Figure 2. Twenty-spotted ladybird responses to natural volatiles emitted from healthy (□) and infected (▪) plants in a Y-tube behavioral assay.

A: an assays using whole plants; B: an assays using volatiles collected from whole plants, eluted in solvent (CH₂Cl₂), and re-evaporated from a filter-paper disc. *: P-value of chi-square test against the expectation of random (1∶1) beetle choices.