Gebäude 35, 22, 23
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An insecticide-treated net was used for the protection of horses kept on pasturage in Brandenburg, Germany during June – September 2004. The height of the net was 100cm from ground level. It consisted of polyester with 150denier strength which had been pre-treated with the pyrethroid deltamethrin. An incorporated UV protection ensured a sufficient insecticidal activity of the pyrethroid throughout the trial period as was regularly confirmed during bio-assays. Three areas with comparable fly pressures were selected for the trial. Fly densities were assessed with twelve Nzi-traps (four per area, but outside the protected pasturage) and measured at weekly intervals for a period of 30h. Digital photographs were also taken at weekly intervals from horses with comparable size and colour during 30min from five different anatomical regions: eye, cervical, dorsal and sternal regions, lateral chest and abdominal wall. In comparison to the horses which were kept on the unprotected pasturage, complete as well as partial protection – 126m out of another pasturage with a perimeter of 941.7m – resulted in immediate reductions averaging more than 90% of all biting and nuisance insects. The trap catches in the vicinity of protected areas were between 50 to 76.8% lower than those ones near the unprotected pasturage. In conclusion, the protection of pasturage with insecticide-treated netting material offers a simple and affordable solution for what is rightly perceived as a considerable constraint to horse keeping in much of north-western Europe.