The world’s fast disappearing mangrove forests have low plant diversity and are often assumed to also have a species-poor insect fauna. We here compare the tropical arthropod fauna across a freshwater swamp and six different forest types (rain-, swamp, dry-coastal, urban, freshwater swamp, mangroves) based on 140,000 barcoded specimens belonging to ca. 8500 species. We find that the globally imperiled habitat “mangroves” is an overlooked hotspot for insect diversity. Our study reveals a species-rich mangrove insect fauna (>3000 species in Singapore alone) that is distinct (>50% of species are mangrove-specific) and has high species turnover across Southeast and East Asia. For most habitats, plant diversity is a good predictor of insect diversity, but mangroves are an exception and compensate for a comparatively low number of phytophagous and fungivorous insect species by supporting an unusually rich community of predators whose larvae feed in the productive mudflats. For the remaining tropical habitats, the insect communities have diversity patterns that are largely congruent across guilds. The discovery of such a sizeable and distinct insect fauna in a globally threatened habitat underlines how little is known about global insect biodiversity. We here show how such knowledge gaps can be closed quickly with new cost-effective NGS barcoding techniques.

中文翻译：

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尽管植物多样性低，但红树林是一个被忽视的昆虫多样性热点

世界上快速消失的红树林植物多样性低，通常被认为也有物种贫乏的昆虫群。我们在这里基于 140,000 个属于约 8500 种。我们发现全球濒临灭绝的栖息地“红树林”是昆虫多样性的一个被忽视的热点。我们的研究揭示了一个物种丰富的红树林昆虫动物群（仅新加坡就有超过 3000 种），它是独特的（>50% 的物种是红树林特有的）并且在东南亚和东亚具有很高的物种周转率。对于大多数栖息地，植物多样性是昆虫多样性的良好预测指标，但红树林是一个例外，它通过支持异常丰富的食肉动物群落来弥补数量相对较少的植食性和食真菌性昆虫物种，这些食肉动物的幼虫以肥沃的泥滩为食。对于剩余的热带栖息地，昆虫群落的多样性模式在各行会中基本一致。在全球受威胁的栖息地中发现了如此庞大而独特的昆虫动物群，这突显出人们对全球昆虫生物多样性知之甚少。我们在这里展示了如何使用新的经济高效的 NGS 条形码技术快速弥合这种知识差距。昆虫群落的多样性模式在各行会中基本一致。在全球受威胁的栖息地中发现了如此庞大而独特的昆虫动物群，这突显出人们对全球昆虫生物多样性知之甚少。我们在这里展示了如何使用新的经济高效的 NGS 条形码技术快速弥合这种知识差距。昆虫群落的多样性模式在各行会中基本一致。在全球受威胁的栖息地中发现了如此庞大而独特的昆虫动物群，这突显出人们对全球昆虫生物多样性知之甚少。我们在这里展示了如何使用新的经济高效的 NGS 条形码技术快速弥合这种知识差距。