CHOLINESTERASE AND TOXICITY IN SCHISTOCERCA GREGARIA BY CARBAMAT INSECTICIDE (FORSKÅL, 1775)

Abstract

The activity of acetylcholinesterase and the cardiac rhythm, studied at individuals female and male of Schistocerca gregaria exposed to Kuik 200 SL, an insecticide of the family of carbamates, are made at various exposure times and concentrations of the insecticide of 2g, 4g and 8g of Kuik 200 SL/l. An inhibition of cholinesterase activity is noted for the different doses of Kuik 200 SL. With a maximum inhibition at a dose of 8g of Kuik 200 SL/l, The cholinesterase activity is only 3,81±3,68 nmol/min/ml for the male individuals of S. gregaria and 5,6±5,98 nmol/min/ml for the individuals females. This inhibition of activity cholinesterasique few persists 24 hours after treatment. The exposure to Kuik 200 SL modifies significantly the cardiac rhythm whatever the dose and duration of exposure. It is perceptible that more the dose increases, the cardiac rhythm decreases. The action of different doses of Kuik 200 SL on the time of mortality of males and females of S. gregaria shows that the shortest time of mortality is observed at locusts treated at a dose of 8g of Kuik 200 SL/l. The male individuals of this locust die faster compared with the individual’s females. The Kuik 200 SL affects the rate of protein also the acetylcholinesterase specific activity according to the dose of the insecticide and the exposure time. It is noticed in view of the results that the low temperature is 18°C, has more effect after treatment on the activity of the acetylcholinesterase and the cardiac rhythm compared than a high temperature to 36°C. The Kuik 200 SL presents shorter time of mortality for the individuals of Schistocerca gregaria in 18°C, compared with the individuals in 36°C.