Fig 1. Effects on respiration.

Individual bumblebee respiration was measured as shown in the schematic to the left. Bumblebees were subjected to 5 day exposure to Imidacloprid and/or 670nm (≥ 18 bees per group). A. Imidacloprid had a significant impact reducing respiration, but this was corrected by exposure to 670nm light. The amount of light required, and the duration of this effect were then determined. B. Bumblebees (≥ 20 bees per group) were exposed to 670nm light for 0.5, 1, 5, 15 or 60mins and respiration measured. Controls (0) were not exposed. Exposure for 0.5 min had no impact. However, 1 min light exposure significantly increased respiration. Longer exposures were similar. The same metric was determined in Imidacloprid exposed bumblebees, again 0.5min exposure had no impact, however durations between 1 and 60mins induced significant increase in respiration (C). Bumblebees (≥ 18 bees per group) were exposed to a single 670nm for 1 min (D) and respiration measured at 24h intervals. This elevated respiration for 144h but then declined rapidly. A single 1min exposure of 670nm in Imidacloprid treated bees also elevated respiration, for 96h (E), a slight reduction in duration compared to the effect of 670nm on non-pesticide exposed bees (D). Abbreviations: *; p < 0.05, ***; p < 0.005, ns; no significance. Imid; Imidacloprid.