TOXICOLOGIC EVALUATION OF PYRETHROID INSE CTICIDE SUPERMETHRIN IN RABBITS END PHEASANTS

Basic information about a toxicologic hazard of the pyrethroid superme thrin (Research Institute of Chemical Technology, Bratislava) is prese nted in this paper for the conditions of acute intoxication in rabbits and pheasants and in the conditions of subacute intoxication in pheas ants. The insecticide supermethrin under observation contains a cyanid e groups in its molecule and can be included in the group of type II p yrethroids comprising among other substances also cypermethrin. Superm ethrin is an analog of the latter and it has a different proportion of cis- and trans-isomers. At acute intoxication, supermethrin was appli ed to adult rabbits at doses of 2,000; 3,000; 4,000; 5,000 and 6,000 m g/kg and to adult pheasants at doses of 2,000; 4,000; 5,000 and 6,000 mg/kg live weight. Supermethrin dissolved in sunflower oil at a 1 : 2 ratio was administered in the above differentiated doses at single app lication by a peroral tube. Not even the highest supermethrin dose (6, 000 mg/kg live weight) caused any clinical signs of intoxication in th e birds. This fact suggests that its LD(50) for rabbits and pheasants will apparently exceed the value of 6,000 mg/kg 1.w. At subacute intox ication, supermethrin was applied as dissolved in sunflower oil (at a 1 : 2 ratio) by per os tube at a dose of 500 mg/kg 1.w. once a day wit hin five days. The subacute doses of supermethrin did not induce, besi des mild diarrhea at the end of the trial, any other clinical signs of intoxication in the pheasants. The negative effect of supermethrin (e ven though negligible) on the digestive tract of pheasants is in agree ment with the results determined in sheep in the conditions of subchro nic intoxication (Neuschl et al., 1995). Supermethrin administration i n sheep resulted in permanent and intensive diarrheas. These findings clearly indicate that supermethrin administered at lower doses primari ly affects the function of digestive tract. Tab. I shows the effect of supermethrin on the live weight of pheasants in the conditions of sub acute intoxication. The negligible decrease in live weight recorded at the end of the trial was not due to supermethrin effects. It was also recorded in the control group. There were no significant differences between the control and experimental group. It was probably induced by the stress resulting from daily applications of the tested substance. In case the guidelines for its areal application (140 g/ha) are obser ved, it will not be toxic for rabbits and pheasants nor probably for h ares and/or other gallinaceous birds. Supermethrin seems to be a littl e toxic substance according to WHO (1975) classification.