Department of Entomology, Washington State University, Puyallup, Washington, USA.
J Environ Sci Health B. 2011;46(4):336-40. doi: 10.1080/03601234.2011.559891.
The effects of the natural insecticide, spinosad, and the agricultural adjuvant, R-11, were evaluated on populations of the water flea, Ceriodaphnia dubia after chronic 8-day exposures. The number of individuals used to start the chronic exposure studies (founders) and the number of offspring/surviving female were significantly reduced after exposure to spinosad concentrations ≥ 2.5 μg/L. The final number of individuals was significantly reduced after exposure to spinosad concentrations ≥ 1.0 μg/L. Population growth rate was significantly reduced after exposure to spinosad concentrations ≥ 1 μg/L. Extinction occurred (defined as negative population growth rate) after exposure to spinosad concentrations of 10 μg/L. Therefore, negative effects were observed in C. dubia after exposure to spinosad at a concentration near the chronic expected environmental concentration (EEC) of 2.3 μg/L. R-11 was much less toxic to C. dubia than spinosad. The number of founders was not significantly reduced until C. dubia were exposed to 12,000 μg/L. The number of offspring/surviving female, final number of individuals, and population growth rate were significantly reduced after exposure to R-11 concentrations ≥ 5,000 μg/L. Extinction occurred after exposure to R-11 concentrations of 12,000 μg/L which was above the EEC of 790 μg/L. These results indicate that spinosad and R-11 both have lethal and sublethal effects on C. dubia. However, spinosad appears to affect C. dubia at or near the EEC while R-11 does not negatively affect this species until concentrations are much higher than the EEC.
自然杀虫剂多杀菌素和农业助剂 R-11 对水蚤 Ceriodaphnia dubia 的种群在慢性 8 天暴露后的影响进行了评估。在接触多杀菌素浓度≥2.5μg/L 后，开始慢性暴露研究的个体数量（创始人）和后代/存活雌性的数量显著减少。在接触多杀菌素浓度≥1.0μg/L 后，最终个体数量显著减少。在接触多杀菌素浓度≥1μg/L 后，种群增长率显著降低。在接触多杀菌素浓度为 10μg/L 后，出现了灭绝（定义为负种群增长率）。因此，在接触多杀菌素浓度接近慢性预期环境浓度（EEC）2.3μg/L 后，水蚤 C. dubia 观察到了负面影响。R-11 对水蚤 C. dubia 的毒性远低于多杀菌素。在接触到 12000μg/L 的 R-11 之前，创始人的数量没有明显减少。在接触到 R-11 浓度≥5000μg/L 后，后代/存活雌性的数量、最终个体数量和种群增长率均显著降低。在接触到 R-11 浓度为 12000μg/L 后，出现了灭绝，该浓度高于 EEC 的 790μg/L。这些结果表明，多杀菌素和 R-11 对水蚤 C. dubia 都有致死和亚致死作用。然而，多杀菌素似乎在 EEC 或接近 EEC 的水平上影响水蚤 C. dubia，而 R-11 在浓度远高于 EEC 时才对该物种产生负面影响。
