Insect declines are being reported worldwide for flying, ground, and aquatic lineages. Most reports come from western and northern Europe, where the insect fauna is well-studied and there are considerable demographic data for many taxonomically disparate lineages. Additional cases of faunal losses have been noted from Asia, North America, the Arctic, the Neotropics, and elsewhere. While this review addresses both species loss and population declines, its emphasis is on the latter. Declines of abundant species can be especially worrisome, given that they anchor trophic interactions and shoulder many of the essential ecosystem services of their respective communities. A review of the factors believed to be responsible for observed collapses and those perceived to be especially threatening to insects form the core of this treatment. In addition to widely recognized threats to insect biodiversity, e.g., habitat destruction, agricultural intensification (including pesticide use), climate change, and invasive species, this assessment highlights a few less commonly considered factors such as atmospheric nitrification from the burning of fossil fuels and the effects of droughts and changing precipitation patterns. Because the geographic extent and magnitude of insect declines are largely unknown, there is an urgent need for monitoring efforts, especially across ecological gradients, which will help to identify important causal factors in declines. This review also considers the status of vertebrate insectivores, reporting bias, challenges inherent in collecting and interpreting insect demographic data, and cases of increasing insect abundance.

中文翻译：

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人类世间的昆虫数量下降。

据报道，全世界飞行，地面和水生世系的昆虫数量都在下降。大多数报道来自西欧和北欧，那里对昆虫的动物区系进行了深入研究，并且有许多分类学上不同的谱系的人口统计数据。亚洲，北美，北极，新热带和其他地区也注意到了其他动物损失的情况。虽然本次审查既解决了物种流失，又解决了种群减少的问题，但重点是后者。丰富物种的衰落尤其令人担忧，因为它们锚定了营养相互作用并承担了各自社区的许多重要生态系统服务。对认为造成倒塌的因素以及认为对昆虫造成特别威胁的因素的审查构成了该处理的核心。除了广泛认识到的对昆虫生物多样性的威胁，例如生境破坏，农业集约化（包括使用杀虫剂），气候变化和入侵物种外，该评估还强调了一些不那么普遍考虑的因素，例如化石燃料燃烧产生的大气硝化和干旱和降雨模式变化的影响。由于昆虫下降的地理范围和程度在很大程度上是未知的，因此迫切需要监测工作，尤其是跨生态梯度的监测工作，这将有助于确定下降的重要原因。这篇综述还考虑了脊椎动物食虫动物的状况，报告偏见，收集和解释昆虫种群数据固有的挑战以及昆虫数量增加的情况。