Densities of the endangered Large blue butterfly Phengaris arion vary by 100-fold in restored conservation grasslands, providing a tool to prioritise future introductions

A long-term study was made of the carrying capacities (K) of UK grasslands restored to support the endangered butterfly Phengaris arion. This iconic species is the focus of major restoration programmes and provides a blueprint for the conservation of other threatened insects. P. arion larvae are phytophagous during their early instars before switching to become obligate social parasites of Myrmica ant colonies for their main growth. A mechanistic model, incorporating life-table measurements of natality and mortalities, was used to predict the value of K on 19 restorations. Predictions were compared with actual butterfly densities measured for up to 33 consecutive generations per site over 43 years. The model suggested that individual sites vary by up to a hundred-fold in the density of butterflies each site would support. Observed densities closely correlated with model predictions, with the most productive site supporting 129-times more butterflies per square metre than the l..., , , # Densities of the endangered Large blue butterfly Phengaris arion vary by 100-fold in restored conservation grasslands, providing a tool to prioritise future introductions

[https://doi.org/10.5061/dryad.4j0zpc8pc](https://doi.org/10.5061/dryad.4j0zpc8pc)

## Description of the data and file structure

The Excel file tabulates data collected in the field on restoration sites for Phengaris arion, a social parasite as a larva of the ant Myrmica sabuleti. The rows refer to each of 19 sites. The columns data consist of 3 columns describing the fitness of the host ant Myrmica sabuleti on each site; site area and ant equivalents calculated as described in methods section of the article; and estimated and observed carrying capacity densities (K) for each site together with the standard errors and ln values of these.  

### Files and variables

#### File: Thomas\_et\_al\_japplecol\_data.xlsx

**Description:** field data used to calculate estimated and mean observed carrying capacities of 19 UK...

本研究针对英国19个修复型草地的承载量（carrying capacity, K）展开长期调查，修复草地的核心目标是支撑濒危蝴蝶大蓝蝶（Phengaris arion）的种群存续。该标志性物种是多项重大生态修复项目的核心关注对象，同时为其他受胁昆虫的保护工作提供了重要参考蓝图。
大蓝蝶幼虫在早期龄期为植食性，之后转变为专性社会性寄生物，寄生于红蚁属（Myrmica）蚁群中完成主要生长阶段。本研究整合出生率与死亡率的生命表测量数据，构建了机械模型，用于预测19个修复样地的承载量K。将模型预测结果与43年间每个样地最多连续33个世代实测的蝴蝶实际种群密度进行对比后发现：模型显示不同样地的理论可承载蝴蝶密度最高可达百倍差异；实测密度与模型预测值高度相关，其中生产力最高的样地每平方米可承载的蝴蝶数量较最低效样地高出129倍……
# 濒危大蓝蝶（Phengaris arion）在修复后的保护草地中的种群密度差异可达百倍，该研究可为未来的蝴蝶引入工作提供优先级判定依据
[https://doi.org/10.5061/dryad.4j0zpc8pc](https://doi.org/10.5061/dryad.4j0zpc8pc)

## 数据与文件结构说明
本Excel文件整理了针对大蓝蝶（Phengaris arion）修复样地的野外采集数据，该蝶幼虫为沙氏红蚁（Myrmica sabuleti）的社会性寄生物。
表格行对应19个样地。列数据包含三类：①描述各修复样地宿主沙氏红蚁适合度的3列数据；②按论文方法部分所述计算得到的样地面积与蚁当量数据；③各修复样地的理论与实测承载密度(K)，以及对应的标准误与自然对数（ln）值。

### 文件与变量
#### 文件：Thomas_et_al_japplecol_data.xlsx
**文件说明：** 用于计算英国19个修复样地大蓝蝶理论承载量与实测平均承载量的野外数据集……