The extreme biological diversity of Oceanian archipelagos has long stimulated research in ecology and evolution. However, parasitic protists in this geographic area remained neglected and no molecular analyses have been carried out to understand the evolutionary patterns and relationships with their hosts. Papua New Guinea (PNG) is a biodiversity hotspot containing over 5% of the world's biodiversity in less than 0.5% of the total land area. In the current work, we examined insect heteropteran hosts collected in PNG for the presence of trypanosomatid parasites. The diversity of insect flagellates was analysed, to our knowledge for the first time, east of Wallace's Line, one of the most distinct biogeographic boundaries of the world. Out of 907 investigated specimens from 138 species and 23 families of the true bugs collected in eight localities, 135 (15%) were infected by at least one trypanosomatid species. High species diversity of captured hosts correlated with high diversity of detected trypanosomatids. Of 46 trypanosomatid Typing Units documented in PNG, only eight were known from other geographic locations, while 38 TUs (~83%) have not been previously encountered. The widespread trypanosomatid TUs were found in both widely distributed and endemic/sub-endemic insects. Approximately one-third of the endemic trypanosomatid TUs were found in widely distributed hosts, while the remaining species were confined to endemic and sub-endemic insects. The TUs from PNG form clades with conspicuous host-parasite coevolutionary patterns, as well as those with a remarkable lack of this trait. In addition, our analysis revealed new members of the subfamilies Leishmaniinae and Strigomonadinae, potentially representing new genera of trypanosomatids.

中文翻译：

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巴布亚新几内亚的昆虫锥虫：高度特有性和多样性。

大洋洲群岛的极端生物多样性长期以来刺激了生态学和进化的研究。然而，该地理区域的寄生原生生物仍然被忽视，并且没有进行分子分析来了解进化模式及其与宿主的关系。巴布亚新几内亚 (PNG) 是一个生物多样性热点，在不到陆地总面积的 0.5% 的范围内拥有世界 5% 以上的生物多样性。在目前的工作中，我们检查了在 PNG 中收集的昆虫异翅目宿主是否存在锥虫寄生虫。据我们所知，第一次在华莱士线以东分析了昆虫鞭毛虫的多样性，华莱士线是世界上最独特的生物地理边界之一。在来自 8 个地点收集的 138 个物种和 23 个真虫科的 907 个调查标本中，135 个（15%）被至少一种锥虫感染。捕获宿主的高物种多样性与检测到的锥虫的高多样性相关。在 PNG 中记录的 46 个锥虫分型单元中，只有 8 个来自其他地理位置，而 38 个 TU（~83%）以前从未遇到过。在广泛分布的和地方性/亚地方性昆虫中都发现了广泛存在的锥虫 TU。在广泛分布的宿主中发现了大约三分之一的地方性锥虫 TU，而其余物种仅限于地方性和亚地方性昆虫。来自 PNG 的 TU 形成了具有明显宿主-寄生虫共同进化模式的进化枝，以及那些明显缺乏这种特征的人。此外，我们的分析揭示了 Leishmaniinae 和 Stigomonadinae 亚科的新成员，它们可能代表锥虫科的新属。