Schultz Cheryl B, Dlugosch Katrina M
Department of Zoology, University of Washington, Seattle, WA 98195, USA, , , , , , US.
Oecologia. 1999 May;119(2):231-238. doi: 10.1007/s004420050781.
As grassland habitats become degraded, declines in juvenile and adult food resources may limit populations of rare insects. Fender's blue butterfly (Icaricia icarioides fenderi), a species proposed for listing as endangered under the US Endangered Species Act, survives in remnants of upland prairie in western Oregon. We investigated the effects of limited larval hostplants and adult nectar sources on butterfly population size at four sites that encompass a range of resource densities. We used coarse and detailed estimates of resource abundance to test hypotheses relating resource quantity to population size. Coarse estimates of resources (percent cover of hostplant and density of nectar flowers) suggest that butterfly population size is not associated with resource availability. However, more detailed estimates of resources (density of hostplant leaves and quantity of nectar from native nectar sources) suggest that butterfly population size is strongly associated with resource availability. The results of this study suggest that restoring degraded habitat by augmenting adult and larval resources will play an important role in managing populations of this rare butterfly.
随着草原栖息地退化，幼虫和成虫食物资源的减少可能会限制珍稀昆虫的数量。芬德氏蓝蝶（Icaricia icarioides fenderi）是一种根据美国《濒危物种法》被提议列为濒危物种的蝴蝶，它生存在俄勒冈州西部高地草原的残余区域。我们在四个涵盖一系列资源密度的地点，研究了有限的幼虫寄主植物和成虫花蜜来源对蝴蝶种群数量的影响。我们使用了资源丰度的粗略估计和详细估计，来检验有关资源数量与种群数量关系的假设。资源的粗略估计（寄主植物的覆盖百分比和花蜜花的密度）表明，蝴蝶种群数量与资源可用性无关。然而，资源的更详细估计（寄主植物叶片的密度和本地花蜜来源的花蜜量）表明，蝴蝶种群数量与资源可用性密切相关。这项研究的结果表明，通过增加成虫和幼虫资源来恢复退化的栖息地，将在管理这种珍稀蝴蝶的种群方面发挥重要作用。
