Faculty of Science and Forestry, Department of Biology, University of Eastern Finland, PO Box 111, FI-80101 Joensuu, Finland.
Parasitology. 2011 Mar;138(3):354-63. doi: 10.1017/S0031182010001332. Epub 2010 Sep 30.
The deer ked (Lipoptena cervi) is a common ectoparasite of cervids. During the last decades the species has rapidly invaded in northern Europe, especially in Finland, towards the north and increased its prevalence on the moose population. Consequently, during this rapid invasion the deer ked has faced more severe climatic conditions. We studied whether pupal size (measured as pupal weight) and pupal development duration of the deer ked varies along historical invasion zones and temperature zones towards north in Finland. Moreover, we explored possible size- and gender-dependent variation in pupal development duration. We divided wild-collected pupae in respect to their origin in two ways: (1) temperature zones (from south-west to colder north-east) and (2) invasion history (from early to late establishment). We reared pupae in the controlled laboratory conditions in identical temperature and light conditions. Pupal size decreased towards north and the smaller pupae developed faster. However, the results do not show differences in pupal size or developmental characteristics between the invasion zones. This supports the idea of rapid developmental plasticity of the deer ked and that not the invasion history but the current temperature regime determines the life history of the deer ked when invading towards a colder environment.
鹿虱（Lipoptena cervi）是一种常见的鹿科外寄生虫。在过去的几十年里，该物种在北欧迅速蔓延，尤其是在芬兰，向北蔓延，并增加了在驼鹿种群中的流行率。因此，在这种快速入侵过程中，鹿虱面临着更严峻的气候条件。我们研究了鹿虱的蛹期大小（以蛹重衡量）和蛹期发育时间是否会随着芬兰北部历史入侵区和温度区的变化而变化。此外，我们还探讨了蛹期发育时间是否存在大小和性别相关的差异。我们根据起源将野外采集的蛹分为两种方式：（1）温度区（从西南到较冷的东北）和（2）入侵历史（从早期到后期建立）。我们在相同的温度和光照条件下，在控制的实验室条件下饲养蛹。随着向北移动，蛹的大小减小，较小的蛹发育得更快。然而，结果并未显示出入侵区之间在蛹大小或发育特征上存在差异。这支持了鹿虱快速发育可塑性的观点，即不是入侵历史，而是当前的温度模式决定了鹿虱在向更冷环境入侵时的生活史。
