Wildlife and Landscape Science Directorate, Environment Canada, 867 Lakeshore Road, Burlington, Ontario, Canada.
Sci Total Environ. 2011 Sep 15;409(20):4306-11. doi: 10.1016/j.scitotenv.2011.06.046. Epub 2011 Aug 9.
Many reptiles oviposit in soils associated with agricultural landscapes. We evaluated the toxicity of a pesticide and fertilizer regime similar to those used in corn production in Ontario on the survivorship of exposed snapping turtle (Chelydra serpentina) eggs. The herbicides atrazine, dimethenamid, and glyphosate, the pyrethroid insecticide tefluthrin, and the fertilizer ammonia, were applied to clean soil, both as partial mixtures within chemical classes, as well as complete mixtures. Eggs were incubated in the soil in a garden plot in which these mixtures were applied at a typical field application rate, and higher rates. Otherwise, the eggs were unmanipulated and were subject to ambient temperature and weather conditions. Eggs were also exposed at male producing temperatures in the laboratory in covered bins in the same soil, where there was less opportunity for loss through volatilization or leaching. Egg mortality was 100% at 10× the typical field application rate of the complete mixture, both with and without tefluthrin. At typical field application rates, hatching success ranged between 91.7 and 95.8%. Eggs exposed only to herbicides were not negatively affected at any application rates. Although fertilizer treatments at typical field application rates did not affect eggs, mortality was remarkably higher at three times this rate, and 100% at higher rates. The frequency of deformities of hatchlings was elevated at the highest application rate of the insecticide tefluthrin. The majority of the toxicity of the mixture was not due to the herbicides or insecticide, but was due to the ammonia fertilizer. At typical field application rates, the chemical regime associated with corn production does not appear to have any detrimental impacts upon turtle egg development; however toxicity dramatically increases if this threshold is passed.
许多爬行动物在与农业景观相关的土壤中产卵。我们评估了一种杀虫剂和肥料制度的毒性，该制度类似于安大略省玉米生产中使用的制度，以评估暴露于杀虫剂和肥料制度下的 snapping 龟（Chelydra serpentina）卵的存活率。除草剂莠去津、二甲吩草胺和草甘膦、拟除虫菊酯杀虫剂四氟甲醚菊酯和肥料氨，被应用于清洁土壤，既可以作为化学物质的部分混合物，也可以作为完全混合物。这些混合物以典型田间应用率和更高的浓度应用于花园地块中的土壤中进行孵化，然后对这些卵进行孵化。否则，这些卵未经处理，并受到环境温度和天气条件的影响。在实验室中，在相同的土壤中，在产生雄性的温度下，卵也暴露在覆盖有容器的环境中，在这种环境中，通过蒸发或浸出而损失的机会较少。在 10×典型田间应用率的完全混合物中，无论是否含有四氟甲醚菊酯，100%的卵死亡。在典型田间应用率下，孵化成功率在 91.7%至 95.8%之间。在任何应用率下，仅暴露于除草剂的卵都不会受到负面影响。尽管在典型田间应用率下，肥料处理不会影响卵，但在该浓度的三倍时死亡率显著升高，而在更高的浓度时则为 100%。在最高的四氟甲醚菊酯应用率下，幼龟畸形的频率升高。该混合物的大部分毒性不是由于除草剂或杀虫剂，而是由于氨肥。在典型的田间应用率下，与玉米生产相关的化学物质制度似乎不会对龟卵的发育产生任何不利影响；然而，如果超过这个阈值，毒性会急剧增加。
