Figure 1. Choice arena adapted to a locomotion compensator (servosphere).

Schematic representation of a choice arena adapted to a servosphere where a Diaprepes abbreviatus weevil walking on the apex of the sphere was stimulated with light emitting diodes (LED) of different wavelengths and chemical stimuli. (A) The sphere compensated for the insect displacement so it remained on its apex (side view). Air passing through a bottle, that contains citrus or males feeding on citrus, carried odors to the weevil. Two different colored lights were presented in paired combinations with LEDs of the same color cue positioned in opposite arms (top view). (B) Walking response of D. abbreviatus adults exposed to colored LEDs in still air expressed as percentage of distance covered in each of four 90° angles projected to 0°, 90°, 180° and 270° where 0° and 180° represent blue and 90° and 270° represent green. Relative displacement in the ‘x’ and ‘y’ corridors for this experiment is also showed in figure 2. Different letters indicate significant pairwise differences across the different directions (α = 0.05, Dunn’s post-hoc 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). (C) Walking trajectories performed by a female (left) and a male (right) weevil stimulated with green and blue on the servosphere showed that both individuals oriented toward the green lights. Relative size of insects has been exaggerated for clarity.