Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
Universidade Federal Do Tocantins, Campus de Gurupi, Gurupi, TO, 77402-970, Brasil.
Environ Sci Pollut Res Int. 2023 Sep;30(41):93779-93785. doi: 10.1007/s11356-023-28956-1. Epub 2023 Jul 29.
Neonicotinoids are highly consumed systemic insecticides that mimic acetylcholine (ACh) with a specific mode of action at the nicotinic acetylcholine receptors (nAChRs). The insecticide Actara® (active ingredient thiamethoxam- TMX) is a commercial formulation widely used for the control of various agricultural pest species. However, negative effects of TMX have been observed in non-target organisms. This work aimed to evaluate the biological effects of the commercial formulation Actara® on the aquatic non-target and non-biting larvae of Chironomus xanthus (Diptera). The lethal (LC) and sublethal (body length, head capsule width, cumulative emergence, and mean time to emergence-EmT) effects were determined in two subsequent generations (P and F1). The estimated 48 h LC for C. xanthus larvae exposed to Actara® was 73.02 µg TMX/L. By looking at the sublethal effects of Actara on the life cycle parameters of C. xanthus, we determined that none of the concentrations used induced a significantly different response in the organisms, compared to the control treatment (NOEC > 2 µg TMX/L). However, the head capsule width in the parental (P) generation exposed to Actara (≥ 0.9 µg TMX/L) was significantly bigger than the head capsule width of control animals. Overall, our results highlight that, at environmentally relevant concentrations, the commercial formulation Actara® is non-toxic to C. xanthus.
新烟碱类杀虫剂是高度消耗的系统性杀虫剂，它们通过与烟碱型乙酰胆碱受体（nAChRs）的特定作用模式模拟乙酰胆碱（ACh）。杀虫剂 Actara®（有效成分噻虫嗪-TMX）是一种广泛用于控制各种农业害虫的商业制剂。然而，TMX 已被观察到对非靶标生物具有负面影响。本工作旨在评估商业制剂 Actara®对水生非靶标和非吸血蝇类 Chironomus xanthus（双翅目）幼虫的生物效应。在两代（P 和 F1）中确定了致死（LC）和亚致死（体长、头壳宽度、累计出现率和平均出现时间-EmT）效应。暴露于 Actara®的 C. xanthus 幼虫的估计 48 h LC 为 73.02 µg TMX/L。通过观察 Actara 对 C. xanthus 生命周期参数的亚致死效应，我们确定与对照处理（NOEC>2 µg TMX/L）相比，使用的任何浓度都没有引起生物体的显著不同反应。然而，暴露于 Actara（≥0.9 µg TMX/L）的亲代（P）代的头壳宽度明显大于对照动物的头壳宽度。总体而言，我们的结果表明，在环境相关浓度下，商业制剂 Actara®对 C. xanthus 是无毒的。
