Showing papers in "Apidologie in 2003"

Nectar sugar content: estimating standing crop and secretion rate in the field

Abstract: fleurs et du taux de secretion au champ. Cet article decrit les methodes pour echantillonner et mesurer les taux de secretion et les quantites de nectar disponibles dans les fleurs au champ. Il vise a resoudre certaines omissions et certains desaccords presents dans d'autres articles de synthese sur les techniques de mesure du nectar. Parce que la valeur energetique du nectar est importante pour les animaux qui visitent les fleurs, la quantite de nectar est souvent exprimee par la teneur en sucre (mg sucre par fleur). Elle peut etre calculee par les mesures au champ du volume du solute et de sa concentration dans des fleurs prises individuellement. Pour l'echantillonnage, je recommande les pipettes microcapillaires en verre, suffisamment fines pour echantillonner quantitativement les fleurs pollinisees par les insectes sans les dechirer et je discute de methodes alternatives d'echantillonnage pour les tres petites quantites ou pour le nectar tres visqueux. J'indique un type de refractometre a main qui peut mesurer la concentration du solute (en g de saccharose pour 100 g de solution) dans de tres petits volumes de nectar et je considere dans quelle mesure les calculs de la valeur energetique du nectar basee sur les lectures du refractometre sont affectes par les facteurs suivants : presence de sucres autres que le saccharose ou de composes autres que les sucres, temperature, regroupement des echantillons de nectar provenant de plusieurs fleurs ou essai de dilution d'un echantillon de nectar dans la micropipette. La quantite de nectar est souvent distribuee irregulierement parmi les fleurs d'une parcelle et la quantite moyenne de sucre par fleur rencontree par un insecte qui butine systematiquement peut depasser celle echantillonnee par un ecologiste non selectif. Le taux de secretion, communement exprime en mg de sucre par fleur et par heure, est mesure par le taux d'accumulation de nectar dans des fleurs videes et dont on a exclu les visiteurs en ensachant les fleurs. Les sachets en voile de mariee ou en moustiquaire agissent moins sur le microclimat, et donc sur la concentration en nectar et le taux de secretion, que les sachets en papier ou en polyethylene. Certaines especes reabsorbent le nectar et cette reabsorption par les fleurs peut reduire le taux apparent de secretion. Pour minimiser cet effet, la duree pendant laquelle la secretion de nectar est mesuree doit etre aussi breve qu'il est possible pour une mesure precise. Un protocole pour suivre la quantite de nectar disponible et le taux de secretion sur une journee de l'aube au crepuscule est indique.

Apis mellifera pomonella, a new honey bee subspecies from Central Asia

Abstract: Endemic honey bees of the Tien Shan Mountains in Central Asia are described as a new subspecies, Apis mellifera pomonella, on the basis of morphometric analyses. Principal component and discriminant analysis of the morphological characters measured clearly place these bees into the oriental evolutionary branch of honey bees, but also show that they are distinct from the other subspecies in this lineage. The existence of this newly described honey bee subspecies extends the range of endemic A. mellifera more than 2000 km eastward than previously estimated. Sequence analysis of mitochondrial DNA places A. m. pomonella within the C mitochondrial lineage (a group that is inclusive of both C and O morphological lineages). These findings support the conclusion that A. m. pomonella has a phylogeographic history shared with subspecies from the eastern limit of the previously known range.

Variation in water and sucrose responsiveness during the foraging season affects proboscis extension learning in honey bees

Abstract: Honey bee foragers often show a variation in laboratory proboscis extension learning during the foraging season, making comparisons between experiments difficult. We analysed whether the seasonal variation in learning performance was related to a variation in sucrose responsiveness in pollen and non- pollen foragers. Pollen foragers were very responsive to water and sucrose throughout the season. Non- pollen foragers were overall less responsive and showed more variation. Sucrose responsiveness strongly correlated with tactile and olfactory learning performance in pollen and non-pollen foragers throughout the season. Learning performance was significantly better when sucrose responsiveness was high than when it was low. We suggest conditioning bees that have uniform sucrose responsiveness throughout the season to reduce experimental variance. Apis mellifera / proboscis extension response / learning / responsiveness to sucrose / seasonal variation

Sperm numbers in drone honeybees (Apis mellifera) depend on body size

Abstract: The effect of drone honeybee's body size on semen production was evaluated. In the same colonies, drones were either reared in drone cells (large drones) or in worker cells (small drones). Wing lengths (size indicator) and sperm numbers of small and large drones were compared. Small drones (~13% reduced wing size) produce significantly fewer spermatozoa (7.5 ± 0.5 million) than normally sized drones (11.9 ± 1.0 million spermatozoa). There is a significant positive correlation between sperm number and wing size within the small drones and in both groups combined. In the large group alone no correlation was found. The rearing investment per spermatozoon is lower for small than for normally sized drones because small drones produce more spermatozoa in relation to their body weight. Since colonies usually produce large drones, the enhanced investment must be outweighed by a mating advantage of large drones. Apis mellifera / spermatozoa / male size / small drone / large drone / reproductive success

