(A) Schematic of the two-choice assay. Two different agarose conditions were prepared in pairs of identical quadrants. A group of 20 larvae were placed in the middle of the dish at the start of the experiment. The number of larvae in each quadrant was counted after 3 min. For more detail about the methodology, see the Materials and methods section. (B) Each independent trial led to a preference index (PI). The means and s.e.m. of the distributions of PIs corresponding to one experimental condition were reported in a bar graph (n = 10 trials, Student’s t-test). The experimental conditions tested in the paper included quadrants with the following properties: (0.5 vs. 2.0% plain agarose gels), (0.5 vs. 2.0% agarose gels mixed with mesocarp-tomato juice), and (2.0% agarose gels mixed with tomato juices obtained from the locular gel or the mesocarp). The two concentrations of agarose gel, 0.5% and 2.0%, are characterized by the same ranges of mechanical hardness of the locular gel and the mesocarp of regular tomatoes, respectively. The significance levels of the statistics are indicated as *p<0.05 and ***p<0.001.