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The aim of this study was to estimate the incidence of COVID-19 disease in the French national population of dialysis patients, their course of illness and to identify the risk factors associated with mortality. Our study included all patients on dialysis recorded in the French REIN Registry in April 2020. Clinical characteristics at last follow-up and the evolution of COVID-19 illness severity over time were recorded for diagnosed cases (either suspicious clinical symptoms, characteristic signs on the chest scan or a positive reverse transcription polymerase chain reaction) for SARS-CoV-2. A total of 1,621 infected patients were reported on the REIN registry from March 16th, 2020 to May 4th, 2020. Of these, 344 died. The prevalence of COVID-19 patients varied from less than 1% to 10% between regions. The probability of being a case was higher in males, patients with diabetes, those in need of assistance for transfer or treated at a self-care unit. Dialysis at home was associated with a lower probability of being infected as was being a smoker, a former smoker, having an active malignancy, or peripheral vascular disease. Mortality in diagnosed cases (21%) was associated with the same causes as in the general population. Higher age, hypoalbuminemia and the presence of an ischemic heart disease were statistically independently associated with a higher risk of death. Being treated at a selfcare unit was associated with a lower risk. Thus, our study showed a relatively low frequency of COVID-19 among dialysis patients contrary to what might have been assumed., Graphical abstract

SummarySince 1999, European beekeepers have reported increased mortality in overwintering honey bee, Apis mellifera L. colonies. Viral infections are often cited as the potential cause for increased mortality. Many honey bee viruses commonly occur within bee populations and in many cases infected colonies appear asymptomatic. There is increasing evidence that the global spread of Varroa destructor has resulted in a significant change in the prevalence, distribution and/or virulence of viruses causing mortality in honey bee colonies. We report here the first survey of the prevalence of five RNA bee viruses and their effect on overwintering survival of Belgian honey bee colonies. In the autumn of 2006, samples of adult bees were removed from 36 apiaries. Adult bee samples were analyzed by using RT-PCR for virus identification. Varroa mite prevalence in these samples was also quantified. A follow up visit of colonies in the spring permitted us to assess colony survivorship which permitted the effect, if any,...

SummarySeveral cases of mortality of honey bee colonies (varying from 38 to 100%) were observed in France during the winter of 2005–6. In order to explain the causes of these mortalities, a case control study was conducted on a limited area, together with a larger survey in 18 other apiaries located in 13 sites over the entire country. Both studies included diagnosis of the main honey bee diseases, assessment of the colony management measures taken by beekeepers and the determination of pesticide residues in apicultural matrices. Pollen analysis was carried out on beebread samples to identify which floral species were used for forage before colony death. Poor Varroa destructor treatments together with Nosema disease and brood diseases were frequent in apiaries with high colony mortalities. The absence of any preventive treatment against V. destructorwas the main risk factor.

A field survey was conducted between 2002 and 2005 to study honey bee colony health under beekeeping conditions. Five colonies were randomly selected in each of 24 apiaries (i.e. 120 colonies). Fou...

International audience; A 3-yr field survey was carried out in France, from 2002 to 2005, to study honey bee (Apis mellifera L.) colony health in relation to pesticide residues found in the colonies. This study was motivated by recent massive losses of honey bee colonies, and our objective was to examine the possible relationship between low levels of pesticide residues in apicultural matrices (honey, pollen collected by honey bees, beeswax) and colony health as measured by colony mortality and adult and brood population abundance. When all apicultural matrices were pooled together, the number of pesticide residue detected per sampling period (four sampling periods per year) and per apiary ranged from 0 to 9, with the most frequent being two (29.6%). No pesticide residues were detected during 12.7% of the sampling periods. Residues of imidacloprid and 6- chloronicotinic acid were the most frequently detected in pollen loads, honey, and honey bee matrices. Several pairs of active ingredients were present concurrently within honey bees and in pollen loads but not in beeswax and honey samples. No statistical relationship was found between colony mortality and pesticide residues. When pesticide residues from all matrices were pooled together, a mixed model analysis did not show a significant relationship between the presence of pesticide residues and the abundance of brood and adults, and no statistical relationship was found between colony mortality and pesticide residues. Thus, although certain pesticide residues were detected in apicultural matrices and occasionally with another pesticide residual, more work is needed to determine the role these residues play in affecting colony health.

