1. Osmia caerulescens is a generalist solitary bee well‐adapted to altered anthropogenic environments, and the kleptoparasitic wasp Sapyga quinquepunctata has been cited among its natural enemies.
2. We analysed offspring characteristics of O. caerulescens and S. quinquepunctata, at population and individual levels, and compared these characteristics between sunny and shady aspects and between two zones within the valley that differed in landscape complexity (simple and complex zones).
3. The offspring production of O. caerulescens was higher in sunny aspect at population and individual levels while S. quinquepunctata was positively associated with the zone with a lower proportion of agricultural land (complex zone). We did not detect a relationship between number of brood cells parasitised and number of brood cells established by host. Despite the parasitism being higher in the area with favourable characteristics for both species, the reproductive success of O. caerulescens did not show signs of reduction. At the individual level, nests with fewer brood cells were more likely to be parasitised.
4. Studying the relationship of environmental factors and landscape features at population and individual levels provides a better understanding of how these characteristics could be driving the offspring production of the solitary bee and their ecological interactions.

中文翻译：

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山坡特征，景观特征和寄生性寄生虫对独居蜂Osmia caerulescens繁殖成功的影响

1. Osmia caerulescens是一种能适应人为环境变化的多才多艺的独居蜂，其寄生天牛被称为kleptoparasitic的黄蜂Sapyga quinquepunctata。
2. 我们在种群和个体水平上分析了青色油菜（O. caerulescens）和西洋参（S. quinquepunctata）的后代特征，并比较了阳光和阴暗面之间以及山谷中景观复杂度不同的两个区域（简单区域和复杂区域）之间的这些特征。
3. 在人口和个体水平上，晴天的后代O. caerulescens的产量较高，而S. quinquepunctata与农业用地比例较低的区域（复杂区域）呈正相关。我们没有发现寄生的育雏细胞数与宿主建立的育雏细胞数之间的关系。尽管该地区的寄生虫较高，并且对这两个物种都具有良好的特性，但是油青紫的生殖成功并未显示出减少的迹象。在个体水平上，巢细胞少的巢更容易被寄生。
4. 研究人口和个人层面的环境因素与景观特征之间的关系，可以更好地理解这些特征如何驱动单蜂的后代生产及其生态相互作用。