, Ahmad Gharaei, , ,
Volume 2, Issue 2 (9-2013)
Abstract
The acute toxicity and histopathology of Schizothorax zarudnyi (2±0.2 g body weight)exposed to diazinon was assessed statically in 22±2°C, following the OECD Guideline. The 96h LC50 value of diazinon for the fish was 14.70 mg/l, therefore making its MAC value 1.47 mg/l in natural waters. According to the table of insecticides sorting, the toxicity of diazinon was low for S. zarudnyi. Some clinical symptoms and abnormal reactions such as lordosis and neural paralytic syndrome, losing the balance and swimming in a half circle, expressive pigmentation mainly on the dorsal part and block of respiration movements in the fish exposed to this pesticide were observed. Histopathological evidence from the tissues of liver, kidney, gill, and gut revealed vascular tissue of the liver, sinusoids, hepatocytes vacuole degeneration, shrinkage and degeneration of some urinary cells, dilatation of Bowman's space, pycnotic nucleus of some kidney cells and increase in the number of interstitial kidney cells. Complications, such as hyperemia, telangiectasia, edema, shrinkage, clubbing and adhesion to the secondary gill filaments were also observed.
Volume 7, Issue 1 (3-2018)
Abstract
Acute toxicity of the field recommended concentration of three conventional insecticides (Diazinon, Malathion and Chlorpyrifos) and mineral oil was evaluated on 3rd and 4th instar larvae and adults of Cryptolaemus montrouzieri Mulsant. The mortalities caused by the insecticides and mineral oil were significantly different. Diazinon and Malathion with 100% mortality showed the highest toxicity to the different stages of the ladybird. Chlorpyrifos and mineral oil caused less than 30% mortality, while mineral oil had the lowest harmful effect on this predator. Based on LC50 and LC90 values 24h after treatment, the male and female adults of C. montrouzieri were more susceptible to Diazinon (701 and 635; 1257 and 1194ppm) than to Chlorpyrifos (4238 and 4316, 5683 and 5480 ppm). Based on International Organization of Biological Control (IOBC) classification, Chlorpyrifos and mineral oil were classified as category 1 (harmless) and Diazinon and Malathion were placed in category 4 (harmful).