International audience; Detection of Chronic bee paralysis virus (CBPV) is reported for the first time in two species of ants (Camponotus vagus and Formica rufa) and in Varroa destructor. A quantitative real-time PCR (qPCR) method was used to detect and quantify CBPV in infected bees, ants and mites. A minus-strand-specific RT-PCR was used to assess viral replication. These results suggest a new way by which the infection may be spread and other sites of viral persistence in the close apiary environment.

Varroosis and others honey bee diseases : major causes for colony mortality in France Various investigations carried out in France since 1987 have shown the correlation between winter mortality and diseases in bees. In 2008, very high mortality rates are back despite the removal from the market of the systemic insecticides Gaucho NT and Regent NT. The overall clinical picture observed in the colonies has not changed since the late 80s. The syndrome includes a small cluster of dead bees in the upper part of the frames, large quantities of honey, and often of bee bread. Laboratory examinations show the presence of Varroa destructor, viruses and concomitant diseases such as nosemosis. The most important treatment period to minimize winter mortality is the very beginning of autumn, when effective acaricidal treatments must be carried out. Information and training of beekeepers play a crucial role and must be implemented as soon as possible., Différentes enquêtes réalisées en France depuis 1987 ont montré une corrélation entre la mortalité hivernale et les maladies des abeilles. En 2008, les taux de mortalité sont de nouveau très importants malgré la suppression des insecticides systémiques GauchoNT et RégentNT. Les symptômes rencontrés dans les colonies, et qui ont très peu évolué au cours du temps, sont principalement une petite grappe d’abeilles mortes à la partie supérieure des cadres, de fortes réserves de miel et souvent de pain d’abeille. Les analyses de laboratoire mettent en évidence la présence de Varroa destructor, de virus et de maladies concourantes comme la nosémose. La période la plus importante à prendre en compte, afin de minimiser le risque de mortalité hivernale, est le tout début de l’automne, période où des traitements acaricides efficaces doivent être appliqués. L’information et la formation des apiculteurs sont primordiales et doivent être mises en place le plus rapidement possible., Faucon Jean-Paul, Chauzat Marie-Pierre. Varroase et autres maladies des abeilles : causes majeures de mortalité des colonies en France. In: Bulletin de l'Académie Vétérinaire de France tome 161 n°3, 2008. pp. 257-263.

Acaricide residues were assessed in French commercial beeswax using newly developed liquid and gas chromatography methods. Most of the commercial wax samples and all samples taken during the industrial recycling process contained coumaphos and fluvalinate. Amitraz and coumaphos residue levels were also followed in several hives experimentally treated with Asuntol®50 or Apivar®, two products used in France to control varroa infestation. After the Asuntol®50 treatment, coumaphos residues increased in honey and wax combs, persisted more than 30 days in honey and one year or more in comb wax. The half-life of coumaphos was 69 and 115–346 days in honey and comb wax respectively. Following Apivar® treatment, amitraz was not detected in honey nor in wax. These results are consistent with and complete other studies: the use of coumaphos entails wax contamination which persists through commercial recycling. As this may be a threat for bee health, the use of Asuntol®50 should be avoided.

International audience; Dialysis patients exhibit an inverse, L- or U-shaped association between blood pressure and mortality risk, in contrast to the linear association in the general population. We prospectively studied 9333 hemodialysis patients in France, aiming to analyze associations between predialysis systolic, diastolic, and pulse pressure with all-cause mortality, cardiovascular mortality, and nonfatal cardiovascular endpoints for a median follow-up of 548 days. Blood pressure components were tested against outcomes in time-varying covariate linear and fractional polynomial Cox models. Changes throughout follow-up were analyzed with a joint model including both the time-varying covariate of sequential blood pressure and its slope over time. A U-shaped association of systolic blood pressure was found with all-cause mortality and of both systolic and diastolic blood pressure with cardiovascular mortality. There was an L-shaped association of diastolic blood pressure with all-cause mortality. The lowest hazard ratio of all-cause mortality was observed for a systolic blood pressure of 165 mm Hg, and of cardiovascular mortality for systolic/diastolic pressures of 157/90 mm Hg, substantially higher than currently recommended values for the general population. The 95% lower confidence interval was approximately 135/70 mm Hg. We found no significant correlation for either systolic, diastolic, or pulse pressure with myocardial infarction or nontraumatic amputations, but there were significant positive associations between systolic and pulse pressure with stroke (per 10-mm Hg increase: hazard ratios 1.15, 95% confidence interval 1.07 and 1.23; and 1.20, 1.11 and 1.31, respectively). Thus, whereas high pre-dialysis blood pressure is associated with stroke risk, low pre-dialysis blood pressure may be both harmful and a proxy for comorbid conditions leading to premature death.

