Benelli Giovanni, Donati Elisa, Romano Donato, Stefanini Cesare, Messing Russell H, Canale Angelo
Insect Behaviour Group, Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124, Pisa, Italy,
Naturwissenschaften. 2015 Feb;102(1-2):1251. doi: 10.1007/s00114-014-1251-6. Epub 2014 Dec 12.
Lateralisation (i.e. different functional and/or structural specialisations of the left and right sides of the brain) of aggression has been examined in several vertebrate species, while evidence for invertebrates is scarce. In this study, we investigated lateralisation of aggressive displays (boxing with forelegs and wing strikes) in the Mediterranean fruit fly, Ceratitis capitata. We attempted to answer the following questions: (1) do medflies show lateralisation of aggressive displays at the population-level; (2) are there sex differences in lateralisation of aggressive displays; and (3) does lateralisation of aggression enhance fighting success? Results showed left-biased population-level lateralisation of aggressive displays, with no consistent differences among sexes. In both male-male and female-female conflicts, aggressive behaviours performed with left body parts led to greater fighting success than those performed with right body parts. As we found left-biased preferential use of body parts for both wing strikes and boxing, we predicted that the left foreleg/wing is quicker in exploring/striking than the right one. We characterised wing strike and boxing using high-speed videos, calculating mean velocity of aggressive displays. For both sexes, aggressive displays that led to success were faster than unsuccessful ones. However, left wing/legs were not faster than right ones while performing aggressive acts. Further research is needed on proximate causes allowing enhanced fighting success of lateralised aggressive behaviour. This is the first report supporting the adaptive role of lateralisation of aggressive displays in insects.
在几种脊椎动物物种中，已经对攻击行为的偏侧化（即大脑左右两侧不同的功能和/或结构特化）进行了研究，而关于无脊椎动物的证据却很少。在本研究中，我们调查了地中海实蝇（Ceratitis capitata）攻击行为表现（用前腿拳击和翅膀攻击）的偏侧化情况。我们试图回答以下问题：（1）地中海实蝇在群体水平上是否表现出攻击行为表现的偏侧化；（2）攻击行为表现的偏侧化是否存在性别差异；以及（3）攻击行为的偏侧化是否能提高战斗成功率？结果显示，在群体水平上攻击行为表现存在左侧偏向的偏侧化，不同性别之间没有一致的差异。在雄性与雄性以及雌性与雌性的冲突中，用身体左侧部位进行的攻击行为比用右侧部位进行的攻击行为带来更大的战斗成功率。由于我们发现无论是翅膀攻击还是拳击，在身体部位的使用上都存在左侧偏向，因此我们预测左前腿/翅膀在探索/攻击方面比右前腿/翅膀更快。我们使用高速视频对翅膀攻击和拳击进行了特征描述，计算了攻击行为表现的平均速度。对于两性来说，导致成功的攻击行为表现比未成功的更快。然而，在进行攻击行为时，左翅膀/腿并不比右翅膀/腿更快。需要进一步研究导致偏侧化攻击行为提高战斗成功率的近因。这是第一份支持攻击行为表现偏侧化在昆虫中具有适应性作用的报告。
