Mosquito larvae that survive a heat spike are less sensitive to subsequent exposure to the pesticide chlorpyrifos. (October 2020)

• Record Type: Journal Article
• Authors: Meng, Shandong; Delnat, Vienna; Stoks, Robby
• Is Part Of: Environmental pollution. Volume 265(2020)Part A
• Publication Date: 2020-10
• Subjects: Climate change -- Cross-tolerance -- Multiple stressors -- "Climate-induced toxicant sensitivity" (CITS) concept -- "Toxicant-induced climate change sensitivity" (TICS) concept; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.114824
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: While extreme high temperatures are an important aspect of global warming, their effects on organisms are relatively understudied, especially in ecotoxicology. Sequential exposure to heat spikes and pesticides is a realistic scenario as both are typically transient stressors and are expected to further increase in frequency under global warming. We tested the effects of exposure to a lethal heat spike and subsequently to an ecologically relevant lethal pulse exposure of the pesticide chlorpyrifos in the larvae of mosquito Culex pipiens . The heat spike caused direct and delayed mortality, and resulted in a higher heat tolerance and activity of acetylcholinesterase, and a lower fat content in the survivors. The chlorpyrifos exposure caused mortality, accelerated growth rate, and decreased the heat tolerance and the activity of acetylcholinesterase. The preceding heat spike did not change how chlorpyrifos reduced the heat tolerance. Notably, the preceding heat spike did lower the lethal effect of the pesticide, which makes an important novel finding at the interface of ecotoxicology and global change biology, and adds a new dimension to the "climate-induced toxicant sensitivity" (CITS) concept. This may be due to both survival selection and cross-tolerance, and therefore likely a widespread phenomenon. Our results emphasize the importance of including extreme high temperatures as an important transient global change stressor in ecotoxicology. Graphical abstract: Image 1 Highlights: Heat spikes and pesticides are often pulse stressors that occur sequentially. Both the heat spike and chlorpyrifos imposed mortality in mosquitoes. Previous heat spike exposure made chlorpyrifos less toxic. Chlorpyrifos exposure reduced the heat tolerance. No interactive effects were observed for physiological traits. Abstract : A heat spike made the pesticide chlorpyrifos less lethal, thereby challenging current insights of ecotoxicology under global warming.