Dataset for: CHRONIC TOXICITIES OF NEONICOTINOIDS TO NYMPHS OF THE COMMON NEW ZEALAND MAYFLY DELEATIDIUM SPP.

Neonicotinoid insecticides have been shown to have high chronic relative to acute toxicity, therefore short-term toxicity tests of ≤ 96 hours in duration may underestimate their environmental risks. Among non-target aquatic invertebrates, insects of the orders Diptera and Ephemeroptera have been found to be the most sensitive to neonicotinoids. To undertake more accurate assessment of the risks posed by neonicotinoids to freshwater ecosystems, more data are needed from long-term tests using the most sensitive taxa. Using nymphs of the common New Zealand mayfly genus Deleatidium spp., we performed 28-day static-renewal exposures with the widely used neonicotinoids imidacloprid, clothianidin and thiamethoxam. We monitored survival, immobility, impairment, and mayfly moulting propensity at varying time points throughout the experiment. Imidacloprid and clothianidin exerted strong chronic toxicity to Deleatidium nymphs, with respective 28-day LC50s of 0.28 and 1.36 µg/L, while thiamethoxam was the least toxic, with a 28-day LC50 > 4 µg/L (highest concentration tested). Mayfly moulting propensity was also negatively affected by clothianidin (during 3 of 4 weeks), imidacloprid (2 of 4) and thiamethoxam (1 of 4). Comparisons with published neonicotinoid chronic toxicity data for other mayfly taxa and larvae of the midge genus Chironomus showed similar sensitivities for mayflies and midges, suggesting experiments using these taxa provide reliable assessments of the threats of neonicotinoids to the most vulnerable freshwater species.

拟除虫菊酯类杀虫剂已被证实具有高慢性相对急性毒性，因此，持续时间为≤96小时的短期毒性测试可能会低估其环境风险。在非靶标水生无脊椎动物中，双翅目和蜉蝣目的昆虫已被发现对拟除虫菊酯最为敏感。为了更准确地评估拟除虫菊酯对淡水生态系统所构成的风险，需要更多来自长期测试的数据，这些测试应使用最敏感的物种。通过使用新西兰常见蜉蝣属Deleatidium spp.的若虫，我们进行了为期28天的静态更新暴露实验，使用的拟除虫菊酯包括广泛使用的吡虫啉、氯虫苯甲酰胺和噻虫嗪。我们在实验的不同时间点监测了生存率、不动性、损伤和蜉蝣蜕皮倾向。吡虫啉和氯虫苯甲酰胺对Deleatidium若虫表现出强烈的慢性毒性，分别的28天LC50值为0.28和1.36 µg/L，而噻虫嗪的毒性最低，28天LC50值大于4 µg/L（最高测试浓度）。蜉蝣的蜕皮倾向也受到氯虫苯甲酰胺（4周中的3周）、吡虫啉（4周中的2周）和噻虫嗪（4周中的1周）的负面影响。与已发表的针对其他蜉蝣类和摇蚊属幼虫的拟除虫菊酯慢性毒性数据进行比较，发现蜉蝣和摇蚊对拟除虫菊酯的敏感性相似，这表明使用这些物种进行的实验能够提供对最脆弱淡水物种所受拟除虫菊酯威胁的可靠评估。