Tradeoff between constitutive and induced defense
For defense assessed by larval weight gain, plant species that had higher constitutive defense had lower induced defense, resulting in a negative correlation across the 12 non-native plant species (r = -0.58, P = 0.048) and the native congeners combined (r = -0.85, P < 0.001) (Figure 4A). This was similar for non-native plant species when defense was assessed by phenolic content (r = -0.76, P = 0.004), but not for native congeners (r = 0.05, P = 0.881) (Figure 4B).