Fipronil is a pesticide suspected of having harmful effects on honey bees at microgram per kilogram levels. Considering the lack of methodology, it thus appeared to be necessary to develop a method for the determination of the lowest amounts of fipronil and its metabolites in pollen. This paper describes a new analytical method with a limit of quantification (LOQ) of 0.1 microg/kg for a representative sample weight of 5 g. In the case of a field study, this tool was used for checking the possible existence of fipronil and/or metabolites in pollen samples, but none of them contained residues higher than the LOQ. This three-step rapid method uses liquid-solid solvent extraction with mechanical grinding, followed by liquid-liquid partitioning and Florisil solid-phase extraction for the two cleanup steps. The quantification is made by liquid chromatography with electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Indeed, combined with an adequate sample treatment, this technique offers good sensitivity and selectivity in such a complex matrix. The method has given good recoveries of 74-104% with relative standard deviations of 5.6-18.2%.

In 2002, a field survey was initiated on French apiaries to monitor weakness of honey bee, Apis mellifera L., colonies. Apiaries were evenly distributed in five sites located on continental France. Five colonies were randomly selected in each apiary, leading to a total of 125 studied honey bee colonies. For 3 yr (starting in autumn 2002), colonies were visited four times per year: after winter, before summer, during summer, and before winter. Pollen loads from traps were collected at each visit. Multiresidue analyses were performed in pollen to search residues of 36 different molecules. Specific analyses were conducted to search fipronil and metabolites and also imidacloprid and metabolites. Residues of 19 searched compounds were found in samples. Contamination by pesticides ranged from 50 to 0%. Coumaphos and tau-fluvalinate residues were the most concentrated of all residues (mean concentrations were 925.0 and 487.2 microg/kg, respectively). Fipronil and metabolite contents were superior to the limit of detection in 16 samples. Residues of fipronil were found in 10 samples. Nine samples contained the sulfone compound, and three samples contained the desulfinyl compound. Residues of imidacloprid and 6-chloronicotinic acid were found in 69% of samples. Imidacloprid contents were quantified in 11 samples with values ranging from 1.1 to 5.7 microg/kg. 6-Chloronicotinic acid content was superior to the limit of quantification in 28 samples with values ranging from 0.6 to 9.3 microg/kg. Statistical tests showed no difference between places of sampling with the exception of fipronil. Possible origins of these contaminations, concentration and toxicity of pesticides, and the possible consequences for bees are discussed.

Two groups of eight honey bee colonies were fed with two different concentrations of imidacloprid in saccharose syrup during summer (each colony was given 1 litre of saccharose syrup containing 0.5 microg litre(-1) or 5 microg litre(-1) of imidacloprid on 13 occasions). Their development and survival were followed in parallel with control hives (unfed or fed with saccharose syrup) until the end of the following winter. The parameters followed were: adult bee activity (number of bee entering the hive and pollen carrying activity), adult bee population level, capped brood area, frequency of parasitic and other diseases, mortality, number of frames with brood after wintering and a global score of colonies after wintering. The only parameters linked to feeding with imidacloprid-supplemented saccharose syrup when compared with feeding with non-supplemented syrup were: a statistically non-significant higher activity index of adult bees, a significantly higher frequency of pollen carrying during the feeding period and a larger number of capped brood cells. When imidacloprid was no longer applied, activity and pollen carrying were re-established at a similar level for all groups. Repeated feeding with syrup supplemented with imidacloprid did not provoke any immediate or any delayed mortality before, during or following the next winter, whereas such severe effects are described by several French bee keepers as a consequence of imidacloprid use for seed dressing in neighbouring cultures. In any case, during the whole study, mortality was very low in all groups, with no difference between imidacloprid-fed and control colonies. Further research should now address several hypotheses: the troubles described by bee keepers have causes other than imidacloprid; if such troubles are really due to this insecticide, they may only be observed either when bees consume contaminated pollen, when no other sources of food are available, in the presence of synergic factors (that still need to be identified), with some particular races of bees or when colonies are not strong and healthy.

