Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Remembrance of tussles past: paper wasps show surprisingly strong memory for previous encounters

23.09.2008
With brains less than a millionth the size of humans', paper wasps hardly seem like mental giants. But new research at the University of Michigan shows that these insects can remember individuals for at least a week, even after meeting and interacting with many other wasps in the meantime.

The finding suggests that the wasps' social interactions are based on memories of past encounters rather than on rote adherence to simple rules.

The research, by graduate student Michael Sheehan and assistant professor of ecology and evolutionary biology Elizabeth Tibbetts, is scheduled to be published in the September 23rd issue of the journal Current Biology.

What's impressive about the wasps' abilities is not simply that they can remember past events. Honeybees, after all, can remember where they've found nectar. "But those memories are pretty fleeting," Sheehan said. "There seems to be a limit to the number of things they can juggle in their head at one time."

... more about:
»Sheehan »individuals »interactions »memories

Until now it was assumed that all social insects had similarly limited memories. But the new work shows that at least one species of paper wasp, Polistes fuscatus, has a strong, long-term memory and bases its behavior on what it remembers of previous social interactions with other wasps.

In earlier research, Tibbetts showed that these wasps recognize individuals by variations in their facial markings and that they behave more aggressively toward wasps with unfamiliar faces. If their memories are robust, the researchers reasoned, wasps should be less aggressive toward individuals they met even some time ago than toward new social partners.

To test the notion, Sheehan measured aggression between 50 wasp queens in four different encounters over eight days. On the first day, two wasps that never had met were placed in an observation chamber for a day and their initial interactions videotaped. Then the pair was separated, and each wasp was put in a communal cage with 10 other wasps. A week later, the pair met again, and again their behavior was videotaped.

When the researchers analyzed the videotapes, scoring the wasps' social interactions on a scale of zero (no aggression) to four (all-out grappling), it was clear that the wasps treated each other better during their second encounter than when they were strangers, suggesting they remembered each other.

"Instead of trying to bite each other and really have a rough-and-tumble encounter, they just sort of hung out next to each other when they met the second time," Sheehan said.

To make sure that any differences in aggression between the first and second encounters actually were based on memory, not just some general mellowing over time, the researchers introduced each wasp to a new stranger on the day before and the day after the encounter with its old familiar social partner. As expected, the wasps were just as nasty to total strangers as they had been to each when they first met.

"The interesting aspect of this work is not just that the wasps have a good memory, but that it's social memory," Sheehan said. "It seems that their specific social history with particular individuals is something they're keeping track of and that it matters to their lives."

It matters because Polistes fuscatus females often share nests. Remembering who they've already settled their differences with makes for a more harmonious home life and keeps them from wasting energy on repeated aggressive encounters.

The findings also challenge assumptions about social cognition, Sheehan said. Scientists have thought the ability to form social memories and use them as the basis for complex relationships was a driving force behind the evolution of large brains. But if tiny-brained wasps have such ability, perhaps it doesn't demand as much brainpower as previously thought.

Nancy Ross-Flanigan | EurekAlert!
Further information:
http://www.umich.edu
http://www.current-biology.com/

Further reports about: Sheehan individuals interactions memories

More articles from Life Sciences:

nachricht Complementing conventional antibiotics
24.05.2018 | Goethe-Universität Frankfurt am Main

nachricht Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
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

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

When corals eat plastics

24.05.2018 | Ecology, The Environment and Conservation

Surgery involving ultrasound energy found to treat high blood pressure

24.05.2018 | Medical Engineering

First chip-scale broadband optical system that can sense molecules in the mid-IR

24.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>