Nickel hyperaccumulator plants contain unusually elevated levels of Ni (＞ 1 000 μg Ni/g). Some insect herbivores, including Lygus hesperus (Western tarnished plant bug), have been observed feeding on the California Ni hyperaccumulator Streptanthus polygaloides. This bug may be able to utilize S. polygaloides as a host either through its feeding behavior or by physiological tolerance of Ni. This experiment determined the Ni tolerance of L. hesperus by offering insects artificial diet amended with 0,0.4, 1, 2, 4.5,10, 20 and 40 mmol Ni/L and recording survival. Survival varied due to Ni concentration, with diets containing 10 mmol Ni/L and greater resulting in significantly lower survival compared to the control (0 mmol Ni/L) treatment. Insects tolerated diet containing as much as 4.5 mmol Ni/L, a relatively elevated Ni concentration. I conclude that L. hesperus can feed on S. polygaloides because it is Ni-tolerant, probably due to physiological mechanisms that provide it with resistance to plant chemical defenses including elemental defenses such as hyperaccumulated Ni.
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机译：镍超富集植物中的镍含量异常高（> 1000μgNi / g）。观察到一些昆虫食草动物以加利福尼亚镍超富集链霉菌多倍体为食，其中包括百日草（西方的失去光泽的植物虫）。通过其摄食行为或对Ni的生理耐受性，该虫可能能够利用多倍体链球菌作为宿主。该实验通过向昆虫提供人工饮食，分别以0、0.4、1、2、4.5、10、20和40 mmol Ni / L修正并记录存活率，从而确定了百日草对镍的耐性。存活率因Ni浓度而异，与对照（0 mmol Ni / L）处理相比，日粮中含10 mmol Ni / L或更高的饲料导致存活率明显降低。昆虫耐受的日粮中镍含量高达4.5 mmol / L，这是相对较高的Ni浓度。我得出结论认为，阔叶麦草可以忍受S. polygaloides，因为它对镍具有耐性，这可能是由于生理机制使它对植物化学防御系统具有抵抗力，包括元素防御系统，例如高积累的镍。
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