Fig. 2.

Path model I based on predicted relationships between phytochemical diversity and associated arthropod parameters for Piper species. Standardized path coefficients are noted. Positive relationships are shown in blue with arrowheads indicating causality; negative relationships are indicated in red with bullet heads. Plots of the partial correlations for each path are shown with the dependent variable on the x axis and the response variable on the y axis. The data support hypothesized causal relationships between insect herbivore species diversity, phytochemical diversity, leaf area lost to herbivores, and phototoxicity in 14 Piper species (model fit: χ² = 0.012, df = 1, P = 0.914).