I

ANNO 3 Numero 1
Cecilia Costa, Marco Lodesani, Giorgia Serra, Roberto Colombo [1]

Monitoring of acaricide residues in Italian beeswax

[1] CRA - Istituto Nazionale di Apicoltura , Bologna, Italy

Corresponding author: ccosta@inapicoltura.org

Due to the lipophilic nature of acaricides, beeswax is the ideal medium for indicating use of chemical ingredients. Samples of Italian beeswax produced between 1990 and 2004 were analysed for residues of acaricides used in beekeeping over the past 10-15 years. From the year 2000 the analyses were carried out by the certified laboratory of the National Institute of Apiculture.

The active ingredient with the highest level of residues in wax was found to be coumaphos, followed by fluvalinate, and to a far lesser degree by clorphenvinphos. The levels of residues of all the active ingredients decreased during the considered time period. Over the years residues of coumaphos declined from an average of 2,490 ppb (1,153 s.e.) in the samples from 1990-1997 to 168 ppb (842 s.e.) in the samples from 2004. Fluvalinate residues declined from an average of 1,587 ppb (908 sd) in the years 1990-1997 to 59 ppb (611 s.e.) in 2004.

The samples analysed for the two most commonly used active ingredients, coumaphos and fluvalinate, were classified according to the production method (organic, traditional or converting) and according to the kind of wax (melted or foundation). The first classification showed the differential decrease of coumaphos and fluvalinate residues in organic beekeeping (-87% and -65% respectively). The percentages of positive samples however do not decrease in the organic samples. Based on this data most Control Bodies fixed residue thresholds for use of wax in organic beekeeping (200 ppb for coumaphos and 100 ppb for fluvalinate).

The classification according to the kind of wax showed that for both active ingredients there is an inverted situation: in the “traditional” samples residue levels were higher in foundation wax compared to melted wax, whereas in the “organic” samples residue levels were higher in melted wax than in foundations. This phenomenon is probably due to the kind of knowledge needed by the organic beekeepers and wax transformation firms, who therefore send selected samples to be analysed.

The reported data shows how levels of residues have generally decreased over the years, especially in the beekeeping firms which converted to the organic production methods.