The use of repetitive element PCR fingerprinting (rep-PCR) for genetic subtyping of German field isolates of Paenibacillus larvae subsp. larvae

Abstract: Studies using the repetitive element PCR fingerprinting technique (rep-PCR) revealed that BOX A1R-, MBO REP1- and ERIC-primers reproducibly generate distinctive DNA fingerprints from Paenibacillus larvae subsp. larvae. Four different genetic subtypes of P. larvae were identified in Germany using the three primers. Correlating the results from genetic and morphological subtyping, the flat and transparent morphotype could be assigned to one genetic group. Geographic evaluation of our results demonstrated that the different genetic subtypes appeared in clusters correlating with different outbreaks of American foulbrood. Taken together, our results indicated that rep-PCR performed with a combination of BOX A1R- and MBO REP1-primers will be an effective tool for establishing a molecular epidemiology of P. l. larvae. American foulbrood / Paenibacillus larvae larvae / DNA-fingerprinting / genetic subtyping / molecular epidemiology

Weight loss in drone pupae (Apis mellifera) multiply infested by Varroa destructor mites

Abstract: Colony losses caused by varroatosis in the western hive bee, Apis mellifera, are mainly due to worker bee injury by Varroa destructor mites during preimaginal development. These effects have been examined repeatedly; however, little is known about effects on drones. Here we present the first exact data on individual drone weight loss, especially from the red eyed pupal stage onwards. The resulting reduction in weight of adult drones was related to the number of female mites (up to 20) that had invaded a brood cell. Weight loss was significant even if only one female mite was present. From several of the heavily infested brood cells adult mini-drones emerged. Varroosis / multiple drone brood infestation / preimaginal weight loss / male fitness / Apis mellifera / Varroa destructor

Swarming in honey bees (Apis mellifera) and Varroa destructor population development in Sweden.

Abstract: In a honey bee population of 150 colonies, the development of an introduced Varroa destructor mite population was monitored in swarming and non-swarming colonies for two years in a Nordic climate. The results demonstrated a reduced mite population as a result of swarming only for the first swarm season studied. In the second swarm season, there were much higher mite levels (based on debris counts of mites) and fewer colonies swarmed, but there was no significant difference in infestation levels of adult bees in the fall between swarming and non-swarming colonies. This result was interpreted as an effect of host-parasite interactions, where the detrimental influence from the infestation prohibited growth (and swarming) in some colonies, but allowed better mite reproduction opportunities (and swarming) in others. Surprisingly, the mite infestation levels of swarms in the late fall were not significantly different from those of swarming colonies the same year, indicating that swarm survival may be almost as much affected by V. destructor, as intact, swarming colonies. No horizontal mite transfer through robbing was observed. The results suggest that, horizontal mite transfer may not be as important in a Nordic climate where many bee colonies die over winter along with their mites, as it is in warmer climates. Varroa destructor / Apis mellifera / swarming / survival / nordic climate / population dynamics

Temporal changes in Varroa destructor fertility and haplotype in Brazil

Abstract: The relationship between fertility and haplotype was studied in Varroa destructor mites sampled from colonies of A. mellifera carnica and Africanized Honeybees (Apis mellifera) in Germany and Brazil respectively. Both in Germany and in Brazil, only the V. destructor Korea haplotype was found, though the Japan-Thailand haplotype was formerly thought to have been more abundant in Brazil. The fertility of Varroa mites in Brazil has increased since 1998 and is currently (2001) at European levels. Temporal changes in mite fertility and haplotype are not fully congruent.

