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

早期个体发育阶段的食物质量经验预计会导致个体发育后期对这种特定饮食的偏好固定。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，具有不同食物专业化程度的叶甲虫，即专业的耳蜗飞蛾和通才的tanaceti Galeruca，被饲养在低质量的饮食中，高质量的饮食中，或者混合食物中，即在2天的间隔内交替使用低质量和高质量的食物。我们发现，在这种饮食环境下长大的成年人更喜欢高质量的饮食。相比之下，饲喂混合质量饮食的个体没有表现出明显的偏好。在不同的环境（记录了5个测试电池，共9个变量）和时间（测量了成年期的3个时间点）中，这种行为是高度一致的。此外，行为表型强烈依赖于经验食物质量；吃低质量食物的个体比吃高质量食物的个体更勇敢，但更不活跃。不同的行为可能是由不同的生活史引起的，因为在低质量饮食中饲养的甲虫发育较慢，体重较低，可能产卵较少。根据资产保护原则，他们可能因此损失更少，因此与以高质量饮食喂养的成年人相比，他们更容易冒险。由于缺乏能量资源，这些个体的低饮食质量可能导致活动减少，因此这是一种限制而不是适应。在第二个资助期，我们的目标是确定1)在成年期不同时间点的不同饮食经验对行为表型的适应性影响；2)经历不同食物质量的个体对优质饮食偏好和行为表型形成的时间点或发育阶段；3)跨代效应对后代性状的影响程度；4)配偶选择是否发生。昆虫将被饲养在单一或混合的饮食中，在质量和它们的偏好、繁殖产出和行为表型上有所不同，现在在延长的时间点上进行测试，从第二幼虫龄开始（行为）。将进行匹配不匹配实验，以确定是否和何时发生整形，以及它是否自适应。在情况下选型交配变得明显，基本原则将确定使用化学生态方法。这种全面的方法将提供一个深刻的洞察行为的可塑性在两种昆虫不同的饮食宽度。

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.