INVESTIGATIONS ON THE CONTROL OF FLIES IN GRAZING-CATTLE - A FIELD TRIAL WITH DELTAMETHRIN AS POUR-ON

During the 1991 grazing period, pour-on formulation of 7,5 % Deltameth rin was applied to cattle on 6 farms in south-west France (3 treated - 3 control). Ten ml per cent kg weight were applied to the backs of 77 cattle (with a maximum of 30 ml) and adequate control of Horn-flies H aematobia irritans and Hippobosca equina (with 95 % or better) was ach ieved during 10 weeks. The protection agains non biting flies Musca au tumnalis was better than 75 % during 6 weeks and better than 50 % duri ng the next 4 weeks in two farms. In the other farm, the number of Mus ca autumnalis fell by 75 % only during the first week. Only one treatm ent with this formulation was required to achieve 95 % control of Haem atobia irritans and Hippobosca equina during the 10 weeks long pasture d season.