title: Flower detection and acuity of the Australian native stingless bee Tetragonula carbonaria Sm.
abstract: We tested the endemic Australian Tetragonula carbonaria bee as a model of how colour vision may allow these small bees to find flowers. In a Y-Maze apparatus, we presented stimuli that contained both chromatic- and green-receptor contrasts, or only had chromatic contrast to free flying bees. Stimuli were detected at visual angles of 9.5° and 9.3°, respectively. We next made morphological measurements of the compound eye under high magnification using a digital microscope, and despite a relatively small eye size with a surface area of 0.64 ± 0.02 mm(2), the compound eye contained 3010 ± 10 ommatidia. Measurements of diverging rays of light using antidromic illumination revealed a mean interommatidial angle in the frontal visual field measures 1.56° ± 0.10°. Finally, we calculate that the minimum number of ommatidia that need to be excited for object detection is 33, which is much higher than for object detection in bumblebees and for the detection of objects providing both colour and green contrasts by honeybees, but lower for the detection of an object lacking green contrast in honeybees. We discuss reasons that may explain potential tradeoff for foraging bees.
authors.affiliation: School of Media and Communication, RMIT University, Melbourne, 3001, Australia. adrian.dyer@rmit.edu.au.|Department of Physiology, Monash University, Melbourne, 3800, Australia. adrian.dyer@rmit.edu.au.
authors.forename: Adrian G
authors.initials: AG
authors.lastname: Dyer
authors.affiliation: Department of Physiology, Monash University, Melbourne, 3800, Australia.|Department of Neurobiology, Faculty of Life Sciences, University of Vienna, Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Streinzer
authors.affiliation: School of Media and Communication, RMIT University, Melbourne, 3001, Australia.
authors.forename: Jair
authors.initials: J
authors.lastname: Garcia
mesh_terms: D000818:Animals; D001315:Australia; D001516:Bees / Q000502:physiology*; D055253:Color Vision / Q000502:physiology*; D035264:Flowers; D010775:Photic Stimulation / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*
keywords: Behaviour; Colour; Insect; Interommatidial angle; Vision