Determination and changes of free amino acids in royal jelly during storage

Abstract: D'un point de vue commercial, la gelee royale (GR) est la nourriture destinee aux larves des futures reines d'abeilles âgees de quatre a cinq jours. Recemment la GR a acquis une place dans le commerce mondial comme supplement dietetique et dans les cosmetiques pour ses effets pretendus toniques et bio-stimulants. Le controle de la qualite de la GR est donc un sujet important qui reste mesestime. L'evaluation de la qualite de la GR implique l'etude de sa composition et des changements des composants au cours du stockage commercial et domestique afin de definir des marqueurs de qualite. Les aspects de la determination des acides amines libres (AAL) dans la GR et les modifications des AAL au cours de la duree de conservation avant la vente sont discutes dans cette etude. Le nettoyage des AAL est l'etape preliminaire a la determination et a ete faite par les techniques de chromatographie. Le but etait de reduire la presence de substances qui interferent, telles que les sucres et les acides organiques a chaine courte, qui sont d'autres composants naturels de la GR. Les principaux AAL des series L sont la proline (2,4-5,4 mg/g GR), la lysine (0,6-2,2),le glutamate (0,5-0,9), la β-alanine (0,3-0,5), la phenylalanine (0,2-0,6), l'aspartate (0,2-0,5) et la serine (0,1-0,3) (domaine de concentration moyenne). La concentration des AAL des series-D etait inferieure a la limite de detection de la methode (0,1 mg/g GR) dans tous les echantillons, ce qui montre que l'activite microbienne etait insignifiante. Les modifications de la fraction AAL ont ete analysees dans la GR immediatement congelee apres le prelevement de l'echantillon (temoin) et dans des fractions du meme echantillon conservees a deux temperatures differentes (temperature ambiante et a 4 °C) durant des periodes de 3, 6 et 10 mois. La teneur en AAL est restee constante durant tout le stockage a 4 °C. Mais a la temperature ambiante, la proline et la lysine ont d'abord augmente jusqu'a 6,8 et 3 mg/g, respectivement, durant les trois premiers mois puis ont diminue pour atteindre 2,5 et 1 mg/g apres 6 mois et 3 et 1 mg/g apres 10 mois de stockage (Tab. II). Cette etude confirme que les AAL ne sont pas des produits terminaux formes au cours de l'evolution de la GR mais des produits intermediaires impliques dans les reactions qui ont lieu a temperature ambiante, telles que le processus de brunissement (reaction de Maillard).

Seed set of male-sterile and male-fertile oilseed rape (Brassica napus) in relation to pollinator density

Abstract: The effects of pollinator density on the seed set of a male-sterile (MS) and a male-fertile (MF) line of winter oilseed rape (Brassica napus) were studied in 24 isolation cages (7.5 m2). Pollinator treatments comprised of high pollinator density (a small honeybee colony and 10 mason bees, Osmia rufa), and a gradient of increasing O. rufa densities from zero (control) up to 100 bees per cage. High pollinator densities increased the seed weight per plant from 6.5 g to 56.9 g for the MS line. However seed weight did not differ between high pollinator densities and controls for the MF line. Increasing densities of O. rufa had a significant effect on almost all yield components of the MS line, but only marginal effects on the MF line. The number of seeds per pod, the seed weight per plant and the harvest index (seed weight/plant dry weight) of the MS line showed a significantly steeper increase with increasing bee density than that of the MF line. The results suggest that solitary bees could be used successfully to replace honeybees as pollinators of MS oilseed rape in isolation cages. Brassica napus / Osmia rufa / Apis mellifera / pollination / plant breeding

Dietary dopamine causes ovary activation in queenless Apis mellifera workers

Abstract: Groups of young honey bee workers were fed a diet containing dopamine while confined in small cages at 34 °C and 80% RH in absence of a queen for 8 to 13 days. The bees in eight pairs of cages, each pair containing an equal number of workers, received a pollen-rich diet supplemented with dopamine (10 µg/g of diet) (DOP groups), or not supplemented (controls). The rate of consumption of the diet was monitored continuously during the confinement period, after which the workers were dissected to assess follicle development in the ovaries. The results showed a significantly higher proportion (P = 0.004) of workers with activated ovaries in the DOP groups than in control groups. The number of bees surviving confinement was significantly higher in the control groups than in the DOP groups (P ≤ 0.01), possibly reflecting a deleterious effect of dopamine. The surviving bees from both groups consumed equivalent amounts of diet (P = 0.687), showing that ovary activation was not due to differential diet consumption. The results suggest a role of dopamine in the chain of events mediating changes in the reproductive status of orphan honey bee workers. Apis mellifera / honeybees / dopamine / ovary activation

A stingless bee marks the feeding site in addition to the scent path (Scaptotrigona aff. depilis)

Abstract: Scaptotrigona depilis uses a scent trail to guide newly recruited bees to a food source. (i) Behavioral experiments show an additional chemical marking at the food source. The bees had to choose between an unused feeder and a feeder, at which their nestmates had fed. 71 to 86% of the bees chose the used feeder where the foragers had left attractants. The used feeder also attracted bees when it was moved away from its original site to a new site halfway along the scent path or 20 m beyond it. (ii) The localization of a food source by S. depilis is very precise with regard to both direction and distance. When control feeders were 1.7 m, 8.5 m, and 17 m away from the experimental feeder (at 50 m from the nest) 97.5-100% of the recruits chose the experimental feeder where the foragers were feeding. When positioned beyond the used feeder the control feeder remained unvisited. We conclude, that markings left at the used feeder represent particular end point tags and differ from scent path markings. stingless bee / Scaptotrigona / scent marking / recruitment

Osmia cornuta (Hymenoptera, Megachilidae) as a pollinator of pear (Pyrus communis): fruit- and seed-set

