Figure 5. Walking speed of weevils elicited by different stimulus treatments.

A. Average speeds of Diaprepes abbreviatus females and males, exposed to the different stimulation treatments , were recorded during the 3 three consecutive 2-minute periods (control, test and end-control). In the first series, weevils were stimulated during the test period with air that had passed over the headspace of citrus leaves (citrus alone) and in the second series, weevils were stimulated with air that had passed over male weevils feeding on citrus leaves (citrus + males). In a third experimental series, weevils were stimulated with colored LEDs during the test period; a blue LED was placed above the tube that served as source of clean air that stimulated the insect and another blue LED was placed on the opposite arm of this corridor, while the other two arms were provided with a green LED each (clean air + blue vs. green). Finally, each insect was given the choice between a blue LED + volatiles from males feeding on citrus versus another opposite blue LED and two green LEDs (citrus + males + blue vs. green); blue and green LEDs were positioned as in series III. B. Speed indices for each series were calculated as the average speed during the test period minus the average speed during the control period. Different letters indicate significant pairwise differences across the different directions (α = 0.05, Dunn’s post-hoc test). Asterisk indicates significance (α = 0.05, Wilcoxon signed rank test). In the boxplots, bold lines indicate medians, segmented line indicate the means, lower and upper boundaries of a box indicate the 25 and 75% quartiles, respectively, whiskers below and above the box indicate the 10th and 90th percentiles, respectively, and circles represent data beyond these limits (outliers).