Department of Entomology, The Ohio State University, Wooster, Ohio, USA.
Department of Biological Sciences, Kent State University, Kent, Ohio, USA.
Ecol Appl. 2024 Oct;34(7):e3024. doi: 10.1002/eap.3024. Epub 2024 Aug 27.
Understanding causes of insect population declines is essential for the development of successful conservation plans, but data limitations restrict assessment across spatial and temporal scales. Museum records represent a source of historical data that can be leveraged to investigate temporal trends in insect communities. Native lady beetle decline has been attributed to competition with established alien species and landscape change, but the relative importance of these drivers is difficult to measure with short-term field-based studies. We assessed distribution patterns for native lady beetles over 12 decades using museum records, and evaluated the relative importance of alien species and landscape change as factors contributing to changes in communities. We compiled occurrence records for 28 lady beetle species collected in Ohio, USA, from 1900 to 2018. Taxonomic beta-diversity was used to evaluate changes in lady beetle community composition over time. To evaluate the relative influence of temporal, spatial, landscape, and community factors on the captures of native species, we constructed negative binomial generalized additive models. We report evidence of declines in captures for several native species. Importantly, the timing, severity, and drivers of these documented declines were species-specific. Land cover change was associated with declines in captures, particularly for Coccinella novemnotata which declined prior to the arrival of alien species. Following the establishment and spread of alien lady beetles, processes of species loss/gain and turnover shifted communities toward the dominance of a few alien species beginning in the 1980s. Because factors associated with declines in captures were highly species-specific, this emphasizes that mechanisms driving population losses cannot be generalized even among closely related native species. These findings also indicate the importance of museum holdings and the analysis of species-level data when studying temporal trends in insect populations.
了解昆虫种群减少的原因对于制定成功的保护计划至关重要,但数据限制限制了在时空尺度上进行评估。博物馆记录是一种可以利用的历史数据来源,可以用来调查昆虫群落的时间趋势。本土瓢虫的减少归因于与已建立的外来物种的竞争和景观变化,但这些驱动因素的相对重要性很难通过短期的实地研究来衡量。我们使用博物馆记录评估了 12 个十年中本土瓢虫的分布模式,并评估了外来物种和景观变化作为导致群落变化的因素的相对重要性。我们整理了 1900 年至 2018 年在美国俄亥俄州收集的 28 种瓢虫的出现记录。分类贝塔多样性用于评估瓢虫群落组成随时间的变化。为了评估时间、空间、景观和群落因素对本土物种捕获的相对影响,我们构建了负二项式广义加性模型。我们报告了一些本土物种捕获量下降的证据。重要的是,这些记录下来的下降的时间、严重程度和驱动因素是特定物种的。土地覆被变化与捕获量下降有关,特别是对于在引入外来物种之前就已经下降的 Coccinella novemnotata。在引入外来瓢虫并扩散后,物种损失/增益和周转率的过程开始使群落向少数几种外来物种的主导地位转变,这一转变始于 20 世纪 80 年代。由于与捕获量下降相关的因素高度特定于物种,这强调了即使在密切相关的本土物种中,驱动种群损失的机制也不能一概而论。这些发现还表明了在研究昆虫种群的时间趋势时,博物馆藏品和物种水平数据分析的重要性。