Moths are the most taxonomically and ecologically diverse insect taxon for which there exist considerable time-series abundance data. There is an alarming record of decreases in moth abundance and diversity from across Europe, with rates varying markedly among and within regions. Recent reports from Costa Rica reveal steep cross-lineage declines of caterpillars, while other sites (Ecuador and Arizona, reported here) show no or only modest long-term decreases over the past two decades. Rates of decline for dietary and ecological specialists are steeper than those for ecologically generalized taxa. Additional traits commonly associated with elevated risks include large wingspans, small geographic ranges, low dispersal ability, and univoltinism; taxa associated with grasslands, aridlands, and nutrient-poor habitats also appear to be at higher risk. In temperate areas, many moth taxa limited historically by abiotic factors are increasing in abundance and range. We regard the most important continental-scale stressors to include reductions in habitat quality and quantity resulting from land-use change and climate change and, to a lesser extent, atmospheric nitrification and introduced species. Site-specific stressors include pesticide use and light pollution. Our assessment of global macrolepidopteran population trends includes numerous cases of both region-wide and local losses and studies that report no declines. Spatial variation of reported losses suggests that multiple stressors are in play. With the exception of recent reports from Costa Rica, the most severe examples of moth declines are from Northern Hemisphere regions of high human-population density and intensive agriculture.

蛾是分类学和生态学上最多样化的昆虫分类单元，对于它们而言，存在大量的时间序列丰度数据。欧洲各地的蛾类数量和多样性减少的记录令人震惊，区域之间和区域内的发生率差异显着。哥斯达黎加的最新报告显示，毛毛虫的跨谱系急剧下降，而其他地点（厄瓜多尔和亚利桑那州，在此报道）在过去的二十年中没有或仅有适度的长期下降。饮食和生态学专家的下降速度比生态学上广义的分类单元的下降速度更大。通常与高风险相关的其他特征包括翼展大，地理范围小，分散能力低和单性化；与草地，干旱地区和营养不良的栖息地相关的分类单元也似乎处于较高的风险中。在温带地区，历史上受非生物因素限制的许多蛾类群的数量和范围都在增加。我们认为，最重要的大陆尺度压力源包括因土地利用变化和气候变化而造成的栖息地质量和数量的减少，以及在较小程度上包括大气硝化作用和引入物种的减少。特定地点的压力源包括农药的使用和光污染。我们对全球大型鳞翅目种群趋势的评估包括区域范围和局部损失的众多案例，以及报告没有下降的研究。报告的损失的空间变化表明存在多个压力源。除哥斯达黎加最近的报道外，最严重的例子是北半球人口密度高和农业集约化的飞蛾。