The thermal behaviour of authentic honeys and sugar syrups (industrial and homemade) was investigated by DSC. To confirm the first previous results concerning the effect of adulteration on the thermal behaviour of authentic honeys, 30 honey samples (Robinia, Lavender, Chestnut and Fir) were analyzed by DSC and their Tg were measured following a suited experimental protocol. The results indicated that this parameter was useful to characterize and to distinguish significantly these varieties between them. Applied to honey samples artificially adulterated with different industrial syrups, DSC showed a detection level of 5–10% depending on the type of syrup. An endothermic phenomenon occurring between 40–90°C during the heating was studied by TMDSC and a new thermal transition similar to a glass-transition was highlighted.

(E)-10-hydroxydec-2-enoic acid (10-HDA) is the main fatty acid present in royal jelly (RJ). Among the criteria for royal jelly quality analysis, 10-HDA content has been proposed as a freshness parameter. In this study, 10-HDA content variations under controlled temperature storage, were evaluated as an aging indicator of RJ samples from two origins (France and Thailand). For a 12 month period, the 10-HDA content loss rates were 0.1 and 0.2% at −18 °C and 4 °C, respectively, whatever the sample origin. At room temperature storage, losses were 0.4 and 0.6% for the French sample and the Thai sample, respectively. No correlation was found between 10-HDA content and storage duration whatever the storage temperature. Even if 10-HDA is specific to RJ, new criteria should be found to estimate the condition and duration of storage for royal jelly samples.

Gravimetric lipid determination is a major parameter for the characterization and the authentication of royal jelly quality. A solid/liquid extraction was compared to the reference method, which is based on liquid/liquid extraction. The amount of royal jelly and the time of the extraction were optimized in comparison to the reference method. Boiling/rinsing ratio and spread of royal jelly onto the extraction thimble were identified as critical parameters, resulting in good accuracy and precision for the alternative method. Comparison of reproducibility and repeatability of both methods associated with gas chromatographic analysis of the composition of the extracted lipids showed no differences between the two methods. As the intra-laboratory validation tests were comparable to the reference method, while offering rapidity and a decrease in amount of solvent used, it was concluded that the proposed method should be used with no modification of quality criteria and norms established for royal jelly characterization.

(2010). A case report of a honey bee colony poisoning incident in France. Journal of Apicultural Research: Vol. 49, Honey bee colony losses, pp. 113-115.

