MS_japan_all_data

This file contains the tabulations of insects sampled from native and non-native plants. The methods involved were as follows: Phytophagous insects were collected on native and non-native plants in two areas: Haren, province of Groningen, the Netherlands (53º10’N 06º36’E) and Sendai, Miyagi prefecture, Japan (38º16’N 140º52’E). In total, 47 plant species were sampled, which could be divided into four groups: (1) plant species native to the Netherlands and non-native to Japan, or vice versa (14 spp.), (2) plant species non-native to both areas (5 spp.), (3) plant species studied only in the Netherlands; either native or non-native (9 spp.), and (4) plant species studied only in Japan; either native or non-native (19 spp.). Most data were collected simultaneously in both areas between late April and early August, 2010. Only the data on the level of herbivory were not collected simultaneously. Insect collection took place in forests, parks, and gardens. In both the Netherlands and Japan the same two standardised methods were used to sample insects. Insects were collected by shaking the branches of the plant for 10 s above a beating sheet of 1 m2 or by sweeping an insect net with a diameter of 50 cm for 10 s through the branches of the plant. All individuals of the same plant species were sampled with the same method. The collecting methods were rehearsed and standardised (in the Netherlands) by all collectors beforehand. Collected insects were stored in 70% ethanol. Insects from nine taxonomic groups (table 2) were collected. For four taxonomic groups experts were found to identify the species (table 2, indicated by *). For all collected insects the insect load was determined in two ways: by counting the number of insect individuals per sample, and by determining their dry weight. The levels of herbivory were estimated for 17 plant species in the Netherlands and 16 in Japan, using other plant individuals than the ones we sampled insects from. We did this as follows. We first randomly collected ten leaves from a plant and counted the leaves with insect damage. This was repeated for 5-27 individuals per plant species (mean: 11.9). Then, the mean leaf area was determined per plant species, by scanning on average 42 (range: 10-190) leaves per plant species using a flatbed scanner, and calculating the surface area using the software Lafore (Lehsten 2005). Finally, a herbivory index was devised, as [proportion leaves damaged / mean leaf area * 10,000].本数据集包含从本土植物与非本土植物上采集的昆虫制表数据。具体采样方法如下：研究人员分别在荷兰格罗宁根省哈伦（53°10′N 06°36′E）与日本宫城县仙台（38°16′N 140°52′E）两个区域，于本土及非本土植物上采集植食性昆虫（Phytophagous insects）。本次共采样47种植物，可划分为4类：（1）仅在荷兰为本土/非本土、在日本为非本土/本土的植物（14种）；（2）在两个区域均为非本土的植物（5种）；（3）仅在荷兰开展采样的植物，无论其为本土或非本土（9种）；（4）仅在日本开展采样的植物，无论其为本土或非本土（19种）。2010年4月下旬至8月上旬，绝大多数数据于两个区域同步采集，仅植食性危害水平相关数据未同步收集。昆虫采样工作在森林、公园及花园中开展。荷兰与日本两地均采用两套统一标准化的昆虫采样方法：一是将植物枝条在1平方米的拍击布（beating sheet）上方震荡10秒以采集昆虫；二是使用直径50厘米的捕虫网在植物枝条间扫动10秒进行采样。同一植物物种的所有个体均采用同一种采样方法。所有采样人员提前在荷兰完成了采样方法的预演与标准化校准。采集到的昆虫均保存于70%乙醇溶液中。本次共采集到9个昆虫分类类群（见表2），其中4个类群的昆虫物种由专业分类学者完成鉴定（见表2，标注*）。针对所有采集到的昆虫，通过两种方式量化其虫量：一是统计每份样本中的昆虫个体数，二是测定其干重。针对荷兰的17种植物与日本的16种植物，研究人员采用未用于昆虫采样的其他植株个体评估其植食性危害水平，具体操作如下：首先从单株植物上随机采集10片叶片，统计其中存在昆虫取食痕迹的叶片数量；针对每一植物物种，该操作重复于5~27株个体（平均11.9株）。随后，通过平板扫描仪扫描每一植物物种的平均42片叶片（范围10~190片），并使用Lafore软件（Lehsten 2005）计算叶片表面积，以此得到该物种的平均叶面积。最终构建植食性危害指数，计算公式为：[受损叶片占比 / 平均叶面积 × 10000]。