema spp. Toutes les expérimentations ont été conduites sur des abeilles naissantes dans des conditions de laboratoire. On a constaté des effets de l’interaction entre l’imidaclopride et Nosema spp. chez l’abeille, en relation avec l’augmentation de la mortalité et de la consommation de nourriture. D’autre part, on a pu envisager que l’imidaclopride a un impact négatif sur la germination des spores ce qui peut avoir une influence sur la charge de spores, un sujet qui doit être étudié plus approfondi. Les mécanismes qui sont à la base des effets observés sont encore inconnus, c’est pourquoi, ces facteurs sont en cours d’analyse afin de mieux comprendre l’origine des effets de l’interaction entre l’imidaclopride et Nosema spp. chez l’abeille.

The dramatic depopulation of honey bee colonies has not yet been associated to a single culprit, although many potential contributing factors have been identified. In an attempt to address the impact of an association of two factors on the honey bee, Apis mellifera, we studied the effects of a joint exposure to the microsporidian Nosema and the systemic insecticide imidacloprid, in the context of parasitisation by the mite Varroa destructor. Young adult bees were exposed to doses found in the field, in a lab rearing experiment. Survival, feeding behaviour, and specific activity of two immunity-related enzymes were investigated. Parasitisation by Nosema combined with sublethal intoxication to imidacloprid triggered energetic stress and mortality. The association of these two factors did not affect phenoloxidase specific activity, but decreased the activity of glucose oxidase. These results reveal a weakening of the jointly treated bees, suggesting that the depopulation phenomenon is likely to be triggered by multifactorial causes and that the two factors studied were amongst.

Published on line : 07 February 2009; International audience; Excitation–contraction coupling was characterized in enzymatically isolated adult honeybee skeletal muscle fibers. The voltage-dependent Ca2+ current (ICa) underlies action potential (AP) depolarization phase in honeybee muscle. A single AP leads to rapid and transient cytoplasmic Ca2+ increase (“Ca2+ transient”), which afterwards returns toward baseline following an exponential time course. Trains of APs elicit a staircase increase of Ca2+, as a result of multiple Ca2+ transient summation. Surprisingly, the nifedipine- sensitive ICa is blocked by allethrin, a pyrethroid insecticide, revealing myotoxic effects of this neurotoxic insecticide for honeybees. Ca2+ transients are under the control of Ca2+ entry through voltage-activated Ca2+ channels. Indeed, Ca2+ transient amplitude depends on extracellular Ca2+ concentration, and bell-shaped relationships are obtained for both ICa integral and the Ca2+ transient peak in response to depolarizations of increasing amplitude. The slow inactivation kinetics of ICa induces long-lasting Ca2+ transients that tend to reach a plateau and to return toward a resting level after the end of the stimulation. A Ca2+-induced Ca2+ release mechanism is suggested by two results. First, caffeine (≥5 mM) and 4-cmc (>0.4 mM), two activators of the sarcoplasmic reticulum Ca2+ release channels (CRCs), induce Ca2+ elevations in the absence of extracellular Ca2+. Second, ryanodine (5 μM) a plant alkaloid that binds specifically to CRCs, depresses voltageinduced Ca2+ transients. Honeybee muscle fibers represent a valuable model to study invertebrate excitation–contraction coupling and insecticide myotoxicity toward useful insects

In order to test the hypothesis whether the queen can mark pheromone on the wall of the cells where the queen laid eggs, three experiments were designed and conducted. The first experiment was to transfer three kinds of eggs–queen laid diploid eggs (QD), queen laid haploid eggs (QH) and worker laid haploid eggs (WH), which came from the same colony into the cells where the queen has laid eggs and has not laid eggs respectively, then observing and counting the number of eggs remaining. The second experiment is similar to the first one, but three kinds of eggs came from the different colonies. The third experiment used only QD to investigate. The results of these experiments did not support the hypothesis that the queen can mark pheromone in the wall of the cell, but supported the viewpoints of worker policing and recognizing in the honeybee

【Objective】 To analyze the brood kairmone and pheromone of different stage brood in Apis cerena cerena and compare it with Apis mellifera. 【Method】 Worker larvae (2-day old, 6-day old and 7-day old) and drone larvae (2-day old, 7-day old and 8-day old) of Apis cerena cerena were extracted with hexane by crushing, the supernatant were then fractioned by chromatography on a column of silica gel and tested by gas chromatogram. 【Result】 It is the first time to identify the components of brood kairmone and pheromone from Apis cerena cerena are methyl palmitate, methyl oleate, methyl stearate, methyl linoleate, methyl linolenate, ethyl palmitate, ethyl oleate, ethyl stearate, ethyl linoleate and ethyl linolenate. 【Conclusion】 The kairmone and 10 aliphatic esters in brood have been found in both Apis mellifera and Apis cerana cerana, while the content and distribution of the two pheromone are different at different brood stages.

