Biogeography and ecology of geographically distant populations of sibling <i>Cryptocephalus</i> leaf beetles

Different populations of two closely related species, Cryptocephalusflavipes and C. bameuli, from western (Alps, Apennines and Pyrenees) and central Europe (Poland, Ukraine and Pannonia) were analysed. On the basis of DNA sequences from two genes, cox1 and ef1-α, distinctiveness of both species was confirmed. Nevertheless, possible hybrids were identified in Carpathian mountains. We found a significant genetic differentiation among populations of C. flavipes and C. bameuli from distant regions but a high genetic similarity between populations of C. bameuli from north and south of the Carpathians. Demographic estimates suggest a past population expansion in the case of C. bameuli and a recent one for C. flavipes, possibly occurred during Pleistocene and Holocene, respectively. Distribution modelling showed that C. flavipes is typically present in the mountain systems, whereas C. bameuli is associated with hilly areas of central and eastern Europe. Based on the present data, Last Glacial Maximum refugia of both species were located in the Alpine region and Black Sea coasts, but on different elevations. The characterization of the insect diet, through a DNA metabarcoding approach targeting the trnL plant intron, demonstrated a significant differentiation of food preferences between the two species, as well as between geographic populations within the species.我们对采自西欧（阿尔卑斯山、亚平宁山脉与比利牛斯山）和中欧（波兰、乌克兰及潘诺尼亚平原）的两种近缘物种——黄足隐头叶甲（Cryptocephalus flavipes）和巴姆隐头叶甲（C. bameuli）的不同种群开展了系统分析。基于cox1与ef1-α两个基因的DNA序列数据，研究证实了这两个物种的遗传分化特性。不过，我们在喀尔巴阡山脉中检测到了可能的杂交个体。 研究发现，分布于不同地理区域的黄足隐头叶甲与巴姆隐头叶甲种群间存在显著的遗传分化，但巴姆隐头叶甲在喀尔巴阡山脉南北两侧的种群却表现出较高的遗传相似性。种群历史动态估算结果显示，巴姆隐头叶甲曾发生过种群扩张事件，其扩张时间对应更新世（Pleistocene）；而黄足隐头叶甲的近期种群扩张则发生在全新世（Holocene）。 物种分布模型模拟结果表明，黄足隐头叶甲主要栖息于山地生态系统，而巴姆隐头叶甲则与中欧及东欧的丘陵地带密切相关。结合现有数据推测，两种物种在末次冰盛期（Last Glacial Maximum）的避难所均位于阿尔卑斯山区与黑海沿岸，但二者所处的海拔高度存在显著差异。 通过靶向trnL植物内含子的DNA宏条形码技术（DNA metabarcoding）对昆虫食性进行表征，结果显示两种隐头叶甲的食物偏好存在显著分化，同一物种内的不同地理种群间亦存在食性差异。