Laboratório de Interações Inseto-Planta, Departamento de Ecologia E Programa de Pós-Gradução Em Ecologia, Instituto de Biologia, Universidade Federal Do Rio de Janeiro, Avenida Carlos Chagas Filho, 373, Rio de Janeiro, RJ, 21901-942, Brazil.
Naturwissenschaften. 2023 Sep 15;110(5):46. doi: 10.1007/s00114-023-01877-2.
In gregarious species, coordinated responses to environmental stimuli are important for a successful habitat and/or food selection. In this sense, maintenance of group cohesion after stochastic disturbances and during collective movements is expected to be advantageous, as is the existence of group leaders. Through laboratory experiments, we examined whether clusters of early instars of Mechanitis polymnia casabranca have both leaders and followers, as well as whether larvae are able to reaggregate depending on neighbors' degree of kinship. In the leadership experiment, clusters of second and third instars were placed in a trail arena having a stimulus leaf at its ending point. Every larva moving ahead from the group was recorded as a leader, and the remaining ones were followers. We also examined whether leaders were temporary or permanent. Of the 195 larvae tested, 22 were permanent leaders (11.28%), 71 larvae were assigned as temporary leaders (36.41%), and 102 larvae never behaved as leaders (52.31%). In the larval cohesion experiment, three treatments were assigned: (i) sibling larvae reared and tested together, (ii) sibling larvae separated after eclosion and tested together, and (iii) non-sibling larvae reared separated and tested together. Sibling larvae reaggregated significantly more compared to non-siblings, regardless of whether they were reared together or separately. Our results show that early instars of M. polymnia casabranca from the same egg cluster are able to recompose aggregations after disrupting disturbances and that group decision-making is mostly dependent on transient leaders.
在群居物种中，对环境刺激做出协调一致的反应对于成功的栖息地选择和/或食物选择很重要。从这个意义上说，在随机干扰后和集体运动期间维持群体凝聚力应该是有利的，因为存在群体领导者。通过实验室实验，我们研究了 Mechanitis polymnia casabranca 的早期幼虫是否既有领导者又有追随者，以及幼虫是否能够根据邻居的亲缘关系重新聚集。在领导实验中，将第二龄和第三龄的幼虫簇放置在具有刺激叶末端的迹线竞技场中。从群体中向前移动的每只幼虫都被记录为领导者，其余的则是追随者。我们还检查了领导者是否是暂时的还是永久的。在测试的 195 只幼虫中，有 22 只为永久领导者（11.28%），71 只为临时领导者（36.41%），102 只为非领导者（52.31%）。在幼虫凝聚力实验中，分配了三种处理：（i）一起饲养和测试的同胞幼虫，（ii）孵化后分开饲养和一起测试的同胞幼虫，以及（iii）分开饲养和一起测试的非同胞幼虫。同胞幼虫无论是否一起饲养，其聚集的可能性都明显高于非同胞幼虫。我们的研究结果表明，来自同一卵簇的 M. polymnia casabranca 的早期幼虫能够在破坏干扰后重新组成聚集，并且群体决策主要取决于短暂的领导者。
