Non-native bark beetle species represent a major threat to forest ecosystems. The bark beetle Ips amitinus has recently expanded its range from Finland into northern Sweden. In the present study, we asked the following questions: (i) What is the distribution status in Sweden? (ii) Is there a difference in preference and reproductive success between Norway spruce and Scots pine? (iii) How common is the species after range expansion and does it influence the native community of bark- and wood-boring beetle species? We established the presence of I. amitinus and co-existence with the native community through checks of logging residues at 382 localities in northern Sweden. In addition, attack densities and reproductive success were compared between spruce and pine through investigating field material and by a no-choice rearing experiment. We found that I. amitinus is distributed over large parts of northern Sweden. Within its distribution area, it was found in 58% of all checked localities. It is one of the most common bark beetle species in logging residues and a higher proportion of Norway spruce objects compared to Scots pine were colonised. Attack density and reproductive success were higher in Norway spruce in field material and in the rearing experiment. There was no significant difference in the number of native bark- and wood-boring beetle taxa between localities where I. amitinus was present or absent.

中文翻译：

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树种偏好和树皮甲虫 Ips amitinus 在最近入侵地区对本地物种群落的影响

 非本地树皮甲虫物种是对森林生态系统的主要威胁。树皮甲虫 Ips amitinus 最近将其活动范围从芬兰扩展到瑞典北部。在本研究中，我们提出了以下问题：(i) 瑞典的分布状况如何？(ii) 挪威云杉和欧洲赤松的偏好和繁殖成功率是否存在差异？(iii) 范围扩大后的物种有多普遍？它是否影响树皮和木材钻甲虫物种的本地群落？我们通过检查瑞典北部 382 个地方的伐木残留物，确定了 I. amitinus 的存在以及与当地社区的共存。此外，通过调查田间材料和无选择饲养实验，比较了云杉和松树的攻击密度和繁殖成功率。我们发现 I. amitinus 分布在瑞典北部的大部分地区。在其分布区域内，58% 的检查地点都发现了它。它是伐木残留物中最常见的树皮甲虫物种之一，与苏格兰松树相比，挪威云杉对象的比例更高。在田间材料和饲养实验中，挪威云杉的攻击密度和繁殖成功率更高。在存在或不存在 I. amitinus 的地区之间，本地树皮和木材钻孔甲虫类群的数量没有显着差异。它是伐木残留物中最常见的树皮甲虫物种之一，与苏格兰松树相比，挪威云杉对象的比例更高。在田间材料和饲养实验中，挪威云杉的攻击密度和繁殖成功率更高。在存在或不存在 I. amitinus 的地区之间，本地树皮和木材钻孔甲虫类群的数量没有显着差异。它是伐木残留物中最常见的树皮甲虫物种之一，与苏格兰松树相比，挪威云杉对象的比例更高。在田间材料和饲养实验中，挪威云杉的攻击密度和繁殖成功率更高。在存在或不存在 I. amitinus 的地区之间，本地树皮和木材钻孔甲虫类群的数量没有显着差异。