Temperature affects the toxicity of pesticides to cercariae of the trematode Echinostoma trivolvis
Temperature affects the toxicity of pesticides to cercariae of the trematode Echinostoma trivolvis
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温度影响农药对三轮棘口吸虫尾蚴的毒性
DOI：
10.1016/j.aquatox.2022.106102
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发表时间：
2022
影响因子：
4.5
通讯作者：
Hoverman, Jason T.
中科院分区：
文献类型：
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作者：
Billet, Logan S.;Belskis, Alice;Hoverman, Jason T.
据预测，全球气候变化将对宿主-寄生虫关系等生态相互作用产生重大影响。温度升高还可能与化学污染物等其他人为压力因素相互作用，加剧或减少寄生虫传播。然而，关于农药对非目标物种影响的研究通常在一个标准温度下进行，尽管许多农用化学品的毒性取决于温度。此外，大多数评估温度对农药毒性影响的研究都是在宿主生物上进行的，这限制了我们对温度如何影响农药毒性的理解，使其局限于在环境中寻找宿主时的自由生活的寄生虫阶段。使用自由游泳的尾蚴阶段的吸虫Echinostoma trivolvis，我们研究了三种不同的农药（氨基甲酸酯杀虫剂，嗜球果伞素杀菌剂，三嗪除草剂）的毒性如何随温度变化，监测尾蚴的游泳活动随着时间的推移。我们的三个主要发现是：1）在所有农药试验中，温度的强烈主效应-较高的温度导致尾蚴更早地停止游泳活动，可能是由于能量消耗速率的增加，2）莠去津、嘧菌酯和西维因在某种程度上对尾蚴具有直接毒性，但不是以可预测的剂量依赖性方式，以及3）农药暴露发生的温度可能影响其对尾蚴的毒性。农药和温度之间的相互作用在嘧菌酯暴露中最为明显;相对于各自的无农药对照处理，嘧菌酯使尾蚴在30 °C下更早地停止游泳活动，但使尾蚴在18 °C下保持更长时间的游泳活动。这些研究结果强调了在多种温度下进行毒性测定的重要性，并表明农药和温度对宿主-寄生虫相互作用的综合影响可能难以概括。
Global climate change is predicted to have significant impacts on ecological interactions such as host-parasite relationships. Increased temperatures may also interact with other anthropogenic stressors, such as chemical contaminants, to exacerbate or reduce parasite transmission. However, studies on the effects of pesticides on non-target species are typically conducted at one standard temperature, despite the toxicity of many agrochemicals being temperature-dependent. Furthermore, most studies assessing the effects of temperature on pesticide toxicity have been conducted on host organisms, limiting our understanding of how temperature affects the toxicity of pesticides to free-living parasite stages as they move through the environment in search of a host. Using the free-swimming cercariae stage of the trematodeEchinostoma trivolvis, we examined how the toxicities of three different pesticides (a carbamate insecticide, strobilurin fungicide, and triazine herbicide) vary by temperature by monitoring cercarial swimming activity over time. Our three main findings were: 1) a strong main effect of temperature across all pesticide trials – higher temperatures caused cercariae to cease swimming activity earlier, likely due to an increased rate of energy expenditure, 2) atrazine, azoxystrobin, and carbaryl were directly toxic to cercariae to some degree, but not in a predictable dose-dependent manner, and 3) the temperature at which pesticide exposure occurs could affect its toxicity to cercariae. The interaction between pesticide and temperature was most evident in the azoxystrobin exposure; azoxystrobin caused cercariae to cease swimming activity earlier at 30 °C but caused cercariae to maintain swimming activity longer at 18 °C relative to their respective pesticide-free control treatments. These findings highlight the importance of conducting toxicity assays at multiple temperatures and suggest that the combined effects of pesticides and temperature on host-parasite interactions may be difficult to generalize.