The study of insect responses to colour has mainly focused on flying species and morphs, however colour cues are likely to be important for insect positioning within the canopy. We examine the role of illumination colour in canopy positioning of apterous Myzus persicae (Sulzer) using both a field experiment, utilising various UV-manipulating optical filters, and a laboratory experiment using video tracking of individuals illuminated by a variable intensity UVA-Blue-Green LED-array. In the field experiment, approximately twice as many aphids were located on exposed leaf surfaces under UV-deficient environments compared to UV-rich environments. The lab experiment showed all three M. persicae photoreceptors were involved in a visually-mediated feeding/avoidance behaviour. Highly UV-rich, green-deficient environments were up to 3 times as likely to trigger an avoidance behaviour compared to UV-absent, green-rich environments such as those found below the leaf surface. We show that apterous M. persicae use this, in addition to other cues, in order to locate feeding positions that minimise exposure to direct sunlight. This has relevance to both the fundamental understanding of photoprotective behaviour in Hemiptera as well as to applied research of crop production environments that disrupt pest behaviour.

昆虫对颜色的反应的研究主要集中在飞行中的物种和形态，但是颜色提示对于昆虫在树冠中的定位很重要。我们使用现场实验（利用各种紫外线操纵的滤光片）和实验室实验（使用视频跟踪由可变强度的UVA-蓝绿色表示的个体）来检查照明颜色在桃蚜（Sulzer）的树冠定位中的作用LED阵列。在田间试验中，在紫外线不足的环境下，暴露于叶片表面的蚜虫数量是紫外线丰富的环境的两倍。实验室实验显示了所有三种桃蚜感光细胞参与视觉介导的进食/回避行为。与缺少紫外线的，富含绿色的环境（例如在叶片表面以下的环境）相比，高度富含紫外线的，缺乏绿色的环境引发逃避行为的可能性高3倍。我们显示，除了其他线索外，无性分枝还可以利用此来定位觅食位置，以最大程度地减少阳光直射。这与对半翅目中的光保护行为的基本了解以及对破坏害虫行为的作物生产环境的应用研究都相关。