Data from: Reproductive behaviour indicates specificity in resource use: phylogenetic examples from temperate and tropical insects

Specificity (= the degree of ecological specialisation) is one of the fundamental concepts of the science of ecology. Ambiguities on how to define and measure specificity have however complicated respective research efforts. Here we propose that, in insects, a behavioural trait –adult oviposition latency in captivity without a favourable host plant – correlates with a species’ specificity in larval host use. In the absence of a suitable host, monophagous insects are expected to wait for a long time before commencing oviposition, with the long waiting time corresponding to careful host location behaviour in nature. Polyphagous insects, in contrast, should be selected for an increased oviposition rate at the expense of the quality of oviposition substrate encountered and will on average have a short latency time. Using experimentally derived data on oviposition latency, we performed a phylogenetically informed analysis based on Bayesian inference to show that this variable correlates with host specificity (larval diet breadth) in a sample of North-European species of geometrid moths. A closely related index – the probability to lay any eggs on an unfavourable substrate – shows an analogous pattern. To provide an example of how these indices can be applied, we compare our sample of geometrid moths from Northern Europe with a sample from equatorial Africa. A comparative analysis based on an original phylogenetic reconstruction found no differences between the two study sites in parameters of oviposition behaviour. We conclude that behavioural tests can provide information about ecological interactions when the latter cannot be directly recorded. Our example study also hints at the possibility that host specificity of herbivores is not necessarily higher in a tropical region compared to a temperate one.

专化性（Specificity，即生态特化程度）是生态学的核心概念之一。然而，专化性的定义与衡量方式尚存歧义，这给相关研究带来了诸多阻碍。本文提出：针对昆虫类群，在无适宜寄主植物的人工饲养环境下，成虫的产卵潜伏期这一行为性状，与该物种幼虫寄主利用的专化性存在关联。当缺乏合适寄主时，单食性昆虫通常会等待较长时间才开始产卵，这种较长的等待时长对应了自然界中其对寄主的精准定位行为。与之相对，多食性昆虫则会被选择出更高的产卵速率，以牺牲所遇产卵基质的质量为代价，其平均潜伏期也更短。我们利用实验获得的产卵潜伏期数据，基于贝叶斯推断开展了基于系统发育信息的分析，结果表明：在北欧尺蛾类物种样本中，该变量与寄主专化性（幼虫食性广度）显著相关。另一项密切相关的指标——即昆虫在不适宜基质上产卵的概率——也呈现出类似的规律。为展示这些指标的应用方式，我们将北欧尺蛾类样本与赤道非洲的尺蛾类样本进行了对比。基于原创性系统发育重建的比较分析显示，两处研究区域的产卵行为参数并无显著差异。我们得出结论：当生态互作无法直接观测时，行为实验可提供相关信息。本研究案例同时也表明，与温带区域相比，热带地区植食性动物的寄主专化性未必更高。