Erhardt Andreas, Rusterholz Hans-Peter
Department of Integrative Biology, Section Conservation Biology (NLU), University of Basel, St. Johanns-Vorstadt 10, CH-4056 Basel, Switzerland e-mail:
Oecologia. 1998 Dec;117(4):536-542. doi: 10.1007/s004420050690.
The preferences for nectar amino acids, urea and ammonium ions of peacock butterflies, Inachis io, were tested experimentally. Females clearly preferred a mimic of Lantana camara nectar containing amino acids to an otherwise similar plain sugar solution, whereas males did not discriminate between these test solutions. Neither males nor females discriminated between the full mixture of amino acids in a mimic of L. camara nectar and similar test solutions containing only the single amino acids arginine or proline. Furthermore, the butterflies were not able to detect methionine in the test solutions. Both sexes detected and preferred ammonium ions in test solutions but showed no response to urea. These results support the hypothesis that butterflies can select for high amino acid concentrations in floral nectar. However, it seems unlikely that they select for particular amino acids. The rather unspecific response of I. io males to the nectar constituents tested may result from their relatively low demand for nitrogen for spermatophore and sperm production, while their high activity may make energy supply (i.e. sugar) more important. The preference for ammonium ions suggests that I. io could also acquire nitrogen from ammonium-contaminated soil by puddling, as has been shown for sodium in swallowtail butterflies.
对孔雀蛱蝶（Inachis io）花蜜中氨基酸、尿素和铵离子的偏好进行了实验测试。雌性明显更喜欢含有氨基酸的马缨丹花蜜模拟物，而不是其他类似的纯糖溶液，而雄性在这些测试溶液之间没有表现出偏好差异。雄性和雌性在马缨丹花蜜模拟物中的氨基酸全混合物与仅含有单个氨基酸精氨酸或脯氨酸的类似测试溶液之间均未表现出偏好差异。此外，蝴蝶无法在测试溶液中检测到蛋氨酸。两性在测试溶液中都能检测到并偏好铵离子，但对尿素无反应。这些结果支持了蝴蝶能够选择花蜜中高氨基酸浓度的假设。然而，它们似乎不太可能选择特定的氨基酸。孔雀蛱蝶雄性对所测试的花蜜成分的反应相当不具特异性，这可能是由于它们对用于精荚和精子产生的氮的需求相对较低，而它们的高活动水平可能使能量供应（即糖）更为重要。对铵离子的偏好表明，孔雀蛱蝶也可以像凤蝶对钠的情况那样，通过在受铵污染的土壤中舐吸来获取氮。
