The Frosted Elfin butterfly (Callophyrs irus) is a locally rare Lycaenid with a wide distribution across the eastern United States but a very patchy distribution. Many populations are either no longer extant or are declining. The Frosted Elfin is currently the focus of a rangewide status assessment by the United States Fish and Wildlife Service (USFWS) in anticipation of a listing determination in 2023. Frosted Elfin caterpillars can be difficult and time consuming to locate on the host plant. Nocturnal surveys with an ultraviolet flashlight were highly effective at reducing the time and increasing the number of caterpillars found compared to daytime searches. The results suggest ultraviolet light surveys for larva can extend the survey period well beyond the adult flight period and should be useful for rapid habitat assessments, presence/absence surveys, and to investigate larval behavior and life history. Ultraviolet light surveys for caterpillars may also be useful for other rare species and for broader faunal surveys.

中文翻译：

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使用紫外线测量稀有蝴蝶的毛毛虫：以磨砂小精灵蝴蝶 (Callophyrs irus) 为例

Frosted Elfin 蝴蝶 (Callophyrs irus) 是一种当地罕见的 Lycaenid，在美国东部广泛分布，但分布非常零散。许多人口要么不再存在，要么正在减少。Frosted Elfin 目前是美国鱼类和野生动物管理局 (USFWS) 进行范围广泛状态评估的重点，预计 2023 年将被列入名单。在寄主植物上定位 Frosted Elfin 毛虫可能既困难又耗时。与白天搜索相比，使用紫外线手电筒进行夜间调查在减少时间和增加发现的毛毛虫数量方面非常有效。结果表明，对幼虫进行紫外线调查可以将调查时间延长到远超过成虫飞行期，应该有助于快速栖息地评估，存在/不存在调查，并调查幼虫行为和生活史。毛毛虫的紫外线调查也可能对其他稀有物种和更广泛的动物群调查有用。