Abstract: Afin d'etudier la possibilite d'utiliser l'abeille Osmia cornuta Latreille comme pollinisateur des poiriers'Abate Fetel' et 'Max Red Bartlett', nous nous sommes poses les questions suivantes : (i) O. cornuta utilise-t-elle les fleurs de poiriers comme source preferee de pollen et de nectar ?, (ii) la presence d'O. cornuta dans un verger de poiriers augmente-telle la fructification et la production grainiere ? Les cellules approvisionnees par des femelles d'O. cornuta lâchees dans un verger ont ete denombrees. En 1998 des conditions meteorologiques favorables ont permis aux femelles de d'O. cornuta de nidifier activement (3,4 cellules par femelle). En 1999, par contre, les mauvaises conditions ont serieusement limite l'activite de nidification (<2 cellules par femelle). En 1998 et 1999, les analyses palynologiques d'echantillons des provisions de pollen ont montre que Pyrus etait de loin la principale source de pollen utilisee par les femelles d'O. cornuta pour approvisionner les cellules (Tab. I). La nouaison des jeunes fruits, la fructification (fruits recoltes) et la production grainiere ont ete mesurees sur des arbres exposes a differents traitements de pollinisation: (1) pollinisation sous cage (paires d'arbres adjacents, 1 'Abate Fetel', 1 'Max Red Bartlett', encages avec cinq femelles et cinq mâles d'O. cornuta), (2) pollinisation libre (paires d'arbres comme en 1, situees a diverses distance, 0, 50, 100 et 150 m, des sites de nidification), (3) pollinisation minimale (comme en 1 mais sans insectes pollinisateurs). En general, le traitement 1 a fourni le plus grand nombre de jeunes fruits, de fruits recoltes et de graines, suivi par le traitement 2 et le traitement 3 (Figs. 1-5). Trois femelles d'O. cornuta par arbre ( 12 000 fleurs par arbre) sont suffisantes pour les amandiers et une femelle pour 3,3 a 5,5 arbres ( 2 000 fleurs par arbre) pour les pommiers. Le traitement 1 comportait 5 femelles par cage (= 1 500 fleurs par arbre) et l'on peut considerer que la pollinisation maximale a ete atteinte. En 1998 sur 'Max Red Bartlett', les arbres encages sans abeilles (traitement 3) ont produit un nombre considerable de fruits (Fig. 2). Cette variete etant sujette a la parthenocarpie, la faible production grainiere de ces memes arbres suggere que la plupart des fruits etaient parthenocarpiques. La production grainiere est un facteur important pour la commercialisation car les poires ayant un nombre eleve de graines ont tendance a etre de taille plus grosse et de forme et saveurs meilleures. En 1998, O. cornuta a ete le pollinisateur le plus abondant dans le vergers (96,7 % des insectes comptes). La majeure partie de la pollinisation effectuee dans le traitement 2 (pollinisation libre) peut donc etre attribuee a O. cornuta. Bien qu'on n'ait pas compte les pollinisateurs en 1999, les observations indiquent qu'O. cornuta etait aussi le pollinisateur le plus abondant. Pour les deux varietes la pollinisation libre a conduit a une production grainiere plus forte (Fig. 5). En conclusion, O cornuta possede un potentiel eleve comme pollinisateur commercial du poirier. Au moins certaines annees et pour certains cultivars, la nouaison des jeunes fruits, la fructification et la production grainiere des arbres pollinises librement principalement par O. cornuta etaient semblables a celles des arbres encages avec des abeilles. Il est donc possible d'accroitre la pollinisation et la production de poires en utilisant O. cornuta.

Longevity of Bombus terrestris workers (Hymenoptera: Apidae) in relation to pollen availability, in the absence of foraging

Abstract: Chez le bourdon Bombus terrestris L. les ouvrieres qui consomment du pollen peuvent etre divisees grossierement en deux groupes : (1) celles qui consomment du pollen des pots de stockage pendant plus de deux minutes et vont ensuite nourrir les larves et (2) celles qui au contraire consomment du pollen pendant un laps de temps plus court et ne nourrissent pas les larves. Leur consommation est supposee satisfaire leurs propres besoins nutritionnels proteiques. Le besoin en proteines des ouvrieres a ete etudie en examinant l'effet de la disponibilite en pollen sur leur longevite. Trois regimes differents ont ete offerts a des ouvrieres orphelines novices : (1) du sirop seulement (2 repetitions); (2) du sirop et du pollen ad libitum (2 repetitions) et (3) du sirop et la possibilite de consommer du pollen pendant 6 h apres l'emergence (une repetition). Le regime 2 montre l'effet de la senescence sur la mortalite des ouvrieres. Les courbes de survie different significativement selon le regime. La longevite mediane etait de 13 et 15 j avec le regime I (n1 = 14, n2 = 50), de 76 et 54 j avec le regime 2 (respectivement n1 = 21, n2 = 38) et de 20 j avec le regime 3 (n2 = 44, Fig. 2). La privation de pollen a provoque un fort declin de la courbe de survie (Figs. 1 et 2). La possibilite de consommer du pollen pendant 6 j a eu un effet restreint et passager sur la longevite des ouvrieres. Ces resultats montrent que les bourdons ont un besoin permanent de nourriture proteique tout au long de leur vie. Il n'y a aucune correlation entre la taille des ouvrieres et leur longevite. Ceci montre que la plus forte mortalite des butineuses trouvee lors des etudes sur le terrain est dite a des problemes environnementaux et non a leur forte taille. Nos resultats montrent que, si l'on exclut les facteurs du milieu, les ouvrieres meurent de vieillesse au bout de deux mois environ, quelle que soit leur taille.