International audience; Chronic paralysis of honey bees is a viral disease caused by chronic paralysis virus (CPV). As its clinical signs are similar to those observed in intoxications or during intense work, it requires sensitive and specific diagnostic tests to identify the infection in colonies. In this report, a rabbit polyclonal antiserum against CPV was obtained after purification of the virus in a Renografin gradient. The viral polypeptide composition was analysed by SDS-PAGE and Western blotting. Four viral-associated polypeptides of molecular weights 75 kDa, 50 kDa, 30 kDa and 20 kDa were identified. Western blotting and an agar gel immunodiffusion test were used for the diagnosis of CPV during a field survey of the prevalence of CPV infection. The two tests demonstrated the presence of the virus in several colonies in the south-east of France.; Détection des infections par le virus de la paralysie chronique de l'abeille domestique (Apis mellifera L.) : application lors d'une enquête de terrain. Le virus de la paralysie chronique (CPV) a été l'un des premiers virus isolés chez l'abeille domestique [3]. Le CPV est responsable d'une maladie infectieuse et contagieuse des abeilles adultes, la paralysie chronique de l'abeille connue par les apiculteurs français sous le nom de "Maladie noire "[16]. à l'origine de mortalités, cette pathologie affaiblit les colonies et provoque des pertes de production. Elle se manifeste au niveau de la colonie par la présence d'abeilles traînantes, tremblantes, incapables de voler et dans certains cas d'abeilles mortes, noires et aux ailes écartées. La recrudescence de symptômes imputables à cette virose dans le sud-est de la France a motivé la reprise des recherches sur ce sujet. Cependant, l'ensemble de ces symptômes peut être confondu avec ceux d'intoxications aiguës ou chroniques par des pesticides ou d'un surmenage de la ruche particulièrement durant les périodes estivales. Le diagnostic de la paralysie chronique par reproduction expérimentale de la maladie [16], n'est pas envisageable en routine. Dans le but de déterminer l'importance des infections par le CPV dans les pertes observées à l'heure actuelle, il est apparu nécessaire de mettre au point des techniques d'étude et de diagnostic plus sensibles. Afin de sélectionner des abeilles naturellement infectées, des prélèvements d'abeilles présentant les symptômes de la paralysie chronique ont été testés (i) par infection expérimentale, afin de reproduire les symptômes et les mortalités caractéristiques de la maladie, (ii) par diagnostic en immunodiffusion en gélose (IDG) utilisant un sérum anti-CPV. Le CPV a ensuite été multiplié par inoculation à des abeilles saines par voie intra-thoracique de préparations issues de ces abeilles contaminées, à la dilution causant 100 % de mortalité une semaine après injection, comme décrit par Bailey et Woods [8, 9]. Le virus a été purifié sur gradient de Rénografine (Fig. 1) et ceci a permis la production d'un antisérum polyclonal de lapin anti-CPV. La composition polypeptidique de cette purification virale a été analysée en SDS-PAGE (Fig. 2B) et en Western blot. Quatre polypeptides associés à l'infection virale et de poids moléculaires 75 kDa, 50 kDa, 30 kDa et 20 kDa ont été identifiés (Fig. 3). Un diagnostic simple de détection du CPV par immunodiffusion en gélose (IDG) a ensuite été mis au point (Fig. 5) et comparé avec la technique de Western blot comme référence (Fig. 4). Lors de tests sur des abeilles infectées expérimentalement ces deux techniques ont permis de détecter la présence du CPV depuis le premier jour post inoculation avant même l'apparition des symptômes, jusqu'au sixième jour correspondant à la mort des abeilles. Une enquête de terrain utilisant ces deux tests diagnostics (Tab. I), a été réalisée afin de déterminer la prévalence du CPV, et a démontré la présence du virus dans six ruchers sur les onze compris dans l'étude qui présentaient tous des symptômes attribuables à la paralysie chronique.

International audience; Bee samples were collected in French apiaries that displayed severe losses and mortality during the winter (from November 2007 to March 2008). They were screened for the presence of Israeli acute paralysis virus (IAPV) by using RT-PCR. Five out of 35 surveyed apiaries, located in two different geographical areas, were found positive. This represents the first reported detection of IAPV in France. The specificity of the PCR products was checked by sequencing. The phylogenetic analysis showed that French isolates of IAPV were closely related to a cluster including American and Australian isolates. Nevertheless, most of American isolates previously reported to be associated to Colony Collapse Disorder (CCD) and an Israeli isolate first isolated in 2004 from dead bees were included in another cluster. Since IAPV was detected in only 14% of the affected apiaries, it was not possible to establish a causal link between IAPV and the severe winter losses that occurred.

Background: We examined the hypothesis that mixed-dilution online hemodiafiltration (MIXED) rather than predilution online hemodiafiltration (PRE) could enable patients with low blood flow rate (Qb) to benefit from advantages of convective therapies. Methods: Thirty-eight patients were included in a prospective, randomized, crossover and multicenter study conducted with a view to comparing the equilibrated Kt/V, reduction ratio (RR) of phosphates, β2-microglobulin (β2-M) and myoglobin (myo) between PRE and MIXED, each at two Qb values of 250 and 300 ml/min during 4 h sessions with a FX1000HDF dialyzer. Albumin losses (Alb) were also measured in 12 patients. Results: MIXED was always found to be more efficient compared to PRE notably for middle molecules (MM). RRβ2-M: MIX250: 81.3 ± 3.6 vs. PRE250: 75.2 ± 5.9; MIX300: 82.7 ± 3.6 vs. PRE300: 78.1 ± 5.4; RRmyo: MIX250: 70.2 ± 3.6 vs. PRE250: 42.6 ± 2.6; MIX300: 70.6 ± 3.6 vs. PRE300: 45.7 ± 3.6 and with Alb Conclusion: MIXED allows patients unable to provide sufficiently high Qb to achieve high levels of MM removal.

