Table 2. Summary of main pesticide residue results of honeybee collected pollen loads for each site and year.
| Meadowa) | grain | fruit a) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Years | 2012 | 2013 | 2014 | 2015 | 2016 | 2012 | 2013 | 2014 | 2015 | 2016 | 2012 | 2013 | 2014 |
| Sampling dates | 02.04.-07.06. | 01.05.-10.08. | 12.04.-05.05. | 21.04.-10.07. | 05.05.-30.07. | 26.03.-30.07. | 18.04.-28.07. | 01.04.-06.07. | 21.04.-21.07. | 19.04.-21.07. | 01.04.-25.06. | 08/09.05.-01/02.08. | 20/21.04.-7/8.06. |
| Nr. analyzed samples (% positive samples) | 16 (50) | 22 (40.9) | 9 (100) | 19 (78.9) | 16 (31.3) | 39 (84.6) | 30 (70) | 20 (80) | 27 (100) | 27 (100) | 24 (100) | 20 (100) | 12 (100) |
| Nr. different pesticides (F/I/H)b) | 7 (6/1/0) | 9 (7/1/1) | 7 (5/1/1) | 8 (6/2/0) | 9 (4/2/3) | 17 (9/4/4) | 14 (9/2/3) | 23 (11/5/7) | 25 (14/5/6) | 18 (12/3/3) | 44 (27/12/5) | 40 (27/10/3) | 34 (26/4/4) |
| Min/max amount of pesticides per sample | 0/2 | 0/7 | 2/5 | 0/6 | 0/5 | 0/8 | 0/7 | 0/11 | 1/10 | 1/9 | 1/18 | 4/20 | 4/16 |
| Range of concentrations (min-max; μg/kg) | 2.3–13.2 | 2.0–294.6 | 2.0–11.1 | 2.0–105.3 | 2.1–19.2 | 2.0–364.3 | 2.2–191.3 | 2.1–871.6 | 2.1–315.6 | 2.0–1,496.4 | 2.0–841.7 | 2.0–7,177.7 | 2.0–6,831.3 |
| min-max tPHQday (n) = times ≥ 50 | 0.00–0.78 | 0.00–46.06 | 0.19–6.85 | 0.00–9.87 | 0.00–0.42 | 0.00–126.50 (2) | 0.00–75.78 (2) | 0.00–107.51 (1) | 0.00–221.99 (1) | 0.00–35.67 | 0.04–534.81 (1 ≥ 500) | 0.20–615.48 (3, 3 ≥ 500) | 0.68–125.89 (6) |
| Month with most pesticide detections (% of annual detections) | May (63.6) | May (96.8) | April (84) | May (45.5) | May (100) | May (46.4) | May (65.1) | April (48.4) | May (51.2) | May (45.8) | June (41.5) | June (39.6) | May (56.9) |
| Substances with the highest concentrations: max. concentration (μg/kg) | trifloxystrobin: 13.2, thiacloprid: 12.3, pencycuron: 4.5 | thiacloprid: 294.6, dimoxystrobin: 161.6, boscalid: 75.9 | fluazifop 11.1, metconazol: 8.9, dimoxystrobin: 7.4 | thiacloprid: 105.3, dimoxystrobin: 93.8, boscalid: 62.6 | fluopyram: 19.2, picaridin: 18.7, prothioconazole-desthio: 8.7 | thiacloprid: 364.3, triadimenol: 72.7, tebuconazole: 50.0 | thiacloprid: 191.3, fluopyram: 134.3, triadimenol: 80.8 | fluazifop: 871.6, thiacloprid: 111.9, fluopyram: 59.7 | picaridin: 315.6, fluroxypyr-methyl: 242.5, thiacloprid: 103.4 | boscalid: 1,496.4, dimoxystrobin: 576.2, picaridin: 412.0 | dimethomorph: 841.7, MCPA: 667,.0 thiacloprid: 470.4 | fenhexamid: 7,177.7, dimethomorph: 2,678.4, iprovalicarb: 974.7 | fluazifop: 6,831.3, cyprodinil: 1,282.6, fludioxonil: 1,085.1 |
| Most frequent pesticides; (n) = times detected per year | thiacloprid (5) | thiacloprid/ fluazifop (each 7), boscalid (4) | metconazol (8), fluazifop (6), thiacloprid (5) | thiacloprid/ cyprodinil (each 9), boscalid (7), prothioconazole-desthio(6) | prothioconazole-desthio (4), fluopyram/ prosulfocarb (each 2) | thiacloprid (25), tebuconazole (17), prothioconazole-desthio (15) | prothioconazole-desthio (16), thiacloprid (14), dimoxystrobin (11) | thiacloprid (13), prothioconazole-desthio (12), fluazifop (11) | prothiconazole-desthio (19), picaridin/ thiacloprid (each 13), pendimethalin/ tebuconazole (each 10) | picaridin (23), prothioconazole-desthio (13), tebuconazole (9) | thiacloprid (21), Boscalid (16), tebuconazole (12) | cyprodinil/ fludioxonil (each 17), thiacloprid (15), boscalid (13) | thiacloprid (10), prosulfocarb (9), fluazifop (8) |
a) Comparison of sites based on the LOD/LOQ as obtained by LUFA Speyer.
b) F = fungicides, I = insecticides, H = herbicides