The effects of adult small hive beetles, Aethina tumida (Coleoptera: Nitidulidae), on nests and flight activity of Cape and European honey bees (Apis mellifera)

Abstract: This study identifies differences in the effects of small hive beetles on flight activity and nests of European-derived honey bees (Apis mellifera) in the United States and Cape honey bees (Apis mellifera capensis) in South Africa. Treatments consisted of control colonies (< 5 beetles/colony) and experimental colonies receiving beetles (treatment). Absconding day did not differ significantly between treatment or bee race but absconding was greater between the two treatments in European colonies than in Cape ones. Cape bees used significantly more propolis than European bees. Honey stores were significantly greater in Cape honey bee colonies than in European ones. Bee weight did not differ significantly between treatments or bee race. Treatment did not significantly affect bee populations, brood area, or average flight activity in Cape colonies but it did significantly lower all of these in European colonies. The effects of treatment in European colonies are symptomatic of absconding preparation. Treatment significantly lowered the amount of pollen stores in Cape colonies, but this effect was not found in European colonies. The number of beetles in control colonies was significantly higher in European colonies than Cape ones while the percentage of beetles remaining in non-absconding treated colonies was higher in Cape colonies than European ones. These data indicate that adult small hive beetles are sufficient to cause significant harmful effects on colonies of European, but not Cape, honey bees. Aethina tumida / Apis mellifera / Apis mellifera capensis / flight activity / honey bee nests

Environmental risk assessment of transgene products using honey bee (Apis mellifera) larvae

Abstract: An environmental concern regarding the cultivation of transgenic crop plants is their effect on non-target organisms. Honey bees are obvious non-target arthropods to be included in a risk assessment procedure but due to their complex social behaviour, testing transgene products on individual bees is not possible in bee colonies. We employed a laboratory larval rearing technique to test the impacts of such transgene products on honey bees. A serine proteinase inhibitor (Kunitz Soybean Trypsin Inhibitor, SBTI), that is a source of insect resistance in transgenic plants, was used as a model insecticidal protein on honey bee larvae reared individually in the laboratory. The addition of 1.0% SBTI (w:w of total protein) to the larval diet created significant additional larval mortality, slowed juvenile development and significantly decreased adult body mass. Our results suggest that the larval rearing technique can be used to monitor direct side-effects of transgene products on individual honey bee larvae. Apis mellifera / risk assessment / larval rearing / transgenic plants / proteinase inhibitor

The influence of different diets on haemocytes of adult worker honey bees, Apis mellifera

Abstract: The influence of different diets on the haemolymph of adult honeybee workers was examined. The laboratory experiments took place in early summer. There were three experimental groups fed with one of the following diets: pollen with sugar, pollen substitute alone, or sugar. A sample of haemolymph was taken from 7-8 day old bees and numbers of haemocytes of each type (plasmatocytes, granular haemocytes, and other types of haemocytes pooled together) were recorded and the metabolic activity of haemocytes was observed. A lack of protein caused a significant increase in the percentage of granular haemocytes, a significant decrease of other types and a lower metabolic activity. The examined pollen substitute caused a decrease of total haemocyte count. The decrease in the metabolic activity of haemocytes was lower than without protein. Apis mellifera / diet / haemocyte / adult worker

Molecular phylogeny of the stingless bees (Apidae, Apinae, Meliponini) inferred from mitochondrial 16S rDNA sequences

Abstract: Sequence data from the mitochondrial 16S rDNA of 34 species from 22 genera of stingless bees plus outgroup sequences from 11 species of other corbiculate bees were used to investigate the phylogenetic relationships among the Meliponini. Equally weighted parsimony and maximum likelihood analyses were performed. Four main clades were recognized in the parsimony consensus tree: (A) Hypotrigona, (B) Austroplebeia, (C) remaining African genera (Plebeina, Meliplebeia, and Axestotrigona) plus the two Oriental genera (Lepidotrigona and Heterotrigona), and (D) Neotropical genera. The African genus Hypotrigona was placed as the most basal branch in the tribe, followed by Austroplebeia as the sister group of other two major clades (C and D). Our results did not support traditional groups with intercontinental composition, e.g. Trigona sensu lato or Plebeia sensu lato. stingless bees / Meliponini / 16S rDNA / phylogeny

