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Honey bee diet surveys require an accurate knowledge of the pollen supply and a rapid counting method for microscopic analyses. Referring to the literature, we aimed at reducing the number of pollen grains counted in order to decrease the time spent for each sample. For this, we compared counts on whole transects to alternative methods of counting by sub-sampling, using the non-acetolysed palynological method. For each pellet sample, a drop of a homogenized suspension was dried, degreased, and mounted onto a slide dressed with glycerol gelatin. The counting was performed through a digital camera fitted on a microscope. The study was carried out in two phases. Phase 1 was a test of slide homogeneity, carried out on a 10-slide set with one replicate. For each slide, we compared an exhaustive count of each present taxon on a whole transect divided in four quarters. Phase 2 was a search for an alternative counting method. The work was performed over the first six samples with replicates retaining exactly the same transect, but counting only one microscope field in three, then four, and finally one in five. Data analyses were carried out with Chi-square tests on taxa that were present in more than 5% of the sample. Phase 1 showed some cases of heterogeneity in microscope slides, leading to an error hazard when counting in a continuous mode up to a defined grain number. In phase 2, the comparison of alternative countings to full transects verified the linearity of the counting results. Suitable results were given by the reading method “one in three”. We improved the accuracy of this method for the particular case of samples containing large pollen grains, e.g., Zea mays, which are unevenly disseminated on the slide.

We used classical conditioning of the proboscis extension response to test whether the natural discrimination ability of honey bees could be used to assess the origin of honeys. Five honeys were used as the conditioning stimuli in the procedure: linden (Tilia spp.), oilseed rape (Brassica napus), eucalyptus, sunflower (Helianthus annuus), and black locust (Robinia pseudoacacia). Bees exhibited high levels of conditioned responses to all honey odours. Responses to the conditioned honey were usually the highest, but high levels of generalisation; i.e. behavioural response to other honeys, were recorded. Using a differential conditioning procedure where one honey odour was rewarded and another odour was explicitly unrewarded, we showed that honey bees could not always differentiate between honey types. The potential use of the honey bee as a biological detector to discriminate among honeys is discussed.

Abstract: The study aimed to evaluate the possible contamination by passive indoor pollen sedimentation in a laboratory where routine pollen analyses were conducted, but where no particular laboratory policies were adopted to limit contamination. Gravimetric pollen deposition was observed on traps (petri dishes soaked with glycerol) set in the palynology laboratory, under an extractor hood and on the bench beside it over 1 year (1995–1996), and in an air filtered room in a flow cabinet and on its roof over 1 month for comparison. Under the extractor hood, three types of airborne particles were deposited: pollen grains, spores and algae, representing 32.35, 67.28 and 0.37%, respectively, of the total sedimented particles over 1 year. The number of pollen grains deposited on the surface trap ranged from 0 (27 November to 4 December 1995) to 707 (10–18 April 1995). The highest number of taxa during a weekly collection was 23 (9–15 May 1995). The pollen flora represented by anemophilous pollen (>90% of the trapped pollen) was related to the vegetation next to the laboratory:Acer, Carpinus, Castanea, Corylus, Cupressaceae, Pinus, Quercus, Salix, Taxus for trees and shrubs andArtemisia, Brassicaceae, Plantago, Poaceae, andUrticaceae for grasses and weeds. Indoor pollen deposition corresponded to the period of the outdoor pollination (macroscopic field observation) which lasted from March to the beginning of August. However, some pollen were almost always present in the collection (Poaceae, Salix, Castanea, Betula), reflecting the occurrence of pollen grains in the atmosphere out of the pollination period. Moreover, about five times more entomophilous pollen was found under the extractor hood compared to the other area of the laboratory; even in the flow cabinet of the air filtered room, 237 particles were captured (versus only 15 on the roof). These data suggest a possible human contamination during operations under the extractor hood or in the flow cabinet. Although few airborne pollen were found, possible contamination has to be considered in investigations where even low pollen quantities are of interest.

