Effect of the Insecticide Chlorpyrifos on Behavioral and Metabolic Aspects of the Spider Polybetes pythagoricus

摘要

The toxicity of pesticides to organisms depends on the total amount of chemical exposure. Toxicity can beminimized if the organism recognizes the pesticide and alters its behavior. Furthermore, the physical barrier of cuticularhydrocarbons can prevent the entrance of the pesticide into the organism. Finally, if the pesticide enters the body, theorganism experiences physiological changes favoring detoxification and the maintenance of homeostasis. We analyzed thebehavioral and metabolic response of the spider Polybetes pythagoricus at different times of exposure to the organophosphatepesticide chlorpyrifos. First we observed that the individuals are capable of recognizing and avoiding surfacestreated with pesticides based on a behavioral analysis. Subsequently, we characterized cuticular hydrocarbons as a possiblebarrier against pesticides. Then we observed that the pesticide provoked histological damage, mainly at the level of themidgut diverticula. Finally, we analyzed the activity of several of the spider's enzymes linked to oxidative stress afterexposure to chlorpyrifos for different lengths of time (6, 24, and 48 h). We observed that catalase activity was high at the start,whereas the activity of superoxide dismutase and glutathione S‐transferase changed significantly at 48 h. Lipid peroxidationbecame high at 6 h, but decreased at 48 h. In conclusion, although P. pythagoricus can avoid contact with chlorpyrifos, thispesticide causes activation of the antioxidant system when it enters the body. Our results make a significant contribution tothe ecotoxicology of spiders.