Reproductivetoxicityandoxidativestressofchlorantraniliproletotwospringtails(Collembola)

Chlorantraniliprole (CAP) is a pesticide widely used in crop protection. In this study, the toxic effects of CAP on the soil system were evaluated. The non-target soil springtails, namely Folsomia candida Willem and Sinella insolens were exposed to CAP for 28 and 21 days, respectively, to examine the reproductive toxicity of CAP and they were exposed to CAP for 10 days in oxidation stress tests. The EC_50-repro of CAP to those two species were 0.533 mg/kg dw (95% confidential interval of 0.370-0.769 mg/kg dw) and >1000 mg/kg dw, respectively. The activities of catalase (CAT), glutathione reductase (GR), glutathione-s-transferase (GST), the content of total glutathione (TG), lipid peroxidation (LPO) and metallothionein (MT) were measured after the springtails were exposed to sub-lethal CAP doses after 0, 2, 4, 6 and 10 days. Under experimental concentrations of CAP, the activities of CAT increased significantly at the early stage of exposure by 113% and 108% (P <0.05), resectively. Aubsequently, the activities of GR were increased by 141% and 74.6% (P <0.05). Eventunally, both the activities decreased to the same levels of the control group . The activities of GST decreased significantly at day 4 by 38.4% and 21.6% (P <0.05), respectively. Then they increased to the same level of control group at day 10. CAP exposure also resulted in an increase in the TG levels within 6 days. Then TG level decreased slightly. The LPO contents showed similar trends as CAT and GR, with slighter changes. However, MT levels were not significantly elevated with the extension of exposure time, suggesting their insensitivity to CAP. The results indicated that F. candida was a better indicator animal.The activities of CAT, GR and GST were sensitive to CAP exposure and could be used as potential biomarkers in CAP early warning. TG and LPO could be used as selective biomarkers for medium and long term CAP warning.