Colour preferences in stingless bees - features of an outstanding visual ecology

• Applicant: Professor Dr. Klaus Lunau
• Subject Area: Sensory and Behavioural Biology
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 286748826

Flower visitors have evolved sensorial capabilities to discover food plants rapidly and reliably. Among the manifold flower visitors bees play an outstanding role as pollinators of natural flowers and of crops as well as in pollination management systems. Colour is probably the most prominent flower signal for bees to detect flowers: bees possess colour vision, have strong learning skills and are able to associate reward with colour cues more efficiently than with cues of other modalities. Moreover, naïve bees have innate colour preferences and use colour signals in order to find flowers of suitable food plants. Most studies of bee colour vision and colour preferences were focused on honeybees and bumblebees. The ecological diversity in regard to various foraging strategies in stingless bees is outstanding: some species are excellent pollinators in the Neotropics, Paleotropics and Australis, some are more effective pollinators than honeybees for specific crop plants, others are ordinary nectar and pollen thieves of bird-pollinated flowers and thus, inter alia, competitors of hummingbirds or other flower visitors. This proposed initial study of colour preferences in stingless bees pursues four major lines of investigation: 1. Invention of a new method confecting colour stimuli for preference tests by mixing coloured, black, grey, and white powdered pigments so that for the first time one single colour attribute, i.e. colour intensity, colour purity or peak wavelength, can be varied while holding the other colour attributes constant. 2. Testing colour preferences of freely flying experienced as well as of naïve stingless bees and thereby covering the largely unexplored ecological diversity of stingless bees. 3. Comparing the colour preferences of stingless bees with those of honeybees and bumblebees while focusing on differences. 4. Providing evidence for the prospective benefit of distinct stingless bee species for crop and greenhouse pollination due to their visual ecology, and for their potential to conquer the sensory exclusion via colour cues of bird-pollinated flowers. A pilot study has shown that the work with stingless bees is highly auspicious to obtain unexpected insights into the complex theme of colour vision in stingless bees. Moreover the establishment of our new method to produce target colours is suitable to demonstrate differences in the colour preferences of stingless bees.

• DFG Programme: Research Grants
• International Connection: Australia, Brazil
• Cooperation Partners: Professorin Dr. Isabel Alves dos Santos; Professor Dr. Adrian Dyer