Table 1 Clothianidin residues in honeybees, pollen and nectar during 2013–2014

From: Clothianidin seed-treatment has no detectable negative impact on honeybee colonies and their pathogens

  Control fieldsa Treated fieldsb
  Rangec Mean ± s.e.m.c Rangec Mean ± s.e.m.c Z d P d n (T, C)e
2013
Honeybees <LOD-0.89 0.13 ± 0.11 0.35–4.90 2.4 ± 0.50 −3.29 0.001 8/8
Pollen <LOD <LOD 6.60–23.00 13.9 ± 1.80 −3.16 0.002 6*/8
Nectar <LOD-0.61 0.11 ± 0.08 6.70–16.00 10.30 ± 1.30 −3.40 < 0.001 8/8
2014
Honeybees <LOD <LOD 0.15–1.50 1.10 ± 0.20 −2.53 0.011 4/6
Pollen <LOD <LOD 2.40–16.00 6.10 ± 2.00 −2.53 0.011 4/6
Nectar <LOD <LOD 2.60–9.80 4.90 ± 1.10 −2.53 0.011 4/6
  1. aSample size: 2013, n = 8; 2014, n = 4. No honeybees with pollen could be found at two of the control fields
  2. bSample size: 2013, n  =  8; 2014, n =  6
  3. cConcentrations of clothianidin in honeybees (ng g−1) and in pollen (ng g−1) and nectar (ng ml−1) sampled from foraging honeybees in clothianidin-treated oilseed rape fields (T) and control fields (C) during 2013–2014
  4. dWilcoxon test for differences between treatments. P values < 0.05 are highlighted in bold
  5. eSample size, T clothianidin-treated oilseed rape fields, C control fields, LOD limit of detection