Latitudinal variation in behaviour in a damselfly

We studied behavioural traits and behavioural correlations in larvae of a univoltine damselfly, Lestes sponsa, along its latitudinal distribution, spreading over 3300 km. We compared behavioural profiles among larvae grown either in native temperatures and photoperiods or averaged constant temperatures and photoperiods. We expected latitudinal differences in behavioural traits regardless of the conditions in which larvae were grown, with northern populations expressing higher activity, boldness and foraging efficiency.

When grown in native conditions, northern larvae were bolder more active and more effective in prey capture than central and low latitude populations, respectively, as well as showed the strongest behavioural syndromes. In contrast, larvae reared in constant common-garden conditions showed no differences between regions in both individual traits and syndromes.

本研究针对分布跨度达3300千米的纬度梯度上的一化性豆娘（Lestes sponsa）幼虫的行为性状与行为相关性展开了研究。我们比较了两类饲养环境下幼虫的行为谱：一类为原生温度与光周期环境，另一类为恒定平均温度与恒定平均光周期环境。本研究推测，无论幼虫的饲养环境如何，行为性状均存在纬度差异：北部种群将表现出更高的活动能力、大胆性与觅食效率。

在原生环境中饲养时，北部种群幼虫的大胆性、活动能力与猎物捕获效率均显著高于中部与低纬度种群，同时其行为综合征的强度也最高。与之相反，在恒定的同质园（common-garden）环境中饲养的幼虫，其个体性状与行为综合征均未表现出区域差异。