Background The golden-headed weevil Compsus auricephalus is a native and fairly widespread species across the southern U.S.A. extending through Central America south to Panama. There are two recognised morphotypes of the species: the typical green form, with pink to cupreous head and part of the legs and the uniformly white to pale brown form. There are other Central and South American species of Compsus and related genera of similar appearance that make it challenging to provide accurate identifications of introduced species at ports of entry. New information Here, we re-describe the species, provide images of the habitus, miscellaneous morphological structures and male and female genitalia. We discuss the morphological variation of Compsus auricephalus across its distributional range, by revising and updating its distributional range, based on data from entomological collections in the U.S.A. and Canada. The revised distribution of C. auricephalus extends as far south as Zacapa in Guatemala. Records south from there correspond to a different species, with affinities to C. auricephalus that we discuss and illustrate. We also discuss morphological affinities and differences with other similar species. Furthermore, we summarise information regarding the biology, host plants and natural enemies of C. auricephalus.

中文翻译：

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金头象鼻虫 Compsus auricephalus (Say) 的变异性和分布 (Curculionidae: Entiminae: Eustylini)。

背景 金头象鼻虫 Compsus auricephalus 是一种原生且相当广泛的物种，横跨美国南部，穿过中美洲向南延伸到巴拿马。该物种有两种公认的形态类型：典型的绿色形态，头部和部分腿呈粉红色至铜色，以及均匀的白色至浅棕色。还有其他中美洲和南美洲的 Compsus 物种以及外观相似的相关属，这使得在入境口岸提供对引入物种的准确识别具有挑战性。新信息 在这里，我们重新描述了物种，提供了习性、杂项形态结构和雄性和雌性生殖器的图像。我们通过修改和更新其分布范围，讨论了 Compsus auricephalus 在其分布范围内的形态变化，基于来自美国和加拿大昆虫学收藏的数据。C. auricephalus 的修订分布向南延伸至危地马拉的 Zacapa。从那里向南的记录对应于一个不同的物种，与我们讨论和说明的 C. auricephalus 有亲缘关系。我们还讨论了与其他类似物种的形态亲和力和差异。此外，我们总结了有关 C. auricephalus 的生物学、寄主植物和天敌的信息。