Kraus Johanna M, Kuivila Kathryn M, Hladik Michelle L, Shook Neil, Mushet David M, Dowdy Kelen, Harrington Rachel
Fort Collins Science Center, US Geological Survey, Fort Collins, Colorado.
Oregon Water Science Center, US Geological Survey, Portland, Oregon.
Environ Toxicol Chem. 2021 Aug;40(8):2282-2296. doi: 10.1002/etc.5111. Epub 2021 Jul 7.
Contaminants alter the quantity and quality of insect prey available to terrestrial insectivores. In agricultural regions, the quantity of aquatic insects emerging from freshwaters can be impacted by insecticides originating from surrounding croplands. We hypothesized that, in such regions, adult aquatic insects could also act as vectors of pesticide transfer to terrestrial food webs. To estimate insect-mediated pesticide flux from wetlands embedded in an important agricultural landscape, semipermanetly and temporarily ponded wetlands were surveyed in cropland and grassland landscapes across a natural salinity gradient in the Prairie Pothole Region of North Dakota (USA) during the bird breeding season in 2015 and 2016 (n = 14 and 15 wetlands, respectively). Current-use pesticides, including the herbicide atrazine and the insecticides bifenthrin and imidacloprid, were detected in newly emerged insects. Pesticide detections were similar in insects emerging from agricultural and grassland wetlands. Biomass of emerging aquatic insects decreased 43%, and insect-mediated pesticide flux increased 50% along the observed gradient in concentrations of insecticides in emerging aquatic insects (from 3 to 577 ng total insecticide g insect). Overall, adult aquatic insects were estimated to transfer between 2 and 180 µg total pesticide wetland d to the terrestrial ecosystem. In one of the 2 study years, biomass of emerging adult aquatic insects was also 73% lower from agricultural than grassland wetlands and was dependent on salinity. Our results suggest that accumulated insecticides reduce the availability of adult aquatic insect prey for insectivores and potentially increase insectivore exposure to insect-borne pesticides. Adult aquatic insects retain pesticides across metamorphosis and may expose insectivores living near both agricultural and grassland wetlands to dietary sources of toxic chemicals. Environ Toxicol Chem 2021;40:2282-2296. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.
污染物会改变陆生食虫动物可获取的昆虫猎物的数量和质量。在农业地区，淡水羽化出的水生昆虫数量可能会受到来自周边农田的杀虫剂的影响。我们推测，在这些地区，成年水生昆虫也可能成为农药向陆地食物网转移的载体。为了估算位于重要农业景观中的湿地通过昆虫介导的农药通量，2015年和2016年鸟类繁殖季节期间，在美国北达科他州草原坑洼地区，沿着自然盐度梯度，在农田和草地景观中对半永久性和临时性积水湿地进行了调查（分别有14个和15个湿地）。在新羽化出的昆虫中检测到了当前使用的农药，包括除草剂阿特拉津以及杀虫剂联苯菊酯和吡虫啉。从农业湿地和草地湿地羽化出的昆虫中的农药检测情况相似。随着观察到的羽化水生昆虫体内杀虫剂浓度梯度（从每克昆虫含3至577纳克总杀虫剂），羽化水生昆虫的生物量下降了43%，而昆虫介导的农药通量增加了50%。总体而言，估计成年水生昆虫每天向陆地生态系统转移2至180微克总农药/湿地。在两个研究年份中的一年，农业湿地羽化出的成年水生昆虫生物量也比草地湿地低73%，且依赖于盐度。我们的结果表明，累积的杀虫剂减少了食虫动物可获取的成年水生昆虫猎物数量，并可能增加食虫动物接触昆虫传播农药的机会。成年水生昆虫在变态过程中会保留农药，并可能使生活在农业和草地湿地附近的食虫动物接触到有毒化学物质的饮食来源。《环境毒理学与化学》2021年；40：2282 - 2296。2021年发表。本文是美国政府作品，在美国属于公共领域。