Diplôme : Master

International audience; The invasion ofApis mellifera by Varroa destructor is attributed to two haplotypes (K and 1) that shifted from A. cerana, in north-east Asia last century. Ofthe eight known haplotypes of V. destructor on A. cerana, only two, the so-called Japan 1 (JI) and Korea 1 (KI) haplotypes, have·colonizedA. mellifera. We have gain further insights into the invasion ofA. mellifèra by V. destructor by identifying and genotyping the mite infesting both A. cerana and A. mellifera in regions where the JI and KI host shifts occurred and in a broader area along the mite geographic range in Asia. Mitochondrial sequences were used and mite samples were first genotyped on the basis of fragment ofthe COI to connect new samples to the known haplotypes. Based on the analysis of expanded mtDNA sequences, new Varroa mitochondriallineages were uncovered. New variants of each ofthe K and J haplotypes were found on Western honeybees and are potential new threats for Western honeybees outside of Asia. The extreme lack of polyniorphism now seen in the K and J haplotypes on Western honeybees outside ofAsia can be plausibly explained from bottlenecks that occurred in Asia before and after mites shifted from their primary host. The presence ofnovel haplotypes of V. destructor parasitizing A. mellifera in Asia highlight the permanent risk that a new Varroa type might extend on A. mellifèra outside Asia, representing a new threat for apiculture.

Since Varroa destructor invaded Apis mellifera populations in Europe in the seventies, this parasitism has been extensively studied, from control management ta molecular approaches of the host-parasite relationships. Chemical control of the mite was followed by c1assical events of pest management: resistance of the mite ta acaricides and pesticide residues in the wax. These events induced the set-up of biological and technical control measures of the mite. In parallel, the equilibrated parasitism of Apis cerana, a honeybee from East Asia, by Varroa destructor has been extensively studied and compared to the interaction with Apis mellifera in an attempt to understand the mechanisms underlying this host-parasite equilibrium. The knowledge of these mechanisms should have helped sort out selection criteria for Apis meflifera breeding programmes. However, despite efforts to breed Varroa resistant bees, little progress had been made. The basic biology of the mite, including chemical ecology, behavioural studies, population . dynamics and genetics, as weil as molecular responses of the honey bees, have been investigated for more than 25 years producing an impressive amount of scientific Iiterature, making the Varroa - honey bee interaction one of the most extensively studied host - parasite model systems. More recently, some natural honey bee populations have been shown to survive ta mite infestations, opening the way to the concept of integrated Varroa management. These bee populations will be particularly useful for determining the mechanisms of mite resistance in Apis mellifera. In addition, the recent sequencing of the honey bee genome should help us learn more about the molecular responses of the bees to mite parasitism. Comparative studies between resistant and susceptible bees are being developed and should be helpful to identify the genes involved in resistance. ln my talk, 1 will describe the different steps of the applied and fundamental research developed since the mite invaded Europe and conclude with a discussion of possible integrated Varroa management strategies for beekeeping

National audience; Après la France et l’Europe, les États-Unis d’Amérique subissent de plein fouet les problèmes de mortalités massives d’abeilles. Un déficit d’abeilles disponibles pour la pollinisation et les résultats d’enquêtes auprès des apiculteurs attestent clairement ce phénomène très préoccupant pour l’apiculture américaine. Y a-t-il des analogies avec ce que nous avons vécu sur nos populations d’abeilles ou bien est-ce un phénomène différent ? L’état américain débloque des fonds importants pour expliquer et lutter contre ce syndrome qui détruit leur cheptel

