Evaluation of pesticide residues in commercial Swiss beeswax collected in 2019 using ultra-high performance liquid chromatographic analysis

Abstract

The aim of this study was to determine residue levels of pesticides in Swiss commercial beeswax. Foundation samples were collected in 2019 from nine commercial manufacturers for analysis of 21 pesticides using ultra-high performance liquid chromatography. Individual samples showed the variability and residue ranges and pooled samples represented the average annual residue values of the Swiss production. In total, 17 pesticides were identified and 13 pesticides were quantified. They included 13 acaricides and/or insecticides, two fungicides as well as a synergist and a repellent. The means calculated from individual samples were similar to the average annual residue values for most tested pesticides. Mean values of 401, 236, 106 and 3 μg·kg−1 were obtained for the beekeeping-associated contaminants coumaphos, tau-fluvalinate, bromopropylate and N-(2,4-Dimethylphenyl)-formamide (DMF; breakdown product of amitraz), respectively. For the other pesticides, the mean values were 203 μg·kg−1 (synergist piperonyl butoxide), 120 μg·kg−1 (repellent N,N-Diethyl-3-methylbenzamide, DEET), 19 μg·kg−1 (chlorfenvinphos) and 4 μg·kg−1 ((E)-fenpyroximate), while the means for acrinathrin, azoxystrobin, bendiocarb, boscalid, chlorpyrifos, flumethrin, permethrin, propoxur and thiacloprid were below the limit of quantification (< LOQ). Individual samples contained from seven to 14 pesticides. The ranges of values for coumaphos and piperonyl butoxide (from 14 to 4270 μg·kg−1; from 6 to 1555 μg·kg−1, respectively) were larger as compared to the ranges of values for DEET and tau-fluvalinate (from < LOQ to 585 μg·kg−1; from 16 to 572 μg·kg−1, respectively). In conclusion, the most prominent contaminants were the pesticides coumaphos and tau-fluvalinate, which are both acaricides with previous authorization for beekeeping in Switzerland, followed by piperonyl butoxide, a synergist to enhance the effect of insecticides. Graphical abstract

Pesticide contamination of beeswax from managed honey bee colonies in New York State

“…36 Several insecticides (bendiocarb, mevinphos, methiocarb) and herbicides (methoprotryne) are not currently in use in the United States, and the insecticide chlorpyrifos is no longer in use in NYS. 25,30,34,42,45 Bromuconazole is a fungicide used primarily on ornamental plants, which may limit its exposure to colonies in our study. 49 Use of the fungicides triadimefon and tetraconazole on food crops has been restricted in the United States, and tetraconazole is further restricted from use in NYS.…”

“…These were the 3 most common pesticides (and metabolites) found in commercial beeswax collected from Swiss apiaries. 21,25 The detection of coumaphos-resistant Varroa mites in the eastern United States has led to reduced use of coumaphos, thus the reduced amount found in NYS wax was expected, although coumaphos residues are known to persist in wax. 6,19,32,53 Piperonyl butoxide was the chemical that we found most commonly.…”

The role of the veterinary diagnostic toxicologist in apiary health

“…Piperonyl butoxide Used with insecticides and other pesticides Log K ow = 4.8 60 Detected in beeswax, 38,81,88,95,112 honey bees, and pollen 138 AChEIs = acetylcholinesterase inhibitors.…”

Quantitation of pesticides in bee bread collected from honey bee colonies in an agricultural environment in Switzerland

“…Many studies have reported pesticide contamination of bee products (Beyer et al, 2018 ; Bokšová et al, 2021 ; Daniele et al, 2018 ; Orantes-Bermejo et al, 2015 ). Pesticides are frequently found in pollen (e.g., Friedle et al, 2021 ), beeswax (e.g., Marti et al, 2022 ; Wilmart et al, 2021 ), or honey (e.g., Souza Tette et al, 2016 ). Within the various hive compartments, lipophilic pesticides with a high logarithmic octanol-water partition coefficient tend to accumulate in beeswax.…”