Response of the small hive beetle (Aethina tumida) to honey bee (Apis mellifera) and beehive-produced volatiles

Abstract: The response of male and female Small Hive Beetle (SHB), Aethina tumida, to air-borne volatiles from adult worker bees, (Apis mellifera), pollen, unripe honey, beeswax, wax by-products ("slumgum"), and bee brood, was investigated in olfactometric and flight-tunnel choice bioassays. In both bioassay systems, males and females responded strongly to the volatiles from worker bees, freshly collected pollen and slumgum but not to those from commercially available pollen, beeswax and bee brood. The response to pollen volatiles was dose dependent, while response to volatiles from worker bees increased with both the number and age of the bees. Females were more responsive than males to the different volatile sources, with greater response in tests with unripe honey. In flight-tunnel choice tests, Super Q-trapped volatiles from worker bees elicited a response comparable to the response to living workers, while trapped volatiles from other sources were not attractive.

A scientific note on the mating frequency of Apis dorsata

Abstract: Wandee WATTANACHAIYINGCHAROENa,b,c, Benjamin P. OLDROYDc*, Siriwat WONGSIRIa, Kellie PALMERc, Jurgen PAARc,d a Bee Biology Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand b Present Address: Department of Biology, Naresuan University, Phitsanulok 65000, Thailand c School of Biological Sciences A12, University of Sydney NSW 2006, Australia d Institute of Zoology, Karl-Franzens University Graz, 8010 Graz, Austria

Evaluation of some essential oils for the control and prevention of American foulbrood disease in honey bees

Abstract: La loque americaine (AFB), causee par la bacterie sporulante Paenibacillus larvae subsp. larvae, est la maladie la plus grave du couvain de l'Abeille domestique (Apis mellifera L.). Dans les regions fortement touchees, au lieu de bruler le materiel infecte, on utilise des antibiotiques, mais avec le risque de contamination du miel. Il a ete montre par des tests in vitro que les huiles essentielles (h.e.) extraites de plantes aromatiques possedaient une activite antimicrobienne (Alippi et al., 1999b ; Calderone et al., 1994 ; Deans et al., 1992) et certaines d'entre elles ont ete utilisees avec succes pour traiter le couvain plâtre (Colin et al., 1989) et la varroose (Imdorf et al., 1994). Le but de cette etude etait de determiner la toxicite aigue orale des h.e. pures et en melange sur des abeilles adultes par la dose letale 50 (DL 50 ) et d'evaluer la reaction des colonies infectees par l'AFB a differents traitements bases sur les h.e. en mesurant la duree de la prise de nourriture. Les tests ont porte sur les h.e. de (1) sarriette (Satureia hortensis), (2) thym (Thymus vulgaris), (3) citronnelle (cymbopogon citratus) et (4) marjolaine (Origanum vulgare) et sur les melanges suivants : (A) citronnelle + thym, (B) citronnelle + thym + origan + basilic (Ocimum basilicum) et (C) citronnelle + thym + basilic. Les principaux composes de chaque h.e. ont ete determines par chromatographie en phase gazeuse sur colonne de silice methylee et sur une colonne enduite de Carbowax 20 M et par detecteurs a ionisation de flamme (Tab. I). Pour evaluer la toxicite aigue orale, des doses d'h.e. pures et en melange (μg d'h.e. ou de melange par abeille) ont ete choisies conformement aux tests biologiques usuels pour determiner les DL 50 (Cox, 1977). Le dimethoate a ete utilise comme reference toxique et le saccharose comme temoin non toxique. On a fait quatre essais de plein champ, deux avec les h.e. pures, le premier a titre curatif et la second a titre preventif, et deux avec les melanges a titre preventif. Les traitements ont ete administres sous forme de sucre candi dans les trois premiers essais et sous forme de sirop de sucre dans le dernier. On a fait cinq repetitions par traitement et utilise deux temoins: pas de traitement (saccharose) et du tartrate de tylosine comme temoin d'efficacite, a l'exception du premier essai en plein champ qui n'a eu que le temoin non traite. Les resultats montrent que le melange A etait legerement toxique (DL 50 a 24 h de 15,94 μg de melange par abeille et DL 50 a 48 h de 18,75 μg) et que le melange C n'etait pas toxique (DL 50 a 24 h de 122 μg de melange par abeille et DL 50 a 48 h de 356,8 μg). Il n'a pas ete possible de calculer les DL 50 dans le cas du melange B et de toutes le h.e. pures car les donnees de mortalite ont fourni des courbes negatives. Les resultats des essais en plein champ montrent que les h.e. pures ou en melange ne sont pas efficaces pour eliminer les signes cliniques de l'AFB aux doses, formulations ou modes d'administration testes, tandis que le traitement a la tylosine s'est montre tres efficace.

