Figure 7. Honey bee forager mortality from a single dose of selenium.

Percentages of honey bee mortality after a single dosage of selenate (N = 20–22), selenomethionine (N = 17–20) or methionine (N = 21–24) in 1 M sucrose at 6 concentrations. Control bees received 0 µg ml⁻¹, or 1 M sucrose only. Mortality was recorded for 5 subsequent days. Final percent mortality is shown. Letters above the means indicate statistically significant differences between groups (α = 0.05) using the Mann-Whitney U test. Values are means ± standard error (SE).