Context Global environmental change is expected to dramatically affect agricultural crop production through a myriad of pathways. One important and thus far poorly understood impact is the effect of land cover and climate change on agricultural insect pests and insecticides. Objectives Here we address the following three questions: (1) how do landscape complexity and weather influence present-day insecticide use, (2) how will changing landscape characteristics and changing climate influence future insecticide use, and how do these effects manifest for different climate and land cover projections? and (3) what are the most important drivers of changing insecticide use? Methods We use panel models applied to county-level agriculture, land cover, and weather data in the US to understand how landscape composition and configuration, weather, and farm characteristics impact present-day insecticide use. We then leverage forecasted changes in land cover and climate under different future scenarios to predict insecticide use in 2050. Results We find different future scenarios—through modifications in both landscape and climate conditions—increase the amount of area treated by ~ 4–20% relative to 2017, with regionally heterogeneous impacts. Of note, we report large farms are more influential than large crop patches and increased winter minimum temperature is more influential than increased summer maximum temperature. However, our results suggest the most important determinants of future insecticide use are crop composition and farm size, variables for which future forecasts are sparse. Conclusions Both landscape and climate change are expected to increase future insecticide use. Yet, crop composition and farm size are highly influential, data-poor variables. Better understanding of future crop composition and farm economics is necessary to effectively predict and mitigate increases in pesticide use.

中文翻译：

---

土地覆盖和气候变化推动美国杀虫剂使用的区域异质性增加

背景 全球环境变化预计将通过无数途径显着影响农作物生产。一个重要但迄今知之甚少的影响是土地覆盖和气候变化对农业害虫和杀虫剂的影响。目标 在这里，我们解决以下三个问题：（1）景观复杂性和天气如何影响当今的杀虫剂使用，（2）不断变化的景观特征和气候变化将如何影响未来的杀虫剂使用，以及这些影响如何在不同气候下表现出来和土地覆盖预测？(3) 改变杀虫剂使用的最重要驱动因素是什么？方法 我们使用应用于美国县级农业、土地覆盖和天气数据的面板模型来了解景观构成和配置、天气、和农场特征影响当今杀虫剂的使用。然后，我们利用不同未来情景下土地覆盖和气候的预测变化来预测 2050 年的杀虫剂使用情况。 结果我们发现不同的未来情景——通过改变景​​观和气候条件——使处理面积增加约 4-20%到 2017 年，具有区域异质性影响。值得注意的是，我们报告说，大型农场比大型作物补丁更有影响力，冬季最低温度升高比夏季最高温度升高的影响更大。然而，我们的结果表明，未来杀虫剂使用的最重要决定因素是作物组成和农场规模，未来预测很少的变量。结论 景观和气候变化预计将增加未来杀虫剂的使用。然而，作物构成和农场规模是影响很大的、缺乏数据的变量。更好地了解未来的作物成分和农场经济对于有效预测和减缓农药使用的增加是必要的。