Abstract：
Behavior and fitness are important ecological traits frequently measured in insect bioassays. A common method to measure them in soft-bodied herbivorous insects involves confining individuals to plant leaves using clip cages. Although studies have previously highlighted the negative effects of clip cages on leaf physiology, little is known about the impact that using this confinement method has on insect fitness. The responses of different aphid genotypes/clones to different containment methods have not previously been investigated. Here we measured key fitness traits (intrinsic rate of natural increase, mean relative growth rate, time to reach reproductive adulthood and population doubling time) in the potato aphid, Macrosiphum euphorbiae Thomas (Hemiptera: Aphididae), when confined to plants using two methods: (1) clip cages to confine aphids to individual strawberry leaves and (2) a mesh bag to confine aphids to whole strawberry plants. Our study identified a strong negative impact on all the measured aphid fitness traits when using clip cages instead of mesh bags. We also identified genotype-specific differences in response to confinement method, where clip cage confinement differentially affected the fitness of a given aphid genotype compared to the same genotype on whole plants. These results suggest that clip cage use should be carefully considered when experiments seek to quantify insect fitness and that whole plants should be used wherever possible. Given the prevalence of clip cage use in insect bioassays, our results highlight the need for caution when interpreting the existing literature as confinement method significantly impacts aphid fitness depending on their genotype.
摘要：
行为和适应性是昆虫生物测定中经常测量的重要生态特征。在柔软的食草昆虫中测量它们的常用方法包括使用夹子将个体限制在种植叶子上。尽管以前的研究已经强调了夹笼对叶片生理的负面影响，关于使用这种禁闭方法对昆虫适应性的影响知之甚少。以前尚未研究过不同蚜虫基因型/克隆对不同遏制方法的反应。在这里，我们测量了关键的健康特征(自然增长率，平均相对增长率，达到生殖成年的时间和种群倍增时间）在马铃薯蚜虫中，大虹藻euphorbiae托马斯（半翅目：蚜科），当使用两种方法限制在植物中时：（1）将蚜虫限制在单个草莓叶上，以及（2）将蚜虫限制在整个草莓植物上的网袋。我们的研究发现，当使用夹子代替网袋时，对所有测得的蚜虫适应性特征都有很大的负面影响。我们还确定了响应于禁闭方法的基因型特异性差异，与整株植物上的相同基因型相比，夹笼限制对给定蚜虫基因型的适应性有不同的影响。这些结果表明，当实验试图量化昆虫的适应性时，应仔细考虑使用夹子笼，并且应尽可能使用整株植物。鉴于昆虫生物测定中使用夹子笼的普遍性，我们的研究结果强调了在解释现有文献时需要谨慎,因为禁闭方法会显著影响蚜虫的适应性,这取决于它们的基因型.
