Effects of rearing conditions on behavioural phenotypes in specialist versus generalist leaf beetles

个体发育早期阶段的食物质量体验预计会导致个体发育后期对这种特定饮食的偏爱的固定。此外，早期经历可能会影响成年人的整体行为表型。在第一个资助期内，具有不同食物专门化程度的叶甲，专家的Phaedon cochleariae和多面手的Galeruca tanacei，要么用低质量的食物饲养，要么用高质量的食物饲养，或者每隔2 d接受一种混合食物，即交替的低质量和高质量的食物。我们发现，成年人更喜欢高质量的饮食，因为他们是在这样的饮食中长大的。相比之下，用混合质量饮食长大的个体并没有表现出明显的偏好。这种行为在不同的环境(总共记录了5个测试电池，9个变量)和时间(成年期间的3个时间点)上高度一致。此外，行为表型强烈依赖于经验丰富的食物质量；以低质量食物喂养的个体比以高质量食物喂养的个体更大胆，但不那么活跃。这些不同的行为可能是由不同的生活史造成的，因为以低质量饮食饲养的甲虫发育较慢，达到较低的体重，可能产卵也较少。根据资产保护原则，与以高质量饮食养育的成年人相比，他们可能会损失更少，因此更容易面临风险。这些人所接受的低饮食质量可能会由于缺乏能源而导致活动减少，因此是一种制约，而不是一种适应。在第二个资助期，我们的目标是确定1)不同饮食体验在成年阶段的不同时间点对行为表型的影响；2)发育过程中不同食物质量的个体形成对高质量饮食的偏好以及行为表型的时间点或阶段；3)对后代特征产生跨代影响的程度；以及4)是否发生配偶选择。昆虫将被保持在单一或混合的食物中，在质量和它们的喜好、生殖输出和行为表型方面存在差异，现在在更多的时间点进行测试，从第二龄幼虫(行为)开始。将进行匹配失配实验，以确定是否以及何时发生整形，以及它是否具有适应性。如果分类交配变得明显，将使用化学生态方法确定潜在的原则。这一综合方法将为两种饮食广度不同的昆虫物种的行为可塑性提供深刻的洞察。

The food quality experience during early ontogenetic stages is expected to lead to a fixation of preference for this particular diet later in ontogeny. Moreover, early experience might affect the overall behavioural phenotype of adults. Within the first funding period, leaf beetles with different degrees of food specialisation, the specialist Phaedon cochleariae and the generalist Galeruca tanaceti, were reared either on low quality diet, on high quality diet, or they received a mixed food, i.e., alternately low and high quality food in a 2 d interval. We found that adults preferred diet of higher quality when they had been reared on this diet. In contrast, individuals reared on mixed quality diet did not show clear preferences. The behaviour was highly consistent across various contexts (5 test batteries with 9 variables in total were recorded) and time (3 time-points during adulthood were measured). Furthermore, the behavioural phenotypes strongly depended on the experienced food quality; individuals having fed on low quality diet were bolder but less active than individuals reared on high quality food. The different behaviours may be caused by contrasting life histories, as beetles reared on low quality diet developed slower, reached lower body masses and probably lay fewer eggs. According to the asset-protection principle, they may thus have less to lose and therefore be more risk-prone compared to adults reared on high quality diet. The low diet quality received by these individuals may result in lower activity due to a lack of energy resources and thus be a constraint rather than an adaptation. In the second funding period, we aim to determine 1) the fitness consequences of different diet experience at various time points during the adult stage in relation to the behavioural phenotype; 2) the time-point or stage during development at which the preference for quality diet as well as the behavioural phenotype is shaped in individuals experiencing different food quality; 3) in how far transgenerational effects on offspring traits occur; and 4) whether mate-choice occurs. Insects will be kept on either single or mixed diet differing in quality and their preferences, reproductive outputs and behavioural phenotypes tested now at an extended number of time-points, starting already within the second larval instar (for behaviours). Match-mismatch experiments will be conducted to determine whether and when a shaping occurs and whether it is adaptive. In case assortative mating becomes evident, the underlying principles will be identified using chemical ecological methods. This comprehensive approach will offer a deep insight in the plasticity of behaviour in two insect species differing in diet breadth.