Social insect are profoundly influenced by primer pheromones (PPhs), which are efficient means for maintaining social harmony in the colony. PPhs act by affecting the physiology of the recipients with a subsequent shift in their behavior, and many PPhs have a releaser effect (i.e., changing the probability of performing a certain behavior upon perception). In this review we try to clarify the interplay between such dual pheromonal effects. Only a few PPhs have been identified, and we provide evidence for their existence in multiple species of social Hymenoptera, which is the most extensively studied of the social insects. We focus on the regulation of reproduction, social policing, and task allocation. Considering PPhs in a broad sense, we also discuss fertility signals and the role of cuticular hydrocarbons as putative PPhs. Identification of the underlying chemistry of PPhs offers insights into insect physiology and the evolution of social behavior. PPhs of the honey bee are used to demonstrate the complexity of pheromonal communication in social insects.

Diplôme : IUT; Populations of insect pollinators, honeybees included, are under threat all over the world, while the pollination service they provide appears more and more important for agriculture. It is therefore urgent to better understand the mechanisms of bee pollination, including for greenhouse crops which are becoming more widespread as pest pressures become greater. We monitored daily over 10 days the foraging activity of two ca. 4000-worker strong honeybee colonies previously fed with pollen and introduced together into a 900 m2 commercial greenhouse maintained beeproof and planted with monoecious cantaloupe in full bloom. We measured also the climate variables from a nearby weather station, and available resources for bees in terms of number of cantaloupe flowers and their nectar production. The pollinating activity was quantified by counting the number of conspecific pollen grains on the stigmas from a random sample of open-pollinated female flowers exposed to pollinators for the full duration of their stigmatic receptivity. Thanks to highly variable weather, recordings were made over a large array of environmental conditions. Foraging activity, measured by forager density, was not correlated with either flower density or nectar production. It was not correlated either with climatic variables, except for the daily maximum temperature (P = 0.006 over the 10 days of monitoring). Stigmatic pollen loads did not correlate with either the number or the proportion of male flowers, nor with any other variables linked to flowering or nectar production, but it was most highly correlated with forager density (r =0.825 ; n = 10 ; P = 0,003) which alone explained 68% of the variability encountered. Beyond factors that may enhance the pollinating effectiveness of individual foragers, these results suggest that foraging activity is the first parameter that growers and beekeepers together must strive to master if they hope to optimize the pollination of entomophilous crops; Les abeilles, abeille domestique comprise, sont aujourd’hui de plus en plus menacées partout dans le monde alors même que leur rôle en agriculture apparaît de plus en plus important. Il est donc urgent de mieux cerner les mécanismes du service de pollinisation qu’elles réalisent, y compris pour les cultures sous abris dont les surfaces continuent à se développer du fait de la pression des ravageurs. Nous avons suivi pendant 10 jours l’activité de butinage de deux colonies d’environ 4000 abeilles préalablement nourries au pollen et introduites dans un tunnel commercial de 900 m2 conduit en ‘abeilleproof ‘ et planté avec une culture de melon monoïque en pleine floraison. En parallèle, nous avons mesuré des variables climatiques ainsi que les ressources disponibles pour les abeilles dans le tunnel et surtout l’activité pollinisatrice des butineuses évaluée par la charge en pollen d’un échantillon de stigmates prélevés sur des fleurs femelles laissées en pollinisation libre exposées aux abeilles pendant toute leur période de réceptivité. Des conditions météorologiques contrastées nous ont permis d’effectuer ce suivi dans une large gamme d’environnement. L’activité de butinage, mesurée par la densité de butineuses, n’était pas corrélée avec la masse florale ou la production nectarifère dans le tunnel. Et elle n’était pas corrélée non plus avec les paramètres climatiques, excepté avec la température maximale journalière (P = 0,006 sur les 10 jours de relevés). La charge en pollen des stigmates n’était pas corrélée avec le nombre ou la proportion de fleurs mâles, ni avec d’autres paramètres de la floraison ou de la production de nectar, mais elle était corrélée le plus fortement avec l’activité de butinage (r =0,825 ; n = 10 ; P = 0,003), ce seul paramètre expliquant à lui-seul 68% de la variabilité. Au delà des facteurs qui peuvent augmenter l’efficacité pollinisatrice individuelle des butineuses, il apparaît donc que l’activité de butinage constitue le premier paramètre que producteurs et apiculteurs doivent s’efforcer ensemble de maîtriser pour optimiser la pollinisation des cultures entomophiles

