Figure 5. Whole body titers of dopamine, serotonin, and octopamine differ between crowded and solitary treatments.

0hr = aphids taken directly from plants, n = 3 sets of 10 aphids each; 24hr Solitary = solitary aphids for 24 hours, n = 10 sets of 10 aphids each; 24hr Crowded = crowded aphids for 24 hours, n = 10 sets of 10 aphids each. Dots are outliers. The 0hr aphid levels of each biogenic amine were highly significantly different than the S and C treatments for dopamine and serotonin, while octopamine was not detected (“nd”) in the 0hr aphids. P values associated with the differences between the solitary and crowded treatments (Mann-Whitney U test) are noted.