Impact of Embryonic Exposure of Atrazine on the Physiological and Behavioral Parameters in <scp> <i>Drosophila melanogaster</i> </scp>

Atrazine is an extensively used herbicide for pre-and post-emergence of grassy and broadleaf weeds. It has become a common environmental contaminant with subsequent residual contamination of water and food, which causes adverse effects on non-target organisms. It is known to induce neurotoxicity, immunotoxicity, genotoxicity, and oxidative stress. The primary objective of the current study was to determine the effect of atrazine on the physiology and behavior of both larvae and adult flies. Newly fertilized eggs were exposed to different concentrations of atrazine (50% WP) (20, 25, 30, and 35 μg/mL) in the diet until the adult fly emerged. To evaluate behavioral changes, larval crawling assay, temperature sensitivity assay (both thermal and cold sensitivity), pupation height preference, adult climbing assay, negative geotaxis, and survival rate were determined on larvae and adult flies fed on atrazine. Capillary feeding assay and metabolic rate were determined in newly emerged flies treated with the same concentration of atrazine during development to measure physiological changes. It was observed that atrazine exposure decreased temperature sensitivity and larval crawling, and also, the pupation height index was lowered. Moreover, it decreased the pupation and survival rate as compared to control, whereas it had no impact on the rate of emergence of flies. Furthermore, the results revealed that with the increase in atrazine concentration, a corresponding decrease in the climbing, feeding, and metabolic rate of the adult flies was observed. In conclusion, the present study demonstrates that atrazine affects a range of physiological and behavioral factors, especially food intake and metabolism, and it also affects neuromuscular activity as apparent from the larval crawling assay and adult climbing assay.