Brazil is the largest producer of sugarcane and the world’s top pesticide market. Therefore, environmental consequences are of concern. The aim of the present study was to evaluate the acute and chronic toxicity of pesticide formulations largely used in sugarcane crops: the herbicide DMA® 806 BR (a.i. 2,4-D) and the insecticide Regent® 800 WG (a.i. fipronil), isolated and in mixture, to the Neotropical cladoceran Ceriodaphnia silvestrii. Toxicity tests with the individual formulated products indicated 48h-EC₅₀ values of 169 ± 18 mg a.i./L for 2,4-D and 3.9 ± 0.50 µg a.i./L for fipronil. In the chronic tests, the 8d-EC₅₀ values for reproduction were 55 mg a.i./L (NOEC/LOEC: 50/60 mg a.i./L) and 1.6 µg a.i./L (NOEC/LOEC: 0.40/0.80 µg a.i./L) for 2,4-D and fipronil, respectively. A significant decrease in reproduction of C. silvestrii in all concentrations tested of fipronil, except at the lowest, was observed. Regarding 2,4-D, the organisms had total inhibition of reproduction in the two highest concentrations. Probably your energy reallocation was focused (trade-off) only on its survival. The acute pesticide mixture toxicity (immobility) revealed a dose level dependent deviation with antagonism at low and synergism at high concentrations. For chronic mixture (reproduction) toxicity, antagonism occurred as a result of the interaction of the pesticides. Based on our results and concentrations measured in Brazilian water bodies, fipronil represents ecological risks for causing direct toxic effects on C. silvestrii. These results are worrisome given that agricultural production is likely to increase in the coming years.

巴西是甘蔗的最大生产国，也是世界上最大的农药市场。因此，环境后果值得关注。本研究的目的是评估主要用于甘蔗作物的农药制剂的急性和慢性毒性：除草剂DMA®806 BR（ai 2,4-D）和杀虫剂Regent®800 WG（ai fipronil），经分离并混合在一起，形成新热带的claderceran Ceriodaphnia silvestrii。个别配方产品的毒性测试表明，48h-EC ₅₀值对于2,4-D为169±18 mg ai / L，对于氟虫腈为3.9±0.50 µg ai / L。在长期测试中，8d-EC ₅₀对于2,4-D和氟虫腈，繁殖值分别为55 mg ai / L（NOEC / LOEC：50/60 mg ai / L）和1.6 µg ai / L（NOEC / LOEC：0.40 / 0.80 µg ai / L），分别。Silvestrii的繁殖显着下降在所有浓度的氟虫腈中，除最低浓度外，均观察到。关于2，4-D，该生物在两个最高浓度下具有完全的繁殖抑制作用。可能您的能量重新分配仅关注（权衡）生存期。急性农药混合物的毒性（不动）显示出剂量水平的偏差，低浓度时有拮抗作用，高浓度时有协同作用。对于慢性混合物（生殖）毒性，由于农药的相互作用而产生了拮抗作用。根据我们的研究结果和在巴西水体中测得的浓度，氟虫腈代表了对C. silvestrii造成直接毒性作用的生态风险。考虑到未来几年农业产量可能会增加，这些结果令人担忧。