Postgraduate Program in Agrochemistry, Goiano Federal Institute of Education, Science and Technology, P.O Box 66, Campus Rio Verde, Rio Verde, Goiás, 75901-970, Brazil.
Federal University of Fronteira Sul, Av. Fernando Machado 108 E, Chapeco, SC, 89802112, Brazil.
Environ Sci Pollut Res Int. 2021 Jun;28(22):27655-27665. doi: 10.1007/s11356-021-12562-0. Epub 2021 Jan 29.
Imidacloprid is one of the most commercialized insecticides in agriculture in the world, with a broad spectrum of action. However, little is known about the effects of commercial formulations containing this active ingredient (a.i.) on non-target organisms in tropical soils. Our objective was to assess the toxicity based on the predicted environmental concentration (PEC) of imidacloprid, in the avoidance behaviour of earthworms and collembolans as well as in the reproduction of collembolans, in two representative soils of the Brazilian Cerrado with contrasting texture (clayey Oxisol and sandy Entisol). Ecotoxicity tests were carried out according to ISO protocols to assess the avoidance behaviour of earthworms (Eisenia andrei) and avoidance and reproduction of collembolans (Folsomia candida). In the earthworm's avoidance test, more than 80% of the individuals were found in the control, in all tested concentrations, indicating a possible habitat function loss in both soils. The avoidance behaviour of collembolans was observed in both soils, being more expressive (up to 75% of escape) in Oxisol. In Entisol, only the two highest concentrations were avoided (up to 63%). There was a negative effect on the reproduction of collembolans in both soils, with a higher EC value (0.255 mg kg) in Oxisol than in Entisol (0.177 mg kg), demonstrating higher toxicity in the sandy soil. These differences were attributed to the contrasting texture of the studied soils, probably due to lower retention of the a.i. in the sandy soil, causing an increased bioavailability. This study demonstrated that imidacloprid can be highly toxic to soil invertebrates, even in soil concentrations lower than those expected from recommended dose, causing an impact on the edaphic organisms and, consequently, compromising its functions in the soil ecosystem.
吡虫啉是世界农业中使用最广泛的杀虫剂之一，具有广谱作用。然而，对于含有这种活性成分（a.i.）的商业制剂对热带土壤中非目标生物的影响知之甚少。我们的目的是根据吡虫啉的预测环境浓度（PEC），评估其对两种具有代表性的巴西塞拉多土壤（粘壤土氧化土和沙壤土）中蚯蚓和弹尾目动物的回避行为以及弹尾目动物的繁殖的毒性。根据 ISO 协议进行了生态毒性测试，以评估蚯蚓（赤子爱胜蚓）的回避行为和弹尾目动物的回避和繁殖。在蚯蚓回避试验中，超过 80%的个体在所有测试浓度的对照中被发现，表明在两种土壤中可能失去了栖息地功能。在两种土壤中都观察到了弹尾目动物的回避行为，在氧化土中更为明显（高达 75%的逃避）。在 Entisol 中，只有两个最高浓度被回避（高达 63%）。吡虫啉对两种土壤中弹尾目动物的繁殖均有负面影响，氧化土中的 EC 值（0.255 mg kg）高于 Entisol（0.177 mg kg），表明在沙质土壤中毒性更高。这些差异归因于所研究土壤的质地差异，可能是由于在沙质土壤中 a.i.的保留率较低，导致生物利用度增加。本研究表明，吡虫啉即使在低于推荐剂量的土壤浓度下也可能对土壤无脊椎动物具有高度毒性，从而对土壤生物产生影响，进而破坏其在土壤生态系统中的功能。
