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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. [ABSTRACT FROM AUTHOR]

The parasitic mite Varroa destructor Anderson&Trueman (Acari: Varroidae) is the most detrimental pest of the honeybee Apis mellifera. Adult female mites are phoreticand feed on adult worker and drone bees. They leave their adult hosts to invade brood cells occupied by mature bee larvae just before worker bees seal the cells with wax. Colonies infested by V. Destructor will eventually suffer delete rious effects. It is observed that the honey bee brood exhibit typical damage symptoms, such as scattered brood nest and crippled bees when the varroosis is at later stage of development. The aim of this work was to evaluate the brood symptoms in correlation with mite detection on adult bees and on sticky boards. We compared three groups of eight colonies. Different modalities were applied to the groups: untreated group (control), Apivar®-treated group, and over-treated group. Four complete visits occurred between October 2009 and April 2010. At each visit, adult bees were sample from each colony. Varroa were dislodged from bees by washing the bees with alcohol. Honeybee population was evaluated on each colony frame. Symptoms on brood and on adult bees were recorded. Varroas were counted on sticky boards every two weeks to look at the natural fall for the control group or falls due to acaricide treatments for the two other groups. [ABSTRACT FROM AUTHOR]

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.

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., (Copyright (c) 2005 Society of Chemical Industry.)