Nav: Home

Honey bees have sharper eyesight than we thought

April 06, 2017

Research conducted at the University of Adelaide has discovered that bees have much better vision than was previously known, offering new insights into the lives of honey bees, and new opportunities for translating this knowledge into fields such as robot vision.

The findings come from "eye tests" given to western honey bees (also known as European honey bees, Apis mellifera) by postdoctoral researcher Dr Elisa Rigosi (Department of Biology, Lund University, Sweden) in the Adelaide Medical School, under the supervision of Dr Steven Wiederman (Adelaide Medical School, University of Adelaide) and Professor David O'Carroll (Department of Biology, Lund University, Sweden).

The results of their work are published today in the Nature journal Scientific Reports.

Bee vision has been studied ever since the pioneering research of Dr Karl von Frisch in 1914, which reported bees' ability to see colors through a clever set of training experiments.

"Today, honey bees are still a fascinating model among scientists, in particular neuroscientists," Dr Rigosi says.

"Among other things, honey bees help to answer questions such as: how can a tiny brain of less than a million neurons achieve complex processes, and what are its utmost limits? In the last few decades it has been shown that bees can see and categorize objects and learn concepts through vision, such as the concept of 'symmetric' and 'above and below'.

"But one basic question that has only been partially addressed is: what actually is the visual acuity of the honey bee eye? Just how good is a bee's eyesight?"

Dr Wiederman says: "Previous researchers have measured the visual acuity of bees, but most of these experiments have been conducted in the dark. Bright daylight and dark laboratories are two completely different environments, resulting in anatomical and physiological changes in the resolution of the eye.

"Photoreceptors in the visual system detect variations in light intensity. There are eight photoreceptors beyond each hexagonal facet of a bee's compound eye, and their eyes are made out of thousands of facets! Naturally, we expected some differences in the quality of bees' eyesight from being tested in brightly lit conditions compared with dim light," he says.

Dr Rigosi, Dr Wiederman and Professor O'Carroll set out to answer two specific questions: first, what is the smallest well-defined object that a bee can see? (ie, its object resolution); and second, how far away can a bee see an object, even if it can't see that object clearly? (ie, maximum detectability limit).

To do so, the researchers took electrophysiological recordings of the neural responses occurring in single photoreceptors in a bee's eyes. The photoreceptors are detectors of light in the retina, and each time an object passes into the field of vision, it registers a neural response.

Dr Rigosi says: "We found that in the frontal part of the eye, where the resolution is maximized, honey bees can clearly see objects that are as small as 1.9° - that's approximately the width of your thumb when you stretch your arm out in front of you.

"This is 30% better eyesight than has been previously recorded," she says.

"In terms of the smallest object a bee can detect, but not clearly, this works out to be about 0.6° - that's one third of your thumb width at arm's length. This is about one third of what bees can clearly see and five times smaller than what has so far been detected in behavioral experiments.

"These new results suggest that bees have the chance to see a potential predator, and thus escape, far earlier than what we thought previously, or perceive landmarks in the environment better than we expected, which is useful for navigation and thus for survival," Dr Rigosi says.

Dr Wiederman says this research offers new and useful information about insect vision more broadly as well as for honey bees.

"We've shown that the honey bee has higher visual acuity than previously reported. They can resolve finer details than we originally thought, which has important implications in interpreting their responses to a range of cognitive experiments scientists have been conducting with bees for years.

"Importantly, these findings could also be useful in our work on designing bio-inspired robotics and robot vision, and for basic research on bee biology," he says.
-end-
This research has been supported with funding from the Australian Research Council (ARC), the Swedish Research Council, and the Swedish Foundation for International Cooperation in Research and Higher Education.

Media Contacts:

Dr Elisa Rigosi
Postdoctoral Fellow
Department of Biology
Lund University
Phone: +46 727296188 or +39 3485290910
elisa.rigosi@biol.lu.se or elisa.rigosi@gmail.com

Dr Steven Wiederman
ARC Discovery Early Career Researcher
Adelaide Medical School
The University of Adelaide
Phone: +61 8 8313 4435
steven.wiederman@adelaide.edu.au

University of Adelaide

Related Bees Articles:

Neonicotinoids: Despite EU moratorium, bees still at risk
Since 2013, a European Union moratorium has restricted the application of three neonicotinoids to crops that attract bees because of the harmful effects they are deemed to have on these insects.
Bees 'surf' atop water
Ever see a bee stuck in a pool? He's surfing to escape.
How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.
Where are the bees? Tracking down which flowers they pollinate
Earlham Institute (EI), with the University of East Anglia (UEA), have developed a new method to rapidly identify the sources of bee pollen to understand which flowers are important for bees.
Pesticides deliver a one-two punch to honey bees
A new paper in Environmental Toxicology and Chemistry reveals that adjuvants, chemicals commonly added to pesticides, amplify toxicity affecting mortality rates, flight intensity, colony intensity, and pupae development in honey bees.
Bees can count with just four nerve cells in their brains
Bees can solve seemingly clever counting tasks with very small numbers of nerve cells in their brains, according to researchers at Queen Mary University of London.
Trees for bees
Planting more hedgerows and trees could hold the key to helping UK bees thrive once again, a new study argues.
The secret to better berries? Wild bees
New research shows wild bees are essential for producing larger and better blueberry yields - with plumper, faster-ripening berries.
How do flying bees make perfect turns?
Bees adjust their speed to keep turning forces constant, new research from the Queensland Brain Institute, The University of Queensland shows.
Bees on the brink
Using an innovative robotic platform to observe bees' behavior, Harvard researchers showed that, following exposure to neonicotinoid pesticides -- the most commonly-used class of pesticides in agriculture -- bees spent less time nursing larvae and were less social that other bees.
More Bees News and Bees Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Accessing Better Health
Essential health care is a right, not a privilege ... or is it? This hour, TED speakers explore how we can give everyone access to a healthier way of life, despite who you are or where you live. Guests include physician Raj Panjabi, former NYC health commissioner Mary Bassett, researcher Michael Hendryx, and neuroscientist Rachel Wurzman.
Now Playing: Science for the People

#544 Prosperity Without Growth
The societies we live in are organised around growth, objects, and driving forward a constantly expanding economy as benchmarks of success and prosperity. But this growing consumption at all costs is at odds with our understanding of what our planet can support. How do we lower the environmental impact of economic activity? How do we redefine success and prosperity separate from GDP, which politicians and governments have focused on for decades? We speak with ecological economist Tim Jackson, Professor of Sustainable Development at the University of Surrey, Director of the Centre for the Understanding of Sustainable Propserity, and author of...
Now Playing: Radiolab

An Announcement from Radiolab