Mosquito swarms shear harden

Area of Science:

• Entomology
• Biophysics
• Mathematical Biology

Background:

• Anopheles gambiae mosquitoes exhibit complex swarming behaviors.
• Previous studies documented laboratory-based mosquito swarming using 3D-video tracking.
• Understanding swarm dynamics is crucial for mosquito control and disease vector research.

Purpose of the Study:

• To model and understand the collective behavior of Anopheles gambiae mosquito swarms.
• To investigate the mechanisms underlying mosquito swarm responses to environmental factors like wind.
• To compare mosquito swarming with other collective behaviors, such as midge swarms.

Main Methods:

• Utilized a minimally structured (maximum entropy) stochastic trajectory model.
• Reproduced key observations from a 3D-video tracking study of laboratory-based mosquito swarms.
• Applied the model to predict mosquito responses to varying wind speeds in wild swarms.

Main Results:

• Unperturbed mosquito swarms behave as collections of individuals, unlike collective midge swarms.
• The model predicts observed mosquito responses to wind speed variations.
• Mosquito swarm response is attributed to shear hardening, where individuals increase flight speed towards the swarm center.
• Increased flight speed enhances resistance to environmental disturbances, unlike other emergent swarm properties.

Conclusions:

• Mosquito swarming is characterized by individual circulation around a fixed point, driven by a speed-dependent attractive force.
• Shear hardening is a key mechanism for mosquito swarm stability against environmental perturbations.
• Perturbations can induce more robust states in mosquito swarms, highlighting adaptive individual behavior.