Table 1.
Summary of 73 pesticides detected in corbicular pollen loads of honeybees at three distinct agricultural production sites in South Germany during 2012–2016.
Fig 1.
Frequency of contaminated pollen trap samples (n = 281) separated for each site overall years.
“Meadow” and “grain” were sampled from 2012–2016, “fruit” was sampled 2012–2014.
Table 2.
Summary of main pesticide residue results of honeybee collected pollen loads for each site and year.
Table 3.
Honeybee risk exposure to pesticide groups as expressed by PHQ.
PHQ values of single detections in the same sample of the same pesticide group were added (mean ± SEM). One-way-ANOVA, followed by a pairwise Student t-test at α = 0.05.
Fig 2.
Number of pollen samples for each site and year that exceed maximum residue limits for apicultural products (MRL, μg/kg) for at least one pesticide per sample.
“Meadow” and “grain” were sampled from 2012–2016, “fruit” was sampled 2012–2014.
Fig 3.
Box-and-whisker-plot of the range of concentrations (μg/kg) of pesticides being identified in at least 8 sub-fractions of the composite sample (06.06.2013) of “fruit” site.
Extreme concentrations exceeding 120 μg/kg: azoxystrobin 567.8 μg/kg, boscalid 207.5 μg/kg, cyprodinil 452.3 μg/kg, fenhexamid 4,452.4 μg/kg, tebuconazole 2,589.3 μg/kg, trifloxystrobin 589.4 μg/kg. Circles and stars indicate outliers.
Fig 4.
Comparison of the concentrations of the same pesticides detected in the composite sample of 03.05.2012 of “fruit” site and in the sub-fraction Brassicae sp. of the same sample.
Fig 5.
Comparison of the concentrations of the same pesticides detected in the composite sample of 14.06.2012 of “fruit” site and in the sub-fraction V. vinifera of the same sample.
Dimethomorph has an extreme value with 3,747.70 μg/kg in the sub-fraction.
Fig 6.
Comparison of the concentrations of the same pesticides detected in the composite sample of 28.05.2012 of “fruit” site and in the sub-fraction Achillea of the same sample.