Figure 1.
Honey bee behavioral responses to antennal stimulation with selenate.
Honey bees were stimulated with 1 M sucrose, water, and selenate in 1 M sucrose (N = 83). Asterisks indicate significance of *P<0.05, **P<0.001, ***P<0.0001 (Logistic regression with multiple comparisons) between 1 M sucrose and treatment lines.
Figure 2.
Honey bee behavioral responses to antennal stimulation with selenomethionine.
Honey bees were stimulated with 1 M sucrose, water, and selenomethionine in 1 M sucrose (N = 94). Asterisks indicate significance of *P<0.05, **P<0.001, ***P<0.0001 (Logistic regression with multiple comparisons) between 1 M sucrose and treatment lines.
Figure 3.
Honey bee behavioral responses to antennal stimulation with methionine.
Honey bees were stimulated with 1 M sucrose, water, and methionine in 1 M sucrose (N = 58). Asterisks indicate significance of *P<0.05, **P<0.001, ***P<0.0001 (Logistic regression with multiple comparisons) between 1 M sucrose and treatment lines.
Figure 4.
Honey bee behavioral responses to proboscis stimulation with selenate.
Honey bees' proboscises were stimulated with 1 M sucrose, water, and selenate in 1 M sucrose (N = 23–30).
Figure 5.
Honey bee behavioral responses to proboscis stimulation with selenomethionine.
Honey bees' proboscises were stimulated with 1 M sucrose, water, and selenomethionine in 1 M sucrose (N = 22–31).
Figure 6.
Honey bee behavioral responses to proboscis stimulation with methionine.
Honey bees' proboscises were stimulated with 1 M sucrose, water, and methionine in 1 M sucrose (N = 19–26).
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).
Figure 8.
Honey bee forager mortality from chronic doses of selenium.
Percentages of honey bee mortality after chronic dosage of selenate (N = 18–21), selenomethionine (N = 19–20) or methionine (N = 19–20) in 1 M sucrose at 6 concentrations. Control bees received 0 µg ml−1, or 1 M sucrose only. Bees were fed 20 µl of each treatment for 6 days. Mortality was recorded for 5 subsequent days after the first dosage. 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).