Pour-On Treatments of DDT or Toxaphene for Horn Fly Control1

Abstract

Cattle naturally infested with horn flies,Haematobia irritans (L.), were treated by the pour-on technique with 100 m!. of aqueousemulsionsofDDT or toxaphene.Treatments with either material at 1~g. per animalprovidedeffectivecontrolin excessof 3 weeks.Treatments with either material at 6 g. per animal providedeffectivecontrol for a period of 1 to 2 weeks.No practical differences in effectiveness were noted between DDT and toxaphene.No evidenceof insecticideresistancewasnoted.