Van den Brink Paul J, Van Smeden Jasper M, Bekele Robel S, Dierick Wiebe, De Gelder Daphne M, Noteboom Maarten, Roessink Ivo
Department of Aquatic Ecology and Water Quality Management, Wageningen University, Wageningen, The Netherlands.
Alterra, Wageningen University and Research Centre, Wageningen, The Netherlands.
Environ Toxicol Chem. 2016 Jan;35(1):128-33. doi: 10.1002/etc.3152. Epub 2015 Dec 3.
Mayfly nymphs are among the most sensitive taxa to neonicotinoids. The present study presents the acute and chronic toxicity of 3 neonicotinoids (imidacloprid, thiacloprid, and thiamethoxam) to a mayfly species (Cloeon dipterum) and some notes on the seasonality of the toxicity of imidacloprid to C. dipterum and 5 other invertebrate species. Imidacloprid and thiamethoxam showed equal acute and chronic toxicity to a winter generation of C. dipterum, whereas thiacloprid was approximately twice as toxic. The acute and chronic toxicity of imidacloprid was much higher for the C. dipterum summer generation than for the winter one. The acute toxicity differs by a factor of 20 for the 96-h 50% effective concentration (EC50) and by a factor of 5.4 for the chronic 28-d EC50. Temperature had only a slight effect on the sensitivity of C. dipterum to imidacloprid because we only found a factor of 1.7 difference in the 96-h EC50 between tests performed at 10 °C and 18 °C. The difference in sensitivity between summer and overwintering generations was also found for 3 other insect species. The results indicate that if the use and environmental fate of the 3 neonicotinoids are comparable, replacing imidacloprid by another neonicotinoid might not reduce the environmental impact on the mayfly nymph C. dipterum. The results also show the importance of reporting which generation is tested because sensitivity values of insects in the summer might be underestimated by the experiments performed with neonicotinoids and an overwintering population.
蜉蝣若虫是对新烟碱类最敏感的生物分类群之一。本研究呈现了3种新烟碱类（吡虫啉、噻虫啉和噻虫嗪）对一种蜉蝣物种（二翼细蜉）的急性和慢性毒性，以及关于吡虫啉对二翼细蜉和其他5种无脊椎动物物种毒性季节性的一些说明。吡虫啉和噻虫嗪对二翼细蜉冬季世代显示出相同的急性和慢性毒性，而噻虫啉的毒性约为前者的两倍。吡虫啉对二翼细蜉夏季世代的急性和慢性毒性远高于冬季世代。对于96小时50%有效浓度（EC50），急性毒性相差20倍，对于慢性28天EC50，相差5.4倍。温度对二翼细蜉对吡虫啉的敏感性影响甚微，因为我们发现在10°C和18°C进行的试验之间，96小时EC50仅相差1.7倍。在其他3种昆虫物种中也发现了夏季和越冬世代之间的敏感性差异。结果表明，如果这3种新烟碱类的使用和环境归宿具有可比性，用另一种新烟碱类替代吡虫啉可能不会降低对蜉蝣若虫二翼细蜉的环境影响。结果还表明报告所测试的世代很重要，因为用新烟碱类和越冬种群进行的实验可能会低估夏季昆虫的敏感性值。
