The critical cue in pattern discrimination for the honey bee: Color or form?

When honey bees approach blossoms, they are attracted by the color and form of the goal in their visual field, and they use these cues for a successful revisit. Their visual system receives cues by two main types of parallel channels behind the retina; one channel for colors, and a monochrome channel for the orientation and edge of the item in their visual field. In the integration process of these 2 channels, the priority and interaction between them are significant due to the fact that these chromatic and achromatic signals coexist naturally. To investigate this issue, we trained bees to detect form and color and then tested them with combinations of opposite patterns. We observed that the bees chose the correct color but the wrong form pattern in the above experiment as well as for other manipulations as follows. The effect of the color training for the blue reward pattern differed from that of the green reward pattern. The color pattern choices tended to be more correct if blue was the target during the training process, indicating that the chromatic signal was the main cue in pattern discrimination. In other words, color tended to be the decisive factor in a conflicting situation. In addition, the color blue was preferred over the color green, indicating that color preference was involved in visual recognition.