Figure 5. Choice behavior of beetles in free-flight experiments.

In free-flight experiments with Cerotoma ruficornis (A) and Gynandrobrotica guerreroensis (B), young potted lima bean plants were offered and choice behavior of the insects was evaluated. Five different setups were included in the experiments, that is jasmonic acid (JA)-induced plants (I; JA concentrations: 1.0, 0.1, 0.01, and 0.001 mmol L⁻¹) and herbivore-induced (HI) vs. control (untreated) plants. In both HI-experiments herbivore damage was invoked be G. guerreroensis. In addition, beetles were given the choice to select between control plants (C∶C). Each beetle was subjected to the same experimental setup 8 times and portions of decision for each plant treatment were used for further analyses. The number of beetles tested in the different setups is indicated for each sex. Asterisks at the left side of the columns represents significant differences in percentage decisions between both odor sources according to Mann-Whitney U-test (* = P<0.05; ** = P<0.01; *** = P<0.001). Asterisks at the right side of the columns represent significant differences in choice behavior between male and female beetles according to Wilcoxon signed-rank test (* = P<0.05; ** = P<0.01; *** = P<0.001).