Data from: Developmental lead exposure has mixed effects on butterfly cognitive processes

While the effects of lead pollution have been well studied in vertebrates, it is unclear to what extent lead may negatively affect insect cognition. Lead pollution in soils can elevate lead in plant tissues, suggesting it could negatively affect neural development of insect herbivores. We used the cabbage white butterfly (Pieris rapae) as a model system to study the effect of lead pollution on insect cognitive processes, which play an important role in how insects locate and handle resources. Cabbage white butterfly larvae were reared on a 4-ppm lead diet, a concentration representative of vegetation in polluted sites; we measured eye size and performance on a foraging assay in adults. Relative to controls, lead-reared butterflies did not differ in time or ability to search for a food reward associated with a less preferred color. Indeed, lead-treated butterflies were more likely to participate in the behavioral assay itself. Lead exposure did not negatively affect survival or body size, and it actually sped up development time. The effects of lead on relative eye size varied with sex: lead tended to reduce eye size in males, but increase eye size in females. These results suggest that low levels of lead pollution may have mixed effects on butterfly vision, but only minimal impacts on performance in foraging tasks, although follow-up work is needed to test whether this result is specific to cabbage whites, which are often associated with disturbed areas.

尽管学界已对脊椎动物的铅污染效应开展了充分研究，但目前仍不清楚铅会在多大程度上对昆虫的认知能力产生负面影响。土壤中的铅污染可提升植物组织的铅富集量，由此推测铅可能会对昆虫植食者的神经发育造成负面影响。本研究以菜粉蝶（Pieris rapae）作为模式生物体系，探究铅污染对昆虫认知过程的影响——认知过程在昆虫定位与利用资源的过程中发挥着关键作用。研究人员将菜粉蝶幼虫饲养于含4ppm铅的人工饲料中，该铅浓度与污染区域内植被的铅含量水平相当；随后测定了成虫的眼部尺寸以及觅食行为测试中的表现。与对照组相比，经铅暴露处理的菜粉蝶在搜寻与非偏好颜色相关的食物奖励时，所需耗时与搜寻能力均无显著差异。事实上，经铅处理的蝴蝶更愿意参与本次行为测试。铅暴露并未对菜粉蝶的存活率或体型产生负面影响，反而缩短了其发育周期。铅暴露对相对眼部尺寸的影响存在性别差异：铅暴露会缩小雄性菜粉蝶的眼部尺寸，却会增大雌性个体的眼部尺寸。上述结果表明，低浓度铅污染可能对菜粉蝶的视觉产生混合效应，但对其觅食任务中的表现仅存在微弱影响；不过仍需开展后续研究，以验证该结果是否仅适用于常栖息于受干扰区域的菜粉蝶。