Hodgkin L K, Symonds M R E, Elgar M A
Department of Zoology, University of Melbourne, Melbourne, Victoria 3010, Australia
Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria 3125, Australia.
Proc Biol Sci. 2014 Dec 7;281(1796):20141700. doi: 10.1098/rspb.2014.1700.
The challenges of maintaining cohesion while making collective decisions in social or aggregating insects can result in the emergence of a leader or leaders. Larval aggregations of the steel-blue sawfly Perga affinis forage nocturnally, and some larvae lead the aggregation on foraging trips more often than expected by chance. We investigated the relationship between these leader and follower roles by comparing the weight and growth of individual larvae with different roles. Our observations reveal no significant difference between the growth of leaders and followers, suggesting that the role of leadership may not provide direct foraging benefits. However, by experimentally manipulating the social structure of larval aggregations, we found that individuals within aggregations that comprise a mixture of leaders and followers enjoy higher growth rates than those in aggregations comprising a single behavioural type. These data demonstrate, for the first time, individual benefits to maintaining a balance of leader and follower roles within larval aggregations, and highlight the importance of considering the perspectives of both leaders and followers when investigating the evolutionary significance of this behavioural variation within animal groups.
在社会性昆虫或聚集性昆虫群体中做出集体决策时，维持凝聚力会面临诸多挑战，这可能导致一个或多个领导者的出现。钢蓝色叶蜂（Perga affinis）的幼虫聚集体在夜间觅食，一些幼虫带领聚集体外出觅食的频率高于随机预期。我们通过比较不同角色的个体幼虫的体重和生长情况，研究了这些领导者和跟随者角色之间的关系。我们的观察结果显示，领导者和跟随者的生长情况没有显著差异，这表明领导角色可能不会带来直接的觅食优势。然而，通过实验操纵幼虫聚集体的社会结构，我们发现，由领导者和跟随者混合组成的聚集体中的个体，比由单一行为类型组成的聚集体中的个体具有更高的生长速率。这些数据首次证明了在幼虫聚集体中维持领导者和跟随者角色平衡对个体的益处，并强调了在研究动物群体中这种行为变异的进化意义时，考虑领导者和跟随者双方视角的重要性。
