Stuligross Clara, Williams Neal M
Graduate Group in Ecology, University of California, Davis, CA 95616;
Department of Entomology and Nematology, University of California, Davis, CA 95616.
Proc Natl Acad Sci U S A. 2021 Nov 30;118(48). doi: 10.1073/pnas.2109909118.
Pesticides are linked to global insect declines, with impacts on biodiversity and essential ecosystem services. In addition to well-documented direct impacts of pesticides at the current stage or time, potential delayed "carryover" effects from past exposure at a different life stage may augment impacts on individuals and populations. We investigated the effects of current exposure and the carryover effects of past insecticide exposure on the individual vital rates and population growth of the solitary bee, Bees in flight cages freely foraged on wildflowers, some treated with the common insecticide, imidacloprid, in a fully crossed design over 2 y, with insecticide exposure or no exposure in each year. Insecticide exposure directly to foraging adults and via carryover effects from past exposure reduced reproduction. Repeated exposure across 2 y additively impaired individual performance, leading to a nearly fourfold reduction in bee population growth. Exposure to even a single insecticide application can have persistent effects on vital rates and can reduce population growth for multiple generations. Carryover effects had profound implications for population persistence and must be considered in risk assessment, conservation, and management decisions for pollinators to mitigate the effects of insecticide exposure.
农药与全球昆虫数量下降有关，对生物多样性和重要的生态系统服务产生影响。除了现阶段或当前已充分记录的农药直接影响外，过去在不同生命阶段接触农药产生的潜在延迟“残留”效应可能会加剧对个体和种群的影响。我们研究了当前接触农药的影响以及过去接触杀虫剂的残留效应对独居蜜蜂个体生命率和种群增长的影响。飞行笼中的蜜蜂自由采食野花，其中一些野花用常见杀虫剂吡虫啉处理，采用完全交叉设计，持续2年，每年都有接触或不接触杀虫剂的情况。直接接触觅食成虫的杀虫剂以及过去接触产生的残留效应都会降低繁殖率。连续两年接触杀虫剂会累加损害个体表现，导致蜜蜂种群增长减少近四倍。即使只接触一次杀虫剂也会对生命率产生持久影响，并会降低多代的种群增长。残留效应对种群持久性具有深远影响，在对传粉者进行风险评估、保护和管理决策时，必须考虑残留效应，以减轻杀虫剂接触的影响。