The frequency of occurrence and relative concentration of 44 pesticides in apicultural (Apis mellifera) matrices collected from five French locations (24 apiaries) were assessed from 2002 to 2005. The number and nature of the pesticides investigated varied with the matrices examined-living honeybees, pollen loads, honey, and beeswax. Pollen loads and beeswax had the highest frequency of pesticide occurrence among the apiary matrices examined in the present study, whereas honey samples had the lowest. The imidacloprid group and the fipronil group were detected in sufficient amounts in all matrices to allow statistical comparisons. Some seasonal variation was shown when residues were identified in pollen loads. Given the results (highest frequency of presence) and practical aspects (easy to collect; matrix with no turnover, unlike with bees that are naturally renewed), pollen loads were the best matrix for assessing the presence of pesticide residues in the environment in our given conditions.

In 2002 a field survey was initiated in French apiaries in order to monitor the health of honey bee colonies (Apis mellifera L.). Studied apiaries were evenly distributed across five sites located in continental France. Beeswax samples were collected once a year over 2 years from a total of 125 honey bee colonies. Multiresidue analyses were performed on these samples in order to identify residues of 16 insecticides and acaricides and two fungicides. Residues of 14 of the searched-for compounds were found in samples. Tau-fluvalinate, coumaphos and endosulfan residues were the most frequently occurring residues (61.9, 52.2 and 23.4% of samples respectively). Coumaphos was found in the highest average quantities (792.6 microg kg(-1)). Residues of cypermethrin, lindane and deltamethrin were found in 21.9, 4.3 and 2.4% of samples respectively. Statistical tests showed no difference between years of sampling, with the exception of the frequency of pyrethroid residues. Beeswax contamination was the result of both in-hive acaricide treatments and, to a much lesser extent, environmental pollution.

International audience; A two-step real-time RT-PCR assay, based on TaqMan technology using a fluorescent probe (FAM-TAMRA) was developed to quantify Chronic bee paralysis virus (CBPV) genome in bee samples. Standard curves obtained from a CBPV control RNA and from a plasmid containing a partial sequence of CBPV showed that this assay provided linear detection over a 7-log range (R(2)>0.99) with a limit of detection of 100 copies, and reliable inter-assay and intra-assay reproducibility. Standardisation including RNA purification and cDNAs synthesis was also validated. The CBPV TaqMan methodology was first evaluated by quantifying the CBPV genomic load in bee samples from an experimental infection obtained by topical application. Up to 1.9 x 10(10) CBPV copies per segment of insect body (head, thorax and abdomen) were revealed whereas a lower CBPV genomic load was detected in dissected organs such as mandibular and hypopharyngeal glands, brain and alimentary canal (up to 7.2 x 10(6) CBPV copies). The CBPV genomic loads in different categories of bees from a hive presenting the trembling symptoms typical of Chronic paralysis were then quantified. Significantly higher CBPV loads were found in guard, symptomatic and dead bees (up to 1.9 x 10(13) CBPV copies) than in forager, drones and house bees (up to 3.4 x 10(6) CBPV copies). The results obtained for symptomatic or dead bees support the correlation between high CBPV genomic load and pathology expression. Moreover, the high CBPV genomic load revealed in guard bees highlights the possible pivotal role played by this category of bees in CBPV infection.

