Figure 2. Ladybird olfactory responses to synthetic blends of volatile organic compounds of onion-exposed and unexposed potato. Behavioral responses of ladybirds to synthetic blends of volatile organic compounds of potato plants that had been previously exposed (treatment) and unexposed (control) to onion plants. Synthetic blends were at 1/100, 1/10, 1, 10, and 100 times the original concentration of volatiles identified in potato headspace. Error bars indicate ± SEM. Asterisks indicate statistical significance levels of * P ≤ 0. 05 (Wilcoxon matched pairs test).