Environmental perturbations induce correlations in midge swarms

Area of Science:

• Collective behavior
• Animal group dynamics
• Swarm intelligence

Background:

• Disordered animal groups, such as insect swarms, may exhibit collective behavior.
• Long-range correlation is proposed as a signature of collective behavior in disordered groups.
• Conflicting literature exists on long-range correlation in insect swarms, with wild swarms showing correlation and lab-based swarms not.

Purpose of the Study:

• To resolve contradictory findings on long-range correlation in insect swarms.
• To investigate the role of external perturbations in inducing correlations.
• To understand the influence of environmental context on collective behavior.

Main Methods:

• Applying various external stimuli to laboratory swarms of *Chironomus riparius* (non-biting midges).
• Observing the emergence of correlations in response to stimuli.
• Validating findings using a stochastic model of swarms.

Main Results:

• External perturbations consistently induced the emergence of correlations in laboratory swarms.
• The observed phenomenon was generic across different types of stimuli.
• A stochastic model successfully reproduced these results.

Conclusions:

• External perturbations are a key factor in generating long-range correlations in insect swarms.
• Previous contradictory findings are harmonized by considering environmental stimuli.
• Collective behavior is inseparable from its environmental context, necessitating research into intrinsic dynamics versus external influences.