Ce travail a pour but de preciser les donnees en pollens de lavande dans des miels francais permettant l'attribution de l'appellation et de mettre en evidence des taxons ou groupes de taxons susceptibles de diflerencier les zones de production. Les resultats obtenus montrent que les valeurs en pourcentage des grains de pollen de lavande/lavandin ne sont pas a prendre comme critere d'appellation de miel de cru. Les donnees en quantite absolue permettent seulement de donner des indications: une valeur seuil de 50 grains de pollen de lavande/lavandin par 10 g est proposee comme condition necessaire (mais non suffisante) pour l'attribution de la qualite miel monofloral. Les miels de ce cru presentent des spectres polliniques homogenes caracterises par 29 taxons presents dans plus de 80% des echantillons. Leur caractere mediterraneen est bien represente soit par des pollens habituellement rencontres dans ces zones de production, soit par taxons dont la repartition est strictement mediterraneenne mais sont presents dans les achantillons de facon aleatoire. De nouveaux taxons ont pu etre determines pour des miels de la France continentale (Cytinus, type Anthyllis, Amorpha, Aphyllantes, Coronilla type scorpioides, type Corrigiola et Diospyros).Pollen analyses were carried out on 36 samples from the two french lavender honey production areas (Drome and Alpes de Haute Provence). The quantitative results show a very low number of Lavandula sp. pollen grains per 10 g (50-250). The percentage on total Lavandula pollen countings is likewise very low (about 5%). The pollen spectra for the main taxa do not show differences between the two areas. However the mediterranean flora appears clearly in both areas. New identifications, for the south of France, were found.

To characterize plant chemicals cueing honeybees preferences between sunflower genotypes selected to produce hybrid seeds, combined behavioral and chemical analyses were undertaken. From observations of the foraging behavior under field conditions, bees' preferences between female and male parent lines were shown. Since bees' attraction to plants is based upon an associative conditioning between food, provided by nectar and pollen, and plant volatiles, these components were compared between genotypes. Sugar composition of nectars was analyzed by gas chromatography: glucose, fructose and sucrose were identified, with sucrose inducing bees' preferences. Pollen production was quantified on parent lines and resulting hybrid varieties, using a coulter-counter device. Differences among parent lines and heredity effect were found. However, there were strong interaction between parental lines and high variability within genotypes. Pollenkitt analysis, using thin layer chromatography was undertaken to separate the main classes of lipids (hydrocarbons, sterols, mono-, di- and triglycerids). Fatty acids composition was analyzed by gas chromatography, the main components being two unsaturated fatty acids. Comparison of volatile components collected by air-entrainment method showed differences between male and female genotypes. Discriminative components were limited to 10% of the volatile blends and were identified by coupled gas chromatography-mass spectrometry.

Dans le but de preciser Ies desplacements migratoires de Agrotis ipsilon, des analyses polliniques ont ete realisees a partir de lavage de tetes entieres (surface, trompes et antennes) de papillons males sur neuf echantillons correspondant a neuf piegeages effectues en Camargue (France) entre le 28.III et le 05.V.1989 et sur un piegeage d'individus males et femelles le 20.IX.1989 au Col du Glandon (2000 m, Savoie, France). Les traitements chimiques classiques de la palynologie ont ete appliques a des groupes de 10 tetes par piegeage donnant une image pollinique de la population.Les resultats obtenus mettent en eevidence des quantites de pollens recueillies et une richesse taxonomique largement suffisantes pour l'etablissement de spectres polliniques. Elles attestent la presence de pollens de plantes a pollinisation entomophile mais aussi anemophile (35%). Les taxons rencontres appartiennent a la flore locale (Tamarix, Matthiola, type Genista, Brassicaceae, Gentianaceae, Rosaceae et Saxifragaceae) et lointaine (Citrus, Eucalyptus, Ostrya, Castanea, Betula, Alnus et Hedera). La reconnaissance dans les spectres polliniques des genres appartenant au citronnier, clementinier, charme-houblon ou a l'eucalyptus suggere une migration sud-est/est a partir de la Corse ou de la region Alpes-Cote-d'Azur. Une migration sud (Afrique du Nord) est suspectee par la presence de pollens en dehors de leur periode de pollinisation (Olea et Castanea). Dans l'etat actuel de nos observations, il n'a pas encore ete possible de mettre en evidence des taxons nord-africains. Les ressources nectariferes ont pu etre precisees: Salix, Citrus, Eucalyptus, Ligustrum, Castanea et Brassicaceae.Pollen analysis were carried out on moths [Agrotis (Scotia) ipsilon] collected on two sites in south-east France, one near the Mediterranean sea (Camargue), the other in the Alps, at 2000 m altitude. A spring migration from east and south-east (Corsica and the French Riviera) was found at the Camargue site, while a possible fall migration from the North (Lyon area) appeared in the Alps. In addition, the analyses indicate that moths visit certain nectariferous floral sources.