The larval morphology of the water scavenger beetle Psalitrus yamatensis Hoshina & Satô, 2005 is described based on a specimen collected from Fukuoka Prefecture, Kyushu, Japan. This is the first description of the larval morphology of the hydrophilid genus Psalitrus d’Orchymont, 1919, as well as the first description of larval chaetotaxy of the tribe Omicrini. Species-level identification of the larva was performed using DNA barcoding of a molecular marker: a 658 bp fragment of the mitochondrial cytochrome oxidase I. A description including chaetotaxy of head capsule and head appendages, diagnosis, and illustrations of the larva is provided. Psalitrus larvae can be distinguished from other known larvae of the tribe Omicrini by the morphology of the head and legs. The larva shares characters with other known larvae of Omicrini; potential plesiomorphies are shared with Cylominae and aquatic hydrophilids; some characters are also shared with larvae of Megasternini and Sphaeridiini.

中文翻译：

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第一个已知的 omicrine 属 Psalitrus d'Orchymont（鞘翅目，亲水科）的幼虫

基于从日本九州福冈县收集的标本描述了水清道夫甲虫 Psalitrus yamatensis Hoshina & Satô, 2005 的幼虫形态。这是 1919 年对亲水性 Psalitrus d'Orchymont 属的幼虫形态的首次描述，也是 Omicrini 部落的幼虫 chaetotaxy 的首次描述。幼虫的物种水平鉴定是使用分子标记的 DNA 条形码进行的：线粒体细胞色素氧化酶 I 的 658 bp 片段。提供了描述，包括头囊和头附件的毛状体、诊断和幼虫的插图。通过头部和腿部的形态，可以将 Psalitrus 幼虫与 Omicrini 部落的其他已知幼虫区分开来。幼虫与其他已知的 Omicrini 幼虫具有相同的特征；潜在的 plesiomorphies 与 Cylominae 和水生亲水动物共享；一些特征也与 Megasternini 和 Sphaeridiini 的幼虫共享。