Visual physiology of Australian stingless bees.

Stingless bees engage in a range of visually guided behaviours that require relatively high spatial resolution and contrast sensitivity. Although the eyes of honeybees, bumblebees, carpenter bees, and sweat bees have been studied extensively, there is limited knowledge of stingless bees. Here, we studied two sympatric Australian species, Tetragonula carbonaria and Austroplebeia australis, which are important crop pollinators. The bigger A. australis had more and larger ommatidial facets compared to T. carbonaria. Using pattern electroretinography, we showed that A. australis had higher contrast sensitivity (13.07) compared to T. carbonaria (5.99), but their spatial resolving power did not differ (0.53 cycles deg^-1). We discuss these differences in visual physiology in the context of the distinct foraging behaviours of the two species.