The detection of Melissococcus pluton in honey bees (Apis mellifera) and their products using a hemi-nested PCR

Abstract: A hemi-nested polymerase chain reaction (PCR) was further developed for the detection of Melissococcus pluton in adult bees and honey bee products. A chloroform:isoamyl alcohol DNA extraction method was used to provide template from 154 samples of adult bee tissues, honey, pollen, whole larvae and comb cells. All 36 honey bee samples tested from a diseased colony were shown to contain M. pluton and sub-clinical infections were detected in adult bee tissues, larvae and honey (49/98; 50.0%) collected from all 9 healthy colonies from areas where EFB was endemic. All 20 adult bee tissue samples from a healthy colony from Western Australia where EFB has never been reported were negative. Of 80 bulk honey samples from six Australian states, 55 of 80 (68.8%) samples were shown to contain M. pluton whereas culture techniques detected M. pluton in 22 of 80 (27.5%) of these samples. M. pluton was detected in honey from all Australian states except Western Australia. polymerase chain reaction / Melissococcus pluton / european foulbrood / honey bees / Australia

Protein content and pattern during mucus gland maturation and its ecdysteroid control in honey bee drones

Abstract: We analyzed mucus gland protein content and pattern for drones of Africanized honey bees. The effect of exogenous ecdysteroids on mucus gland maturation was judged against the endogenous ecdysteroid titer. During the first 5 days of adult life, the mucus protein content increases steeply, whereas the protein pattern becomes reduced in complexity. Subsequently, the protein content decreases, reaching a plateau level at day 8. The protein pattern of mature glands is characterized by three dominant polypeptides. Injection of 20-hydroxyecdysone into newly emerged drones abolished the normal increase in protein content and prolonged the persistence of the protein pattern typical for immature glands. Ecdysteroids thus appear to act as negative regulators in the maturation process of drone mucus glands. This hypothesis received support from analyses of the hemolymph ecdysteroid titer, which was found to rapidly decline soon after emergence. male accessory gland / ecdysone / radioimmunoassay / Apis mellifera / mucus protein

Determination of oxalic acid and other organic acids in honey and in some anatomic structures of bees

Abstract: The use of two ion-exclusion columns coupled in series allows the liquid chromatographic determination of the oxalic acid content in honey and in some anatomic structures of bees, and avoids interference from other components of the matrix. To obtain a profile of organic acids, it is advisable to couple of four columns in series. The oxalic acid concentration in the rectum, Malpighian tubules, digestive tract and haemolymph is strongly influenced by the application mode (topical or oral). Results obtained demonstrate that in topical administration oxalic acid penetrates through the keratin. ion exclusion chromatography / oxalic acid / organic acids / honey / honeybee

Comparison of propolis from Apis mellifera and Tetragonisca angustula

Abstract: Dans cette etude la chromatographie en phase gazeuse a haute temperature et haute resolution couplee a la spectrometrie de masse (HT-HRGC-MS) a ete appliquee a l'etude chimique de la propolis recoltee dans la meme zone geographique par l'Abeille domestique Apis mellifera L. et l'abeille sans dard Tetragonisca angustula Illiger (Apidae, Meliponinae). Au total 64 composes ont ete caracterises et les rendements d'extraction ont ete similaires pour les deux types de propolis (Tab. I). Les chromatogrammes des extraits au dichloromethane des deux propolis sont pratiquement semblables (Fig. 1), suggerant que les abeilles butinent les exsudats sur la meme flore disponible. Les echantillons de propolis presentent une activite antimicrobienne (Tab. III) et une composition semblables, a l'exception des acides amines, de quelques sucres et de poliols). La diversite des plantes butinees par les abeilles fournit dans les deux types echantillons de propolis analyses une predominance de triterpenes, principalement le lupeole et le lupenone, qui representent plus de 35 % de l'extrait total (Tab. II).

Controlling European foulbrood with the shook swarm method and oxytetracycline in the UK

Abstract: Colonies infected with European foulbrood (EFB) were treated with the shook swarm method in combination with oxytetracycline (OTC) and compared with those treated with OTC alone, the usual treatment for EFB in England and Wales. Success rates and instances of recurrence in the following season were recorded in the seasons 2000 and 2001 respectively. Both treatments had similar success rates with respect to elimination of EFB in 2000. Shook swarm plus OTC treatment resulted in a lower level of EFB recurrence in the 2001 season than OTC treatment alone. Colonies treated with the shook swarm plus OTC method showed a recurrence rate of 4.8%, whereas those treated with OTC alone had a recurrence in 21.1% of cases. The differences were shown to be significant at the 10% level. These results suggest that the shook swarm plus OTC method could be a valid method for EFB treatment and control in the UK. European foulbrood / shook swarm / oxytetracycline / disease control / alternative method

