Figure 4. Ladybird olfactory responses to (E)-nerolidol. Behavioral responses of ladybirds to (E)-nerolidol, a terpenoid released in higher amounts from potato plants after exposure to volatiles from onion plants, vs. n-hexane controls. Error bars indicate ± SEM. Asterisks indicate statistical significance levels of * P ≤ 0. 05, and *** P ≤ 0. 001 (Wilcoxon matched pairs test).