The insect police: Why social insects punish cheating comrades

August 23, 2004

Colonies of social insects, such as bees and ants, typically consist of one or more 'queens ' and the 'workers' that support their reproduction. In some social insect colonies, however, workers do lay unfertilised eggs - which develop into males - essentially "cheating" on the other workers who are investing in only the queen's reproduction. Such action can be severely penalized by other workers - in honeybees, where this behavior was first shown, workers remove worker-laid eggs within hours by eating them, and, in some ants, more draconian methods lead to the mutilation of the culprit caught in the act of laying. In the open access journal, PLoS Biology, Rob Hammond and Laurent Keller explain how these policemen arise.

The apparently altruistic behavior of workers in supporting their queen is generally explained by 'kin selection', whereby the worker obtains more 'reproductive payoffs' indirectly by producing the queen's offspring than by having their own. Kin selection revolves around relatedness because relatedness determines the magnitude of the payoffs. Based on a detailed comparative phylogenetic analysis of 50 species of ants, wasps, Hammond and Keller now demonstrate that the 'policing' behavior of workers cannot be accounted for just by relatedness - as traditionally thought - but that it is necessary to consider how the efficiency of the colony influences behavior. The key appears to be that energy invested by workers into laying eggs - which would otherwise be used in foraging and legitimate brood rearing - can detract from the overall efficiency and growth of the colony.

To test this, Hammond and Keller estimated the extent to which workers produce their own male offspring and whether this was determined by how related the workers are to each other (e.g. some colonies are run by more than one queen); the 'efficiency hypothesis' predicts no such relationship. Contrary to expectations, they found evidence that a genetic incentive for workers to police the reproduction of other workers cannot account for its widespread prevalence among social insects. Other factors--such as colony efficiency--must therefore act as an important constraint on worker reproduction. This, Hammond and Keller emphasize, does not amount to showing that kin selection is unimportant--but it does mean that the harmony and regulation of reproduction in social insects is much more complex than expected from simple theoretical expectations based solely on relatedness.
-end-
Citation: Hammond R, Keller L. (2004) Conflict over Male Parentage in Social Insects. PLoS Biol 2 (9): e248.

CONTACT:
Rob Hammond
University of Lausanne
Lausanne, Switzerland
+41-21-692-2125
+41-21-692-4165 (fax)
rob.hammond@ie-zea.unil.ch

PLEASE MENTION PLoS BIOLOGY (www.plosbiology.org) AS THE SOURCE FOR THESE ARTICLES. THANK YOU.

All works published in PLoS Biology are open access. Everything is immediately available without cost to anyone, anywhere--to read, download, redistribute, include in databases, and otherwise use--subject only to the condition that the original authorship is properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.

PLOS

Related Behavior Articles from Brightsurf:

Variety in the migratory behavior of blackcaps
The birds have variable migration strategies.

Fishing for a theory of emergent behavior
Researchers at the University of Tsukuba quantified the collective action of small schools of fish using information theory.

How synaptic changes translate to behavior changes
Learning changes behavior by altering many connections between brain cells in a variety of ways all at the same time, according to a study of sea slugs recently published in JNeurosci.

I won't have what he's having: The brain and socially motivated behavior
Monkeys devalue rewards when they anticipate that another monkey will get them instead.

Unlocking animal behavior through motion
Using physics to study different types of animal motion, such as burrowing worms or flying flocks, can reveal how animals behave in different settings.

AI to help monitor behavior
Algorithms based on artificial intelligence do better at supporting educational and clinical decision-making, according to a new study.

Increasing opportunities for sustainable behavior
To mitigate climate change and safeguard ecosystems, we need to make drastic changes in our consumption and transport behaviors.

Predicting a protein's behavior from its appearance
Researchers at EPFL have developed a new way to predict a protein's interactions with other proteins and biomolecules, and its biochemical activity, merely by observing its surface.

Spirituality affects the behavior of mortgagers
According to Olga Miroshnichenko, a Sc.D in Economics, and a Professor at the Department of Economics and Finance, Tyumen State University, morals affect the thinking of mortgage payers and help them avoid past due payments.

Asking if behavior can be changed on climate crisis
One of the more complex problems facing social psychologists today is whether any intervention can move people to change their behavior about climate change and protecting the environment for the sake of future generations.

Read More: Behavior News and Behavior Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.