Double allomimesis of advancing and retreating individuals maintains cohesion in exploring groups of nomadic caterpillars

作者：Despland Emma^*; Gervais David; Morcos Lisanne

来源：Behavioral Ecology and Sociobiology, 2017, 71(3): UNSP 56.

DOI：10.1007/s00265-017-2285-5

• Collective locomotion
• Self-organization
• Emergence
• Lepidoptera
• Social

Group-living entails that animals maintain cohesion during collective locomotion: This cohesion often requires that each individual respond to cues from several neighbours. Social insects generally use pheromone trails to integrate information from multiple group members. We demonstrate mechanisms used by nomadic social caterpillars to maintain cohesionwhen exploring off-trail. Our results show that forest tent caterpillars ( Malacosoma disstria) use double allomimesis, responding to cues from both advancing and retreating neighbours. A group-level experiment measured cohesion and persistence of locomotion according to caterpillar age and group size. An individual-level experiment quantified responses to cues from neighbours, and a model was used to predict the group-level patterns that emerge from these responses. We show that double allomimesis generates feedback that maintains group cohesion, but at the price of locomotion efficiency, particularly in small groups of young caterpillars. We also show that the importance of allomimesis decreases as caterpillars age and show lesser responses to social cues. Finally, we demonstrate that, especially in the early instars, efficient collective locomotion is only possible in the large group sizes typically of field colonies.

• 出版日期2017-3