Environmental Toxicology Program, Clemson University, Clemson, SC 29634, USA.
Chemosphere. 2013 Aug;92(9):1260-6. doi: 10.1016/j.chemosphere.2013.04.061. Epub 2013 May 25.
Pyriproxyfen is an insecticidal juvenile hormone analog that perturbs insect and tick development. Pyriproxyfen also alters parthenogenic reproduction in non-target cladoceran species as it induces male production that can lead to a decrease in fecundity, a reduction in population density, and subsequent ecological effects. In this study, we investigate the impacts of pyriproxyfen on Daphnia magna reproduction using a series of male production screening assays. These assays demonstrate that pyriproxyfen increases male production in a concentration-dependent fashion with an EC50 of 156pM (50.24ngL(-1)); a concentration considered environmentally relevant. Furthermore, pyriproxyfen decreases overall fecundity at all ages tested (7, 14, 21-d old female parthenogenic daphnids). Juvenile (3-d old) and reproductively mature (10-d old) female daphnids were also exposed to 155pM pyriproxyfen for 2-12d and reproduction measured for 16d to compare the effects of short-term and prolonged exposures, and determine the potential for recovery. Results indicate that longer pyriproxyfen exposures (8-12d) extend male production and decrease reproduction; however, daphnids exposed for only 2-4d recover and produce a relatively normal abundance of neonates. In addition, juvenile daphnids are also very sensitive to pyriproxyfen, but the primary effect on juvenile daphnids is reduced reproduction and protracted development not male production. Taken together, continued use of pyriproxyfen around water bodies needs due caution because of its potential adverse effects with significant developmental delays and male production compounded by prolonged exposure.
吡丙醚是一种昆虫生长调节剂，能扰乱昆虫和蜱的发育。吡丙醚还改变了非靶标枝角类物种的孤雌生殖，因为它诱导雄性产生，这可能导致生育能力下降、种群密度降低，以及随后的生态影响。在这项研究中，我们使用一系列雄性生产筛选试验来研究吡丙醚对大型溞繁殖的影响。这些试验表明，吡丙醚以浓度依赖的方式增加雄性产生，EC50 为 156pM（50.24ngL(-1)）；这一浓度被认为具有环境相关性。此外，吡丙醚在所有测试的年龄（7、14、21 天龄的孤雌生殖溞）都降低了总生育力。还对 155pM 吡丙醚暴露 2-12d 的幼年（3 天龄）和生殖成熟（10 天龄）雌性溞进行了暴露，并对 16d 进行了繁殖测量，以比较短期和长期暴露的影响，并确定恢复的潜力。结果表明，较长时间的吡丙醚暴露（8-12d）会延长雄性产生并降低繁殖能力；然而，仅暴露 2-4d 的溞会恢复并产生相对正常数量的幼体。此外，幼年溞也对吡丙醚非常敏感，但对幼年溞的主要影响是繁殖减少和发育延长，而不是雄性产生。综上所述，由于吡丙醚具有潜在的不利影响，包括发育迟缓、雄性产生和长期暴露，因此在水体周围继续使用吡丙醚需要谨慎。
