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.

特异性（Specificity，即生态特化程度）是生态学的核心概念之一。然而，围绕特异性的定义与测量所存在的歧义，却给相关研究工作带来了诸多阻碍。本文针对昆虫类群提出，在无适宜寄主植物的人工饲养条件下，成虫产卵潜伏期这一行为性状，与该物种幼虫寄主利用的特异性存在显著关联。当缺乏合适寄主时，单食性（monophagous）昆虫通常会等待更长时间才启动产卵，这种较长的等待时长对应其野外环境中审慎的寄主定位行为。与之相对，广食性（polyphagous）昆虫会被自然选择偏好提升产卵速率，而非优先考量所遇产卵基质的质量，因此其平均潜伏期更短。我们利用实验获取的产卵潜伏期数据，基于贝叶斯推断（Bayesian inference）开展了纳入系统发育信息的分析，结果表明，在北欧尺蛾科（Geometridae）蛾类样本中，该变量与寄主特异性（即幼虫食性广度）显著相关。另一项与之紧密相关的指标——即在非适宜产卵基质上产卵的概率——也呈现出类似的关联模式。为展示上述指标的应用方法，我们将北欧尺蛾科蛾类样本与赤道非洲的尺蛾样本进行了对比分析。基于全新系统发育重建的比较分析显示，两个研究区域的产卵行为参数并无显著差异。我们由此得出结论：当无法直接记录生态相互作用时，行为实验可用于获取相关生态信息。本研究案例同时也提示，与温带区域相比，植食性动物的寄主特异性未必在热带区域更高。