Model field study of Sumithion 50 EC and Fusilades on pheasants

Toxicological studies on wild animals play an important role in the ecotoxi cological examination of pesticides. The applied model tests enable the ass essment of toxicological consequences with particular regard to the life an d nutrition of wild animals in the ploughed field among plants treated with pesticides. The application of different pesticide formulations on plough- land may pose a simultaneous chemical burden to wild birds. In this model s tudy, manifestations of the interaction between an insecticide and a herbic ide were studied in pheasants. The birds were placed on lucerne in cages (4 8 m(2)) and sprayed once. The applied doses were: Sumithion 50 EC 1 litre/h a + Fusilade S 6 litres/ha (practical doses) and Sumithion 50 EC 5 litres/h a + Fusilade S 30 litres/ha. The analytically determined pesticide concentr ation of the lucerne was taken as a basis in the further treatment of fodde r. The fodder of pheasants contained the following chemicals: 85 mg/kg Sumi thion 50 EC + 510 mg/kg Fusilade S and 425 mg/kg Sumithion 50 EC + 2250 mg/ kg Fusilade S. Sporadic deaths observed among the pheasants were of traumat ic origin and not due to a toxic effect. The decrease of body weight was si gnificant only at the higher dose levels. Acetylcholinesterase (AChE) activ ity of the blood decreased significantly in both dose groups. On the basis of the results obtained it can be established that at the dose level used i n the practice the pesticides studied do not give rise to a toxic interacti on in pheasants.