Morphological characterization of Apis cerana in the Yunnan Province of China

Abstract: Morphological features of Apis cerana Fabr. in Yunnan Province of China were studied using morphometrical methods. Samples of A. cerana were collected from feral colonies in 14 locations of Yunnan Province, covering the main ecological regions. 38 standard morphometric characters recommended by Ruttner et al. (Apidologie 9, 363-381, 1978) were measured. The data were statistically analysed by factor analysis, discriminant analysis, and cluster analysis and compared to samples from the Oberursel data bank from Beijing, Japan, Korea, Thailand, India, Burma, Vietnam, and Nepal. The results showed a high degree of variation, which correlated to geographical parameters. Bees from the northern high-altitude areas were clearly larger and darker, and showed similarity to data bank samples from Beijing, Nepal, or northern India, whereas bees from lower, southern areas clustered with bees from Thailand and Vietnam. Apis cerana / Yunnan / China / morphometry / biogeography

Tracking an invasive honey bee pest: mitochondrial DNA variation in North American small hive beetles

Abstract: Le Petit Coleoptere des ruches (PCR), Aethina tumida Murray (Coleoptera, Nitidulidae), se nourrit de pollen et de miel et detruit les rayons des colonies d'abeilles domestiques (Apis mellifera L.). Ces PCRs, originaires d'Afrique, ont ete trouves pour la premiere fois aux Etats-Unis en 1996. En six ans ils se sont repandus dans au moins 25 etats des Etats-Unis, provoquant des pertes de colonies dans toute la region du sud-est. Dans ce travail nous avons utilise la variation du gene mitochondrial COI pour decrire les populations de PCRs. Les sequences de l'ADN mitochondrial placent les populations de PCRs des Etats-Unis au sein d'un clade de coleopteres d'Afrique du Sud. Il est interessant de noter que deux haplotypes distincts existent aux Etats-Unis. Une recolte de 539 PCRs dans 26 ruchers repartis en Floride, Georgie, Caroline du Nord et du Sud (Tab. I) a montre des repartitions irregulieres de ces deux haplotypes dans la region du sud est des Etats-Unis. Les PCRs des premieres recoltes faites en Caroline du Sud presentaient une frequence elevee de l'haplotype NA1, haplotype generalement rare en Floride et en Georgie et absent de l'echantillon de Caroline du Nord. Les recoltes recentes en Caroline du Sud ressemblent plus a celles des autres etats. La taille corporelle des PCRs n'est pas correlee a l'haplotype (Tab. II), ce qui suggere que la frequence des haplotypes ne reflete pas les pressions de selection sur les differences covariantes dans les genomes de ces PCRs. Nous discutons des implications qu'ont ces resultats dans les problemes suivants : deduction du nombre d'introductions separees de ces PCRs aux Etats-Unis, identification de nouvelles introductions et estimation de la dynamique de migration des PCRs au fur et a mesure qu'il etendent leur aire de repartition dans le Nouveau Monde. Les haplotypes des coleopteres des ruches aux Etats-Unis indiquent, soit deux introductions separees soit des effets de derive suivis d'une dispersion extremement limitee.

Susceptibility of Apis mellifera (Hymenoptera: Apidae) to pellitorine, an amide isolated from Piper tuberculatum (Piperaceae)

Abstract: The acute toxicity of pellitorine, an amide isolated from Piper tuberculatum (Piperaceae) which is studied as a biopesticide in European corner borer, was evaluated on larvae and newly emerged adults of honeybee Apis mellifera by means of contact and ingestion bioassays. Workers in the larval and adult phase were separated in groups, which received pellitorine in different concentrations. The larvae were maintained in their own original cells, receiving feeding and normal care from the nurses. The adults were confined in wooden cages with screens, receiving artificial diet made up of sugar and water (1:1). The concentrations of 40, 200, 1 000, 5 000 and 25 000 ng a.i./individual were obtained diluting pellitorine in 98% ethanol. LD10 values of 39.14, 36.16 and 13.79 ng a.i./insect were determined for larvae, for adults by ingestion and adults by contact, respectively. The honeybee larvae were shown to be highly susceptible to the amide pellitorine. Apis mellifera / toxicity / contact / ingestion / pellitorine / biopesticide

Antennal glands in male bees: structures for sexual communication by pheromones?

Abstract: Morphological investigations were conducted on male antennae of three Apidae species, Apis mellifera, Bombus pascuorum and Xylocopa violacea. Male antennal glands were present in all species, with some differences regarding both external morphological characters and internal cytological features. There are externally obvious sites of pheromonal release (provided with evident pores) in B. pascuorum and X. violacea males, while pores are lacking in A. mellifera males. Internally A. mellifera presents a glandular complex composed of class 1 secretory cells, while the two other species possess two types of glands (with class 1 and class 3 secretory cells) associated with the same release sites. The functional hypothesis for the secretion of these glands is that they may act as a sex pheromone during courtship behaviour. Apis / Bombus / Xylocopa / gland / ultrastructure / sex recognition