Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Parasitic tapeworm influences the behavior and lifespan of uninfected members of ant colonies

02.12.2015

Aggressive behavior of entire ant colony reduced / Lifespan of uninfected nest-mates curtailed but increased in infected ants

Ants are quite often infected by parasites. For example, tapeworms use ants as intermediate hosts for a part of their development phase before they complete their life cycle in their main host. Researchers at Johannes Gutenberg University Mainz (JGU) have now discovered that such parasites not only change the appearance and behavior of infected ants but also have an effect on the behavior of uninfected members of the colony.


A healthy brown and an infected yellow ant (at the top) and the Anomotaenia brevis tapeworm in its larval stage as it is found in ants (below)

photo/©: Susanne Foitzik

The overall aggressiveness of an ant colony diminishes if it contains members who are infected with a parasite. The investigations being undertaken by a team of Mainz-based evolutionary biologists headed by Professor Susanne Foitzik are designed to uncover the effects that parasites have on animal societies and to find out how the parasites manipulate the behavior of their hosts in order to better survive. Their findings have recently been published in Proceedings of the Royal Society B.

The Temnothorax nylanderi ant species is native to western Europe and prefers to build its nests in acorns or dead wood on forest floors. The workers are two to three millimeters long and form colonies of 50 to 200 insects.

They serve as an intermediate host for the Anomotaenia brevis tapeworm, which infects the ants during the larval stage and lives in their intestines. Infected ants turn yellow and thus differ noticeably from their predominantly brown colleagues.

They also become inactive and remain in the nest where they barely participate in social activities, such as caring for the brood. So that the tapeworm can complete its life cycle, its host ant must be eaten by the main host, a woodpecker. In the Lennebergwald forest, a wooded area of 700 hectares to the northwest of the city of Mainz, about a third of all ant colonies have the parasite and some 13 percent of the insects are infected.

"The parasites have developed fascinating strategies to protect their interests and so ensure, for example, their proliferation," explained Professor Susanne Foitzik. "They attempt to influence the ants in such a way that they are more likely to be eaten by a woodpecker." There are various methods they employ in the case of Temnothorax nylanderi to achieve their ends.

The study has shown that infected ants live longer than their uninfected nest-mates. "The longer lifespan may be due to modified genetic regulation but could also be the result of the fact that the infected insects enjoy a better level of feeding," points out Sara Beros, primary author of the study. They also exhibit less marked flight behavior in response to simulated woodpecker attacks, an effect that would increase the parasites' chances of being eaten by their definitive host.

"The parasite's long arm" is how the authors of the study describe the effect that enables the tapeworms to manipulate both the infected ants as well as their uninfected nest-mates. One factor is that these nest-mates have a shorter lifespan and not just relative to the infected animals but also relative to the other ants from uninfected colonies. This is probably the result of the additional stress they experience because of the need to care for the infected animals while also having to do without their help when it comes to other social tasks.

A parasitized colony is also far less aggressive towards intruders of the same species. The researchers assume that the reason for this is associated with the chemical profile of the infected insects that emit a different scent. Each colony has its own nest-specific odor that normally serves as a recognition signal for the group members. If the odor is disrupted by the presence of other scents, this has a negative effect on the readiness to defend the colony against intruders.

Publication:
Sara Beros et al.
The parasite’s long arm: a tapeworm parasite induces behavioural changes in uninfected group members of its social host
Proceedings of the Royal Society B, 18 November 2015
DOI: 10.1098/rspb.2015.1473

Photos:
http://www.uni-mainz.de/bilder_presse/10_zoologie_ameisen_bandwurm_01.jpg
A healthy brown and an infected yellow Temnothorax nylanderi ant
photo/©: Susanne Foitzik

http://www.uni-mainz.de/bilder_presse/10_zoologie_ameisen_bandwurm_02.jpg
A yellow ant infected by the Anomotaenia brevis tapeworm
photo/©: Susanne Foitzik

http://www.uni-mainz.de/bilder_presse/10_zoologie_ameisen_bandwurm_03.jpg
A healthy brown and an infected yellow ant (at the top) and the Anomotaenia brevis tapeworm in its larval stage as it is found in ants (below)
photo/©: Susanne Foitzik

Further information:
Professor Dr. Susanne Foitzik
Department of Evolutionary Biology
Institute of Zoology
Johannes Gutenberg University Mainz (JGU)
55099 Mainz, GERMANY
phone +49 6131 39-27840
fax +49 6131 39-27850
e-mail: foitzik@uni-mainz.de
http://www.bio.uni-mainz.de/zoo/evobio/index_ENG.php

Weitere Informationen:

http://www.uni-mainz.de/presse/17031_ENG_HTML.php - press release "Novel genes determine division of labor in insect societies", 30 January 2014

Petra Giegerich | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht Closing the carbon loop
08.12.2016 | University of Pittsburgh

nachricht Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>