A behavioral analysis of achromatic cue perception by the ant Cataglyphis aenescens (Hymenoptera; Formicidae)


Abstract: Behavioral responses of Cataglyphis aenescens foragers to various monochromatic light stimuli were tested. Foragers were trained to associate lights of 370 (UV), 440 (blue), 540 (green), and 640 nm (red) with a food reward on a circular orientation platform and were then tested to determine the threshold intensity values of these wavelengths they could perceive. Foragers significantly responded to all wavelengths at training intensities but their homeward orientation diminished with decreasing stimulus intensity. The results showed that UV and green lights could be perceived at lower intensities compared to blue and red lights. Foragers were further trained in a Y-maze apparatus to discriminate 2 monochromatic light stimuli of the same wavelength but different in their intensities. The results showed that they failed to make a significant discrimination except for the 440 and 640 nm pairs. Overall results revealed a broad spectral sensitivity for foragers ranging from at least 370 nm (UV) to 640 nm (red) mediated by both chromatic and achromatic cue perception.

Keywords: Cataglyphis aenescens, achromatic vision, intensity threshold, intensity discrimination

Full Text: PDF