Diplôme : Master

Pre-steady-state catalytic properties of insect acetylcholinesterase (AChE, EC 3.1.1.7) were studied with the neutral substrate N-methylindoxylacetate. Kinetics of soluble Apis mellifera and Drosophila melanogaster AChE forms showed lags ( v i = 0 ) before reaching the steady-state. Results were interpreted in terms of slow equilibrium between two conformational states E and E′ of insect AChE. Hysteresis of insect AChE has been pointed out for the first time. The hysteretic behaviour was found to depend on the NMIA concentration and the nature of the enzyme. The maximum induction times (τmax) to reach the steady-state were 800 and 1000 s with soluble AChE from A. mellifera and D.melanogaster, respectively. The orders of magnitude of the τmax were high and similar to human AChE and BuChE.

National audience

Diplôme : DUT

Diplôme : DUT

Social insects live in colonies; each colony, composed of up to hùndreds of thousands or evenmillions of individuals, called workers, behaves as a single integratedentity. A colony reproduces as a unit, and its properties are believed to result from selectionmainly at the level ofthe whole colony (25).Although social insects possess brains capable of sophisticated cognitive functions (22), it is unlikely that an individual colony member has the capacity to acquire and integrate information on the global state ofits colony and how that changes as a result of changing internaI and external conditions (28). One ofthe central problems in social insect biology, therefore, is that ofcolony integration: how the activities of thousands of individual workers are integrated to form a productive colony (37). Colony integration in the insect societies has been studied· intensively, and much has been learned about the mechanisms by which it is governed (4, 5, 32). Several different types of group decision-making activities in insect societies appear to be regulated by processes similar to quorum sensing in bacteria, includingdecisionsonnest sites (32a) and the allocation of labor to different activities.. Identifyingcommonalities · in the social behavior of social insects and microbes might provide ideas on social regulation in general. Studies of sorne species of microorganisms have revealed that the core elements of sociality-altruism and division oflabor-are possible without a brain at aIl (7,29). This chapter teviews our understanding of the regulation of division of labor in honeybee colonies from the perspective of quorum sensing.

International audience; Bee pollinators are currently recorded with many different sampling methods. However, the relative performances of these methods have not been systematically evaluated and compared. In response to the strong need to record ongoing shifts in pollinator diversity and abundance, global and regional pollinator initiatives must adopt standardized sampling protocols when developing large-scale and long-term monitoring schemes. We systematically evaluated the performance of six sampling methods (observation plots, pan traps, standardized and variable transect walks, trap nests with reed internodes or paper tubes) that are commonly used across a wide range of geographical regions in Europe and in two habitat types (agricultural and seminatural). We focused on bees since they represent the most important pollinator group worldwide. Several characteristics of the methods were considered in order to evaluate their performance in assessing bee diversity: sample coverage, observed species richness, species richness estimators, collector biases (identified by subunit-based rarefaction curves), species composition of the samples, and the indication of overall bee species richness (estimated from combined total samples). The most efficient method in all geographical regions, in both the agricultural and seminatural habitats, was the pan trap method. It had the highest sample coverage, collected the highest number of species, showed negligible collector bias, detected similar species as the transect methods, and was the best indicator of overall bee species richness. The transect methods were also relatively efficient, but they had a significant collector bias. The observation plots showed poor performance. As trap nests are restricted to cavity-nesting bee species, they had a naturally low sample coverage. However, both trap nest types detected additional species that were not recorded by any of the other methods. For large-scale and long-term monitoring schemes with surveyors with different experience levels, we recommend pan traps as the most efficient, unbiased, and cost-effective method for sampling bee diversity. Trap nests with reed internodes could be used as a complementary sampling method to maximize the numbers of collected species. Transect walks are the principal method for detailed studies focusing on plant–pollinator associations. Moreover, they can be used in monitoring schemes after training the surveyors to standardize their collection skills.

Après la France et l’Europe, l’Amérique du Nord subit des problèmes de mortalités massives d’abeilles. Un déficit d’abeilles pour la pollinisation et les résultats d’enquêtes auprès des apiculteurs attestent clairement que ce phénomène est très préoccupant pour l’apiculture américaine. Le déclin de ce pollinisateur peut constituer un problème environnemental grave pour les écosystèmes.