Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study of bees by UC San Diego biologist provides insight into evolution of bee communication

23.09.2003


A team of biologists working in Brazil may have found the clues to resolving the longstanding mystery of why some species of bees, such as honey bees, communicate the location of food with dances in their hives and why other bees simply leave scent trails from the food source to the nest.





In the paper to appear in the October 22nd issue of the Proceedings of the Royal Society, biologists at the University of California, San Diego and the University of São Paulo report that one species of Brazilian stingless bee uses a slightly different form of communication, presumably in an effort to confuse its foraging competitors. An early on-line version of the paper is available at www.pubs.royalsoc.ac.uk/proc_bio/proc_bio.html.

“Previously, biologists thought different species of bees either marked the food source or left an odor trail from the food all the way to the nest,” says James Nieh, an assistant professor of biology at UCSD who headed the study. “We have discovered an intermediate strategy, in which bees leave an odor trail extending a short distance from the food source. This abbreviated trail may be less conspicuous to foraging competitors.”


The discovery is significant because it may help scientists understand how “functionally referential communication,” or the use of abstract representations to convey information about the physical world, could have evolved.

Bees and humans are among a small number of species that can use abstract representations to communicate. For example, honeybees use a “waggle dance” in which a returning forager bee runs up and down the honeycombs and shakes her abdomen to communicate distance and direction to a food source. Honeybees communicate within the nest how to get to the food source and do not leave a scent trail between the nest and the food source. However, they can mark flowers with special odors to help guide nestmates to the correct spot. Species of bees that do not have such sophisticated referential communication, leave a scent trail from the hive to the food source.

Nieh suggests that communicating the location of the food source to nestmates within the confines of the nest may have evolved as a strategy to avoid broadcasting information about the food source to competitors, which may also be able to follow the scent trail. The abbreviated scent trail strategy was observed in T. hyalinata, one species of stingless bee, a diverse group prevalent in South America. This discovery by Nieh and his colleagues Felipe Contrera and Paulo Nogueira-Neto from the University of São Paulo lends support to the notion of chemical eavesdropping, “espionage,” driving the evolution of communication.

Besides the length of the stingless bees’ scent trail the short trail has a second unique feature. The scent drops are more concentrated at one end of the trail than the other.

“All previously discovered bee scent trails had a roughly equal number of drops per unit distance,” says Nieh. “Here the scent markings are highly concentrated around the feeder and they taper off at increasing distance from it, in a trail that is roughly teardrop-shaped.”

Remarkably, the bees fly to the point with the highest scent concentration, and will ignore food placed at other locations along this scent trail, even if it is closer to the hive. Nieh hypothesizes that this scent gradient permits the bees to pinpoint a specific food source, enabling them to arrive en masse.

T. hyalinata is very aggressive. These bees will readily attack other bees of different species, or bees of the same species from different colonies. Because they can better compete for food, Nieh says it is advantageous for aggressive bees to arrive at a food source in large groups. Similar behavior occurs in other types of aggressive insects; for example, army ants arrive in “enormous hordes,” according to Nieh. A scent trail with concentration clues, like that of T. hyalinata, he concludes, is able to provide the guidance needed for the bees to arrive as a swarm.

To test their hypotheses about how bees follow the scent trail, Nieh and his colleagues needed to be able to change the location of the food source and the trail itself. This would be extremely difficult with real plants and flowers; thus they used bowls of scented sugar water as the food source and used ropes decorated with leaves, as moveable foliage.

To analyze marking behavior in detail, the researchers also videotaped the bees as they were depositing odor marks. They found that the bees landed briefly and then rubbed their mandibles, or mouth parts, against the leaves or ropes to leave the scent. When the researchers made an extract from ground-up mandibular glands (analogous to salivary glands), they found that the extract had the same effects on bee behavior as the odor marks deposited by other bees. This confirmed that the mandibular glands are the source of the odor cues that constitute the scent trail.

These mandibular gland odors actually have a complex effect on the behavior of the bees. “The odors initially elicit an attack response, but then after 10 to 15 minutes they elicit feeding,” explains Nieh. “The mandibular gland odors are actually a cocktail of chemicals, which evaporate at different rates.”

This explains the dual effect on behavior because a chemical cocktail that initially stimulated the bees to attack could later change into one that stimulates bees to eat. “Thus mandibular gland odors could enable foragers to draw in reinforcements precisely where they are most needed to take over a rich food source,” Nieh surmises.

Sherry Seethaler | UCSD
Further information:
http://ucsdnews.ucsd.edu/newsrel/science/beetrail.htm
http://www.pubs.royalsoc.ac.uk/proc_bio/proc_bio.html

More articles from Life Sciences:

nachricht Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>