International audience; Tetracyclines are used to control bacterial diseases like European and American foulbrood which may cause severe losses in honey bee population and honey production. This study, using 24 hives randomly distributed into four groups of 6 hives, was performed for measuring the occurrence of tetracycline (TC) residue levels in honey following two types of TC application. Two groups of colonies were treated 3 times with 0.5 g of TC in 1 litre of syrup (group S) or in 10 g of powdered sugar (group P). Six hives of a first control group (group C) fed with untreated syrup were installed at 20 and 45 metres from groups S and P respectively. A second control group (group DC) was disposed 3 km apart. TC residues in honey sampled at different times in all hives and in honey artificially contaminated with TC and stored in the laboratory at 4, 20 and 35°C were analysed by ELISA and HPLC methods. One day after the last application, the mean TC concentration in brood chamber honey was ten times higher in group S (40.7 mg.kg-1) than in group P (4.34 mg.kg-1). After 8 days, TC residues were detected in all hives of group C. After 146 days, the mean TC concentration in harvested honey was 1.54, 0.35, and 0.15 mg.kg-1 for groups S, P and C respectively. The control group C had been contaminated by drifting. In all hives of the group DC, no residues were detected at any time of the study. The honey harvested at day 504 did not contained any detectable TC residues, except in one super from group C (0.026 mg.kg-1). The half-life time of TC in honey from supers was similar in groups C, S and P and equal to 65 days. This duration was twice lower than in honey stored in laboratory in similar conditions : at 35°C in the dark (t1/2 = 121 days). In honey stored at 20°C, TC was quite stable as its half-life time was 242 days. The data from these experiments specify levels of TC residues in honey after a treatment in hives, their persistence and diffusion into the apiary. These results show that the TC must be used with precaution in honey production.

Two groups of eight honey bee colonies were fed with two different concentrations of imidacloprid in saccharose syrup during summer (each colony was given 1 litre of saccharose syrup containing 0.5 microg litre(-1) or 5 microg litre(-1) of imidacloprid on 13 occasions). Their development and survival were followed in parallel with control hives (unfed or fed with saccharose syrup) until the end of the following winter. The parameters followed were: adult bee activity (number of bee entering the hive and pollen carrying activity), adult bee population level, capped brood area, frequency of parasitic and other diseases, mortality, number of frames with brood after wintering and a global score of colonies after wintering. The only parameters linked to feeding with imidacloprid-supplemented saccharose syrup when compared with feeding with non-supplemented syrup were: a statistically non-significant higher activity index of adult bees, a significantly higher frequency of pollen carrying during the feeding period and a larger number of capped brood cells. When imidacloprid was no longer applied, activity and pollen carrying were re-established at a similar level for all groups. Repeated feeding with syrup supplemented with imidacloprid did not provoke any immediate or any delayed mortality before, during or following the next winter, whereas such severe effects are described by several French bee keepers as a consequence of imidacloprid use for seed dressing in neighbouring cultures. In any case, during the whole study, mortality was very low in all groups, with no difference between imidacloprid-fed and control colonies. Further research should now address several hypotheses: the troubles described by bee keepers have causes other than imidacloprid; if such troubles are really due to this insecticide, they may only be observed either when bees consume contaminated pollen, when no other sources of food are available, in the presence of synergic factors (that still need to be identified), with some particular races of bees or when colonies are not strong and healthy.

International audience; Differential scanning calorimetry (DSC) was used to study the thermal behavior of authentic honeys (Lavandula, Robinia, and Fir honeys) and industrial sugar syrups. Thermal or thermochemical parameters such as the glass transition temperature (Tg), enthalpies of fusion (DeltaH(fus)), and heat capacity variation (DeltaC(p)) were measured. The syrups and honeys showed significant differences in thermal phenomena, as well as in their amplitude and position on the temperature scale. Results showed good reproducibility of the method for all samples studied. The effect of adulteration of honey with different amounts of syrup (5, 10, 20, 40, and 60%) was investigated. A linear relationship was found between the percentage of added syrup and the glass transition temperature. A similar relationship was obtained from the enthalpy of fusion results in the temperature range of 40-90 degrees C. Under applied conditions, the effects of adulteration of honeys by industrial syrups appeared to be detectable from a level as low as 5%.

(2007). Presence of Nosema ceranae in French honey bee colonies. Journal of Apicultural Research: Vol. 46, No. 2, pp. 127-128.

A new RT-PCR test was developed for the diagnosis of chronic bee paralysis virus (CBPV) infection. Used in parallel with an experimental infection test, the RT-PCR test was less fas- tidious and allowed the detection of latent CBPV infection in colonies. The new test is based on the fact that clinical CBPV infections (but not latent infections) yield a high viral antigen load that can be easily revealed using the agarose gel immunodiffusion (AGID) test. The combination of the AGID and the RT-PCR tests allowed us to characterise the CBPV status of hives from various apiaries in France as non infected, latently infected or clinically infected. The RT-PCR test proved highly sensi- tive for detecting inapparent infections. It may be a useful tool for studying the epidemiology of the disease.