Influence of the brood rearing temperature on honey bee development and susceptibility to intoxication by pesticides

contribution to session IV Test methodolog

Spring honey bee losses in Italy

Honey bee poisoning incidents and monitoring schemes Background: During last years several cases of bee losses have been reported during the period of corn sowing in different European countries. In Italy an institutional system for bee losses survey does not exist and therefore some Italian regions decided to organise an official network to collect data and analyse dead bee samples. Results: Collected data indicate that the higher number of bee losses events occurred in intensively cultivated flat areas, located in the North of Italy, mainly during or after corn sowing. The chemical analyses of dead bees revealed the presence of three neonicotinoid residues: imidacloprid was found in 25.7% of the sample, thiamethoxam in 2.8%, clothianidin in 25.7%, both imidacloprid and thiamethoxam in 4.7%. The visual examination and the virological analyses excluded pathological causes. Conclusion: The spatial and temporal correlation between hive damages and corn sowing and the presence of residues of active ingredients used for seed dressing (imidacloprid, thiamethoxam and clothianidin) in almost half of the samples confirms the connection between spring mortality and the sowing of corn seed dressed with neonicotinoids. Keywords: honeybee mortality, neonicotinoids, seed dressing, corn sowing, dust dispersion.      

Nectar Flavonol Rhamnosides Are Floral Markers of Acacia (Robinia pseudacacia) Honey

10 pages, 4 tables, 9 figures.With the objective of finding floral markers for the determination of the botanical origin of acacia (robinia) honey, the phytochemicals present in nectar collected from Robinia pseudacacia flowers were analyzed by high-performance liquid chromatography−tandem mass spectrometry. Eight flavonoid glycosides were detected and characterized as kaempferol combinations with rhamnose and hexose. Acacia honey produced in the same location where the nectar was collected contained nectar-derived kaempferol rhamnosides. This is the first time that flavonoid glycosides have been found as honey constituents. Differences in the stability of nectar flavonoids during honey elaboration and ripening in the hive were shown to be due to hydrolytic enzymatic activity and to oxidation probably related to hydrogen peroxide (glucose-oxidase) activity. Acacia honeys contained propolis-derived flavonoid aglycones (468−4348 μg/100 g) and hydroxycinnamic acid derivatives (281−3249 μg/100 g). In addition, nectar-derived kaempferol glycosides were detected in all of the acacia honey samples analyzed (100−800 μg/100 g). These flavonoids were not detected in any of the different honey samples analyzed previously from different floral origins other than acacia. Finding flavonoid glycosides in honey related to floral origin is particularly relevant as it considerably enlarges the number of possible suitable markers to be used for the determination of the floral origin of honeys.This work has been funded by the European Commission, project Beeshop, FOOD CT-2006-022568.Peer reviewe

A scientific note on the determination of oxytetracycline residues in honey by high-performance liquid chromatography with UV detection

(without abstract

Electronic nose and neural network use for the classification of honey

Seventy samples of honey of different geographical and botanical origin were analysed with an electronic nose. The instrument, equipped with 10 Metal Oxide Semiconductor Field Effect Transistors (MOSFET) and 12 Metal Oxide Semiconductor (MOS) sensors, was used to generate a pattern of the volatile compounds present in the honey samples. The sensor responses were evaluated by Principal Component Analysis (PCA) and Artificial Neural Network (ANN). Good results were obtained in the classification of honey samples by using a neural network model based on a multilayer perceptron that learned using a backpropagation algorithm. The methodology is simple, rapid and results suggest that the electronic nose could be a useful tool for the characterisation and control of honey

Acaricide residues in beeswax after conversion to organic beekeeping methods

Beekeepers interested in converting their honey farms to organic management must replace old combs with organic foundations. The experiment described in this paper compares two methods of replacement of old combs, “fast” (5 combs per year) and “slow” (2 combs per year), by measuring the levels of acaricide residues in the newly built combs. Tested acaricides were coumaphos (Perizin and Asuntol), fluvalinate (Apistan), and chlorfenvinphos (Supona). Significant differences between the two replacement groups were observed only for the Apistan group in the third year, confirming high lipophilicity of fluvalinate. The residue levels in the new combs three years after beginning the conversion were significantly lower than initial levels for all products. Direct contamination of the combs was highest in Asuntol-treated hives and lowest in Perizin-treated hives. Residues in honey exceeding EU Maximum Residue Limit were found only in the case of Asuntol

COMPOSITION DE LA FRACTION LIPIDIQUE DE LA GELÉE DE LARVES D'ABEILLES REINES ET OUVRIÈRES (APIS MELLIFERA LIGUSTICA SPINOLA) EN FONCTION DE L'ÂGE DES LARVES

International audienc